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Move the check for vprintf* functions inside of SemaCheckStringLiteral. Fixes PR4470. 

llvm-svn: 74413
This commit is contained in:
Anders Carlsson 2009-06-28 19:55:58 +00:00
parent 877a48e67a
commit b012ca92ac
2 changed files with 33 additions and 25 deletions
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47
clang/lib/Sema/SemaChecking.cpp
View File

@ -717,8 +717,6 @@ bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall,
if (E->isTypeDependent() || E->isValueDependent())
return false;
E = E->IgnoreParenCasts();
switch (E->getStmtClass()) {
case Stmt::ConditionalOperatorClass: {
const ConditionalOperator *C = cast<ConditionalOperator>(E);
@ -763,6 +761,28 @@ bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall,
return SemaCheckStringLiteral(Init, TheCall,
HasVAListArg, format_idx, firstDataArg);
}
// For vprintf* functions (i.e., HasVAListArg==true), we add a
// special check to see if the format string is a function parameter
// of the function calling the printf function. If the function
// has an attribute indicating it is a printf-like function, then we
// should suppress warnings concerning non-literals being used in a call
// to a vprintf function. For example:
//
// void
// logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
// va_list ap;
// va_start(ap, fmt);
// vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
// ...
//
//
// FIXME: We don't have full attribute support yet, so just check to see
// if the argument is a DeclRefExpr that references a parameter. We'll
// add proper support for checking the attribute later.
if (HasVAListArg)
if (isa<ParmVarDecl>(VD))
return true;
}
return false;
@ -901,29 +921,6 @@ Sema::CheckPrintfArguments(const CallExpr *TheCall, bool HasVAListArg,
firstDataArg))
return; // Literal format string found, check done!
// For vprintf* functions (i.e., HasVAListArg==true), we add a
// special check to see if the format string is a function parameter
// of the function calling the printf function. If the function
// has an attribute indicating it is a printf-like function, then we
// should suppress warnings concerning non-literals being used in a call
// to a vprintf function. For example:
//
// void
// logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...) {
// va_list ap;
// va_start(ap, fmt);
// vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
// ...
//
//
// FIXME: We don't have full attribute support yet, so just check to see
// if the argument is a DeclRefExpr that references a parameter. We'll
// add proper support for checking the attribute later.
if (HasVAListArg)
if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OrigFormatExpr))
if (isa<ParmVarDecl>(DR->getDecl()))
return;
// If there are no arguments specified, warn with -Wformat-security, otherwise
// warn only with -Wformat-nonliteral.
if (TheCall->getNumArgs() == format_idx+1)

11
clang/test/Sema/format-attr-pr4470.c Normal file
View File

@ -0,0 +1,11 @@
// RUN: clang-cc -fsyntax-only -verify -Wformat=2 %s
#include <stdio.h>
const char *foo(const char *format) __attribute__((format_arg(1)));
void __attribute__((format(printf, 1, 0)))
foo2(const char *fmt, va_list va)
{
vprintf(foo(fmt), va);
}