Debug Info: Fix the source range for IfStmt's ConditionScope.

Since the continuation block of the if statement is emitted within the
condition scope this had the undesirable effect of creating a line table
entry at the end of the then or else statement, a line that may have never
been executed.
PR19864 / rdar://problem/17052973

llvm-svn: 209764

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 573973a..534c16d 100644 (file)
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -436,7 +436,7 @@ void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) {
 void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
   // C99 6.8.4.1: The first substatement is executed if the expression compares
   // unequal to 0.  The condition must be a scalar type.
-  LexicalScope ConditionScope(*this, S.getSourceRange());
+  LexicalScope ConditionScope(*this, S.getCond()->getSourceRange());
   RegionCounter Cnt = getPGORegionCounter(&S);
 
   if (S.getConditionVariable())

diff --git a/clang/test/CodeGenCXX/debug-info-line-if.cpp b/clang/test/CodeGenCXX/debug-info-line-if.cpp
new file mode 100644 (file)
index 0000000..0d4d223
--- /dev/null
+++ b/clang/test/CodeGenCXX/debug-info-line-if.cpp
@@ -0,0 +1,20 @@
+// RUN: %clang -g -std=c++11 -S -emit-llvm %s -o - | FileCheck %s
+// PR19864
+int main() {
+    int v[] = {13, 21, 8, 3, 34, 1, 5, 2};
+    int a = 0, b = 0;
+    for (int x : v)
+      if (x >= 3)
+        ++b;     // CHECK: add nsw{{.*}}, 1
+      else if (x >= 0)
+        ++a;    // CHECK: add nsw{{.*}}, 1
+    // The continuation block if the if statement should not share the
+    // location of the ++a statement. Having it point to the end of
+    // the condition is not ideal either, but it's less missleading.
+
+    // CHECK: br label
+    // CHECK: br label
+    // CHECK: br label {{.*}}, !dbg ![[DBG:.*]]
+    // CHECK: ![[DBG]] = metadata !{i32 [[@LINE-11]], i32 0, metadata !{{.*}}, null}
+
+}