From 52d6bbe3aa1e70d40c7cc892a12f41b6017f5c6c Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Sat, 5 Feb 2011 01:10:26 +0000
Subject: [PATCH] Don't crash when generating USRs for ObjC methods in
 protocols.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124920 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Index/usrs.m             | 10 ++++++++--
 tools/libclang/CIndexUSRs.cpp | 21 +++++++++++++--------
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/test/Index/usrs.m b/test/Index/usrs.m
index d5da2dcf5e..edfb81437d 100644
--- a/test/Index/usrs.m
+++ b/test/Index/usrs.m
@@ -76,6 +76,10 @@ int test_multi_declaration(void) {
   return 0;
 }
 
+@protocol P1
+- (void)method;
+@end
+
 // CHECK: usrs.m c:usrs.m@85@F@my_helper Extent=[3:19 - 3:60]
 // CHECK: usrs.m c:usrs.m@95@F@my_helper@x Extent=[3:29 - 3:34]
 // CHECK: usrs.m c:usrs.m@102@F@my_helper@y Extent=[3:36 - 3:41]
@@ -131,6 +135,8 @@ int test_multi_declaration(void) {
 // CHECK: usrs.m c:usrs.m@980@F@test_multi_declaration@foo Extent=[74:3 - 74:14]
 // CHECK: usrs.m c:usrs.m@980@F@test_multi_declaration@bar Extent=[74:16 - 74:23]
 // CHECK: usrs.m c:usrs.m@980@F@test_multi_declaration@baz Extent=[74:25 - 74:32]
+// CHECK: usrs.m c:objc(pl)P1 Extent=[79:1 - 81:5]
+// CHECK: usrs.m c:objc(pl)P1(im)method Extent=[80:1 - 80:16]
 
 // RUN: c-index-test -test-load-source all %s | FileCheck -check-prefix=CHECK-source %s
 // CHECK-source: usrs.m:3:19: FunctionDecl=my_helper:3:19 (Definition) Extent=[3:19 - 3:60]
@@ -259,6 +265,6 @@ int test_multi_declaration(void) {
 // CHECK-source: usrs.m:75:19: DeclRefExpr=baz:74:25 Extent=[75:19 - 75:22]
 // CHECK-source: usrs.m:76:3: UnexposedStmt= Extent=[76:3 - 76:11]
 // CHECK-source: usrs.m:76:10: UnexposedExpr= Extent=[76:10 - 76:11]
-
-
+// CHECK-source: usrs.m:79:1: ObjCProtocolDecl=P1:79:1 (Definition) Extent=[79:1 - 81:5]
+// CHECK-source: usrs.m:80:1: ObjCInstanceMethodDecl=method:80:1 Extent=[80:1 - 80:16]
 
diff --git a/tools/libclang/CIndexUSRs.cpp b/tools/libclang/CIndexUSRs.cpp
index 36b91cf978..6843f924c7 100644
--- a/tools/libclang/CIndexUSRs.cpp
+++ b/tools/libclang/CIndexUSRs.cpp
@@ -283,15 +283,20 @@ void USRGenerator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
 }
 
 void USRGenerator::VisitObjCMethodDecl(ObjCMethodDecl *D) {
-  // The USR for a method declared in a class extension or category is based on
-  // the ObjCInterfaceDecl, not the ObjCCategoryDecl.
-  ObjCInterfaceDecl *ID = D->getClassInterface();
-  if (!ID) {
-    IgnoreResults = true;
-    return;
+  DeclContext *container = D->getDeclContext();
+  if (ObjCProtocolDecl *pd = dyn_cast<ObjCProtocolDecl>(container)) {
+    Visit(pd);
+  }
+  else {
+    // The USR for a method declared in a class extension or category is based on
+    // the ObjCInterfaceDecl, not the ObjCCategoryDecl.
+    ObjCInterfaceDecl *ID = D->getClassInterface();
+    if (!ID) {
+      IgnoreResults = true;
+      return;
+    }
+    Visit(ID);
   }
-  Visit(ID);
-  
   // Ideally we would use 'GenObjCMethod', but this is such a hot path
   // for Objective-C code that we don't want to use
   // DeclarationName::getAsString().
-- 
2.50.1