[clang] 463e30f - [Clang] Fix crash in coverage of if consteval.
Corentin Jabot via cfe-commits
cfe-commits at lists.llvm.org
Fri Aug 26 08:47:03 PDT 2022
Author: Corentin Jabot
Date: 2022-08-26T17:46:53+02:00
New Revision: 463e30f51fd07921f32c6630afb3f8dd18d6d2f5
URL: https://github.com/llvm/llvm-project/commit/463e30f51fd07921f32c6630afb3f8dd18d6d2f5
DIFF: https://github.com/llvm/llvm-project/commit/463e30f51fd07921f32c6630afb3f8dd18d6d2f5.diff
LOG: [Clang] Fix crash in coverage of if consteval.
Clang crashes when encountering an `if consteval` statement.
This is the minimum fix not to crash.
The fix is consistent with the current behavior of if constexpr,
which does generate coverage data for the discarded branches.
This is of course not correct and a better solution is
needed for both if constexpr and if consteval.
See https://github.com/llvm/llvm-project/issues/54419.
Fixes #57377
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D132723
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/lib/CodeGen/CoverageMappingGen.cpp
clang/test/CoverageMapping/if.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 3f7eec1effd46..b6d1dbedb2c59 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -78,6 +78,10 @@ Bug Fixes
- ``-Wtautological-compare`` missed warnings for tautological comparisons
involving a negative integer literal. This fixes
`Issue 42918 <https://github.com/llvm/llvm-project/issues/42918>`_.
+- Fix a crash when generating code coverage information for an
+ ``if consteval`` statement. This fixes
+ `Issue 57377 <https://github.com/llvm/llvm-project/issues/57377>`_.
+
Improvements to Clang's diagnostics
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index 0fe084b628dab..836aabf80179d 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -1377,19 +1377,23 @@ struct CounterCoverageMappingBuilder
// Extend into the condition before we propagate through it below - this is
// needed to handle macros that generate the "if" but not the condition.
- extendRegion(S->getCond());
+ if (!S->isConsteval())
+ extendRegion(S->getCond());
Counter ParentCount = getRegion().getCounter();
Counter ThenCount = getRegionCounter(S);
- // Emitting a counter for the condition makes it easier to interpret the
- // counter for the body when looking at the coverage.
- propagateCounts(ParentCount, S->getCond());
+ if (!S->isConsteval()) {
+ // Emitting a counter for the condition makes it easier to interpret the
+ // counter for the body when looking at the coverage.
+ propagateCounts(ParentCount, S->getCond());
- // The 'then' count applies to the area immediately after the condition.
- auto Gap = findGapAreaBetween(S->getRParenLoc(), getStart(S->getThen()));
- if (Gap)
- fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), ThenCount);
+ // The 'then' count applies to the area immediately after the condition.
+ Optional<SourceRange> Gap =
+ findGapAreaBetween(S->getRParenLoc(), getStart(S->getThen()));
+ if (Gap)
+ fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), ThenCount);
+ }
extendRegion(S->getThen());
Counter OutCount = propagateCounts(ThenCount, S->getThen());
@@ -1398,9 +1402,9 @@ struct CounterCoverageMappingBuilder
if (const Stmt *Else = S->getElse()) {
bool ThenHasTerminateStmt = HasTerminateStmt;
HasTerminateStmt = false;
-
// The 'else' count applies to the area immediately after the 'then'.
- Gap = findGapAreaBetween(getEnd(S->getThen()), getStart(Else));
+ Optional<SourceRange> Gap =
+ findGapAreaBetween(getEnd(S->getThen()), getStart(Else));
if (Gap)
fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), ElseCount);
extendRegion(Else);
@@ -1416,9 +1420,11 @@ struct CounterCoverageMappingBuilder
GapRegionCounter = OutCount;
}
- // Create Branch Region around condition.
- createBranchRegion(S->getCond(), ThenCount,
- subtractCounters(ParentCount, ThenCount));
+ if (!S->isConsteval()) {
+ // Create Branch Region around condition.
+ createBranchRegion(S->getCond(), ThenCount,
+ subtractCounters(ParentCount, ThenCount));
+ }
}
void VisitCXXTryStmt(const CXXTryStmt *S) {
diff --git a/clang/test/CoverageMapping/if.cpp b/clang/test/CoverageMapping/if.cpp
index 5b705cd46ab72..de3554c100b96 100644
--- a/clang/test/CoverageMapping/if.cpp
+++ b/clang/test/CoverageMapping/if.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -std=c++1z -triple %itanium_abi_triple -main-file-name if.cpp %s | FileCheck %s
+// RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -std=c++2b -triple %itanium_abi_triple -main-file-name if.cpp %s | FileCheck %s
int nop() { return 0; }
@@ -13,6 +13,22 @@ void foo() { // CHECK-NEXT: Gap,File 0, [[@LINE+1]]:21 -> [[@
++j; // CHECK-NEXT: Branch,File 0, [[@LINE-1]]:7 -> [[@LINE-1]]:8 = #1, (#0 - #1)
} // CHECK-NEXT: [[@LINE-2]]:9 -> [[@LINE-1]]:5 = #1
// CHECK-NEXT: [[@LINE-2]]:5 -> [[@LINE-2]]:8 = #1
+
+// FIXME: Do not generate coverage for discarded branches in if consteval and if constexpr statements
+constexpr int check_consteval(int i) {
+ if consteval {
+ i++;
+ }
+ if !consteval {
+ i++;
+ }
+ if consteval {
+ return 42;
+ } else {
+ return i;
+ }
+}
+
// CHECK-LABEL: main:
int main() { // CHECK: File 0, [[@LINE]]:12 -> {{[0-9]+}}:2 = #0
int i = 0;
@@ -50,6 +66,10 @@ int main() { // CHECK: File 0, [[@LINE]]:12 -> {{[0-9]+}}:2 =
// CHECK-NEXT: File 0, [[@LINE+1]]:14 -> [[@LINE+1]]:20 = #6
i = i == 0?i + 12:i + 10; // CHECK-NEXT: File 0, [[@LINE]]:21 -> [[@LINE]]:27 = (#0 - #6)
+ // GH-57377
+ constexpr int c_i = check_consteval(0);
+ check_consteval(i);
+
return 0;
}
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