Don't warn when NULL is used within a macro but its conversion is outside a macro.

This fixes the included test case & was reported by Nico Weber.

It's a little bit nasty using the difference in the conversion context, but
seems to me like a not unreasonable solution. I did have to fix up the
conversion context for conditional operators (it seems correct to me to include
the context for which we're actually doing the comparison - across all the
nested conditionals, rather than the innermost conditional which might not
actually have the problematic implicit conversion at all) and template default
arguments (this is a bit of a hack, since we don't have the source location of
the '=' anymore, so I just used the start of the parameter - open to
suggestions there)

llvm-svn: 156861
This commit is contained in:
David Blaikie 2012-05-15 21:57:38 +00:00
parent edd124ec72
commit 18e9ac7914
3 changed files with 16 additions and 14 deletions

View File

@ -4250,6 +4250,7 @@ void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
SourceLocation Loc = E->getSourceRange().getBegin();
if (Loc.isMacroID())
Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
if (!Loc.isMacroID() || CC.isMacroID())
S.Diag(Loc, diag::warn_impcast_null_pointer_to_integer)
<< T << clang::SourceRange(CC)
<< FixItHint::CreateReplacement(Loc, S.getFixItZeroLiteralForType(T));
@ -4345,14 +4346,15 @@ void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
return;
}
void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T);
void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
SourceLocation CC, QualType T);
void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
SourceLocation CC, bool &ICContext) {
E = E->IgnoreParenImpCasts();
if (isa<ConditionalOperator>(E))
return CheckConditionalOperator(S, cast<ConditionalOperator>(E), T);
return CheckConditionalOperator(S, cast<ConditionalOperator>(E), CC, T);
AnalyzeImplicitConversions(S, E, CC);
if (E->getType() != T)
@ -4360,9 +4362,8 @@ void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
return;
}
void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T) {
SourceLocation CC = E->getQuestionLoc();
void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
SourceLocation CC, QualType T) {
AnalyzeImplicitConversions(S, E->getCond(), CC);
bool Suspicious = false;
@ -4404,7 +4405,7 @@ void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) {
// were being fed directly into the output.
if (isa<ConditionalOperator>(E)) {
ConditionalOperator *CO = cast<ConditionalOperator>(E);
CheckConditionalOperator(S, CO, T);
CheckConditionalOperator(S, CO, CC, T);
return;
}

View File

@ -3314,7 +3314,7 @@ ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc,
return ExprError();
Expr *Arg = Result.takeAs<Expr>();
CheckImplicitConversions(Arg, Arg->getExprLoc());
CheckImplicitConversions(Arg, Param->getOuterLocStart());
// Build the default argument expression.
return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, Arg));
}

View File

@ -73,13 +73,14 @@ void test3() {
// Use FileCheck to ensure we don't get any unnecessary macro-expansion notes
// (that don't appear as 'real' notes & can't be seen/tested by -verify)
// CHECK-NOT: note:
// CHECK: note: expanded from macro 'FNULL'
#define FNULL NULL
int a2 = FNULL; // expected-warning {{implicit conversion of NULL constant to 'int'}}
// CHECK-NOT: note:
// CHECK: note: expanded from macro 'FINIT'
#define FINIT int a3 = NULL;
FINIT // expected-warning {{implicit conversion of NULL constant to 'int'}}
// we don't catch the case of #define FOO NULL ... int i = FOO; but that seems a bit narrow anyway
// and avoiding that helps us skip these cases:
#define NULL_COND(cond) ((cond) ? &a : NULL)
bool bl2 = NULL_COND(true); // don't warn on NULL conversion through the conditional operator across a macro boundary
}
namespace test4 {