From a657d11051c95473727ca5e9f6a8e8ab195fe590 Mon Sep 17 00:00:00 2001 From: Oliver Stannard Date: Wed, 30 Oct 2024 12:01:56 +0000 Subject: [PATCH 1/4] [Clang] Fix crash in __builtin_assume_aligned The CodeGen for __builtin_assume_aligned assumes that the first argument is a pointer, so crashes if the int-conversion error is downgraded or disabled. Emit a non-downgradable error if the argument is not a pointer, like we currently do for __builtin_launder. Fixes #110914. --- clang/include/clang/Basic/DiagnosticSemaKinds.td | 2 ++ clang/lib/Sema/SemaChecking.cpp | 5 ++++- clang/test/Sema/builtin-assume-aligned.c | 2 +- 3 files changed, 7 insertions(+), 2 deletions(-) diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 34ff49d7238a7..67ef5fcae142c 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -12271,6 +12271,8 @@ def warn_noderef_to_dereferenceable_pointer : Warning< def err_builtin_launder_invalid_arg : Error< "%select{non-pointer|function pointer|void pointer}0 argument to " "'__builtin_launder' is not allowed">; +def err_builtin_assume_aligned_invalid_arg : Error< + "non-pointer argument to '__builtin_assume_aligned' is not allowed">; def err_builtin_is_within_lifetime_invalid_arg : Error< "%select{non-|function }0pointer argument to '__builtin_is_within_lifetime' " diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 3308b898a5b68..f6f67895973cc 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -5272,8 +5272,11 @@ bool Sema::BuiltinAssumeAligned(CallExpr *TheCall) { { ExprResult FirstArgResult = DefaultFunctionArrayLvalueConversion(FirstArg); - if (checkBuiltinArgument(*this, TheCall, 0)) + if (!FirstArgResult.get()->getType()->isPointerType()) { + Diag(TheCall->getBeginLoc(), diag::err_builtin_assume_aligned_invalid_arg) + << TheCall->getSourceRange(); return true; + } /// In-place updation of FirstArg by checkBuiltinArgument is ignored. TheCall->setArg(0, FirstArgResult.get()); } diff --git a/clang/test/Sema/builtin-assume-aligned.c b/clang/test/Sema/builtin-assume-aligned.c index 33e8557845152..57378a3426524 100644 --- a/clang/test/Sema/builtin-assume-aligned.c +++ b/clang/test/Sema/builtin-assume-aligned.c @@ -74,7 +74,7 @@ int test13(int *a) { } int test14(int *a, int b) { - a = (int *)__builtin_assume_aligned(b, 32); // expected-error {{incompatible integer to pointer conversion passing 'int' to parameter of type 'const void *}} + a = (int *)__builtin_assume_aligned(b, 32); // expected-error {{non-pointer argument to '__builtin_assume_aligned' is not allowed}} } int test15(int *b) { From fe68409901a3415aade3a20a0baf35b4be3c6d2e Mon Sep 17 00:00:00 2001 From: Oliver Stannard Date: Wed, 18 Dec 2024 11:13:13 +0000 Subject: [PATCH 2/4] Remove obsolete comment --- clang/lib/Sema/SemaChecking.cpp | 1 - 1 file changed, 1 deletion(-) diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index f35d170f99391..cd8ad126269f0 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -5325,7 +5325,6 @@ bool Sema::BuiltinAssumeAligned(CallExpr *TheCall) { << TheCall->getSourceRange(); return true; } - /// In-place updation of FirstArg by checkBuiltinArgument is ignored. TheCall->setArg(0, FirstArgResult.get()); } From fed607e33f6edfd77afb086366c19c5a90cf392f Mon Sep 17 00:00:00 2001 From: Oliver Stannard Date: Wed, 18 Dec 2024 11:13:34 +0000 Subject: [PATCH 3/4] Add test --- clang/test/Sema/builtin-assume-aligned-downgrade.c | 9 +++++++++ 1 file changed, 9 insertions(+) create mode 100644 clang/test/Sema/builtin-assume-aligned-downgrade.c diff --git a/clang/test/Sema/builtin-assume-aligned-downgrade.c b/clang/test/Sema/builtin-assume-aligned-downgrade.c new file mode 100644 index 0000000000000..93631e7364373 --- /dev/null +++ b/clang/test/Sema/builtin-assume-aligned-downgrade.c @@ -0,0 +1,9 @@ +// RUN: %clang_cc1 -fsyntax-only -Wno-int-conversion -triple x86_64-linux -verify %s + +// Check that the pointer->int conversion error is not downgradable for the +// pointer argument to __builtin_assume_aligned. + +int test(int *a, int b) { + a = (int *)__builtin_assume_aligned(b, 32); // expected-error {{non-pointer argument to '__builtin_assume_aligned' is not allowed}} + int *y = __builtin_assume_aligned(1, 1); // expected-error {{non-pointer argument to '__builtin_assume_aligned' is not allowed}} +} From 58c8f4914bcbf7cda8af3eb75586522e70bd3f5a Mon Sep 17 00:00:00 2001 From: Oliver Stannard Date: Thu, 19 Dec 2024 09:30:23 +0000 Subject: [PATCH 4/4] Fix clang-tidy test --- .../clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp index 6792c7920dd11..3f73d1de333f4 100644 --- a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp +++ b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp @@ -51,8 +51,8 @@ void my_printf(const char* format, ...) { int my_vprintf(const char* format, va_list arg ); // OK to declare function taking va_list -void ignoredBuiltinsTest() { - (void)__builtin_assume_aligned(0, 8); +void ignoredBuiltinsTest(void *ptr) { + (void)__builtin_assume_aligned(ptr, 8); (void)__builtin_constant_p(0); (void)__builtin_fpclassify(0, 0, 0, 0, 0, 0.f); (void)__builtin_isinf_sign(0.f);