From 8d378585f66c0562a818f60d3b003a6f55054dbe Mon Sep 17 00:00:00 2001
From: Adrian Prantl <aprantl@apple.com>
Date: Sat, 8 Jun 2013 00:16:55 +0000
Subject: [PATCH] Debug info: An if condition now creates a lexical scope of
 its own. Two variables with the same name declared in two if conditions in
 the same scope are no longer coalesced into one.

rdar://problem/14024005

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183597 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGStmt.cpp                   | 10 ++++++++
 test/CodeGenCXX/debug-info-namespace.cpp |  5 ++--
 test/CodeGenCXX/debug-info-scope.cpp     | 32 ++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 2 deletions(-)
 create mode 100644 test/CodeGenCXX/debug-info-scope.cpp

diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 3e9b8d47ea..0db31ac49c 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -419,6 +419,11 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
   // unequal to 0.  The condition must be a scalar type.
   RunCleanupsScope ConditionScope(*this);
 
+  // Also open a debugger-visible lexical scope for the condition.
+  CGDebugInfo *DI = getDebugInfo();
+  if (DI)
+    DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
+
   if (S.getConditionVariable())
     EmitAutoVarDecl(*S.getConditionVariable());
 
@@ -439,6 +444,8 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
         RunCleanupsScope ExecutedScope(*this);
         EmitStmt(Executed);
       }
+      if (DI)
+        DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
       return;
     }
   }
@@ -476,6 +483,9 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
     EmitBranch(ContBlock);
   }
 
+  if (DI)
+    DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
+
   // Emit the continuation block for code after the if.
   EmitBlock(ContBlock, true);
 }
diff --git a/test/CodeGenCXX/debug-info-namespace.cpp b/test/CodeGenCXX/debug-info-namespace.cpp
index aa739ab933..623005b068 100644
--- a/test/CodeGenCXX/debug-info-namespace.cpp
+++ b/test/CodeGenCXX/debug-info-namespace.cpp
@@ -50,8 +50,9 @@ int func(bool b) {
 // CHECK: [[M1]] = metadata !{i32 {{[0-9]*}}, metadata [[CTXT]], metadata [[NS]], i32 9} ; [ DW_TAG_imported_module ]
 // CHECK: [[M2]] = metadata !{i32 {{[0-9]*}}, metadata [[CU]], metadata [[CTXT]], i32 12} ; [ DW_TAG_imported_module ]
 // CHECK: [[M3]] = metadata !{i32 {{[0-9]*}}, metadata [[CU]], metadata [[CTXT]], i32 13, metadata !"E"} ; [ DW_TAG_imported_module ]
-// CHECK: [[M4]] = metadata !{i32 {{[0-9]*}}, metadata [[LEX:![0-9]*]], metadata [[NS]], i32 17} ; [ DW_TAG_imported_module ]
-// CHECK: [[LEX]] = metadata !{i32 {{[0-9]*}}, metadata [[FILE2]], metadata [[FUNC]], i32 16, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
+// CHECK: [[M4]] = metadata !{i32 {{[0-9]*}}, metadata [[LEX2:![0-9]*]], metadata [[NS]], i32 17} ; [ DW_TAG_imported_module ]
+// CHECK: [[LEX2]] = metadata !{i32 {{[0-9]*}}, metadata [[FILE2]], metadata [[LEX1:![0-9]+]], i32 16, i32 0, i32 {{.*}}} ; [ DW_TAG_lexical_block ]
+// CHECK: [[LEX1]] = metadata !{i32 {{[0-9]*}}, metadata [[FILE2]], metadata [[FUNC]], i32 16, i32 0, i32 {{.*}}} ; [ DW_TAG_lexical_block ]
 // CHECK: [[M5]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[CTXT]], i32 20} ; [ DW_TAG_imported_module ]
 // CHECK: [[M6]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[FOO:![0-9]*]], i32 21} ; [ DW_TAG_imported_declaration ]
 // CHECK: [[FOO]] {{.*}} ; [ DW_TAG_structure_type ] [foo] [line 5, size 0, align 0, offset 0] [fwd] [from ]
diff --git a/test/CodeGenCXX/debug-info-scope.cpp b/test/CodeGenCXX/debug-info-scope.cpp
new file mode 100644
index 0000000000..557ee31783
--- /dev/null
+++ b/test/CodeGenCXX/debug-info-scope.cpp
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -g -emit-llvm %s -o -| FileCheck %s
+//
+// Two variables with the same name in subsequent if staments need to be in separate scopes.
+//
+// rdar://problem/14024005
+//
+
+int printf(const char*, ...);
+
+char *return_char (int input)
+{
+  if (input%2 == 0)
+    return "I am even.\n";
+  else
+    return "I am odd.\n";
+}
+
+int main2() {
+// CHECK: [ DW_TAG_auto_variable ] [ptr] [line [[@LINE+2]]]
+// CHECK metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
+  if (char *ptr = return_char(1)) {
+    printf ("%s", ptr);
+  }
+// CHECK: [ DW_TAG_auto_variable ] [ptr] [line [[@LINE+2]]]
+// CHECK metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
+  if (char *ptr = return_char(2)) {
+    printf ("%s", ptr);
+  }
+  else printf ("%s", ptr);
+
+  return 0;
+}
-- 
2.40.0