https://github.com/ziqingluo-90 updated
https://github.com/llvm/llvm-project/pull/137248
>From f9e68fd71677e047ee82992f2034bd62958ecbed Mon Sep 17 00:00:00 2001
From: Ziqing Luo <ziqing_...@apple.com>
Date: Thu, 24 Apr 2025 13:29:24 -0700
Subject: [PATCH 1/3] [-Wunsafe-buffer-usage] Fix a bug that wrongly assumed
CXXMethodDecl always has an identifier
Fix a bug in UnsafeBufferUsage.cpp that wrongly assumed CXXMethodDecl always
has an identifier.
rdar://149071318
---
clang/lib/Analysis/UnsafeBufferUsage.cpp | 2 +-
clang/test/SemaCXX/bug149071318.cpp | 25 ++++++++++++++++++++++++
2 files changed, 26 insertions(+), 1 deletion(-)
create mode 100644 clang/test/SemaCXX/bug149071318.cpp
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{{}}
+}
>From 62f606ac453796d5e857a88ea62187b56af6bedc Mon Sep 17 00:00:00 2001
From: Ziqing Luo <ziq...@udel.edu>
Date: Thu, 24 Apr 2025 13:41:08 -0700
Subject: [PATCH 2/3] Add more comments to the test
---
clang/test/SemaCXX/bug149071318.cpp | 1 +
1 file changed, 1 insertion(+)
diff --git a/clang/test/SemaCXX/bug149071318.cpp
b/clang/test/SemaCXX/bug149071318.cpp
index 0dbe66f6e37a6..41c41a704104a 100644
--- a/clang/test/SemaCXX/bug149071318.cpp
+++ b/clang/test/SemaCXX/bug149071318.cpp
@@ -21,5 +21,6 @@ namespace std { // fake std namespace; to reproduce the bug,
a CXXConversionDecl
}
void test(std::Y &y) {
+ // Here `y.x` involves an implicit cast and calls the conversion
overloading, which has no identifier:
printf("%s", y.x); // expected-warning{{function 'printf' is unsafe}}
expected-note{{}}
}
>From 26747459a2fd774a42d7a7ef7d4917daf5a1e970 Mon Sep 17 00:00:00 2001
From: Ziqing Luo <ziq...@udel.edu>
Date: Thu, 24 Apr 2025 15:26:52 -0700
Subject: [PATCH 3/3] Revise comments in the test
---
clang/test/SemaCXX/bug149071318.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/test/SemaCXX/bug149071318.cpp
b/clang/test/SemaCXX/bug149071318.cpp
index 41c41a704104a..596d0e238dfba 100644
--- a/clang/test/SemaCXX/bug149071318.cpp
+++ b/clang/test/SemaCXX/bug149071318.cpp
@@ -21,6 +21,6 @@ namespace std { // fake std namespace; to reproduce the bug,
a CXXConversionDecl
}
void test(std::Y &y) {
- // Here `y.x` involves an implicit cast and calls the conversion
overloading, which has no identifier:
+ // Here `y.x` involves an implicit cast and calls the overloaded cast
operator, which has no identifier:
printf("%s", y.x); // expected-warning{{function 'printf' is unsafe}}
expected-note{{}}
}
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