Adjust format attribute index for implicit object arguments. Fixes PR5521.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89113 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 92f1ba5..9060fe6 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -91,6 +91,12 @@
if (Format->getType() == "printf0") {
// printf0 allows null "format" string; if so don't check format/args
unsigned format_idx = Format->getFormatIdx() - 1;
+ // Does the index refer to the implicit object argument?
+ if (isa<CXXMemberCallExpr>(TheCall)) {
+ if (format_idx == 0)
+ return false;
+ --format_idx;
+ }
if (format_idx < TheCall->getNumArgs()) {
Expr *Format = TheCall->getArg(format_idx)->IgnoreParenCasts();
if (!Format->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
@@ -204,7 +210,7 @@
if (!HasVAListArg) {
if (const FunctionProtoType *Proto
= FDecl->getType()->getAs<FunctionProtoType>())
- HasVAListArg = !Proto->isVariadic();
+ HasVAListArg = !Proto->isVariadic();
}
CheckPrintfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1,
HasVAListArg ? 0 : Format->getFirstArg() - 1);
@@ -970,6 +976,18 @@
unsigned format_idx, unsigned firstDataArg) {
const Expr *Fn = TheCall->getCallee();
+ // The way the format attribute works in GCC, the implicit this argument
+ // of member functions is counted. However, it doesn't appear in our own
+ // lists, so decrement format_idx in that case.
+ if (isa<CXXMemberCallExpr>(TheCall)) {
+ // Catch a format attribute mistakenly referring to the object argument.
+ if (format_idx == 0)
+ return;
+ --format_idx;
+ if(firstDataArg != 0)
+ --firstDataArg;
+ }
+
// CHECK: printf-like function is called with no format string.
if (format_idx >= TheCall->getNumArgs()) {
Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string)