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🍒 [BoundsSafety] Don't drop va_list typedef during function merging #10771

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Merged
merged 1 commit into from
Jun 3, 2025
Merged

🍒 [BoundsSafety] Don't drop va_list typedef during function merging #10771

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15 changes: 15 additions & 0 deletions clang/lib/AST/ASTContext.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3707,6 +3707,21 @@ QualType ASTContext::mergeBoundsSafetyPointerTypes(
if (OrigDstTy.isNull())
OrigDstTy = DstTy;

// An ugly way to keep va_list typedef in DstTy if the merge type doesn't
// change.
// TODO: We need a general way of not stripping sugars.
QualType DesugaredDstTy;
if (const auto *TDT = dyn_cast<TypedefType>(DstTy))
DesugaredDstTy = TDT->desugar();
else if (const auto *ET = dyn_cast<ElaboratedType>(DstTy))
DesugaredDstTy = ET->desugar();
if (!DesugaredDstTy.isNull()) {
QualType MergeTy = mergeBoundsSafetyPointerTypes(DesugaredDstTy, SrcTy,
MergeFunctor, OrigDstTy);
if (MergeTy == DesugaredDstTy)
return DstTy;
}

// FIXME: a brittle hack to avoid skipping ValueTerminatedType outside
// this PtrAutoAttr AttributedType.
bool RecoverPtrAuto = false;
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22 changes: 22 additions & 0 deletions clang/test/BoundsSafety/AST/merge-vsnprintf.c
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@@ -0,0 +1,22 @@
// RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -fbounds-safety -ast-dump %s 2>&1 | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -fbounds-safety -x c++ -fexperimental-bounds-safety-cxx -ast-dump %s 2>&1 | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -fbounds-safety -x objective-c -fexperimental-bounds-safety-objc -ast-dump %s 2>&1 | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -fexperimental-bounds-safety-attributes -x c -ast-dump %s 2>&1 | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -fexperimental-bounds-safety-attributes -x c++ -ast-dump %s 2>&1 | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -fexperimental-bounds-safety-attributes -x objective-c -ast-dump %s 2>&1 | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -fexperimental-bounds-safety-attributes -x objective-c++ -ast-dump %s 2>&1 | FileCheck %s

#include <ptrcheck.h>
#include <stdarg.h>
#include <stddef.h>

#define __printf(string_index, first_to_check) \
__attribute__((__format__(__printf__, string_index, first_to_check)))

#ifndef __cplusplus
#define __restrict restrict
#endif

// CHECK: ParmVarDecl {{.+}} foo_args 'va_list':'char *'
int vsnprintf(char *__restrict __counted_by(__size) __str, size_t __size,
const char *__restrict __format, va_list foo_args) __printf(3, 0);