[clang] 090dc77 - [-Wunsafe-buffer-usage] Fix a bug and suppress libc warnings for C files (#109496)
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cfe-commits at lists.llvm.org
Sun Sep 22 12:29:10 PDT 2024
Author: Ziqing Luo
Date: 2024-09-22T12:29:06-07:00
New Revision: 090dc77a8d636415b772f7e5f95cd120370e41d1
URL: https://github.com/llvm/llvm-project/commit/090dc77a8d636415b772f7e5f95cd120370e41d1
DIFF: https://github.com/llvm/llvm-project/commit/090dc77a8d636415b772f7e5f95cd120370e41d1.diff
LOG: [-Wunsafe-buffer-usage] Fix a bug and suppress libc warnings for C files (#109496)
- Fix a bug in UnsafeBufferUsage.cpp related to casting to PointerType
- Suppress -Wunsafe-buffer-usage-in-libc-call for C files
(rdar://117182250)
Added:
clang/test/SemaCXX/warn-unsafe-buffer-usage-no-libc-functions-in-c.c
Modified:
clang/lib/Analysis/UnsafeBufferUsage.cpp
clang/lib/Sema/AnalysisBasedWarnings.cpp
clang/test/SemaCXX/warn-unsafe-buffer-usage-libc-functions.cpp
Removed:
################################################################################
diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp
index a16762244b1766..97f1c4f16b8f4c 100644
--- a/clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -250,7 +250,9 @@ AST_MATCHER_P(Stmt, ignoreUnsafeBufferInContainer,
AST_MATCHER_P(Stmt, ignoreUnsafeLibcCall, const UnsafeBufferUsageHandler *,
Handler) {
- return Handler->ignoreUnsafeBufferInLibcCall(Node.getBeginLoc());
+ if (Finder->getASTContext().getLangOpts().CPlusPlus)
+ return Handler->ignoreUnsafeBufferInLibcCall(Node.getBeginLoc());
+ return true; /* Only warn about libc calls for C++ */
}
AST_MATCHER_P(CastExpr, castSubExpr, internal::Matcher<Expr>, innerMatcher) {
@@ -784,12 +786,12 @@ AST_MATCHER_P(CallExpr, hasUnsafePrintfStringArg,
return false; // possibly some user-defined printf function
ASTContext &Ctx = Finder->getASTContext();
- QualType FristParmTy = FD->getParamDecl(0)->getType();
+ QualType FirstParmTy = FD->getParamDecl(0)->getType();
- if (!FristParmTy->isPointerType())
+ if (!FirstParmTy->isPointerType())
return false; // possibly some user-defined printf function
- QualType FirstPteTy = (cast<PointerType>(FristParmTy))->getPointeeType();
+ QualType FirstPteTy = FirstParmTy->castAs<PointerType>()->getPointeeType();
if (!Ctx.getFILEType()
.isNull() && //`FILE *` must be in the context if it is fprintf
@@ -865,7 +867,7 @@ AST_MATCHER(CallExpr, hasUnsafeSnprintfBuffer) {
if (!FirstParmTy->isPointerType())
return false; // Not an snprint
- QualType FirstPteTy = cast<PointerType>(FirstParmTy)->getPointeeType();
+ QualType FirstPteTy = FirstParmTy->castAs<PointerType>()->getPointeeType();
const Expr *Buf = Node.getArg(0), *Size = Node.getArg(1);
if (FirstPteTy.isConstQualified() || !Buf->getType()->isPointerType() ||
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 117b2c8bc57935..6496a33b8f5a50 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2581,7 +2581,8 @@ void clang::sema::AnalysisBasedWarnings::IssueWarnings(
!Diags.isIgnored(diag::warn_unsafe_buffer_variable, SourceLocation()) ||
!Diags.isIgnored(diag::warn_unsafe_buffer_usage_in_container,
SourceLocation()) ||
- !Diags.isIgnored(diag::warn_unsafe_buffer_libc_call, SourceLocation())) {
+ (!Diags.isIgnored(diag::warn_unsafe_buffer_libc_call, SourceLocation()) &&
+ S.getLangOpts().CPlusPlus /* only warn about libc calls in C++ */)) {
CallableVisitor(CallAnalyzers).TraverseTranslationUnitDecl(TU);
}
}
diff --git a/clang/test/SemaCXX/warn-unsafe-buffer-usage-libc-functions.cpp b/clang/test/SemaCXX/warn-unsafe-buffer-usage-libc-functions.cpp
index 25b6d8e9e22dc2..a7c19bcac16078 100644
--- a/clang/test/SemaCXX/warn-unsafe-buffer-usage-libc-functions.cpp
+++ b/clang/test/SemaCXX/warn-unsafe-buffer-usage-libc-functions.cpp
@@ -1,5 +1,7 @@
// RUN: %clang_cc1 -std=c++20 -Wno-all -Wunsafe-buffer-usage \
// RUN: -verify %s
+// RUN: %clang_cc1 -std=c++20 -Wno-all -Wunsafe-buffer-usage \
+// RUN: -verify %s -x objective-c++
// RUN: %clang_cc1 -std=c++20 -Wno-all -Wunsafe-buffer-usage-in-libc-call \
// RUN: -verify %s
@@ -56,6 +58,11 @@ namespace std {
}
void f(char * p, char * q, std::span<char> s, std::span<char> s2) {
+ typedef FILE * _Nullable aligned_file_ptr_t __attribute__((align_value(64)));
+ typedef char * _Nullable aligned_char_ptr_t __attribute__((align_value(64)));
+ aligned_file_ptr_t fp;
+ aligned_char_ptr_t cp;
+
memcpy(); // expected-warning{{function 'memcpy' is unsafe}}
std::memcpy(); // expected-warning{{function 'memcpy' is unsafe}}
__builtin_memcpy(p, q, 64); // expected-warning{{function '__builtin_memcpy' is unsafe}}
@@ -71,9 +78,11 @@ void f(char * p, char * q, std::span<char> s, std::span<char> s2) {
printf("%s%d", // expected-warning{{function 'printf' is unsafe}}
p, // expected-note{{string argument is not guaranteed to be null-terminated}} note attached to the unsafe argument
*p);
+ printf(cp, p, *p); // expected-warning{{function 'printf' is unsafe}} // expected-note{{string argument is not guaranteed to be null-terminated}}
sprintf(q, "%s%d", "hello", *p); // expected-warning{{function 'sprintf' is unsafe}} expected-note{{change to 'snprintf' for explicit bounds checking}}
swprintf(q, "%s%d", "hello", *p); // expected-warning{{function 'swprintf' is unsafe}} expected-note{{change to 'snprintf' for explicit bounds checking}}
snprintf(q, 10, "%s%d", "hello", *p); // expected-warning{{function 'snprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
+ snprintf(cp, 10, "%s%d", "hello", *p); // expected-warning{{function 'snprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
snprintf(s.data(), s2.size(), "%s%d", "hello", *p); // expected-warning{{function 'snprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
snwprintf(s.data(), s2.size(), "%s%d", "hello", *p); // expected-warning{{function 'snwprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
snwprintf_s( // expected-warning{{function 'snwprintf_s' is unsafe}}
@@ -84,8 +93,10 @@ void f(char * p, char * q, std::span<char> s, std::span<char> s2) {
sscanf(p, "%s%d", "hello", *p); // expected-warning{{function 'sscanf' is unsafe}}
sscanf_s(p, "%s%d", "hello", *p); // expected-warning{{function 'sscanf_s' is unsafe}}
fprintf((FILE*)p, "%P%d%p%i hello world %32s", *p, *p, p, *p, p); // expected-warning{{function 'fprintf' is unsafe}} expected-note{{string argument is not guaranteed to be null-terminated}}
+ fprintf(fp, "%P%d%p%i hello world %32s", *p, *p, p, *p, p); // expected-warning{{function 'fprintf' is unsafe}} expected-note{{string argument is not guaranteed to be null-terminated}}
wprintf(L"hello %s", p); // expected-warning{{function 'wprintf' is unsafe}} expected-note{{string argument is not guaranteed to be null-terminated}}
+
char a[10], b[11];
int c[10];
std::wstring WS;
@@ -93,6 +104,7 @@ void f(char * p, char * q, std::span<char> s, std::span<char> s2) {
snprintf(a, sizeof(b), "%s", __PRETTY_FUNCTION__); // expected-warning{{function 'snprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
snprintf((char*)c, sizeof(c), "%s", __PRETTY_FUNCTION__); // expected-warning{{function 'snprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
fprintf((FILE*)p, "%P%d%p%i hello world %32s", *p, *p, p, *p, "hello"); // no warn
+ fprintf(fp, "%P%d%p%i hello world %32s", *p, *p, p, *p, "hello"); // no warn
printf("%s%d", "hello", *p); // no warn
snprintf(s.data(), s.size_bytes(), "%s%d", "hello", *p); // no warn
snprintf(s.data(), s.size_bytes(), "%s%d", __PRETTY_FUNCTION__, *p); // no warn
diff --git a/clang/test/SemaCXX/warn-unsafe-buffer-usage-no-libc-functions-in-c.c b/clang/test/SemaCXX/warn-unsafe-buffer-usage-no-libc-functions-in-c.c
new file mode 100644
index 00000000000000..01d5a1a521318e
--- /dev/null
+++ b/clang/test/SemaCXX/warn-unsafe-buffer-usage-no-libc-functions-in-c.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -Wunsafe-buffer-usage %s -verify %s -x c
+// RUN: %clang_cc1 -Wunsafe-buffer-usage %s -verify %s -x objective-c
+
+void* __asan_memcpy(void *dst,const void *src, unsigned long size);
+
+void f(int *p, int *q) {
+
+ __asan_memcpy(p, q, 10); // no libc warn in C
+ ++p[5]; // expected-warning{{unsafe buffer access}}
+}
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