From 2bb6dad4a44569dd2f86e7500a5ba21680718736 Mon Sep 17 00:00:00 2001
From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Wed, 11 Sep 2013 12:33:58 +0000
Subject: [PATCH] Fix 2 cases of uninitialized reads of an invalid PresumedLoc.

The code in CGExpr was added back in 2012 (r165536) but not exercised in tests
until recently.

Detected on the MemorySanitizer bootstrap bot.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190521 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGExpr.cpp              |  4 ++--
 tools/libclang/CXSourceLocation.cpp | 28 +++++++++++++++-------------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 12aa0a2b7c..89340b4db8 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -2095,8 +2095,8 @@ llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
     PLoc.isValid() ? cast<llvm::Constant>(
                        Builder.CreateGlobalStringPtr(PLoc.getFilename()))
                    : llvm::Constant::getNullValue(Int8PtrTy),
-    Builder.getInt32(PLoc.getLine()),
-    Builder.getInt32(PLoc.getColumn())
+    Builder.getInt32(PLoc.isValid() ? PLoc.getLine() : 0),
+    Builder.getInt32(PLoc.isValid() ? PLoc.getColumn() : 0)
   };
 
   return llvm::ConstantStruct::getAnon(Data);
diff --git a/tools/libclang/CXSourceLocation.cpp b/tools/libclang/CXSourceLocation.cpp
index a33c9d4f26..64b2908c49 100644
--- a/tools/libclang/CXSourceLocation.cpp
+++ b/tools/libclang/CXSourceLocation.cpp
@@ -266,7 +266,7 @@ void clang_getPresumedLocation(CXSourceLocation location,
                                CXString *filename,
                                unsigned *line,
                                unsigned *column) {
-  
+
   if (!isASTUnitSourceLocation(location)) {
     // Other SourceLocation implementations do not support presumed locations
     // at this time.
@@ -276,20 +276,22 @@ void clang_getPresumedLocation(CXSourceLocation location,
 
   SourceLocation Loc = SourceLocation::getFromRawEncoding(location.int_data);
 
-  if (!location.ptr_data[0] || Loc.isInvalid())
+  if (!location.ptr_data[0] || Loc.isInvalid()) {
     createNullLocation(filename, line, column);
-  else {
-    const SourceManager &SM =
-    *static_cast<const SourceManager*>(location.ptr_data[0]);
-    PresumedLoc PreLoc = SM.getPresumedLoc(Loc);
-    
-    if (filename)
-      *filename = cxstring::createRef(PreLoc.getFilename());
-    if (line)
-      *line = PreLoc.getLine();
-    if (column)
-      *column = PreLoc.getColumn();
+    return;
   }
+
+  const SourceManager &SM =
+      *static_cast<const SourceManager *>(location.ptr_data[0]);
+  PresumedLoc PreLoc = SM.getPresumedLoc(Loc);
+  if (PreLoc.isInvalid()) {
+    createNullLocation(filename, line, column);
+    return;
+  }
+
+  if (filename) *filename = cxstring::createRef(PreLoc.getFilename());
+  if (line) *line = PreLoc.getLine();
+  if (column) *column = PreLoc.getColumn();
 }
 
 void clang_getInstantiationLocation(CXSourceLocation location,
-- 
2.40.0