From 688e2b031a0a0d85cc6c7405922212b20fd19d30 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Thu, 22 May 2025 18:53:18 +0800
Subject: [PATCH 01/28] Use STL for MethodCallSummarizer

---
 .../methodcallsummarizer.cpp                  | 99 ++++---------------
 .../methodcallsummarizer.h                    | 10 +-
 2 files changed, 23 insertions(+), 86 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 6928201fce4979..3866d965efa97d 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -5,102 +5,39 @@
 #include "methodcallsummarizer.h"
 #include "logging.h"
 #include "spmiutil.h"
+#include <iostream>
+#include <fstream>
 
 MethodCallSummarizer::MethodCallSummarizer(WCHAR* logPath)
 {
-    numNames = 0;
-    names    = nullptr;
-    counts   = nullptr;
-
-    const WCHAR* fileName  = GetCommandLineW();
+    std::wstring fileName(GetCommandLineW());
     const WCHAR* extension = W(".csv");
 
-    dataFileName = GetResultFileName(logPath, fileName, extension);
+    dataFileName = GetResultFileName(logPath, fileName.c_str(), extension);
 }
 
-MethodCallSummarizer::~MethodCallSummarizer()
-{
-    delete [] dataFileName;
-    delete [] counts;
-    for (int i = 0; i < numNames; i++)
-    {
-        delete [] names[i];
-    }
-    delete [] names;
-}
-
-// lots of ways will be faster.. this happens to be decently simple and good enough for the task at hand and nicely
-// sorts the output. in this approach the most commonly added items are at the top of the list... 60% landed in the
-// first
-// three slots in short runs
+// Use ordered map to make the most commonly added items are at the top of the list...
+// 60% landed in the first three slots in short runs
 void MethodCallSummarizer::AddCall(const char* name)
 {
-    // if we can find it already in our list, increment the count
-    for (int i = 0; i < numNames; i++)
-    {
-        if (strcmp(name, names[i]) == 0)
-        {
-            counts[i]++;
-            for (i = 1; i < numNames; i++)
-                if (counts[i] > counts[i - 1])
-                {
-                    unsigned int tempui = counts[i - 1];
-                    counts[i - 1]       = counts[i];
-                    counts[i]           = tempui;
-                    char* tempc         = names[i - 1];
-                    names[i - 1]        = names[i];
-                    names[i]            = tempc;
-                }
-            return;
-        }
-    }
-
-    // else we didn't find it, so add it
-    char**        tnames  = names;
-    unsigned int* tcounts = counts;
-
-    names = new char*[numNames + 1];
-    if (tnames != nullptr)
-    {
-        memcpy(names, tnames, numNames * sizeof(char*));
-        delete [] tnames;
-    }
-
-    size_t tlen     = strlen(name);
-    names[numNames] = new char[tlen + 1];
-    memcpy(names[numNames], name, tlen + 1);
-
-    counts = new unsigned int[numNames + 1];
-    if (tcounts != nullptr)
-    {
-        memcpy(counts, tcounts, numNames * sizeof(unsigned int));
-        delete [] tcounts;
-    }
-    counts[numNames] = 1;
-
-    numNames++;
+    // std::map initialized integer values to zero
+    namesAndCounts[std::string(name)]++;
 }
 
 void MethodCallSummarizer::SaveTextFile()
 {
-    char   buff[512];
-    DWORD  bytesWritten = 0;
-    HANDLE hFile        = CreateFileW(dataFileName, GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_ALWAYS,
-                               FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
-
-    if (hFile == INVALID_HANDLE_VALUE)
+    try
     {
-        LogError("Couldn't open file '%ws': error %d", dataFileName, ::GetLastError());
-        return;
-    }
-
-    DWORD len = (DWORD)sprintf_s(buff, 512, "FunctionName,Count\n");
-    WriteFile(hFile, buff, len, &bytesWritten, NULL);
+        std::ofstream outFile(dataFileName);
+        outFile << "FunctionName,Count" << std::endl;
 
-    for (int i = 0; i < numNames; i++)
+        for (auto& elem : namesAndCounts)
+        {
+            outFile << elem.first << "," << elem.second << std::endl;
+        }
+    }
+    catch (std::exception& ex)
     {
-        len = sprintf_s(buff, 512, "%s,%u\n", names[i], counts[i]);
-        WriteFile(hFile, buff, len, &bytesWritten, NULL);
+        LogError("Couldn't write file '%ws': %s", dataFileName.c_str(), ex.what());
     }
-    CloseHandle(hFile);
 }
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
index 333e4a1e88b7a2..c98eab03202568 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
@@ -4,19 +4,19 @@
 #ifndef _MethodCallSummarizer
 #define _MethodCallSummarizer
 
+#include <string>
+#include <map>
+
 class MethodCallSummarizer
 {
 public:
     MethodCallSummarizer(WCHAR* name);
-    ~MethodCallSummarizer();
     void AddCall(const char* name);
     void SaveTextFile();
 
 private:
-    char**        names;
-    unsigned int* counts;
-    int           numNames;
-    WCHAR*        dataFileName;
+    std::map<std::string, int> namesAndCounts;
+    std::wstring               dataFileName;
 };
 
 #endif

From 6df1501bfa1b95f06fcaee62d14203987c7a1934 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 16:24:06 +0800
Subject: [PATCH 02/28] Use std::string for manipulating file name

---
 .../superpmi/superpmi-shared/spmiutil.cpp     | 52 +++++++++++++++++++
 .../tools/superpmi/superpmi-shared/spmiutil.h |  2 +
 .../methodcallsummarizer.cpp                  | 19 ++++---
 .../methodcallsummarizer.h                    |  2 +-
 4 files changed, 68 insertions(+), 7 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 9bba21b1bfd8e5..329923000e13a8 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -9,6 +9,8 @@
 #include "logging.h"
 #include "spmiutil.h"
 
+#include <sstream>
+#include <iomanip>
 #include <minipal/debugger.h>
 #include <minipal/random.h>
 
@@ -187,6 +189,41 @@ void ReplaceIllegalCharacters(WCHAR* fileName)
     }
 }
 
+void ReplaceIllegalCharacters(std::string& fileName)
+{
+    // Perform the following transforms:
+    //  - Convert non-ASCII to ASCII for simplicity
+    //  - Remove any illegal or annoying characters from the file name by
+    // converting them to underscores.
+    //  - Replace any quotes in the file name with spaces.
+
+    for (char& quote : fileName)
+    {
+        char ch = quote;
+        if ((ch <= 32) || (ch >= 127)) // Only allow textual ASCII characters
+        {
+            quote = '_';
+        }
+        else
+        {
+            switch (ch)
+            {
+                case '(': case ')': case '=': case '<':
+                case '>': case ':': case '/': case '\\':
+                case '|': case '?': case '!': case '*':
+                case '.': case ',':
+                    quote = '_';
+                    break;
+                case '"':
+                    quote = ' ';
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+}
+
 // All lengths in this function exclude the terminal NULL.
 WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const WCHAR* extension)
 {
@@ -250,6 +287,21 @@ WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const W
     return fullPath;
 }
 
+std::string GetResultFileName(const std::string& folderPath, const std::string& fileName, const std::string& extension)
+{
+    // Append a random string to improve uniqueness.
+    //
+    uint32_t randomNumber = 0;
+    minipal_get_non_cryptographically_secure_random_bytes((uint8_t*)&randomNumber, sizeof(randomNumber));
+
+    std::stringstream ss;
+    ss << folderPath << DIRECTORY_SEPARATOR_STR_A << fileName << std::hex << std::setw(8) << std::setfill('0') << randomNumber << extension;
+
+    std::string result = ss.str();
+    ReplaceIllegalCharacters(result);
+    return result;
+}
+
 #ifdef TARGET_AMD64
 static SPMI_TARGET_ARCHITECTURE SpmiTargetArchitecture = SPMI_TARGET_ARCHITECTURE_AMD64;
 #elif defined(TARGET_X86)
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index 9ff49500321217..e0971202d6c945 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -8,6 +8,7 @@
 #define _SPMIUtil
 
 #include "methodcontext.h"
+#include <string>
 
 bool BreakOnDebugBreakorAV();
 void SetBreakOnDebugBreakOrAV(bool value);
@@ -28,6 +29,7 @@ LPSTR GetCommandLineA();
 bool LoadRealJitLib(HMODULE& realJit, WCHAR* realJitPath);
 
 WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const WCHAR* extension);
+std::string GetResultFileName(const std::string& folderPath, const std::string& fileName, const std::string& extension);
 
 // SuperPMI stores handles as unsigned 64-bit integers, no matter the platform the collection happens on
 // (32 or 64 bit). Handles are defined as pointers. We need to be careful when converting from a handle
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 3866d965efa97d..5610ef9a8524dd 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -5,15 +5,22 @@
 #include "methodcallsummarizer.h"
 #include "logging.h"
 #include "spmiutil.h"
-#include <iostream>
 #include <fstream>
 
 MethodCallSummarizer::MethodCallSummarizer(WCHAR* logPath)
 {
-    std::wstring fileName(GetCommandLineW());
-    const WCHAR* extension = W(".csv");
-
-    dataFileName = GetResultFileName(logPath, fileName.c_str(), extension);
+#ifdef HOST_WINDOWS
+    std::string fileName(GetCommandLineA());
+#else
+    std::string fileName("");
+    std::ifstream proc("/proc/self/cmdline");
+    if (proc)
+    {
+        std::getline(proc, fileName);
+    }
+#endif
+    const std::string extension = ".csv";
+    dataFileName = GetResultFileName(ConvertToUtf8(logPath), fileName, extension);
 }
 
 // Use ordered map to make the most commonly added items are at the top of the list...
@@ -38,6 +45,6 @@ void MethodCallSummarizer::SaveTextFile()
     }
     catch (std::exception& ex)
     {
-        LogError("Couldn't write file '%ws': %s", dataFileName.c_str(), ex.what());
+        LogError("Couldn't write file '%s': %s", dataFileName.c_str(), ex.what());
     }
 }
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
index c98eab03202568..4a71d18bb28bdc 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
@@ -16,7 +16,7 @@ class MethodCallSummarizer
 
 private:
     std::map<std::string, int> namesAndCounts;
-    std::wstring               dataFileName;
+    std::string                dataFileName;
 };
 
 #endif

From 0ba0e96d76f839d75c2cd77fc58ea572d2f8f5bd Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 17:29:09 +0800
Subject: [PATCH 03/28] Use std::string for global strings

---
 .../superpmi/superpmi-shared/spmiutil.cpp     |  7 +++
 .../tools/superpmi/superpmi-shared/spmiutil.h |  2 +
 .../methodcallsummarizer.cpp                  |  4 +-
 .../methodcallsummarizer.h                    |  2 +-
 .../superpmi-shim-counter.cpp                 | 44 ++++++++-----------
 5 files changed, 30 insertions(+), 29 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 329923000e13a8..9221c736b11c17 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -101,6 +101,13 @@ WCHAR* GetEnvironmentVariableWithDefaultW(const WCHAR* envVarName, const WCHAR*
     return retString;
 }
 
+std::string GetEnvWithDefault(const std::string& envVarName, const std::string& defaultValue = "")
+{
+    // getenv isn't thread safe, but it's simple and sufficient since we are development-only tool
+    char* env = getenv(envVarName.c_str());
+    return env ? env : defaultValue;
+}
+
 #ifdef TARGET_UNIX
 // For some reason, the PAL doesn't have GetCommandLineA(). So write it.
 LPSTR GetCommandLineA()
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index e0971202d6c945..b656cb6904c966 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -22,6 +22,8 @@ char* GetEnvironmentVariableWithDefaultA(const char* envVarName, const char* def
 
 WCHAR* GetEnvironmentVariableWithDefaultW(const WCHAR* envVarName, const WCHAR* defaultValue = nullptr);
 
+std::string GetEnvWithDefault(const std::string& envVarName, const std::string& defaultValue = "");
+
 #ifdef TARGET_UNIX
 LPSTR GetCommandLineA();
 #endif // TARGET_UNIX
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 5610ef9a8524dd..5c25f72fb3a2f0 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -7,7 +7,7 @@
 #include "spmiutil.h"
 #include <fstream>
 
-MethodCallSummarizer::MethodCallSummarizer(WCHAR* logPath)
+MethodCallSummarizer::MethodCallSummarizer(const std::string& logPath)
 {
 #ifdef HOST_WINDOWS
     std::string fileName(GetCommandLineA());
@@ -20,7 +20,7 @@ MethodCallSummarizer::MethodCallSummarizer(WCHAR* logPath)
     }
 #endif
     const std::string extension = ".csv";
-    dataFileName = GetResultFileName(ConvertToUtf8(logPath), fileName, extension);
+    dataFileName = GetResultFileName(logPath, fileName, extension);
 }
 
 // Use ordered map to make the most commonly added items are at the top of the list...
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
index 4a71d18bb28bdc..befc5c4bfeb70e 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
@@ -10,7 +10,7 @@
 class MethodCallSummarizer
 {
 public:
-    MethodCallSummarizer(WCHAR* name);
+    MethodCallSummarizer(const std::string& name);
     void AddCall(const char* name);
     void SaveTextFile();
 
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index de3cac7cec4b6c..c7ea918f834330 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -15,53 +15,48 @@
 #include "jithost.h"
 
 HMODULE               g_hRealJit      = 0; // We leak this currently (could do the proper shutdown in process_detach)
-WCHAR*                g_realJitPath   = nullptr; // We leak this (could do the proper shutdown in process_detach)
-WCHAR*                g_logPath       = nullptr; // Again, we leak this one too...
-char*                 g_logFilePath   = nullptr; // We *don't* leak this, hooray!
-WCHAR*                g_HomeDirectory = nullptr;
-WCHAR*                g_DefaultRealJitPath = nullptr;
+std::string           g_realJitPath   = ""; // std::string will be cleaned up and won't leak
+std::string           g_logPath            = "";
+std::string           g_logFilePath        = "";
+std::string           g_HomeDirectory      = "";
+std::string           g_DefaultRealJitPath = "";
 MethodCallSummarizer* g_globalContext      = nullptr;
 
 void SetDefaultPaths()
 {
-    if (g_HomeDirectory == nullptr)
+    if (g_HomeDirectory.empty())
     {
-        g_HomeDirectory = GetEnvironmentVariableWithDefaultW(W("HOME"), W("."));
+        g_HomeDirectory = GetEnvWithDefault("HOME", ".");
     }
 
-    if (g_DefaultRealJitPath == nullptr)
+    if (g_DefaultRealJitPath.empty())
     {
-        size_t len           = u16_strlen(g_HomeDirectory) + 1 + u16_strlen(DEFAULT_REAL_JIT_NAME_W) + 1;
-        g_DefaultRealJitPath = new WCHAR[len];
-        wcscpy_s(g_DefaultRealJitPath, len, g_HomeDirectory);
-        wcscat_s(g_DefaultRealJitPath, len, DIRECTORY_SEPARATOR_STR_W);
-        wcscat_s(g_DefaultRealJitPath, len, DEFAULT_REAL_JIT_NAME_W);
+        g_DefaultRealJitPath = g_HomeDirectory + DIRECTORY_SEPARATOR_STR_A + DEFAULT_REAL_JIT_NAME_A;
     }
 }
 
 void SetLibName()
 {
-    if (g_realJitPath == nullptr)
+    if (g_realJitPath.empty())
     {
-        g_realJitPath = GetEnvironmentVariableWithDefaultW(W("SuperPMIShimPath"), g_DefaultRealJitPath);
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath);
     }
 }
 
 void SetLogPath()
 {
-    if (g_logPath == nullptr)
+    if (g_logPath.empty())
     {
-        g_logPath = GetEnvironmentVariableWithDefaultW(W("SuperPMIShimLogPath"), g_HomeDirectory);
+        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory);
     }
 }
 
-// TODO: this only works for ANSI file paths...
 void SetLogFilePath()
 {
-    if (g_logFilePath == nullptr)
+    if (g_logFilePath.empty())
     {
         // If the environment variable isn't set, we don't enable file logging
-        g_logFilePath = GetEnvironmentVariableWithDefaultA("SuperPMIShimLogFilePath", nullptr);
+        g_logFilePath = GetEnvWithDefault("SuperPMIShimLogFilePath", nullptr);
     }
 }
 
@@ -85,15 +80,12 @@ extern "C"
 
             Logger::Initialize();
             SetLogFilePath();
-            Logger::OpenLogFile(g_logFilePath);
+            Logger::OpenLogFile(g_logFilePath.c_str());
             break;
 
         case DLL_PROCESS_DETACH:
             Logger::Shutdown();
 
-            delete[] g_logFilePath;
-            g_logFilePath = nullptr;
-
             if (g_globalContext != nullptr)
             {
                 g_globalContext->SaveTextFile();
@@ -114,7 +106,7 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* host)
     SetLibName();
     SetDebugDumpVariables();
 
-    if (!LoadRealJitLib(g_hRealJit, g_realJitPath))
+    if (!LoadRealJitLib(g_hRealJit, g_realJitPath.c_str()))
     {
         return;
     }
@@ -152,7 +144,7 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
     SetLibName();
     SetDebugDumpVariables();
 
-    if (!LoadRealJitLib(g_hRealJit, g_realJitPath))
+    if (!LoadRealJitLib(g_hRealJit, g_realJitPath.c_str()))
     {
         return nullptr;
     }

From ff5058e3baad14aa44ac0d7113f363e763001731 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 17:36:17 +0800
Subject: [PATCH 04/28] Use unique_ptr for destruction

---
 .../methodcallsummarizer.cpp                  |  5 ++++
 .../methodcallsummarizer.h                    |  1 +
 .../superpmi-shim-counter.cpp                 | 29 +++++++++----------
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 5c25f72fb3a2f0..6ec8575a76ac97 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -48,3 +48,8 @@ void MethodCallSummarizer::SaveTextFile()
         LogError("Couldn't write file '%s': %s", dataFileName.c_str(), ex.what());
     }
 }
+
+MethodCallSummarizer::~MethodCallSummarizer()
+{
+    SaveTextFile();
+}
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
index befc5c4bfeb70e..3a2b3a67d04ec8 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
@@ -13,6 +13,7 @@ class MethodCallSummarizer
     MethodCallSummarizer(const std::string& name);
     void AddCall(const char* name);
     void SaveTextFile();
+    ~MethodCallSummarizer();
 
 private:
     std::map<std::string, int> namesAndCounts;
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index c7ea918f834330..a41e4f4cb8c304 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -13,14 +13,16 @@
 #include "logging.h"
 #include "spmiutil.h"
 #include "jithost.h"
+#include <memory>
 
-HMODULE               g_hRealJit      = 0; // We leak this currently (could do the proper shutdown in process_detach)
-std::string           g_realJitPath   = ""; // std::string will be cleaned up and won't leak
-std::string           g_logPath            = "";
-std::string           g_logFilePath        = "";
-std::string           g_HomeDirectory      = "";
-std::string           g_DefaultRealJitPath = "";
-MethodCallSummarizer* g_globalContext      = nullptr;
+HMODULE     g_hRealJit           = 0;  // We leak this currently (could do the proper shutdown in process_detach)
+std::string g_realJitPath        = ""; // std::string will be cleaned up and won't leak
+std::string g_logPath            = "";
+std::string g_logFilePath        = "";
+std::string g_HomeDirectory      = "";
+std::string g_DefaultRealJitPath = "";
+
+std::unique_ptr<MethodCallSummarizer> g_globalContext = nullptr;
 
 void SetDefaultPaths()
 {
@@ -86,11 +88,6 @@ extern "C"
         case DLL_PROCESS_DETACH:
             Logger::Shutdown();
 
-            if (g_globalContext != nullptr)
-            {
-                g_globalContext->SaveTextFile();
-            }
-
             break;
 
         case DLL_THREAD_ATTACH:
@@ -125,10 +122,10 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* host)
     if (g_globalContext == nullptr)
     {
         SetLogPath();
-        g_globalContext = new MethodCallSummarizer(g_logPath);
+        g_globalContext = std::make_unique<MethodCallSummarizer>(g_logPath);
     }
 
-    g_ourJitHost->setMethodCallSummarizer(g_globalContext);
+    g_ourJitHost->setMethodCallSummarizer(g_globalContext.get());
 
     pnjitStartup(g_ourJitHost);
 }
@@ -170,8 +167,8 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
     if (g_globalContext == nullptr)
     {
         SetLogPath();
-        g_globalContext = new MethodCallSummarizer(g_logPath);
+        g_globalContext = std::make_unique<MethodCallSummarizer>(g_logPath);
     }
-    pJitInstance->mcs = g_globalContext;
+    pJitInstance->mcs = g_globalContext.get();
     return pJitInstance;
 }

From 01f4be790cabbe24fed7c6b57913a4700113a281 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 17:45:36 +0800
Subject: [PATCH 05/28] Use RAII for logger

---
 .../superpmi/superpmi-shared/logging.cpp      |  2 +-
 .../tools/superpmi/superpmi-shared/logging.h  |  2 +-
 .../superpmi/superpmi-shared/spmiutil.cpp     |  4 +-
 .../tools/superpmi/superpmi-shared/spmiutil.h |  2 +-
 .../superpmi-shim-counter.cpp                 | 43 ++++++++++---------
 5 files changed, 28 insertions(+), 25 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/logging.cpp b/src/coreclr/tools/superpmi/superpmi-shared/logging.cpp
index 63b2c5ee4a1121..a0de0cda60d122 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/logging.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/logging.cpp
@@ -53,7 +53,7 @@ void Logger::Shutdown()
 // Opens a log file at the given path and enables file-based logging, if the given path is valid.
 //
 /* static */
-void Logger::OpenLogFile(char* logFilePath)
+void Logger::OpenLogFile(const char* logFilePath)
 {
     if (s_logFile == INVALID_HANDLE_VALUE && logFilePath != nullptr)
     {
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/logging.h b/src/coreclr/tools/superpmi/superpmi-shared/logging.h
index f7af0132630284..83559df9befdbf 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/logging.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/logging.h
@@ -73,7 +73,7 @@ class Logger
     static void Initialize();
     static void Shutdown();
 
-    static void OpenLogFile(char* logFilePath);
+    static void OpenLogFile(const char* logFilePath);
     static void CloseLogFile();
 
     static UINT32 ParseLogLevelString(const char* specifierStr);
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 9221c736b11c17..940dd672cdc4e3 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -101,10 +101,10 @@ WCHAR* GetEnvironmentVariableWithDefaultW(const WCHAR* envVarName, const WCHAR*
     return retString;
 }
 
-std::string GetEnvWithDefault(const std::string& envVarName, const std::string& defaultValue = "")
+const char* GetEnvWithDefault(const char* envVarName, const char* defaultValue)
 {
     // getenv isn't thread safe, but it's simple and sufficient since we are development-only tool
-    char* env = getenv(envVarName.c_str());
+    char* env = getenv(envVarName);
     return env ? env : defaultValue;
 }
 
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index b656cb6904c966..be11a886a49c08 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -22,7 +22,7 @@ char* GetEnvironmentVariableWithDefaultA(const char* envVarName, const char* def
 
 WCHAR* GetEnvironmentVariableWithDefaultW(const WCHAR* envVarName, const WCHAR* defaultValue = nullptr);
 
-std::string GetEnvWithDefault(const std::string& envVarName, const std::string& defaultValue = "");
+const char* GetEnvWithDefault(const char* envVarName, const char* defaultValue = nullptr);
 
 #ifdef TARGET_UNIX
 LPSTR GetCommandLineA();
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index a41e4f4cb8c304..26fb81f71222d7 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -18,12 +18,32 @@
 HMODULE     g_hRealJit           = 0;  // We leak this currently (could do the proper shutdown in process_detach)
 std::string g_realJitPath        = ""; // std::string will be cleaned up and won't leak
 std::string g_logPath            = "";
-std::string g_logFilePath        = "";
 std::string g_HomeDirectory      = "";
 std::string g_DefaultRealJitPath = "";
 
 std::unique_ptr<MethodCallSummarizer> g_globalContext = nullptr;
 
+// RAII holder for logger
+class LoggerHolder
+{
+public:
+    LoggerHolder()
+    {
+    Logger::Initialize();
+    // If the environment variable isn't set, we don't enable file logging
+    const char* logFilePath = GetEnvWithDefault("SuperPMIShimLogFilePath", nullptr);
+    if (logFilePath)
+    {
+        Logger::OpenLogFile(logFilePath);
+    }
+}
+
+    ~LoggerHolder()
+    {
+        Logger::Shutdown();
+    }
+} loggerHolder;
+
 void SetDefaultPaths()
 {
     if (g_HomeDirectory.empty())
@@ -41,7 +61,7 @@ void SetLibName()
 {
     if (g_realJitPath.empty())
     {
-        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath);
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.c_str());
     }
 }
 
@@ -49,16 +69,7 @@ void SetLogPath()
 {
     if (g_logPath.empty())
     {
-        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory);
-    }
-}
-
-void SetLogFilePath()
-{
-    if (g_logFilePath.empty())
-    {
-        // If the environment variable isn't set, we don't enable file logging
-        g_logFilePath = GetEnvWithDefault("SuperPMIShimLogFilePath", nullptr);
+        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.c_str());
     }
 }
 
@@ -79,17 +90,9 @@ extern "C"
                 exit(1);
             }
 #endif // HOST_UNIX
-
-            Logger::Initialize();
-            SetLogFilePath();
-            Logger::OpenLogFile(g_logFilePath.c_str());
             break;
 
         case DLL_PROCESS_DETACH:
-            Logger::Shutdown();
-
-            break;
-
         case DLL_THREAD_ATTACH:
         case DLL_THREAD_DETACH:
             break;

From 0a95bc99343049c52c4b11104f4331098da342be Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 18:10:29 +0800
Subject: [PATCH 06/28] Load JIT with std::string

---
 .../superpmi/superpmi-shared/spmiutil.cpp     | 27 +++++++++++++++++++
 .../tools/superpmi/superpmi-shared/spmiutil.h |  1 +
 .../superpmi-shim-counter.cpp                 | 18 ++++++-------
 3 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 940dd672cdc4e3..9a1652028a60e1 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -13,6 +13,9 @@
 #include <iomanip>
 #include <minipal/debugger.h>
 #include <minipal/random.h>
+#ifdef TARGET_UNIX
+#include <dlfcn.h>
+#endif
 
 static bool breakOnDebugBreakorAV = false;
 
@@ -160,6 +163,30 @@ bool LoadRealJitLib(HMODULE& jitLib, WCHAR* jitLibPath)
     return true;
 }
 
+bool LoadRealJitLib(HMODULE& jitLib, const std::string& jitLibPath)
+{
+    // Load Library
+    if (jitLib == NULL)
+    {
+        if (jitLibPath.empty())
+        {
+            LogError("LoadRealJitLib - No real jit path");
+            return false;
+        }
+#ifdef TARGET_WINDOWS
+        jitLib = ::LoadLibraryExA(jitLibPath.c_str(), NULL, 0);
+#else
+        jitLib = ::dlopen(jitLibPath.c_str(), RTLD_LAZY);
+#endif
+        if (jitLib == NULL)
+        {
+            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.c_str(), errno);
+            return false;
+        }
+    }
+    return true;
+}
+
 void ReplaceIllegalCharacters(WCHAR* fileName)
 {
     WCHAR* quote = nullptr;
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index be11a886a49c08..8653befb7b7df7 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -29,6 +29,7 @@ LPSTR GetCommandLineA();
 #endif // TARGET_UNIX
 
 bool LoadRealJitLib(HMODULE& realJit, WCHAR* realJitPath);
+bool LoadRealJitLib(HMODULE& realJit, const std::string& realJitPath);
 
 WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const WCHAR* extension);
 std::string GetResultFileName(const std::string& folderPath, const std::string& fileName, const std::string& extension);
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index 26fb81f71222d7..74a50b10d4dcc0 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -29,14 +29,14 @@ class LoggerHolder
 public:
     LoggerHolder()
     {
-    Logger::Initialize();
-    // If the environment variable isn't set, we don't enable file logging
-    const char* logFilePath = GetEnvWithDefault("SuperPMIShimLogFilePath", nullptr);
-    if (logFilePath)
-    {
-        Logger::OpenLogFile(logFilePath);
+        Logger::Initialize();
+        // If the environment variable isn't set, we don't enable file logging
+        const char* logFilePath = GetEnvWithDefault("SuperPMIShimLogFilePath", nullptr);
+        if (logFilePath)
+        {
+            Logger::OpenLogFile(logFilePath);
+        }
     }
-}
 
     ~LoggerHolder()
     {
@@ -106,7 +106,7 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* host)
     SetLibName();
     SetDebugDumpVariables();
 
-    if (!LoadRealJitLib(g_hRealJit, g_realJitPath.c_str()))
+    if (!LoadRealJitLib(g_hRealJit, g_realJitPath))
     {
         return;
     }
@@ -144,7 +144,7 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
     SetLibName();
     SetDebugDumpVariables();
 
-    if (!LoadRealJitLib(g_hRealJit, g_realJitPath.c_str()))
+    if (!LoadRealJitLib(g_hRealJit, g_realJitPath))
     {
         return nullptr;
     }

From 84b95f34c03811db4cf9827141fd0cd9b4f0eb78 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 18:18:45 +0800
Subject: [PATCH 07/28] Enable C++ 17 for superpmi

---
 src/coreclr/tools/superpmi/CMakeLists.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/coreclr/tools/superpmi/CMakeLists.txt b/src/coreclr/tools/superpmi/CMakeLists.txt
index d4308d2e03cabd..e92d5e235e9ed8 100644
--- a/src/coreclr/tools/superpmi/CMakeLists.txt
+++ b/src/coreclr/tools/superpmi/CMakeLists.txt
@@ -1,3 +1,8 @@
+# SuperPMI is development-only toolset.
+# Enable C++ 17 to get more handy stuffs from STL.
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
 add_subdirectory(superpmi)
 add_subdirectory(mcs)
 add_subdirectory(superpmi-shim-collector)

From 9d8e705360e5637f04179d94e0ab2cb68700f44f Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 19:56:20 +0800
Subject: [PATCH 08/28] Use std::filesystem for path manipulation

---
 .../superpmi/superpmi-shared/spmiutil.cpp     | 20 ++++++++++---------
 .../tools/superpmi/superpmi-shared/spmiutil.h |  7 ++++---
 .../superpmi/superpmi-shared/standardpch.h    |  3 +++
 .../methodcallsummarizer.cpp                  |  2 +-
 .../methodcallsummarizer.h                    |  4 ++--
 .../superpmi-shim-counter.cpp                 | 16 +++++++--------
 6 files changed, 29 insertions(+), 23 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 9a1652028a60e1..00ad82dc6e6e9b 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -163,7 +163,7 @@ bool LoadRealJitLib(HMODULE& jitLib, WCHAR* jitLibPath)
     return true;
 }
 
-bool LoadRealJitLib(HMODULE& jitLib, const std::string& jitLibPath)
+bool LoadRealJitLib(HMODULE& jitLib, const std::filesystem::path& jitLibPath)
 {
     // Load Library
     if (jitLib == NULL)
@@ -174,13 +174,14 @@ bool LoadRealJitLib(HMODULE& jitLib, const std::string& jitLibPath)
             return false;
         }
 #ifdef TARGET_WINDOWS
-        jitLib = ::LoadLibraryExA(jitLibPath.c_str(), NULL, 0);
+        jitLib = ::LoadLibraryExW(jitLibPath.c_str(), NULL, 0);
 #else
         jitLib = ::dlopen(jitLibPath.c_str(), RTLD_LAZY);
+        // The simulated DllMain of JIT doesn't do any meaningful initialization. Skip it.
 #endif
         if (jitLib == NULL)
         {
-            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.c_str(), errno);
+            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.string().c_str(), errno);
             return false;
         }
     }
@@ -321,19 +322,20 @@ WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const W
     return fullPath;
 }
 
-std::string GetResultFileName(const std::string& folderPath, const std::string& fileName, const std::string& extension)
+std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
+                                        const std::string&           fileName,
+                                        const std::string&           extension)
 {
     // Append a random string to improve uniqueness.
     //
     uint32_t randomNumber = 0;
     minipal_get_non_cryptographically_secure_random_bytes((uint8_t*)&randomNumber, sizeof(randomNumber));
-
     std::stringstream ss;
-    ss << folderPath << DIRECTORY_SEPARATOR_STR_A << fileName << std::hex << std::setw(8) << std::setfill('0') << randomNumber << extension;
+    ss << std::hex << std::setw(8) << std::setfill('0') << randomNumber;
 
-    std::string result = ss.str();
-    ReplaceIllegalCharacters(result);
-    return result;
+    std::string nameAndExtension = fileName + ss.str() + extension;
+    ReplaceIllegalCharacters(nameAndExtension);
+    return folderPath / nameAndExtension;
 }
 
 #ifdef TARGET_AMD64
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index 8653befb7b7df7..8160ba913e0dbe 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -8,7 +8,6 @@
 #define _SPMIUtil
 
 #include "methodcontext.h"
-#include <string>
 
 bool BreakOnDebugBreakorAV();
 void SetBreakOnDebugBreakOrAV(bool value);
@@ -29,10 +28,12 @@ LPSTR GetCommandLineA();
 #endif // TARGET_UNIX
 
 bool LoadRealJitLib(HMODULE& realJit, WCHAR* realJitPath);
-bool LoadRealJitLib(HMODULE& realJit, const std::string& realJitPath);
+bool LoadRealJitLib(HMODULE& realJit, const std::filesystem::path& realJitPath);
 
 WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const WCHAR* extension);
-std::string GetResultFileName(const std::string& folderPath, const std::string& fileName, const std::string& extension);
+std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
+                                        const std::string&           fileName,
+                                        const std::string&           extension);
 
 // SuperPMI stores handles as unsigned 64-bit integers, no matter the platform the collection happens on
 // (32 or 64 bit). Handles are defined as pointers. We need to be careful when converting from a handle
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
index e18cb57a76a002..195230468b8f80 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
@@ -15,6 +15,9 @@
 #define DEBUG_BREAK DebugBreak()
 #endif
 
+// filesystem fails parsing if included after PAL header
+#include <filesystem>
+
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif // WIN32_LEAN_AND_MEAN
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 6ec8575a76ac97..8bedbcd672a684 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -7,7 +7,7 @@
 #include "spmiutil.h"
 #include <fstream>
 
-MethodCallSummarizer::MethodCallSummarizer(const std::string& logPath)
+MethodCallSummarizer::MethodCallSummarizer(const std::filesystem::path& logPath)
 {
 #ifdef HOST_WINDOWS
     std::string fileName(GetCommandLineA());
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
index 3a2b3a67d04ec8..df45654f594c59 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
@@ -10,14 +10,14 @@
 class MethodCallSummarizer
 {
 public:
-    MethodCallSummarizer(const std::string& name);
+    MethodCallSummarizer(const std::filesystem::path& name);
     void AddCall(const char* name);
     void SaveTextFile();
     ~MethodCallSummarizer();
 
 private:
     std::map<std::string, int> namesAndCounts;
-    std::string                dataFileName;
+    std::filesystem::path      dataFileName;
 };
 
 #endif
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index 74a50b10d4dcc0..58abb428697064 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -15,11 +15,11 @@
 #include "jithost.h"
 #include <memory>
 
-HMODULE     g_hRealJit           = 0;  // We leak this currently (could do the proper shutdown in process_detach)
-std::string g_realJitPath        = ""; // std::string will be cleaned up and won't leak
-std::string g_logPath            = "";
-std::string g_HomeDirectory      = "";
-std::string g_DefaultRealJitPath = "";
+HMODULE               g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
+std::filesystem::path g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
+std::filesystem::path g_logPath{""};
+std::filesystem::path g_HomeDirectory{""};
+std::filesystem::path g_DefaultRealJitPath{""};
 
 std::unique_ptr<MethodCallSummarizer> g_globalContext = nullptr;
 
@@ -53,7 +53,7 @@ void SetDefaultPaths()
 
     if (g_DefaultRealJitPath.empty())
     {
-        g_DefaultRealJitPath = g_HomeDirectory + DIRECTORY_SEPARATOR_STR_A + DEFAULT_REAL_JIT_NAME_A;
+        g_DefaultRealJitPath = g_HomeDirectory / DEFAULT_REAL_JIT_NAME_A;
     }
 }
 
@@ -61,7 +61,7 @@ void SetLibName()
 {
     if (g_realJitPath.empty())
     {
-        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.c_str());
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.string().c_str());
     }
 }
 
@@ -69,7 +69,7 @@ void SetLogPath()
 {
     if (g_logPath.empty())
     {
-        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.c_str());
+        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.string().c_str());
     }
 }
 

From 137e9e3eee2b302ddcab5acb816e5ddd005f9b09 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 20:18:11 +0800
Subject: [PATCH 09/28] Use dlsym since dlopen has been used

---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp     | 3 ---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h       | 6 ++++++
 .../superpmi-shim-counter/superpmi-shim-counter.cpp         | 4 ++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 00ad82dc6e6e9b..96a353ebdbdce4 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -13,9 +13,6 @@
 #include <iomanip>
 #include <minipal/debugger.h>
 #include <minipal/random.h>
-#ifdef TARGET_UNIX
-#include <dlfcn.h>
-#endif
 
 static bool breakOnDebugBreakorAV = false;
 
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index 8160ba913e0dbe..b49f59b6210a83 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -8,6 +8,12 @@
 #define _SPMIUtil
 
 #include "methodcontext.h"
+#ifdef TARGET_WINDOWS
+#define GET_PROC_ADDRESS ::GetProcAddress
+#else
+#include <dlfcn.h>
+#define GET_PROC_ADDRESS ::dlsym
+#endif
 
 bool BreakOnDebugBreakorAV();
 void SetBreakOnDebugBreakOrAV(bool value);
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index 58abb428697064..8e33d5f46a9978 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -112,7 +112,7 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* host)
     }
 
     // Get the required entrypoint
-    PjitStartup pnjitStartup = (PjitStartup)::GetProcAddress(g_hRealJit, "jitStartup");
+    PjitStartup pnjitStartup = (PjitStartup)GET_PROC_ADDRESS(g_hRealJit, "jitStartup");
     if (pnjitStartup == nullptr)
     {
         // This portion of the interface is not used by the JIT under test.
@@ -150,7 +150,7 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
     }
 
     // get the required entrypoints
-    pngetJit = (PgetJit)::GetProcAddress(g_hRealJit, "getJit");
+    pngetJit = (PgetJit)GET_PROC_ADDRESS(g_hRealJit, "getJit");
     if (pngetJit == 0)
     {
         LogError("getJit() - GetProcAddress 'getJit' failed (0x%08x)", ::GetLastError());

From 65cdfa52d5ca8325e885193e4a552adbf92eb137 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 20:34:47 +0800
Subject: [PATCH 10/28] Port changes to other shims

---
 .../superpmi-shim-collector.cpp               | 85 +++++++++----------
 .../superpmi-shim-simple.cpp                  | 69 +++++++--------
 2 files changed, 73 insertions(+), 81 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
index a8f4046d83d660..e486051b6f9a81 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
@@ -17,47 +17,63 @@
 // -We'll never be unloaded - we leak memory and have no facility to unload libraries
 // -printf output to console is okay
 
-HMODULE        g_hRealJit           = 0; // We leak this currently (could do the proper shutdown in process_detach)
-WCHAR*         g_realJitPath        = nullptr; // We leak this (could do the proper shutdown in process_detach)
-WCHAR*         g_logPath            = nullptr; // Again, we leak this one too...
-WCHAR*         g_dataFileName       = nullptr; // We leak this
-char*          g_logFilePath        = nullptr; // We *don't* leak this, hooray!
-WCHAR*         g_HomeDirectory      = nullptr;
-WCHAR*         g_DefaultRealJitPath = nullptr;
-MethodContext* g_globalContext      = nullptr;
-bool           g_initialized        = false;
-char*          g_collectionFilter   = nullptr;
+HMODULE               g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
+std::filesystem::path g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
+std::filesystem::path g_logPath{""};
+std::filesystem::path g_HomeDirectory{""};
+std::filesystem::path g_DefaultRealJitPath{""};
+WCHAR*                g_dataFileName     = nullptr; // We leak this
+MethodContext*        g_globalContext    = nullptr;
+bool                  g_initialized      = false;
+char*                 g_collectionFilter = nullptr;
+
+// RAII holder for logger
+class LoggerHolder
+{
+public:
+    LoggerHolder()
+    {
+        Logger::Initialize();
+        // If the environment variable isn't set, we don't enable file logging
+        const char* logFilePath = GetEnvWithDefault("SuperPMIShimLogFilePath", nullptr);
+        if (logFilePath)
+        {
+            Logger::OpenLogFile(logFilePath);
+        }
+    }
+
+    ~LoggerHolder()
+    {
+        Logger::Shutdown();
+    }
+} loggerHolder;
 
 void SetDefaultPaths()
 {
-    if (g_HomeDirectory == nullptr)
+    if (g_HomeDirectory.empty())
     {
-        g_HomeDirectory = GetEnvironmentVariableWithDefaultW(W("HOME"), W("."));
+        g_HomeDirectory = GetEnvWithDefault("HOME", ".");
     }
 
-    if (g_DefaultRealJitPath == nullptr)
+    if (g_DefaultRealJitPath.empty())
     {
-        size_t len           = u16_strlen(g_HomeDirectory) + 1 + u16_strlen(DEFAULT_REAL_JIT_NAME_W) + 1;
-        g_DefaultRealJitPath = new WCHAR[len];
-        wcscpy_s(g_DefaultRealJitPath, len, g_HomeDirectory);
-        wcscat_s(g_DefaultRealJitPath, len, DIRECTORY_SEPARATOR_STR_W);
-        wcscat_s(g_DefaultRealJitPath, len, DEFAULT_REAL_JIT_NAME_W);
+        g_DefaultRealJitPath = g_HomeDirectory / DEFAULT_REAL_JIT_NAME_A;
     }
 }
 
 void SetLibName()
 {
-    if (g_realJitPath == nullptr)
+    if (g_realJitPath.empty())
     {
-        g_realJitPath = GetEnvironmentVariableWithDefaultW(W("SuperPMIShimPath"), g_DefaultRealJitPath);
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.string().c_str());
     }
 }
 
 void SetLogPath()
 {
-    if (g_logPath == nullptr)
+    if (g_logPath.empty())
     {
-        g_logPath = GetEnvironmentVariableWithDefaultW(W("SuperPMIShimLogPath"), g_HomeDirectory);
+        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.string().c_str());
     }
 }
 
@@ -71,16 +87,6 @@ void SetLogPathName()
     g_dataFileName = GetResultFileName(g_logPath, fileName, extension);
 }
 
-// TODO: this only works for ANSI file paths...
-void SetLogFilePath()
-{
-    if (g_logFilePath == nullptr)
-    {
-        // If the environment variable isn't set, we don't enable file logging
-        g_logFilePath = GetEnvironmentVariableWithDefaultA("SuperPMIShimLogFilePath", nullptr);
-    }
-}
-
 void SetCollectionFilter()
 {
     g_collectionFilter = GetEnvironmentVariableWithDefaultA("SuperPMIShimFilter", nullptr);
@@ -114,10 +120,6 @@ void InitializeShim()
     _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
 #endif // HOST_WINDOWS
 
-    Logger::Initialize();
-    SetLogFilePath();
-    Logger::OpenLogFile(g_logFilePath);
-
     g_initialized = true;
 }
 
@@ -135,13 +137,6 @@ extern "C"
             break;
 
         case DLL_PROCESS_DETACH:
-            Logger::Shutdown();
-
-            delete[] g_logFilePath;
-            g_logFilePath = nullptr;
-
-            break;
-
         case DLL_THREAD_ATTACH:
         case DLL_THREAD_DETACH:
             break;
@@ -165,7 +160,7 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* host)
     }
 
     // Get the required entrypoint
-    PjitStartup pnjitStartup = (PjitStartup)::GetProcAddress(g_hRealJit, "jitStartup");
+    PjitStartup pnjitStartup = (PjitStartup)GET_PROC_ADDRESS(g_hRealJit, "jitStartup");
     if (pnjitStartup == nullptr)
     {
         // This portion of the interface is not used by the JIT under test.
@@ -196,7 +191,7 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
     }
 
     // get the required entrypoints
-    pngetJit = (PgetJit)::GetProcAddress(g_hRealJit, "getJit");
+    pngetJit = (PgetJit)GET_PROC_ADDRESS(g_hRealJit, "getJit");
     if (pngetJit == 0)
     {
         LogError("getJit() - GetProcAddress 'getJit' failed (0x%08x)", ::GetLastError());
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp b/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
index 27fe53c8b4782f..ea764b921c390d 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
@@ -14,44 +14,52 @@
 #include "spmiutil.h"
 #include "jithost.h"
 
-HMODULE g_hRealJit           = 0;       // We leak this currently (could do the proper shutdown in process_detach)
-WCHAR*  g_realJitPath        = nullptr; // We leak this (could do the proper shutdown in process_detach)
-char*   g_logFilePath        = nullptr; // We *don't* leak this, hooray!
-WCHAR*  g_HomeDirectory      = nullptr;
-WCHAR*  g_DefaultRealJitPath = nullptr;
 
-void SetDefaultPaths()
+HMODULE               g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
+std::filesystem::path g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
+std::filesystem::path g_logPath{""};
+std::filesystem::path g_HomeDirectory{""};
+std::filesystem::path g_DefaultRealJitPath{""};
+
+// RAII holder for logger
+class LoggerHolder
 {
-    if (g_HomeDirectory == nullptr)
+public:
+    LoggerHolder()
     {
-        g_HomeDirectory = GetEnvironmentVariableWithDefaultW(W("HOME"), W("."));
+        Logger::Initialize();
+        // If the environment variable isn't set, we don't enable file logging
+        const char* logFilePath = GetEnvWithDefault("SuperPMIShimLogFilePath", nullptr);
+        if (logFilePath)
+        {
+            Logger::OpenLogFile(logFilePath);
+        }
     }
 
-    if (g_DefaultRealJitPath == nullptr)
+    ~LoggerHolder()
     {
-        size_t len           = u16_strlen(g_HomeDirectory) + 1 + u16_strlen(DEFAULT_REAL_JIT_NAME_W) + 1;
-        g_DefaultRealJitPath = new WCHAR[len];
-        wcscpy_s(g_DefaultRealJitPath, len, g_HomeDirectory);
-        wcscat_s(g_DefaultRealJitPath, len, DIRECTORY_SEPARATOR_STR_W);
-        wcscat_s(g_DefaultRealJitPath, len, DEFAULT_REAL_JIT_NAME_W);
+        Logger::Shutdown();
     }
-}
+} loggerHolder;
 
-void SetLibName()
+void SetDefaultPaths()
 {
-    if (g_realJitPath == nullptr)
+    if (g_HomeDirectory.empty())
+    {
+        g_HomeDirectory = GetEnvWithDefault("HOME", ".");
+    }
+
+    if (g_DefaultRealJitPath.empty())
     {
-        g_realJitPath = GetEnvironmentVariableWithDefaultW(W("SuperPMIShimPath"), g_DefaultRealJitPath);
+        g_DefaultRealJitPath = g_HomeDirectory / DEFAULT_REAL_JIT_NAME_A;
     }
 }
 
-// TODO: this only works for ANSI file paths...
-void SetLogFilePath()
+void SetLibName()
 {
-    if (g_logFilePath == nullptr)
+    if (g_realJitPath.empty())
     {
-        // If the environment variable isn't set, we don't enable file logging
-        g_logFilePath = GetEnvironmentVariableWithDefaultA("SuperPMIShimLogFilePath", nullptr);
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.string().c_str());
     }
 }
 
@@ -72,20 +80,9 @@ extern "C"
                 exit(1);
             }
 #endif // HOST_UNIX
-
-            Logger::Initialize();
-            SetLogFilePath();
-            Logger::OpenLogFile(g_logFilePath);
             break;
 
         case DLL_PROCESS_DETACH:
-            Logger::Shutdown();
-
-            delete[] g_logFilePath;
-            g_logFilePath = nullptr;
-
-            break;
-
         case DLL_THREAD_ATTACH:
         case DLL_THREAD_DETACH:
             break;
@@ -105,7 +102,7 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* host)
     }
 
     // Get the required entrypoint
-    PjitStartup pnjitStartup = (PjitStartup)::GetProcAddress(g_hRealJit, "jitStartup");
+    PjitStartup pnjitStartup = (PjitStartup)GET_PROC_ADDRESS(g_hRealJit, "jitStartup");
     if (pnjitStartup == nullptr)
     {
         // This portion of the interface is not used by the JIT under test.
@@ -134,7 +131,7 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
     }
 
     // get the required entrypoints
-    pngetJit = (PgetJit)::GetProcAddress(g_hRealJit, "getJit");
+    pngetJit = (PgetJit)GET_PROC_ADDRESS(g_hRealJit, "getJit");
     if (pngetJit == 0)
     {
         LogError("getJit() - GetProcAddress 'getJit' failed (0x%08x)", ::GetLastError());

From 67d2f11d70e3b448962114265e71ad0cf9b06415 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 20:42:41 +0800
Subject: [PATCH 11/28] Update g_dataFileName

---
 .../superpmi-shim-collector.cpp               | 24 ++++++++++++-------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
index e486051b6f9a81..727745a4e47d97 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
@@ -12,6 +12,7 @@
 #include "logging.h"
 #include "spmiutil.h"
 #include "jithost.h"
+#include <fstream>
 
 // Assumptions:
 // -We'll never be unloaded - we leak memory and have no facility to unload libraries
@@ -22,7 +23,7 @@ std::filesystem::path g_realJitPath{""}; // Destructable objects will be cleaned
 std::filesystem::path g_logPath{""};
 std::filesystem::path g_HomeDirectory{""};
 std::filesystem::path g_DefaultRealJitPath{""};
-WCHAR*                g_dataFileName     = nullptr; // We leak this
+std::filesystem::path g_dataFileName{""};
 MethodContext*        g_globalContext    = nullptr;
 bool                  g_initialized      = false;
 char*                 g_collectionFilter = nullptr;
@@ -79,10 +80,17 @@ void SetLogPath()
 
 void SetLogPathName()
 {
-    // NOTE: under PAL, we don't get the command line, so we depend on the random number generator to give us a unique
-    // filename
-    const WCHAR* fileName  = GetCommandLineW();
-    const WCHAR* extension = W(".mc");
+#ifdef HOST_WINDOWS
+    std::string fileName(GetCommandLineA());
+#else
+    std::string   fileName("");
+    std::ifstream proc("/proc/self/cmdline");
+    if (proc)
+    {
+        std::getline(proc, fileName);
+    }
+#endif
+    const std::string extension = ".mc";
 
     g_dataFileName = GetResultFileName(g_logPath, fileName, extension);
 }
@@ -219,11 +227,11 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
 #endif
 
     // create our datafile
-    pJitInstance->hFile = CreateFileW(g_dataFileName, GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_ALWAYS,
-                                      FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
+    pJitInstance->hFile = CreateFileW((const WCHAR*)g_dataFileName.u16string().c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL,
+                                      CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
     if (pJitInstance->hFile == INVALID_HANDLE_VALUE)
     {
-        LogError("Couldn't open file '%ws': error %d", g_dataFileName, GetLastError());
+        LogError("Couldn't open file '%s': error %d", g_dataFileName.string().c_str(), GetLastError());
     }
 
     return pJitInstance;

From ce5d486fde946bc925bd430dddacd9c3ca771eab Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Sun, 8 Jun 2025 21:02:26 +0800
Subject: [PATCH 12/28] Cleanup

---
 .../superpmi/superpmi-shared/spmiutil.cpp     | 156 ++----------------
 .../tools/superpmi/superpmi-shared/spmiutil.h |   6 +-
 .../superpmi/superpmi-shared/standardpch.h    |   1 +
 .../icorjitcompiler.cpp                       |   2 +-
 .../superpmi-shim-collector.cpp               |  15 +-
 .../methodcallsummarizer.cpp                  |  13 +-
 6 files changed, 15 insertions(+), 178 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 96a353ebdbdce4..783581912bd3ff 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -108,56 +108,19 @@ const char* GetEnvWithDefault(const char* envVarName, const char* defaultValue)
     return env ? env : defaultValue;
 }
 
-#ifdef TARGET_UNIX
-// For some reason, the PAL doesn't have GetCommandLineA(). So write it.
-LPSTR GetCommandLineA()
+std::string GetProcessCommandLine()
 {
-    LPSTR  pCmdLine  = nullptr;
-    LPWSTR pwCmdLine = GetCommandLineW();
-
-    if (pwCmdLine != nullptr)
-    {
-        // Convert to ASCII
-
-        int n = WideCharToMultiByte(CP_ACP, 0, pwCmdLine, -1, nullptr, 0, nullptr, nullptr);
-        if (n == 0)
-        {
-            LogError("MultiByteToWideChar failed %d", GetLastError());
-            return nullptr;
-        }
-
-        pCmdLine = new char[n];
-
-        int n2 = WideCharToMultiByte(CP_ACP, 0, pwCmdLine, -1, pCmdLine, n, nullptr, nullptr);
-        if ((n2 == 0) || (n2 != n))
-        {
-            LogError("MultiByteToWideChar failed %d", GetLastError());
-            return nullptr;
-        }
-    }
-
-    return pCmdLine;
-}
-#endif // TARGET_UNIX
-
-bool LoadRealJitLib(HMODULE& jitLib, WCHAR* jitLibPath)
-{
-    // Load Library
-    if (jitLib == NULL)
+#ifdef TARGET_WINDOWS
+    return ::GetCommandLineA();
+#else
+    std::string   cmdLine("");
+    std::ifstream proc("/proc/self/cmdline");
+    if (proc)
     {
-        if (jitLibPath == nullptr)
-        {
-            LogError("LoadRealJitLib - No real jit path");
-            return false;
-        }
-        jitLib = ::LoadLibraryExW(jitLibPath, NULL, 0);
-        if (jitLib == NULL)
-        {
-            LogError("LoadRealJitLib - LoadLibrary failed to load '%ws' (0x%08x)", jitLibPath, ::GetLastError());
-            return false;
-        }
+        std::getline(proc, cmdLine);
     }
-    return true;
+    return cmdLine;
+#endif
 }
 
 bool LoadRealJitLib(HMODULE& jitLib, const std::filesystem::path& jitLibPath)
@@ -185,42 +148,6 @@ bool LoadRealJitLib(HMODULE& jitLib, const std::filesystem::path& jitLibPath)
     return true;
 }
 
-void ReplaceIllegalCharacters(WCHAR* fileName)
-{
-    WCHAR* quote = nullptr;
-
-    // Perform the following transforms:
-    //  - Convert non-ASCII to ASCII for simplicity
-    //  - Remove any illegal or annoying characters from the file name by
-    // converting them to underscores.
-    //  - Replace any quotes in the file name with spaces.
-    for (quote = fileName; *quote != '\0'; quote++)
-    {
-        WCHAR ch = *quote;
-        if ((ch <= 32) || (ch >= 127)) // Only allow textual ASCII characters
-        {
-            *quote = W('_');
-        }
-        else
-        {
-            switch (ch)
-            {
-                case W('('): case W(')'): case W('='): case W('<'):
-                case W('>'): case W(':'): case W('/'): case W('\\'):
-                case W('|'): case W('?'): case W('!'): case W('*'):
-                case W('.'): case W(','):
-                    *quote = W('_');
-                    break;
-                case W('"'):
-                    *quote = W(' ');
-                    break;
-                default:
-                    break;
-            }
-        }
-    }
-}
-
 void ReplaceIllegalCharacters(std::string& fileName)
 {
     // Perform the following transforms:
@@ -256,69 +183,6 @@ void ReplaceIllegalCharacters(std::string& fileName)
     }
 }
 
-// All lengths in this function exclude the terminal NULL.
-WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const WCHAR* extension)
-{
-    const size_t extensionLength    = u16_strlen(extension);
-    const size_t fileNameLength     = u16_strlen(fileName);
-    const size_t randomStringLength = 8;
-    const size_t maxPathLength      = MAX_PATH - 50;
-
-    // See how long the folder part is, and start building the file path with the folder part.
-    //
-    WCHAR* fullPath = new WCHAR[MAX_PATH];
-    fullPath[0] = W('\0');
-    const size_t folderPathLength = GetFullPathNameW(folderPath, MAX_PATH, (LPWSTR)fullPath, NULL);
-
-    if (folderPathLength == 0)
-    {
-        LogError("GetResultFileName - can't resolve folder path '%ws'", folderPath);
-        return nullptr;
-    }
-
-    // Account for the folder, directory separator and extension.
-    //
-    size_t fullPathLength = folderPathLength + 1 + extensionLength;
-
-    // If we won't have room for a minimal file name part, bail.
-    //
-    if ((fullPathLength + randomStringLength) > maxPathLength)
-    {
-        LogError("GetResultFileName - folder path '%ws' length + minimal file name exceeds limit %d", fullPath, maxPathLength);
-        return nullptr;
-    }
-
-    // Now figure out the file name part.
-    //
-    const size_t maxFileNameLength = maxPathLength - fullPathLength;
-    size_t usableFileNameLength = min(fileNameLength, maxFileNameLength - randomStringLength);
-    fullPathLength += usableFileNameLength + randomStringLength;
-
-    // Append the file name part
-    //
-    wcsncat_s(fullPath, fullPathLength + 1, DIRECTORY_SEPARATOR_STR_W, 1);
-    wcsncat_s(fullPath, fullPathLength + 1, fileName, usableFileNameLength);
-
-    // Clean up anything in the file part that can't be in a file name.
-    //
-    ReplaceIllegalCharacters(fullPath + folderPathLength + 1);
-
-    // Append a random string to improve uniqueness.
-    //
-    unsigned int randomNumber = 0;
-    minipal_get_non_cryptographically_secure_random_bytes((uint8_t*)&randomNumber, sizeof(randomNumber));
-
-    WCHAR randomString[randomStringLength + 1];
-    FormatInteger(randomString, randomStringLength + 1, "%08X", randomNumber);
-    wcsncat_s(fullPath, fullPathLength + 1, randomString, randomStringLength);
-
-    // Append extension
-    //
-    wcsncat_s(fullPath, fullPathLength + 1, extension, extensionLength);
-
-    return fullPath;
-}
-
 std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
                                         const std::string&           fileName,
                                         const std::string&           extension)
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index b49f59b6210a83..cd54d244966299 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -29,14 +29,10 @@ WCHAR* GetEnvironmentVariableWithDefaultW(const WCHAR* envVarName, const WCHAR*
 
 const char* GetEnvWithDefault(const char* envVarName, const char* defaultValue = nullptr);
 
-#ifdef TARGET_UNIX
-LPSTR GetCommandLineA();
-#endif // TARGET_UNIX
+std::string GetProcessCommandLine();
 
-bool LoadRealJitLib(HMODULE& realJit, WCHAR* realJitPath);
 bool LoadRealJitLib(HMODULE& realJit, const std::filesystem::path& realJitPath);
 
-WCHAR* GetResultFileName(const WCHAR* folderPath, const WCHAR* fileName, const WCHAR* extension);
 std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
                                         const std::string&           fileName,
                                         const std::string&           extension);
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
index 195230468b8f80..5e6dfbd0ad0569 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
@@ -71,6 +71,7 @@
 #include <string>
 #include <algorithm>
 #include <vector>
+#include <fstream>
 
 
 #ifdef USE_MSVCDIS
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-collector/icorjitcompiler.cpp b/src/coreclr/tools/superpmi/superpmi-shim-collector/icorjitcompiler.cpp
index b6209f97a325f7..d7f15ea6cd1fc3 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-collector/icorjitcompiler.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-collector/icorjitcompiler.cpp
@@ -68,7 +68,7 @@ CorJitResult interceptor_ICJC::compileMethod(ICorJitInfo*                comp,
     auto* mc = new MethodContext();
     interceptor_ICJI our_ICorJitInfo(this, comp, mc);
 
-    mc->cr->recProcessName(GetCommandLineA());
+    mc->cr->recProcessName(GetProcessCommandLine().c_str());
 
     mc->recCompileMethod(info, flags, currentOs);
 
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
index 727745a4e47d97..ef25cfa82ddd40 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
@@ -12,7 +12,6 @@
 #include "logging.h"
 #include "spmiutil.h"
 #include "jithost.h"
-#include <fstream>
 
 // Assumptions:
 // -We'll never be unloaded - we leak memory and have no facility to unload libraries
@@ -80,19 +79,7 @@ void SetLogPath()
 
 void SetLogPathName()
 {
-#ifdef HOST_WINDOWS
-    std::string fileName(GetCommandLineA());
-#else
-    std::string   fileName("");
-    std::ifstream proc("/proc/self/cmdline");
-    if (proc)
-    {
-        std::getline(proc, fileName);
-    }
-#endif
-    const std::string extension = ".mc";
-
-    g_dataFileName = GetResultFileName(g_logPath, fileName, extension);
+    g_dataFileName = GetResultFileName(g_logPath, GetProcessCommandLine(), ".mc");
 }
 
 void SetCollectionFilter()
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 8bedbcd672a684..69fb6b9cb0195d 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -9,18 +9,7 @@
 
 MethodCallSummarizer::MethodCallSummarizer(const std::filesystem::path& logPath)
 {
-#ifdef HOST_WINDOWS
-    std::string fileName(GetCommandLineA());
-#else
-    std::string fileName("");
-    std::ifstream proc("/proc/self/cmdline");
-    if (proc)
-    {
-        std::getline(proc, fileName);
-    }
-#endif
-    const std::string extension = ".csv";
-    dataFileName = GetResultFileName(logPath, fileName, extension);
+    dataFileName = GetResultFileName(logPath, GetProcessCommandLine(), ".csv");
 }
 
 // Use ordered map to make the most commonly added items are at the top of the list...

From 93224cfbf4c427ca9c0081417eb4eeed4b090e10 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Tue, 10 Jun 2025 15:51:29 +0800
Subject: [PATCH 13/28] Don't replace . in extension

---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 783581912bd3ff..2dba9b53b40331 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -194,9 +194,9 @@ std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
     std::stringstream ss;
     ss << std::hex << std::setw(8) << std::setfill('0') << randomNumber;
 
-    std::string nameAndExtension = fileName + ss.str() + extension;
-    ReplaceIllegalCharacters(nameAndExtension);
-    return folderPath / nameAndExtension;
+    std::string copy = fileName;
+    ReplaceIllegalCharacters(copy);
+    return folderPath / (copy + ss.str() + extension);
 }
 
 #ifdef TARGET_AMD64

From 08d99e415b4caf127a1a876f463e9802aa4bdf90 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Tue, 10 Jun 2025 16:51:30 +0800
Subject: [PATCH 14/28] Limit result file path

---
 .../tools/superpmi/superpmi-shared/spmiutil.cpp  | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 2dba9b53b40331..c1a259217f1ba1 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -193,10 +193,24 @@ std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
     minipal_get_non_cryptographically_secure_random_bytes((uint8_t*)&randomNumber, sizeof(randomNumber));
     std::stringstream ss;
     ss << std::hex << std::setw(8) << std::setfill('0') << randomNumber;
+    std::string suffix = ss.str() + extension;
+
+    // Limit the total file name length to MAX_PATH - 50
+    int usableLength = MAX_PATH - 50 - (int)folderPath.native().size() - (int)suffix.size();
+    if (usableLength < 0)
+    {
+        LogError("GetResultFileName - folder path '%ws' length + minimal file name exceeds limit %d", folderPath.u16string().c_str(), MAX_PATH - 50);
+        return "";
+    }
 
     std::string copy = fileName;
+    if (copy.size() > usableLength)
+    {
+        copy = copy.substr(0, usableLength);
+    }
+
     ReplaceIllegalCharacters(copy);
-    return folderPath / (copy + ss.str() + extension);
+    return folderPath / (copy + suffix);
 }
 
 #ifdef TARGET_AMD64

From b22e3a972ecc381d8fcd0e1e44a983acb6f7bf63 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Tue, 10 Jun 2025 16:53:08 +0800
Subject: [PATCH 15/28] Add comment about destructor

---
 .../superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp | 1 +
 .../superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp     | 1 +
 .../tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp | 1 +
 3 files changed, 3 insertions(+)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
index ef25cfa82ddd40..bf2d26c0cf5fbe 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
@@ -28,6 +28,7 @@ bool                  g_initialized      = false;
 char*                 g_collectionFilter = nullptr;
 
 // RAII holder for logger
+// Global deconstructors are unreliable. We only use it for superpmi shim.
 class LoggerHolder
 {
 public:
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index 8e33d5f46a9978..d7848bee67d70b 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -24,6 +24,7 @@ std::filesystem::path g_DefaultRealJitPath{""};
 std::unique_ptr<MethodCallSummarizer> g_globalContext = nullptr;
 
 // RAII holder for logger
+// Global deconstructors are unreliable. We only use it for superpmi shim.
 class LoggerHolder
 {
 public:
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp b/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
index ea764b921c390d..cd1d6255e4fad0 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
@@ -22,6 +22,7 @@ std::filesystem::path g_HomeDirectory{""};
 std::filesystem::path g_DefaultRealJitPath{""};
 
 // RAII holder for logger
+// Global deconstructors are unreliable. We only use it for superpmi shim.
 class LoggerHolder
 {
 public:

From 407af70c7f48c68caece6454c45a81156869f130 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Tue, 10 Jun 2025 17:36:53 +0800
Subject: [PATCH 16/28] Fix sign/unsigned mismatch

---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index c1a259217f1ba1..78505e904c326c 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -204,7 +204,7 @@ std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
     }
 
     std::string copy = fileName;
-    if (copy.size() > usableLength)
+    if ((int)copy.size() > usableLength)
     {
         copy = copy.substr(0, usableLength);
     }

From 9f1fcc808cba968dca705393827e4e16e39d6b2d Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 01:17:56 +0800
Subject: [PATCH 17/28] Remove C++ 17 and fstream usage

---
 src/coreclr/tools/superpmi/CMakeLists.txt                | 5 -----
 src/coreclr/tools/superpmi/superpmi-shared/standardpch.h | 4 ----
 2 files changed, 9 deletions(-)

diff --git a/src/coreclr/tools/superpmi/CMakeLists.txt b/src/coreclr/tools/superpmi/CMakeLists.txt
index e92d5e235e9ed8..d4308d2e03cabd 100644
--- a/src/coreclr/tools/superpmi/CMakeLists.txt
+++ b/src/coreclr/tools/superpmi/CMakeLists.txt
@@ -1,8 +1,3 @@
-# SuperPMI is development-only toolset.
-# Enable C++ 17 to get more handy stuffs from STL.
-set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-
 add_subdirectory(superpmi)
 add_subdirectory(mcs)
 add_subdirectory(superpmi-shim-collector)
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
index 5e6dfbd0ad0569..e18cb57a76a002 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
@@ -15,9 +15,6 @@
 #define DEBUG_BREAK DebugBreak()
 #endif
 
-// filesystem fails parsing if included after PAL header
-#include <filesystem>
-
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif // WIN32_LEAN_AND_MEAN
@@ -71,7 +68,6 @@
 #include <string>
 #include <algorithm>
 #include <vector>
-#include <fstream>
 
 
 #ifdef USE_MSVCDIS

From 70152a8d89c677957341828db7670a45cce9c56e Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 01:34:35 +0800
Subject: [PATCH 18/28] Remove usages of std::filesystem::path

---
 .../superpmi/superpmi-shared/spmiutil.cpp     | 18 ++++++------
 .../tools/superpmi/superpmi-shared/spmiutil.h |  8 +++---
 .../superpmi-shim-collector.cpp               | 28 +++++++++----------
 .../methodcallsummarizer.cpp                  |  2 +-
 .../methodcallsummarizer.h                    |  4 +--
 .../superpmi-shim-counter.cpp                 | 16 +++++------
 .../superpmi-shim-simple.cpp                  | 14 +++++-----
 7 files changed, 45 insertions(+), 45 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 14616dd074f04f..243d3b61777fe6 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -123,7 +123,7 @@ std::string GetProcessCommandLine()
 #endif
 }
 
-bool LoadRealJitLib(HMODULE& jitLib, const std::filesystem::path& jitLibPath)
+bool LoadRealJitLib(HMODULE& jitLib, const std::string& jitLibPath)
 {
     // Load Library
     if (jitLib == NULL)
@@ -134,14 +134,14 @@ bool LoadRealJitLib(HMODULE& jitLib, const std::filesystem::path& jitLibPath)
             return false;
         }
 #ifdef TARGET_WINDOWS
-        jitLib = ::LoadLibraryExW(jitLibPath.c_str(), NULL, 0);
+        jitLib = ::LoadLibraryExA(jitLibPath.c_str(), NULL, 0);
 #else
         jitLib = ::dlopen(jitLibPath.c_str(), RTLD_LAZY);
         // The simulated DllMain of JIT doesn't do any meaningful initialization. Skip it.
 #endif
         if (jitLib == NULL)
         {
-            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.string().c_str(), errno);
+            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.c_str(), errno);
             return false;
         }
     }
@@ -183,9 +183,9 @@ void ReplaceIllegalCharacters(std::string& fileName)
     }
 }
 
-std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
-                                        const std::string&           fileName,
-                                        const std::string&           extension)
+std::string GetResultFileName(const std::string& folderPath,
+                              const std::string& fileName,
+                              const std::string& extension)
 {
     // Append a random string to improve uniqueness.
     //
@@ -196,10 +196,10 @@ std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
     std::string suffix = ss.str() + extension;
 
     // Limit the total file name length to MAX_PATH - 50
-    int usableLength = MAX_PATH - 50 - (int)folderPath.native().size() - (int)suffix.size();
+    int usableLength = MAX_PATH - 50 - (int)folderPath.size() - (int)suffix.size();
     if (usableLength < 0)
     {
-        LogError("GetResultFileName - folder path '%ws' length + minimal file name exceeds limit %d", folderPath.u16string().c_str(), MAX_PATH - 50);
+        LogError("GetResultFileName - folder path '%s' length + minimal file name exceeds limit %d", folderPath.c_str(), MAX_PATH - 50);
         return "";
     }
 
@@ -210,7 +210,7 @@ std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
     }
 
     ReplaceIllegalCharacters(copy);
-    return folderPath / (copy + suffix);
+    return folderPath + DIRECTORY_SEPARATOR_CHAR_A + copy + suffix;
 }
 
 #ifdef TARGET_AMD64
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
index 26d5656c179ff6..93e6547d1cf1b5 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.h
@@ -31,11 +31,11 @@ const char* GetEnvWithDefault(const char* envVarName, const char* defaultValue =
 
 std::string GetProcessCommandLine();
 
-bool LoadRealJitLib(HMODULE& realJit, const std::filesystem::path& realJitPath);
+bool LoadRealJitLib(HMODULE& realJit, const std::string& realJitPath);
 
-std::filesystem::path GetResultFileName(const std::filesystem::path& folderPath,
-                                        const std::string&           fileName,
-                                        const std::string&           extension);
+std::string GetResultFileName(const std::string& folderPath,
+                              const std::string& fileName,
+                              const std::string& extension);
 
 // SuperPMI stores handles as unsigned 64-bit integers, no matter the platform the collection happens on
 // (32 or 64 bit). Handles are defined as pointers. We need to be careful when converting from a handle
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
index bf2d26c0cf5fbe..f3ff4af0e6f9db 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-collector/superpmi-shim-collector.cpp
@@ -17,15 +17,15 @@
 // -We'll never be unloaded - we leak memory and have no facility to unload libraries
 // -printf output to console is okay
 
-HMODULE               g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
-std::filesystem::path g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
-std::filesystem::path g_logPath{""};
-std::filesystem::path g_HomeDirectory{""};
-std::filesystem::path g_DefaultRealJitPath{""};
-std::filesystem::path g_dataFileName{""};
-MethodContext*        g_globalContext    = nullptr;
-bool                  g_initialized      = false;
-char*                 g_collectionFilter = nullptr;
+HMODULE        g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
+std::string    g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
+std::string    g_logPath{""};
+std::string    g_HomeDirectory{""};
+std::string    g_DefaultRealJitPath{""};
+std::string    g_dataFileName{""};
+MethodContext* g_globalContext    = nullptr;
+bool           g_initialized      = false;
+char*          g_collectionFilter = nullptr;
 
 // RAII holder for logger
 // Global deconstructors are unreliable. We only use it for superpmi shim.
@@ -58,7 +58,7 @@ void SetDefaultPaths()
 
     if (g_DefaultRealJitPath.empty())
     {
-        g_DefaultRealJitPath = g_HomeDirectory / DEFAULT_REAL_JIT_NAME_A;
+        g_DefaultRealJitPath = g_HomeDirectory + DIRECTORY_SEPARATOR_CHAR_A + DEFAULT_REAL_JIT_NAME_A;
     }
 }
 
@@ -66,7 +66,7 @@ void SetLibName()
 {
     if (g_realJitPath.empty())
     {
-        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.string().c_str());
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.c_str());
     }
 }
 
@@ -74,7 +74,7 @@ void SetLogPath()
 {
     if (g_logPath.empty())
     {
-        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.string().c_str());
+        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.c_str());
     }
 }
 
@@ -215,11 +215,11 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
 #endif
 
     // create our datafile
-    pJitInstance->hFile = CreateFileW((const WCHAR*)g_dataFileName.u16string().c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL,
+    pJitInstance->hFile = CreateFileA(g_dataFileName.c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL,
                                       CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
     if (pJitInstance->hFile == INVALID_HANDLE_VALUE)
     {
-        LogError("Couldn't open file '%s': error %d", g_dataFileName.string().c_str(), GetLastError());
+        LogError("Couldn't open file '%s': error %d", g_dataFileName.c_str(), GetLastError());
     }
 
     return pJitInstance;
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 69fb6b9cb0195d..4bacebbb53ae35 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -7,7 +7,7 @@
 #include "spmiutil.h"
 #include <fstream>
 
-MethodCallSummarizer::MethodCallSummarizer(const std::filesystem::path& logPath)
+MethodCallSummarizer::MethodCallSummarizer(const std::string& logPath)
 {
     dataFileName = GetResultFileName(logPath, GetProcessCommandLine(), ".csv");
 }
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
index df45654f594c59..3a2b3a67d04ec8 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
@@ -10,14 +10,14 @@
 class MethodCallSummarizer
 {
 public:
-    MethodCallSummarizer(const std::filesystem::path& name);
+    MethodCallSummarizer(const std::string& name);
     void AddCall(const char* name);
     void SaveTextFile();
     ~MethodCallSummarizer();
 
 private:
     std::map<std::string, int> namesAndCounts;
-    std::filesystem::path      dataFileName;
+    std::string                dataFileName;
 };
 
 #endif
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index d7848bee67d70b..c479ca85ad9c04 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -15,11 +15,11 @@
 #include "jithost.h"
 #include <memory>
 
-HMODULE               g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
-std::filesystem::path g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
-std::filesystem::path g_logPath{""};
-std::filesystem::path g_HomeDirectory{""};
-std::filesystem::path g_DefaultRealJitPath{""};
+HMODULE     g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
+std::string g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
+std::string g_logPath{""};
+std::string g_HomeDirectory{""};
+std::string g_DefaultRealJitPath{""};
 
 std::unique_ptr<MethodCallSummarizer> g_globalContext = nullptr;
 
@@ -54,7 +54,7 @@ void SetDefaultPaths()
 
     if (g_DefaultRealJitPath.empty())
     {
-        g_DefaultRealJitPath = g_HomeDirectory / DEFAULT_REAL_JIT_NAME_A;
+        g_DefaultRealJitPath = g_HomeDirectory + DIRECTORY_SEPARATOR_CHAR_A + DEFAULT_REAL_JIT_NAME_A;
     }
 }
 
@@ -62,7 +62,7 @@ void SetLibName()
 {
     if (g_realJitPath.empty())
     {
-        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.string().c_str());
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.c_str());
     }
 }
 
@@ -70,7 +70,7 @@ void SetLogPath()
 {
     if (g_logPath.empty())
     {
-        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.string().c_str());
+        g_logPath = GetEnvWithDefault("SuperPMIShimLogPath", g_HomeDirectory.c_str());
     }
 }
 
diff --git a/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp b/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
index cd1d6255e4fad0..2cc1ef2a268170 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-simple/superpmi-shim-simple.cpp
@@ -15,11 +15,11 @@
 #include "jithost.h"
 
 
-HMODULE               g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
-std::filesystem::path g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
-std::filesystem::path g_logPath{""};
-std::filesystem::path g_HomeDirectory{""};
-std::filesystem::path g_DefaultRealJitPath{""};
+HMODULE     g_hRealJit = 0;    // We leak this currently (could do the proper shutdown in process_detach)
+std::string g_realJitPath{""}; // Destructable objects will be cleaned up and won't leak
+std::string g_logPath{""};
+std::string g_HomeDirectory{""};
+std::string g_DefaultRealJitPath{""};
 
 // RAII holder for logger
 // Global deconstructors are unreliable. We only use it for superpmi shim.
@@ -52,7 +52,7 @@ void SetDefaultPaths()
 
     if (g_DefaultRealJitPath.empty())
     {
-        g_DefaultRealJitPath = g_HomeDirectory / DEFAULT_REAL_JIT_NAME_A;
+        g_DefaultRealJitPath = g_HomeDirectory + DIRECTORY_SEPARATOR_CHAR_A + DEFAULT_REAL_JIT_NAME_A;
     }
 }
 
@@ -60,7 +60,7 @@ void SetLibName()
 {
     if (g_realJitPath.empty())
     {
-        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.string().c_str());
+        g_realJitPath = GetEnvWithDefault("SuperPMIShimPath", g_DefaultRealJitPath.c_str());
     }
 }
 

From 4db4066afb5d3d32ed2b745efc42df3f3c6e14e6 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 01:48:34 +0800
Subject: [PATCH 19/28] Don't introduce fstream

---
 .../methodcallsummarizer.cpp                  | 22 +++++++++----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
index 4bacebbb53ae35..ce9f142119c9c9 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.cpp
@@ -5,7 +5,6 @@
 #include "methodcallsummarizer.h"
 #include "logging.h"
 #include "spmiutil.h"
-#include <fstream>
 
 MethodCallSummarizer::MethodCallSummarizer(const std::string& logPath)
 {
@@ -22,20 +21,21 @@ void MethodCallSummarizer::AddCall(const char* name)
 
 void MethodCallSummarizer::SaveTextFile()
 {
-    try
+    FILE* fp = fopen(dataFileName.c_str(), "w");
+    if (fp == NULL)
     {
-        std::ofstream outFile(dataFileName);
-        outFile << "FunctionName,Count" << std::endl;
-
-        for (auto& elem : namesAndCounts)
-        {
-            outFile << elem.first << "," << elem.second << std::endl;
-        }
+        LogError("Couldn't open file '%s': error %d", dataFileName.c_str(), errno);
+        return;
     }
-    catch (std::exception& ex)
+
+    fprintf(fp, "FunctionName,Count\n");
+
+    for (auto& elem : namesAndCounts)
     {
-        LogError("Couldn't write file '%s': %s", dataFileName.c_str(), ex.what());
+        fprintf(fp, "%s,%d\n", elem.first.c_str(), elem.second);
     }
+
+    fclose(fp);
 }
 
 MethodCallSummarizer::~MethodCallSummarizer()

From 58183b3bd7486038c32b24be8a5483bcd82646a9 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 02:10:42 +0800
Subject: [PATCH 20/28] Cleanup UNIX usage

---
 .../tools/superpmi/superpmi-shared/spmiutil.cpp    | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 243d3b61777fe6..98161f7a537652 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -113,13 +113,17 @@ std::string GetProcessCommandLine()
 #ifdef TARGET_WINDOWS
     return ::GetCommandLineA();
 #else
-    std::string   cmdLine("");
-    std::ifstream proc("/proc/self/cmdline");
-    if (proc)
+    char cmdLine[256];
+
+    FILE* fp = fopen("/proc/self/cmdline", "r");
+    if (fp != NULL)
     {
-        std::getline(proc, cmdLine);
+        fgets(cmdLine, sizeof(cmdLine), fp);
+        fclose(fp);
+        return cmdLine;
     }
-    return cmdLine;
+
+    return "";
 #endif
 }
 

From b3ce44d8ef67e20e1d4365299c26af50b7f3f1eb Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 10:35:28 +0800
Subject: [PATCH 21/28] Mark method as private

---
 .../superpmi/superpmi-shim-counter/methodcallsummarizer.h      | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
index 3a2b3a67d04ec8..aca87d55e91dd8 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/methodcallsummarizer.h
@@ -12,12 +12,13 @@ class MethodCallSummarizer
 public:
     MethodCallSummarizer(const std::string& name);
     void AddCall(const char* name);
-    void SaveTextFile();
     ~MethodCallSummarizer();
 
 private:
     std::map<std::string, int> namesAndCounts;
     std::string                dataFileName;
+
+    void SaveTextFile();
 };
 
 #endif

From 7e81613032ace94ac6114851b5412b820130f07c Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 10:44:26 +0800
Subject: [PATCH 22/28] make_unique is not available in C++ 11

---
 .../superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
index c479ca85ad9c04..a56c6d1bd8c264 100644
--- a/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shim-counter/superpmi-shim-counter.cpp
@@ -126,7 +126,7 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* host)
     if (g_globalContext == nullptr)
     {
         SetLogPath();
-        g_globalContext = std::make_unique<MethodCallSummarizer>(g_logPath);
+        g_globalContext = std::unique_ptr<MethodCallSummarizer>(new MethodCallSummarizer(g_logPath));
     }
 
     g_ourJitHost->setMethodCallSummarizer(g_globalContext.get());
@@ -171,7 +171,7 @@ extern "C" DLLEXPORT ICorJitCompiler* getJit()
     if (g_globalContext == nullptr)
     {
         SetLogPath();
-        g_globalContext = std::make_unique<MethodCallSummarizer>(g_logPath);
+        g_globalContext = std::unique_ptr<MethodCallSummarizer>(new MethodCallSummarizer(g_logPath));
     }
     pJitInstance->mcs = g_globalContext.get();
     return pJitInstance;

From c16969529259e85e233e2dbe604c162955e1402a Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 10:45:10 +0800
Subject: [PATCH 23/28] Update LoadLibrary error checking

---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 98161f7a537652..ecf20b095e1f02 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -139,15 +139,20 @@ bool LoadRealJitLib(HMODULE& jitLib, const std::string& jitLibPath)
         }
 #ifdef TARGET_WINDOWS
         jitLib = ::LoadLibraryExA(jitLibPath.c_str(), NULL, 0);
+        if (jitLib == NULL)
+        {
+            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.c_str(), ::GetLastError());
+            return false;
+        }
 #else
         jitLib = ::dlopen(jitLibPath.c_str(), RTLD_LAZY);
         // The simulated DllMain of JIT doesn't do any meaningful initialization. Skip it.
-#endif
         if (jitLib == NULL)
         {
-            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.c_str(), errno);
+            LogError("LoadRealJitLib - dlopen failed to load '%s' (%s)", jitLibPath.c_str(), ::dlerror());
             return false;
         }
+#endif
     }
     return true;
 }

From f0f1857bded3a114bdd959cd1180adc922b63cad Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 13 Aug 2025 23:09:32 +0800
Subject: [PATCH 24/28] Handle long cmdline

---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index ecf20b095e1f02..1f3bed55e1483c 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -118,9 +118,13 @@ std::string GetProcessCommandLine()
     FILE* fp = fopen("/proc/self/cmdline", "r");
     if (fp != NULL)
     {
-        fgets(cmdLine, sizeof(cmdLine), fp);
+        std::string result;
+        while (fgets(cmdLine, sizeof(cmdLine), fp) != NULL)
+        {
+            result += cmdLine;
+        }
         fclose(fp);
-        return cmdLine;
+        return result;
     }
 
     return "";

From b1d29874b250101d117c9d718e86aabf230c6a40 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Thu, 14 Aug 2025 00:49:24 +0800
Subject: [PATCH 25/28] Use getline instead

---
 .../tools/superpmi/superpmi-shared/spmiutil.cpp       | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 1f3bed55e1483c..2f9d6fc7bee148 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -113,16 +113,21 @@ std::string GetProcessCommandLine()
 #ifdef TARGET_WINDOWS
     return ::GetCommandLineA();
 #else
-    char cmdLine[256];
-
     FILE* fp = fopen("/proc/self/cmdline", "r");
     if (fp != NULL)
     {
         std::string result;
-        while (fgets(cmdLine, sizeof(cmdLine), fp) != NULL)
+        char*       cmdLine = nullptr;
+        size_t      size    = 0;
+
+        while (getline(&cmdLine, &size, fp) != -1)
         {
             result += cmdLine;
+            free(cmdLine);
+            cmdLine = nullptr;
+            size    = 0;
         }
+
         fclose(fp);
         return result;
     }

From 899f12de6ec957390c244c6590069a279561cdae Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Thu, 14 Aug 2025 12:44:59 +0800
Subject: [PATCH 26/28] Handle \0 delimiter

---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 2f9d6fc7bee148..45abb61485df17 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -120,9 +120,12 @@ std::string GetProcessCommandLine()
         char*       cmdLine = nullptr;
         size_t      size    = 0;
 
-        while (getline(&cmdLine, &size, fp) != -1)
+        while (getdelim(&cmdLine, &size, '\0', fp) != -1)
         {
+            // /proc/self/cmdline uses \0 as delimeter, convert it to space
             result += cmdLine;
+            result += ' ';
+
             free(cmdLine);
             cmdLine = nullptr;
             size    = 0;

From 16f6ee199940f804a4dc236bde37536907ec849c Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Thu, 14 Aug 2025 13:03:25 +0800
Subject: [PATCH 27/28] Update
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp

Co-authored-by: Jan Kotas <jkotas@microsoft.com>
---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 45abb61485df17..e57ae820e56df1 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -123,8 +123,10 @@ std::string GetProcessCommandLine()
         while (getdelim(&cmdLine, &size, '\0', fp) != -1)
         {
             // /proc/self/cmdline uses \0 as delimeter, convert it to space
+            if (!result.empty())
+                result += ' ';
+
             result += cmdLine;
-            result += ' ';
 
             free(cmdLine);
             cmdLine = nullptr;

From dd225a6f5cd287710460e2073bb1ef3cef171a90 Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Fri, 15 Aug 2025 10:18:48 +0800
Subject: [PATCH 28/28] Apply suggestions from code review

Co-authored-by: Aaron Robinson <arobins@microsoft.com>
---
 src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index e57ae820e56df1..20f5f1bf295b33 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -122,7 +122,7 @@ std::string GetProcessCommandLine()
 
         while (getdelim(&cmdLine, &size, '\0', fp) != -1)
         {
-            // /proc/self/cmdline uses \0 as delimeter, convert it to space
+            // /proc/self/cmdline uses \0 as delimiter, convert it to space
             if (!result.empty())
                 result += ' ';
 
@@ -155,7 +155,7 @@ bool LoadRealJitLib(HMODULE& jitLib, const std::string& jitLibPath)
         jitLib = ::LoadLibraryExA(jitLibPath.c_str(), NULL, 0);
         if (jitLib == NULL)
         {
-            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (%d)", jitLibPath.c_str(), ::GetLastError());
+            LogError("LoadRealJitLib - LoadLibrary failed to load '%s' (0x%08x)", jitLibPath.c_str(), ::GetLastError());
             return false;
         }
 #else