diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 1c93931b5c10..bb567d0986af 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -4275,7 +4275,7 @@ static bool IsTailPaddedMemberArray(Sema &S, llvm::APInt Size, void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr, bool isSubscript, bool AllowOnePastEnd) { - const Type* EffectiveType = getElementType(BaseExpr); + const Type *EffectiveType = getElementType(BaseExpr); BaseExpr = BaseExpr->IgnoreParenCasts(); IndexExpr = IndexExpr->IgnoreParenCasts(); @@ -4381,6 +4381,16 @@ void Sema::CheckArrayAccess(const Expr *expr) { switch (expr->getStmtClass()) { case Stmt::ArraySubscriptExprClass: { const ArraySubscriptExpr *ASE = cast(expr); + // Suppress the warning if the subscript expression (as identified by + // the ']' location) and the index expression are both from macro + // expansions within a system header. + SourceLocation RBracketLoc = SourceMgr.getSpellingLoc( + ASE->getRBracketLoc()); + SourceLocation IndexLoc = SourceMgr.getSpellingLoc( + ASE->getIdx()->IgnoreParens()->getLocStart()); + if (SourceMgr.isFromSameFile(RBracketLoc, IndexLoc) && + SourceMgr.isInSystemHeader(RBracketLoc)) + return; CheckArrayAccess(ASE->getBase(), ASE->getIdx(), true, AllowOnePastEnd > 0); return; diff --git a/clang/test/SemaCXX/Inputs/array-bounds-system-header.h b/clang/test/SemaCXX/Inputs/array-bounds-system-header.h new file mode 100644 index 000000000000..07cde80e9afb --- /dev/null +++ b/clang/test/SemaCXX/Inputs/array-bounds-system-header.h @@ -0,0 +1,11 @@ +// "System header" for testing that -Warray-bounds is properly suppressed in +// certain cases. + +#define BAD_MACRO_1 \ + int i[3]; \ + i[3] = 5 +#define BAD_MACRO_2(_b, _i) \ + (_b)[(_i)] = 5 +#define QUESTIONABLE_MACRO(_a) \ + sizeof(_a) > 3 ? (_a)[3] = 5 : 5 +#define NOP(x) (x) diff --git a/clang/test/SemaCXX/array-bounds-system-header.cpp b/clang/test/SemaCXX/array-bounds-system-header.cpp new file mode 100644 index 000000000000..34de5b5819d0 --- /dev/null +++ b/clang/test/SemaCXX/array-bounds-system-header.cpp @@ -0,0 +1,9 @@ +// RUN: %clang_cc1 -isystem %S/Inputs -verify %s +#include +void test_system_header_macro() { + BAD_MACRO_1; // no-warning + char a[3]; // expected-note 2 {{declared here}} + BAD_MACRO_2(a, 3); // expected-warning {{array index 3}} + QUESTIONABLE_MACRO(a); + NOP(a[3] = 5); // expected-warning {{array index 3}} +}