Author: Jun Zhang Date: 2022-09-28T12:30:02+08:00 New Revision: 89e56e732d5e89d8715a501158793ac305bc4b70
URL: https://github.com/llvm/llvm-project/commit/89e56e732d5e89d8715a501158793ac305bc4b70 DIFF: https://github.com/llvm/llvm-project/commit/89e56e732d5e89d8715a501158793ac305bc4b70.diff LOG: [Clang] Don't warn if deferencing void pointers in unevaluated context After https://reviews.llvm.org/D134461, Clang will diagnose a warning if trying to deference void pointers in C mode. However, this causes a lot of noises when compiling a 5.19.11 Linux kernel. This patch reduces the warning by marking deferencing void pointers in unevaluated context OK, like `sizeof(*void_ptr)`, `typeof(*void_ptr)` and etc. Fixes https://github.com/ClangBuiltLinux/linux/issues/1720 Signed-off-by: Jun Zhang <j...@junz.org> Differential Revision: https://reviews.llvm.org/D134702 Added: clang/test/Sema/no-warn-void-ptr-uneval.c Modified: clang/lib/Sema/SemaExpr.cpp clang/test/Analysis/misc-ps.m Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index acbf7d534d49f..fca9240362e76 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -14536,7 +14536,7 @@ static QualType CheckIndirectionOperand(Sema &S, Expr *Op, ExprValueKind &VK, // [...] the expression to which [the unary * operator] is applied shall // be a pointer to an object type, or a pointer to a function type LangOptions LO = S.getLangOpts(); - if (LO.CPlusPlus || !(LO.C99 && IsAfterAmp)) + if (LO.CPlusPlus || !(LO.C99 && (IsAfterAmp || S.isUnevaluatedContext()))) S.Diag(OpLoc, diag::ext_typecheck_indirection_through_void_pointer) << LO.CPlusPlus << OpTy << Op->getSourceRange(); } diff --git a/clang/test/Analysis/misc-ps.m b/clang/test/Analysis/misc-ps.m index 4e3783dfc93ac..e9e56315eb268 100644 --- a/clang/test/Analysis/misc-ps.m +++ b/clang/test/Analysis/misc-ps.m @@ -133,7 +133,7 @@ void handle_sizeof_void(unsigned flag) { void* q; if (!flag) { - if (sizeof(*q) == 1) // expected-warning {{ISO C does not allow indirection on operand of type 'void *'}} + if (sizeof(*q) == 1) return; // Infeasibe. *p = 1; // no-warning diff --git a/clang/test/Sema/no-warn-void-ptr-uneval.c b/clang/test/Sema/no-warn-void-ptr-uneval.c new file mode 100644 index 0000000000000..2aed1180ab0da --- /dev/null +++ b/clang/test/Sema/no-warn-void-ptr-uneval.c @@ -0,0 +1,8 @@ +// RUN: %clang_cc1 -fsyntax-only -Wno-unused-value -verify %s + +// expected-no-diagnostics +void foo(void *vp) { + sizeof(*vp); + sizeof(*(vp)); + void inner(typeof(*vp)); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
