[PATCH] D95987: [llvm-cov] Reset ExecutionCount only if first line segment is start of a new region.

[Zequan Wu via Phabricator via llvm-commits]

zequanwu created this revision.
zequanwu added reviewers: vsk, pirama, rnk.
Herald added a subscriber: hiraditya.
zequanwu requested review of this revision.
Herald added projects: Sanitizers, LLVM.
Herald added subscribers: llvm-commits, Sanitizers.

To fix the bug, introduced by D85036 <https://reviews.llvm.org/D85036>, llvm-cov shows the following:

  1|       |#include <stdlib.h>
  2|       |
  3|      1|int main() {
  4|      1|  return getenv(
  5|      0|      "TEST") ? 1
  6|      1|              : 0;
  7|      1|}


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D95987

Files:
  compiler-rt/test/profile/coverage_wrappedsegments.cpp
  llvm/lib/ProfileData/Coverage/CoverageMapping.cpp


Index: llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
===================================================================
--- llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
+++ llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
@@ -794,7 +794,10 @@
     ExecutionCount = WrappedSegment->Count;
   if (!MinRegionCount)
     return;
-  ExecutionCount = 0;
+  // If the first line segment is start of region, discard wrapped segment
+  // count.
+  if (isStartOfRegion(LineSegments[0]))
+    ExecutionCount = 0;
   for (const auto *LS : LineSegments)
     if (isStartOfRegion(LS))
       ExecutionCount = std::max(ExecutionCount, LS->Count);
Index: compiler-rt/test/profile/coverage_wrappedsegments.cpp
===================================================================
--- /dev/null
+++ compiler-rt/test/profile/coverage_wrappedsegments.cpp
@@ -0,0 +1,51 @@
+// RUN: %clangxx_profgen -fcoverage-mapping -o %t %s
+// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t
+// RUN: llvm-profdata merge -o %t.profdata %t.profraw
+// RUN: llvm-cov show %t -instr-profile %t.profdata 2>&1 | FileCheck %s
+
+#include <stdlib.h>
+
+int f1() {                  // CHECK:      [[# @LINE]]| 1|int f1() {
+  return getenv(            // CHECK-NEXT: [[# @LINE]]| 1|
+             "TEST") ? 1    // CHECK-NEXT: [[# @LINE]]| 1|
+                     : 0;   // CHECK-NEXT: [[# @LINE]]| 1|
+}                           // CHECK-NEXT: [[# @LINE]]| 1|}
+
+int f2() {                  // CHECK:      [[# @LINE]]| 1|int f2() {
+  return getenv(            // CHECK-NEXT: [[# @LINE]]| 1|
+             "TEST"         // CHECK-NEXT: [[# @LINE]]| 1|
+             "TEST") ? 1    // CHECK-NEXT: [[# @LINE]]| 1|
+                     : 0;   // CHECK-NEXT: [[# @LINE]]| 1|
+}                           // CHECK-NEXT: [[# @LINE]]| 1|}
+
+int f3() {                  // CHECK:      [[# @LINE]]| 1|int f3() {
+  return 0;                 // CHECK-NEXT: [[# @LINE]]| 1|
+  return 1;                 // CHECK-NEXT: [[# @LINE]]| 0|
+}                           // CHECK-NEXT: [[# @LINE]]| 1|}
+
+int f4() {                  // CHECK:      [[# @LINE]]| 1|int f4() {
+  int a = 0;                // CHECK-NEXT: [[# @LINE]]| 1|
+  for (; a < 9;)            // CHECK-NEXT: [[# @LINE]]| 1|
+    return a;               // CHECK-NEXT: [[# @LINE]]| 1|
+  return a;                 // CHECK-NEXT: [[# @LINE]]| 0|
+}                           // CHECK-NEXT: [[# @LINE]]| 1|}
+
+int f5() {                  // CHECK:      [[# @LINE]]| 1|int f5() {
+  int i=1, j=1;             // CHECK-NEXT: [[# @LINE]]| 1|
+  if (i > 0) {              // CHECK-NEXT: [[# @LINE]]| 1|
+    if (j > 0)              // CHECK-NEXT: [[# @LINE]]| 1|
+      return 0;             // CHECK-NEXT: [[# @LINE]]| 1|
+    else                    // CHECK-NEXT: [[# @LINE]]| 0|
+      j++;                  // CHECK-NEXT: [[# @LINE]]| 0|
+  }                         // CHECK-NEXT: [[# @LINE]]| 1|
+  return 1;                 // CHECK-NEXT: [[# @LINE]]| 0|
+}                           // CHECK-NEXT: [[# @LINE]]| 1|}
+
+int main() {
+    f1();
+    f2();
+    f3();
+    f4();
+    f5();
+    return 0;
+}


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