[clang] [clang] Catch missing format attributes (PR #70024)
Aaron Puchert via cfe-commits
cfe-commits at lists.llvm.org
Sun Dec 10 14:06:44 PST 2023
================
@@ -6849,6 +6849,73 @@ static void handleSwiftAsyncAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
checkSwiftAsyncErrorBlock(S, D, ErrorAttr, AsyncAttr);
}
+// Warn if parent function misses format attribute. Parent function misses
+// format attribute if there is an argument format string forwarded to calling
+// function with format attribute, parent function has a parameter which type
+// is either string or pointer to char and parent function format attribute
+// type does not match with calling function format attribute type.
+void Sema::DiagnoseMissingFormatAttributes(const FunctionDecl *FDecl,
+ ArrayRef<const Expr *> Args,
+ SourceLocation Loc) {
+ assert(FDecl);
+
+ // Check if function has format attribute with forwarded format string.
+ IdentifierInfo *AttrType;
+ if (!llvm::any_of(
+ FDecl->specific_attrs<FormatAttr>(), [&](const FormatAttr *Attr) {
+ if (!Args[Attr->getFirstArg()]->getReferencedDeclOfCallee())
+ return false;
+
+ AttrType = Attr->getType();
+ return true;
+ }))
+ return;
+
+ const FunctionDecl *ParentFuncDecl = getCurFunctionDecl();
+ if (!ParentFuncDecl)
+ return;
+
+ // Check if parent function has string or pointer to char parameter.
+ unsigned int StringIndex = 0;
+ if (!llvm::any_of(
+ ParentFuncDecl->parameters(), [&](const ParmVarDecl *Param) {
+ StringIndex = Param->getFunctionScopeIndex() + 1;
+ QualType Ty = Param->getType();
+ if (isNSStringType(Ty, Context, true))
+ return true;
+ if (isCFStringType(Ty, Context))
+ return true;
+ if (Ty->isPointerType() &&
+ Ty->castAs<PointerType>()
+ ->getPointeeType()
+ ->isSpecificBuiltinType(BuiltinType::Char_S))
+ return true;
+ return false;
+ }))
+ return;
----------------
aaronpuchert wrote:
I don't think we can decide this based on the type. We should look at the argument and check if it's a `DeclRefExpr` referring to a parameter of the parent function. There can be other (unrelated) string arguments. (See also my comments in the tests.)
https://github.com/llvm/llvm-project/pull/70024
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