[-Wunsafe-buffer-usage] Fix a bug that wrongly assumed CXXMethodDecl always has an identifier #137248
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…always has an identifier Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed CXXMethodDecl always has an identifier. rdar://149071318
llvmbot
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@llvm/pr-subscribers-clang @llvm/pr-subscribers-clang-analysis Author: Ziqing Luo (ziqingluo-90) ChangesFix a bug in UnsafeBufferUsage.cpp that wrongly assumed that CXXMethodDecl always has an identifier. rdar://149071318 Full diff: https://github.com/llvm/llvm-project/pull/137248.diff 2 Files Affected:
diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp
index 4eaf8ba61eaec..5b72382ca9772 100644
--- a/clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -675,7 +675,7 @@ static bool isNullTermPointer(const Expr *Ptr) {
const CXXMethodDecl *MD = MCE->getMethodDecl();
const CXXRecordDecl *RD = MCE->getRecordDecl()->getCanonicalDecl();
- if (MD && RD && RD->isInStdNamespace())
+ if (MD && RD && RD->isInStdNamespace() && MD->getIdentifier())
if (MD->getName() == "c_str" && RD->getName() == "basic_string")
return true;
}
diff --git a/clang/test/SemaCXX/bug149071318.cpp b/clang/test/SemaCXX/bug149071318.cpp
new file mode 100644
index 0000000000000..0dbe66f6e37a6
--- /dev/null
+++ b/clang/test/SemaCXX/bug149071318.cpp
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -std=c++20 -Wno-all -Wunsafe-buffer-usage \
+// RUN: -verify %s
+
+// This example uncovered a bug in UnsafeBufferUsage.cpp, where the
+// code assumed that a CXXMethodDecl always have an identifier.
+
+int printf( const char* format, char *); // <-- Fake decl of `printf`; to reproduce the bug, this example needs an implicit cast within a printf call.
+
+namespace std { // fake std namespace; to reproduce the bug, a CXXConversionDecl needs to be in std namespace.
+ class X {
+ char * p;
+ public:
+ operator char*() {return p;}
+ };
+
+ class Y {
+ public:
+ X x;
+ };
+
+}
+
+void test(std::Y &y) {
+ printf("%s", y.x); // expected-warning{{function 'printf' is unsafe}} expected-note{{}}
+}
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CC: @dtarditi |
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LGTM. Thanks! |
malavikasamak
approved these changes
Apr 24, 2025
jkorous-apple
approved these changes
Apr 24, 2025
clang/test/SemaCXX/bug149071318.cpp
Outdated
| } | ||
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| void test(std::Y &y) { | ||
| // Here `y.x` involves an implicit cast and calls the conversion overloading, which has no identifier: |
There was a problem hiding this comment.
nit: "calls the overloaded cast operator"
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/162/builds/20928 Here is the relevant piece of the build log for the reference |
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…always has an identifier (llvm#137248) Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed that CXXMethodDecl always has an identifier. rdar://149071318 (cherry picked from commit be48c0d)
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…always has an identifier (llvm#137248) Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed that CXXMethodDecl always has an identifier. rdar://149071318 (cherry picked from commit be48c0d)
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…always has an identifier (llvm#137248) Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed that CXXMethodDecl always has an identifier. rdar://149071318
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…always has an identifier (llvm#137248) Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed that CXXMethodDecl always has an identifier. rdar://149071318
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…always has an identifier (llvm#137248) Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed that CXXMethodDecl always has an identifier. rdar://149071318
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Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed that CXXMethodDecl always has an identifier.
rdar://149071318