[llvm-objdump] Fix --source with --macho flag (llvm#163810)

The --source option was broken when using the --macho flag because
DisassembleMachO() only initialized debug info when UseDbg was true, and
would return early if no dSYM was found.

Author: rjmansfield

llvm/test/tools/llvm-objdump/MachO/disassemble-source-dsym.test

@@ -13,4 +13,35 @@
 # RUN: dsymutil -f  -oso-prepend-path=%p/../../dsymutil/ %t3 -o %t3.dSYM
 # RUN: llvm-objdump --source --prefix=%p/../../dsymutil  %t3 | FileCheck --check-prefix=SOURCE %s
 
+## Test that --source works with --macho flag.
+
+## --macho w/ explicit .dSYM
+# RUN: llvm-objdump < %p/../../dsymutil/Inputs/basic.macho.x86_64 - --source --macho --dsym=%t1.dSYM --prefix=%p/../../dsymutil | \
+# RUN:   FileCheck --check-prefix=SOURCE %s
+
+## --macho w/ auto-detected .dSYM (dir)
+# RUN: llvm-objdump --source --macho --prefix=%p/../../dsymutil %t2 | FileCheck --check-prefix=SOURCE %s
+
+## --macho w/ auto-detected .dSYM (file)
+# RUN: llvm-objdump --source --macho --prefix=%p/../../dsymutil %t3 | FileCheck --check-prefix=SOURCE %s
+
 # SOURCE: ; int bar(int arg) {
+
+## Test that --line-numbers works with --macho flag.
+
+## --macho -l w/ explicit .dSYM
+# RUN: llvm-objdump -d -l --macho --dsym=%t1.dSYM %p/../../dsymutil/Inputs/basic.macho.x86_64 | FileCheck --check-prefix=LINE %s
+
+## --macho -l w/ object file (embedded debug info)
+# RUN: llvm-objdump -d -l --macho %p/../../dsymutil/Inputs/basic1.macho.x86_64.o | FileCheck --check-prefix=LINE_OBJ %s
+
+# LINE: (__TEXT,__text) section
+# LINE: _bar:
+# LINE: ; bar():
+# LINE: ; {{.*}}basic3.c:
+
+# LINE_OBJ: (__TEXT,__text) section
+# LINE_OBJ: _main:
+# LINE_OBJ: ; main():
+# LINE_OBJ: ; {{.*}}basic1.c:23
+# LINE_OBJ: pushq %rbp ## basic1.c:23:0

llvm/tools/llvm-objdump/MachODump.cpp

@@ -13,6 +13,7 @@
 #include "MachODump.h"
 
 #include "ObjdumpOptID.h"
+#include "SourcePrinter.h"
 #include "llvm-objdump.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
@@ -7411,18 +7412,28 @@ static void DisassembleMachO(StringRef Filename, MachOObjectFile *MachOOF,
   std::unique_ptr<DIContext> diContext;
   std::unique_ptr<Binary> DSYMBinary;
   std::unique_ptr<MemoryBuffer> DSYMBuf;
-  if (UseDbg) {
-    // If separate DSym file path was specified, parse it as a macho file,
-    // get the sections and supply it to the section name parsing machinery.
-    if (const ObjectFile *DbgObj =
-            getMachODSymObject(MachOOF, Filename, DSYMBinary, DSYMBuf)) {
+  const ObjectFile *DbgObj = MachOOF;
+  if (UseDbg || PrintSource || PrintLines) {
+    // Look for debug info in external dSYM file or embedded in the object.
+    // getMachODSymObject returns MachOOF by default if no external dSYM found.
+    const ObjectFile *DSym =
+        getMachODSymObject(MachOOF, Filename, DSYMBinary, DSYMBuf);
+    if (!DSym)
+      return;
+    DbgObj = DSym;
+    if (UseDbg || PrintLines) {
       // Setup the DIContext
       diContext = DWARFContext::create(*DbgObj);
-    } else {
-      return;
     }
   }
 
+  std::optional<SourcePrinter> SP;
+  std::optional<LiveVariablePrinter> LVP;
+  if (PrintSource || PrintLines) {
+    SP.emplace(DbgObj, TheTarget->getName());
+    LVP.emplace(*MRI.get(), *STI.get());
+  }
+
   if (FilterSections.empty())
     outs() << "(" << DisSegName << "," << DisSectName << ") section\n";
 
@@ -7601,6 +7612,12 @@ static void DisassembleMachO(StringRef Filename, MachOObjectFile *MachOOF,
           outs() << SymName << ":\n";
 
         uint64_t PC = SectAddress + Index;
+
+        if (PrintSource || PrintLines) {
+          formatted_raw_ostream FOS(outs());
+          SP->printSourceLine(FOS, {PC, SectIdx}, Filename, *LVP);
+        }
+
         if (LeadingAddr) {
           if (FullLeadingAddr) {
             if (MachOOF->is64Bit())
@@ -7692,6 +7709,11 @@ static void DisassembleMachO(StringRef Filename, MachOObjectFile *MachOOF,
 
         uint64_t PC = SectAddress + Index;
 
+        if (PrintSource || PrintLines) {
+          formatted_raw_ostream FOS(outs());
+          SP->printSourceLine(FOS, {PC, SectIdx}, Filename, *LVP);
+        }
+
         if (DumpAndSkipDataInCode(PC, Bytes.data() + Index, Dices, InstSize))
           continue;