InstrProf: Fix a coverage crash where a macro begins in an unreachable block

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236335 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CoverageMappingGen.cpp

@@ -447,7 +447,10 @@ struct CounterCoverageMappingBuilder
   /// This should be used after visiting any statements in non-source order.
   void adjustForOutOfOrderTraversal(SourceLocation EndLoc) {
     MostRecentLocation = EndLoc;
-    if (MostRecentLocation == getEndOfFileOrMacro(MostRecentLocation))
+    // Avoid adding duplicate regions if we have a completed region on the top
+    // of the stack and are adjusting to the end of a virtual file.
+    if (getRegion().hasEndLoc() &&
+        MostRecentLocation == getEndOfFileOrMacro(MostRecentLocation))
       MostRecentLocation = getIncludeOrExpansionLoc(MostRecentLocation);
   }
 

test/CoverageMapping/unreachable-macro.c

+// RUN: %clang_cc1 -fprofile-instr-generate -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only %s | FileCheck %s
+
+#define WHILE while (0) {}
+
+// CHECK: counters_in_macro_following_unreachable
+void counters_in_macro_following_unreachable() {
+  // CHECK-NEXT: File 0, [[@LINE-1]]:48 -> {{[0-9]+}}:2 = #0
+  return;
+  // CHECK-NEXT: Expansion,File 0, [[@LINE+2]]:3 -> [[@LINE+2]]:8 = 0
+  // CHECK-NEXT: File 0, [[@LINE+1]]:8 -> [[@LINE+2]]:2 = 0
+  WHILE
+}
+// CHECK-NEXT: File 1, 3:15 -> 3:27 = 0
+// CHECK-NEXT: File 1, 3:22 -> 3:23 = #1
+// CHECK-NEXT: File 1, 3:25 -> 3:27 = #1