r313603 - [Coverage] Remove deferred region for trailing return, fixes PR34611

[Vedant Kumar via cfe-commits]

Author: vedantk
Date: Mon Sep 18 17:29:46 2017
New Revision: 313603

URL: http://llvm.org/viewvc/llvm-project?rev=313603&view=rev
Log:
[Coverage] Remove deferred region for trailing return, fixes PR34611

As a special case, throw away deferred regions for trailing returns.
This allows the closing curly brace to have a count, and is less
distracting.

Modified:
    cfe/trunk/lib/CodeGen/CoverageMappingGen.cpp
    cfe/trunk/test/CoverageMapping/deferred-region.cpp

Modified: cfe/trunk/lib/CodeGen/CoverageMappingGen.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CoverageMappingGen.cpp?rev=313603&r1=313602&r2=313603&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CoverageMappingGen.cpp (original)
+++ cfe/trunk/lib/CodeGen/CoverageMappingGen.cpp Mon Sep 18 17:29:46 2017
@@ -770,7 +770,13 @@ struct CounterCoverageMappingBuilder
     Counter ExitCount = propagateCounts(getRegionCounter(Body), Body);
     assert(RegionStack.empty() && "Regions entered but never exited");
 
-    // Complete any deferred regions introduced by the last statement in a decl.
+    // Special case: if the last statement is a return, throw away the
+    // deferred region. This allows the closing brace to have a count.
+    if (auto *CS = dyn_cast_or_null<CompoundStmt>(Body))
+      if (dyn_cast_or_null<ReturnStmt>(CS->body_back()))
+        DeferredRegion = None;
+
+    // Complete any deferred regions introduced by the last statement.
     popRegions(completeDeferred(ExitCount, getEnd(Body)));
   }
 

Modified: cfe/trunk/test/CoverageMapping/deferred-region.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CoverageMapping/deferred-region.cpp?rev=313603&r1=313602&r2=313603&view=diff
==============================================================================
--- cfe/trunk/test/CoverageMapping/deferred-region.cpp (original)
+++ cfe/trunk/test/CoverageMapping/deferred-region.cpp Mon Sep 18 17:29:46 2017
@@ -28,6 +28,14 @@ void baz() { // CHECK: [[@LINE]]:12 -> [
   return;    // CHECK-NOT: File
 }
 
+// CHECK-LABEL: _Z3mazv:
+void maz() {
+  if (true)
+    return; // CHECK: Gap,File 0, [[@LINE]]:11 -> 36:3 = (#0 - #1)
+
+  return; // CHECK-NOT: Gap
+}
+
 // CHECK-LABEL: _Z3bari:
 void bar(int x) {
   IF (x)