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

llvm-svn: 183597

clang/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);
 }

clang/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 ]

clang/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;
+}