[compiler-rt] f4cf610 - [Coverage] Add gap region between binary operator '&& and ||' and RHS (#149085)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 8 10:50:57 PDT 2025
Author: int-zjt
Date: 2025-08-08T12:50:52-05:00
New Revision: f4cf610159189ec877142313a18698434386afb0
URL: https://github.com/llvm/llvm-project/commit/f4cf610159189ec877142313a18698434386afb0
DIFF: https://github.com/llvm/llvm-project/commit/f4cf610159189ec877142313a18698434386afb0.diff
LOG: [Coverage] Add gap region between binary operator '&& and ||' and RHS (#149085)
## Issue Summary
We identified an inaccuracy in line coverage reporting when short-circuit evaluation occurs in multi-line conditional expressions.
Specifically:
1. Un-executed conditions following line breaks may be incorrectly marked as covered
(e.g., conditionB in a non-executed && chain shows coverage)
```
1| |#include <iostream>
2| |
3| 1|int main() {
4| 1| bool conditionA = false;
5| 1| bool conditionB = true;
6| 1| if (conditionA &&
7| 1| conditionB) {
8| 0| std::cout << "IF-THEN" << std::endl;
9| 0| }
10| 1| return 0;
11| 1|}
```
2. Inconsistent coverage reporting across un-executed conditions
*(adjacent un-executed conditions may show 1 vs 0 line coverage)*
```
1| |#include <iostream>
2| |
3| 1|int main() {
4| 1| bool conditionA = false;
5| 1| bool conditionB = true;
6| 1| bool conditionC = true;
7| 1| if (conditionA &&
8| 1| (conditionB ||
9| 0| conditionC)) {
10| 0| std::cout << "IF-THEN" << std::endl;
11| 0| }
12| 1| return 0;
13| 1|}
```
This is resolved by inserting a GapRegion when mapping logical operators to isolate coverage contexts around short-circuit evaluation.
Added:
compiler-rt/test/profile/Linux/coverage_short_circuit.cpp
Modified:
clang/lib/CodeGen/CoverageMappingGen.cpp
clang/test/CoverageMapping/logical.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index 38aaceb6c462d..05fb137ca0575 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -2269,6 +2269,11 @@ struct CounterCoverageMappingBuilder
// Track LHS True/False Decision.
const auto DecisionLHS = MCDCBuilder.pop();
+ if (auto Gap =
+ findGapAreaBetween(getEnd(E->getLHS()), getStart(E->getRHS()))) {
+ fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), getRegionCounter(E));
+ }
+
// Counter tracks the right hand side of a logical and operator.
extendRegion(E->getRHS());
propagateCounts(getRegionCounter(E), E->getRHS());
@@ -2330,6 +2335,11 @@ struct CounterCoverageMappingBuilder
// Track LHS True/False Decision.
const auto DecisionLHS = MCDCBuilder.pop();
+ if (auto Gap =
+ findGapAreaBetween(getEnd(E->getLHS()), getStart(E->getRHS()))) {
+ fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), getRegionCounter(E));
+ }
+
// Counter tracks the right hand side of a logical or operator.
extendRegion(E->getRHS());
propagateCounts(getRegionCounter(E), E->getRHS());
diff --git a/clang/test/CoverageMapping/logical.cpp b/clang/test/CoverageMapping/logical.cpp
index 2a22d6cca4518..caa773cfec3a5 100644
--- a/clang/test/CoverageMapping/logical.cpp
+++ b/clang/test/CoverageMapping/logical.cpp
@@ -1,27 +1,31 @@
// RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -main-file-name logical.cpp %s | FileCheck %s
// RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fcoverage-mcdc -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -main-file-name logical.cpp %s | FileCheck %s -check-prefix=MCDC
-int main() { // CHECK: File 0, [[@LINE]]:12 -> [[@LINE+23]]:2 = #0
+int main() { // CHECK: File 0, [[@LINE]]:12 -> [[@LINE+27]]:2 = #0
bool bt = true;
bool bf = false; // MCDC: Decision,File 0, [[@LINE+1]]:12 -> [[@LINE+1]]:20 = M:3, C:2
bool a = bt && bf; // CHECK-NEXT: File 0, [[@LINE]]:12 -> [[@LINE]]:14 = #0
// CHECK-NEXT: Branch,File 0, [[@LINE-1]]:12 -> [[@LINE-1]]:14 = #1, (#0 - #1)
- // CHECK-NEXT: File 0, [[@LINE-2]]:18 -> [[@LINE-2]]:20 = #1
- // CHECK-NEXT: Branch,File 0, [[@LINE-3]]:18 -> [[@LINE-3]]:20 = #2, (#1 - #2)
+ // CHECK-NEXT: Gap,File 0, [[@LINE-2]]:14 -> [[@LINE-2]]:18 = #1
+ // CHECK-NEXT: File 0, [[@LINE-3]]:18 -> [[@LINE-3]]:20 = #1
+ // CHECK-NEXT: Branch,File 0, [[@LINE-4]]:18 -> [[@LINE-4]]:20 = #2, (#1 - #2)
// MCDC: Decision,File 0, [[@LINE+1]]:7 -> [[@LINE+2]]:9 = M:6, C:2
a = bt && // CHECK-NEXT: File 0, [[@LINE]]:7 -> [[@LINE]]:9 = #0
bf; // CHECK-NEXT: Branch,File 0, [[@LINE-1]]:7 -> [[@LINE-1]]:9 = #3, (#0 - #3)
- // CHECK-NEXT: File 0, [[@LINE-1]]:7 -> [[@LINE-1]]:9 = #3
- // CHECK-NEXT: Branch,File 0, [[@LINE-2]]:7 -> [[@LINE-2]]:9 = #4, (#3 - #4)
+ // CHECK-NEXT: Gap,File 0, [[@LINE-2]]:9 -> [[@LINE-1]]:7 = #3
+ // CHECK-NEXT: File 0, [[@LINE-2]]:7 -> [[@LINE-2]]:9 = #3
+ // CHECK-NEXT: Branch,File 0, [[@LINE-3]]:7 -> [[@LINE-3]]:9 = #4, (#3 - #4)
// MCDC: Decision,File 0, [[@LINE+1]]:7 -> [[@LINE+1]]:15 = M:9, C:2
a = bf || bt; // CHECK-NEXT: File 0, [[@LINE]]:7 -> [[@LINE]]:9 = #0
// CHECK-NEXT: Branch,File 0, [[@LINE-1]]:7 -> [[@LINE-1]]:9 = (#0 - #5), #5
- // CHECK-NEXT: File 0, [[@LINE-2]]:13 -> [[@LINE-2]]:15 = #5
- // CHECK-NEXT: Branch,File 0, [[@LINE-3]]:13 -> [[@LINE-3]]:15 = (#5 - #6), #6
+ // CHECK-NEXT: Gap,File 0, [[@LINE-2]]:9 -> [[@LINE-2]]:13 = #5
+ // CHECK-NEXT: File 0, [[@LINE-3]]:13 -> [[@LINE-3]]:15 = #5
+ // CHECK-NEXT: Branch,File 0, [[@LINE-4]]:13 -> [[@LINE-4]]:15 = (#5 - #6), #6
// MCDC: Decision,File 0, [[@LINE+1]]:7 -> [[@LINE+2]]:9 = M:12, C:2
a = bf || // CHECK-NEXT: File 0, [[@LINE]]:7 -> [[@LINE]]:9 = #0
bt; // CHECK-NEXT: Branch,File 0, [[@LINE-1]]:7 -> [[@LINE-1]]:9 = (#0 - #7), #7
- // CHECK-NEXT: File 0, [[@LINE-1]]:7 -> [[@LINE-1]]:9 = #7
- // CHECK-NEXT: Branch,File 0, [[@LINE-2]]:7 -> [[@LINE-2]]:9 = (#7 - #8), #8
+ // CHECK-NEXT: Gap,File 0, [[@LINE-2]]:9 -> [[@LINE-1]]:7 = #7
+ // CHECK-NEXT: File 0, [[@LINE-2]]:7 -> [[@LINE-2]]:9 = #7
+ // CHECK-NEXT: Branch,File 0, [[@LINE-3]]:7 -> [[@LINE-3]]:9 = (#7 - #8), #8
return 0;
}
diff --git a/compiler-rt/test/profile/Linux/coverage_short_circuit.cpp b/compiler-rt/test/profile/Linux/coverage_short_circuit.cpp
new file mode 100644
index 0000000000000..54f0c4cebc44c
--- /dev/null
+++ b/compiler-rt/test/profile/Linux/coverage_short_circuit.cpp
@@ -0,0 +1,36 @@
+// RUN: %clangxx_profgen -std=c++17 -fuse-ld=lld -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
+
+void foo() { // CHECK: [[@LINE]]| 1|void foo() {
+ bool cond1 = false; // CHECK-NEXT: [[@LINE]]| 1| bool cond1 = false;
+ bool cond2 = true; // CHECK-NEXT: [[@LINE]]| 1| bool cond2 = true;
+ if (cond1 && // CHECK-NEXT: [[@LINE]]| 1| if (cond1 &&
+ cond2) { // CHECK-NEXT: [[@LINE]]| 0| cond2) {
+ } // CHECK-NEXT: [[@LINE]]| 0| }
+} // CHECK-NEXT: [[@LINE]]| 1|}
+
+void bar() { // CHECK: [[@LINE]]| 1|void bar() {
+ bool cond1 = true; // CHECK-NEXT: [[@LINE]]| 1| bool cond1 = true;
+ bool cond2 = false; // CHECK-NEXT: [[@LINE]]| 1| bool cond2 = false;
+ if (cond1 && // CHECK-NEXT: [[@LINE]]| 1| if (cond1 &&
+ cond2) { // CHECK-NEXT: [[@LINE]]| 1| cond2) {
+ } // CHECK-NEXT: [[@LINE]]| 0| }
+} // CHECK-NEXT: [[@LINE]]| 1|}
+
+void baz() { // CHECK: [[@LINE]]| 1|void baz() {
+ bool cond1 = false; // CHECK-NEXT: [[@LINE]]| 1| bool cond1 = false;
+ bool cond2 = true; // CHECK-NEXT: [[@LINE]]| 1| bool cond2 = true;
+ if (cond1 // CHECK-NEXT: [[@LINE]]| 1| if (cond1
+ && // CHECK-NEXT: [[@LINE]]| 0| &&
+ cond2) { // CHECK-NEXT: [[@LINE]]| 0| cond2) {
+ } // CHECK-NEXT: [[@LINE]]| 0| }
+} // CHECK-NEXT: [[@LINE]]| 1|}
+
+int main() {
+ foo();
+ bar();
+ baz();
+ return 0;
+}
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