Stop listing .gcno files as outputs when using LLVM coverage map fo…

…rmat When using `--experimental_use_llvm_covmap`, no `.gcno` files are output. By listing them as outputs there is a mismatch between expected and actual outputs. Bazel will create these empty files after the action is run, but they non-deterministically get counted in the `Action` outputs, which can lead to cache misses on subsequent runs. Closes #22132. PiperOrigin-RevId: 630996820 Change-Id: Ia7de7a05305095c8befee4f86181cf84d9737814
bazelbuild · May 6, 2024 · a4d77c5 · a4d77c5
1 parent 7637f62
commit a4d77c5
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Showing 4 changed files with 25 additions and 3 deletions.
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCompilationHelper.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCompilationHelper.java
@@ -1151,6 +1151,7 @@ private Artifact createCompileActionTemplate(
             usePic,
             /* needsFdoBuildVariables= */ false,
             ccCompilationContext.getCppModuleMap(),
+            /* enableCoverage= */ false,
             /* gcnoFile= */ null,
             /* isUsingFission= */ false,
             /* dwoFile= */ null,
@@ -1262,6 +1263,7 @@ private CcToolchainVariables setupCompileBuildVariables(
       boolean usePic,
       boolean needsFdoBuildVariables,
       CppModuleMap cppModuleMap,
+      boolean enableCoverage,
       Artifact gcnoFile,
       boolean isUsingFission,
       Artifact dwoFile,
@@ -1352,6 +1354,7 @@ private CcToolchainVariables setupCompileBuildVariables(
         buildVariables,
         toPathString(sourceFile),
         toPathString(builder.getOutputFile()),
+        enableCoverage,
         toPathString(gcnoFile),
         toPathString(dwoFile),
         isUsingFission,
@@ -1410,7 +1413,7 @@ private void createModuleCodegenAction(
             ccToolchain, ArtifactCategory.COVERAGE_DATA_FILE, outputName);
     // TODO(djasper): This is now duplicated. Refactor the various create..Action functions.
     Artifact gcnoFile =
-        isCodeCoverageEnabled
+        isCodeCoverageEnabled && !cppConfiguration.useLLVMCoverageMapFormat()
             ? CppHelper.getCompileOutputArtifact(
                 actionConstructionContext, label, gcnoFileName, configuration)
             : null;
@@ -1431,6 +1434,7 @@ private void createModuleCodegenAction(
             /* usePic= */ pic,
             /* needsFdoBuildVariables= */ ccRelativeName != null,
             ccCompilationContext.getCppModuleMap(),
+            isCodeCoverageEnabled,
             gcnoFile,
             generateDwo,
             dwoFile,
@@ -1477,6 +1481,7 @@ private void createHeaderAction(
             generatePicAction,
             /* needsFdoBuildVariables= */ false,
             ccCompilationContext.getCppModuleMap(),
+            /* enableCoverage= */ false,
             /* gcnoFile= */ null,
             /* isUsingFission= */ false,
             /* dwoFile= */ null,
@@ -1541,7 +1546,7 @@ private ImmutableList<Artifact> createSourceAction(
           CppHelper.getArtifactNameForCategory(
               ccToolchain, ArtifactCategory.COVERAGE_DATA_FILE, picOutputBase);
       Artifact gcnoFile =
-          enableCoverage
+          enableCoverage && !cppConfiguration.useLLVMCoverageMapFormat()
               ? CppHelper.getCompileOutputArtifact(
                   actionConstructionContext, label, gcnoFileName, configuration)
               : null;
@@ -1557,6 +1562,7 @@ private ImmutableList<Artifact> createSourceAction(
               /* usePic= */ true,
               /* needsFdoBuildVariables= */ ccRelativeName != null && addObject,
               cppModuleMap,
+              enableCoverage,
               gcnoFile,
               generateDwo,
               dwoFile,
@@ -1615,7 +1621,7 @@ private ImmutableList<Artifact> createSourceAction(
 
       // Create no-PIC compile actions
       Artifact gcnoFile =
-          enableCoverage
+          isCodeCoverageEnabled && !cppConfiguration.useLLVMCoverageMapFormat()
               ? CppHelper.getCompileOutputArtifact(
                   actionConstructionContext, label, gcnoFileName, configuration)
               : null;
@@ -1630,6 +1636,7 @@ private ImmutableList<Artifact> createSourceAction(
               /* usePic= */ false,
               /* needsFdoBuildVariables= */ ccRelativeName != null,
               cppModuleMap,
+              isCodeCoverageEnabled,
               gcnoFile,
               generateDwo,
               noPicDwoFile,
@@ -1796,6 +1803,7 @@ private ImmutableList<Artifact> createTempsActions(
             usePic,
             /* needsFdoBuildVariables= */ ccRelativeName != null,
             ccCompilationContext.getCppModuleMap(),
+            /* enableCoverage= */ false,
             /* gcnoFile= */ null,
             /* isUsingFission= */ false,
             /* dwoFile= */ null,
@@ -1821,6 +1829,7 @@ private ImmutableList<Artifact> createTempsActions(
             usePic,
             /* needsFdoBuildVariables= */ ccRelativeName != null,
             ccCompilationContext.getCppModuleMap(),
+            /* enableCoverage= */ false,
             /* gcnoFile= */ null,
             /* isUsingFission= */ false,
             /* dwoFile= */ null,

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcModule.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcModule.java
@@ -326,6 +326,7 @@ public CcToolchainVariables getCompileBuildVariables(
                     ccToolchainProvider,
                     convertFromNoneable(sourceFile, /* defaultValue= */ null),
                     convertFromNoneable(outputFile, /* defaultValue= */ null),
+                    /* isCodeCoverageEnabled= */ false,
                     /* gcnoFile= */ null,
                     /* isUsingFission= */ false,
                     /* dwoFile= */ null,

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CompileBuildVariables.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CompileBuildVariables.java
@@ -142,6 +142,7 @@ public static CcToolchainVariables setupVariablesOrReportRuleError(
       CcToolchainProvider ccToolchainProvider,
       String sourceFile,
       String outputFile,
+      boolean isCodeCoverageEnabled,
       String gcnoFile,
       boolean isUsingFission,
       String dwoFile,
@@ -173,6 +174,7 @@ public static CcToolchainVariables setupVariablesOrReportRuleError(
         ccToolchainProvider.getBuildVars(),
         sourceFile,
         outputFile,
+        isCodeCoverageEnabled,
         gcnoFile,
         isUsingFission,
         dwoFile,
@@ -204,6 +206,7 @@ public static CcToolchainVariables setupVariablesOrThrowEvalException(
       CcToolchainProvider ccToolchainProvider,
       String sourceFile,
       String outputFile,
+      boolean isCodeCoverageEnabled,
       String gcnoFile,
       boolean isUsingFission,
       String dwoFile,
@@ -238,6 +241,7 @@ public static CcToolchainVariables setupVariablesOrThrowEvalException(
         ccToolchainProvider.getBuildVars(),
         sourceFile,
         outputFile,
+        isCodeCoverageEnabled,
         gcnoFile,
         isUsingFission,
         dwoFile,
@@ -269,6 +273,7 @@ private static CcToolchainVariables setupVariables(
       CcToolchainVariables parent,
       String sourceFile,
       String outputFile,
+      boolean isCodeCoverageEnabled,
       String gcnoFile,
       boolean isUsingFission,
       String dwoFile,
@@ -314,6 +319,7 @@ private static CcToolchainVariables setupVariables(
         buildVariables,
         sourceFile,
         outputFile,
+        isCodeCoverageEnabled,
         gcnoFile,
         dwoFile,
         isUsingFission,
@@ -334,6 +340,7 @@ public static void setupSpecificVariables(
       CcToolchainVariables.Builder buildVariables,
       String sourceFile,
       String outputFile,
+      boolean isCodeCoverageEnabled,
       String gcnoFile,
       String dwoFile,
       boolean isUsingFission,
@@ -371,6 +378,10 @@ public static void setupSpecificVariables(
 
     if (gcnoFile != null) {
       buildVariables.addStringVariable(GCOV_GCNO_FILE.getVariableName(), gcnoFile);
+    } else if (isCodeCoverageEnabled) {
+      // TODO: Blaze currently uses `gcov_gcno_file` to detect if code coverage is enabled. It
+      // should use a different signal.
+      buildVariables.addStringVariable(GCOV_GCNO_FILE.getVariableName(), "");
     }
 
     if (dwoFile != null) {

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppLinkstampCompileHelper.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppLinkstampCompileHelper.java
@@ -151,6 +151,7 @@ private static CcToolchainVariables getVariables(
         ccToolchainProvider,
         sourceFile.getExecPathString(),
         outputFile.getExecPathString(),
+        /* isCodeCoverageEnabled= */ false,
         /* gcnoFile= */ null,
         /* isUsingFission= */ false,
         /* dwoFile= */ null,