Author: Timm Baeder Date: 2025-10-05T08:35:56+02:00 New Revision: 8dac6e28c951b33659f1f1f80e0dd553788abaab
URL: https://github.com/llvm/llvm-project/commit/8dac6e28c951b33659f1f1f80e0dd553788abaab DIFF: https://github.com/llvm/llvm-project/commit/8dac6e28c951b33659f1f1f80e0dd553788abaab.diff LOG: Reapply "[clang] Convert second arg of __builtin_assume_aligned to Co… (#161945) …nstantExpr (#161314)" (#161719) This reverts commit f1650cf91b01470ce44f47797663d59f00828493. Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/CodeGen/CGExprScalar.cpp clang/lib/Sema/SemaChecking.cpp clang/test/SemaCXX/builtin-assume-aligned.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 2ac5f4aab75dc..ab536adcd3ba0 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -250,6 +250,8 @@ Non-comprehensive list of changes in this release - ``__builtin_assume_dereferenceable`` now accepts non-constant size operands. +- Fixed a crash when the second argument to ``__builtin_assume_aligned`` was not constant (#GH161314) + New Compiler Flags ------------------ - New option ``-fno-sanitize-debug-trap-reasons`` added to disable emitting trap reasons into the debug info when compiling with trapping UBSan (e.g. ``-fsanitize-trap=undefined``). diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp index f319b176513f8..c961222766475 100644 --- a/clang/lib/CodeGen/CGExprScalar.cpp +++ b/clang/lib/CodeGen/CGExprScalar.cpp @@ -465,11 +465,16 @@ class ScalarExprEmitter return nullptr; if (Value *Result = ConstantEmitter(CGF).tryEmitConstantExpr(E)) { - if (E->isGLValue()) + if (E->isGLValue()) { + // This was already converted to an rvalue when it was constant + // evaluated. + if (E->hasAPValueResult() && !E->getAPValueResult().isLValue()) + return Result; return CGF.EmitLoadOfScalar( Address(Result, CGF.convertTypeForLoadStore(E->getType()), CGF.getContext().getTypeAlignInChars(E->getType())), /*Volatile*/ false, E->getType(), E->getExprLoc()); + } return Result; } return Visit(E->getSubExpr()); diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 7ce3513fe0969..3cc61b167ba98 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -5954,6 +5954,9 @@ bool Sema::BuiltinAssumeAligned(CallExpr *TheCall) { if (Result > Sema::MaximumAlignment) Diag(TheCall->getBeginLoc(), diag::warn_assume_aligned_too_great) << SecondArg->getSourceRange() << Sema::MaximumAlignment; + + TheCall->setArg(1, + ConstantExpr::Create(Context, SecondArg, APValue(Result))); } if (NumArgs > 2) { diff --git a/clang/test/SemaCXX/builtin-assume-aligned.cpp b/clang/test/SemaCXX/builtin-assume-aligned.cpp index 48bd8414fc50a..30296c72c6be8 100644 --- a/clang/test/SemaCXX/builtin-assume-aligned.cpp +++ b/clang/test/SemaCXX/builtin-assume-aligned.cpp @@ -47,3 +47,16 @@ constexpr void *s1 = __builtin_assume_aligned(x, 32); constexpr void *s2 = __builtin_assume_aligned(x, 32, 5); constexpr void *s3 = __builtin_assume_aligned(x, 32, -1); + +constexpr int add(int a, int b) { + return a+b; +} +constexpr void *c1 = __builtin_assume_aligned(p, add(1,1)); +constexpr void *c2 = __builtin_assume_aligned(p, add(2,1)); // expected-error {{not a power of 2}} + +constexpr long kAlignment = 128; +long AllocateAlignedBytes_payload; +void AllocateAlignedBytes() { + void *m = __builtin_assume_aligned( + reinterpret_cast<void *>(AllocateAlignedBytes_payload), kAlignment); +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
