From 91b6014876e9186f968f74a8975ab8fc08ef1b68 Mon Sep 17 00:00:00 2001 From: John McCall Date: Thu, 11 Nov 2010 05:33:51 +0000 Subject: [PATCH] Undo a refactor-o and base the bitfield-truncation warning on the uncoerced value. Also, whitelist bool bitfields, which aren't really a truncation. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@118778 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Sema/SemaChecking.cpp | 6 +++++- test/Sema/constant-conversion.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp index 4fc16f51ee..56a0c076ad 100644 --- a/lib/Sema/SemaChecking.cpp +++ b/lib/Sema/SemaChecking.cpp @@ -2617,12 +2617,16 @@ bool AnalyzeBitFieldAssignment(Sema &S, FieldDecl *Bitfield, Expr *Init, if (Bitfield->isInvalidDecl()) return false; + // White-list bool bitfields. + if (Bitfield->getType()->isBooleanType()) + return false; + Expr *OriginalInit = Init->IgnoreParenImpCasts(); llvm::APSInt Width(32); Expr::EvalResult InitValue; if (!Bitfield->getBitWidth()->isIntegerConstantExpr(Width, S.Context) || - !Init->Evaluate(InitValue, S.Context) || + !OriginalInit->Evaluate(InitValue, S.Context) || !InitValue.Val.isInt()) return false; diff --git a/test/Sema/constant-conversion.c b/test/Sema/constant-conversion.c index af77741fc1..7c6b9b81bd 100644 --- a/test/Sema/constant-conversion.c +++ b/test/Sema/constant-conversion.c @@ -37,3 +37,21 @@ void test3() { struct A d = (struct A) { 10, 0 }; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 10 to 2}} struct A e = { .foo = 10 }; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 10 to 2}} } + +void test4() { + struct A { + char c : 2; + } a; + + a.c = 0x101; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 257 to 1}} +} + +void test5() { + struct A { + _Bool b : 1; + } a; + + // Don't warn about this implicit conversion to bool, or at least + // don't warn about it just because it's a bitfield. + a.b = 100; +} -- 2.40.0