From a18829860c8b186d3a7f6a4ba83e21e9cbbffac1 Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Wed, 9 Oct 2013 22:34:33 +0000
Subject: [PATCH] Refine string literal concatenation warning within an NSArray
 literal to not warn when the literal comes from a macro expansion.  Fixes
 <rdar://problem/15147688>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192328 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaExprObjC.cpp          | 22 ++++++++++++++++++----
 test/SemaObjC/objc-array-literal.m |  8 ++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index 5550eb8cf9..7efa08b45c 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -410,10 +410,24 @@ static ExprResult CheckObjCCollectionLiteralElement(Sema &S, Expr *Element,
     }
   }
   if (ArrayLiteral)
-    if (ObjCStringLiteral *getString = dyn_cast<ObjCStringLiteral>(OrigElement)) {
-      if (getString->getString() && getString->getString()->getNumConcatenated() > 1)
-        S.Diag(Element->getLocStart(), diag::warn_concatenated_nsarray_literal)
-        << Element->getType();
+    if (ObjCStringLiteral *getString =
+          dyn_cast<ObjCStringLiteral>(OrigElement)) {
+      if (StringLiteral *SL = getString->getString()) {
+        unsigned numConcat = SL->getNumConcatenated();
+        if (numConcat > 1) {
+          // Only warn if the concatenated string doesn't come from a macro.
+          bool hasMacro = false;
+          for (unsigned i = 0; i < numConcat ; ++i)
+            if (SL->getStrTokenLoc(i).isMacroID()) {
+              hasMacro = true;
+              break;
+            }
+          if (!hasMacro)
+            S.Diag(Element->getLocStart(),
+                   diag::warn_concatenated_nsarray_literal)
+              << Element->getType();
+        }
+      }
     }
 
   // Make sure that the element has the type that the container factory 
diff --git a/test/SemaObjC/objc-array-literal.m b/test/SemaObjC/objc-array-literal.m
index e6e4c471b5..a3e29bf122 100644
--- a/test/SemaObjC/objc-array-literal.m
+++ b/test/SemaObjC/objc-array-literal.m
@@ -45,3 +45,11 @@ id Test14303083() {
   id obj = @[ @"A", (@"B" @"C")];
   return @[ @"A", @"B" @"C"]; // expected-warning {{concatenated NSString literal for an NSArray expression - possibly missing a comma}}
 }
+id radar15147688() {
+#define R15147688_A @"hello"
+#define R15147688_B "world"
+#define CONCATSTR R15147688_A R15147688_B
+  id x = @[ @"stuff", CONCATSTR ]; // no-warning
+  x = @[ @"stuff", @"hello" "world"]; // expected-warning {{concatenated NSString literal for an NSArray expression}}
+  return x;
+}
-- 
2.40.0