From e98e5b54543f8a9e35626fb44dc0c649e71917d9 Mon Sep 17 00:00:00 2001
From: Jean-Daniel Dupas <devlists@shadowlab.org>
Date: Wed, 25 Jan 2012 10:35:33 +0000
Subject: [PATCH] Add support for const pointer to literal-objc string as
 format attribute.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148948 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaChecking.cpp           |  4 ++++
 test/SemaObjC/format-strings-objc.m | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index f5a8b448a1..950a575891 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -1441,6 +1441,10 @@ bool Sema::SemaCheckStringLiteral(const Expr *E, Expr **Args,
       } else if (const PointerType *PT = T->getAs<PointerType>()) {
         isConstant = T.isConstant(Context) &&
                      PT->getPointeeType().isConstant(Context);
+      } else if (T->isObjCObjectPointerType()) {
+        // In ObjC, there is usually no "const ObjectPointer" type,
+        // so don't check if the pointee type is constant.
+        isConstant = T.isConstant(Context);
       }
 
       if (isConstant) {
diff --git a/test/SemaObjC/format-strings-objc.m b/test/SemaObjC/format-strings-objc.m
index a2fe841ced..b0c87fe243 100644
--- a/test/SemaObjC/format-strings-objc.m
+++ b/test/SemaObjC/format-strings-objc.m
@@ -89,3 +89,21 @@ void rdar10743758(id x) {
   NSLog(@"%@ %@", x, (BOOL) 1); // expected-warning {{format specifies type 'id' but the argument has type 'BOOL' (aka 'signed char')}}
 }
 
+NSString *test_literal_propagation(void) {
+  const char * const s1 = "constant string %s"; // expected-note {{format string is defined here}}
+  printf(s1); // expected-warning {{more '%' conversions than data arguments}}
+  const char * const s5 = "constant string %s"; // expected-note {{format string is defined here}}
+  const char * const s2 = s5;
+  printf(s2); // expected-warning {{more '%' conversions than data arguments}}
+
+  const char * const s3 = (const char *)0;
+  printf(s3); // expected-warning {{format string is not a string literal}}
+
+  NSString * const ns1 = @"constant string %s"; // expected-note {{format string is defined here}}
+  NSLog(ns1); // expected-warning {{more '%' conversions than data arguments}}
+  NSString * const ns5 = @"constant string %s"; // expected-note {{format string is defined here}}
+  NSString * const ns2 = ns5;
+  NSLog(ns2); // expected-warning {{more '%' conversions than data arguments}}
+  NSString * ns3 = ns1;
+  NSLog(ns3); // expected-warning {{format string is not a string literal}}}
+}
-- 
2.40.0