Only compile a single source file once for a given cc_* rule.

RELNOTES: None.
PiperOrigin-RevId: 203934582

1 files changed, 18 insertions, 13 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
index 08ae86068f..384d98959f 100644
--- 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
@@ -201,7 +201,7 @@ public final class CcCompilationHelper {
   private final List<Artifact> additionalIncludeScanningRoots = new ArrayList<>();
   private final List<PathFragment> additionalExportedHeaders = new ArrayList<>();
   private final List<CppModuleMap> additionalCppModuleMaps = new ArrayList<>();
-  private final Set<CppSource> compilationUnitSources = new LinkedHashSet<>();
+  private final LinkedHashMap<Artifact, CppSource> compilationUnitSources = new LinkedHashMap<>();
   private final List<Artifact> objectFiles = new ArrayList<>();
   private final List<Artifact> picObjectFiles = new ArrayList<>();
   private ImmutableList<String> copts = ImmutableList.of();
@@ -408,8 +408,10 @@ public final class CcCompilationHelper {
     Preconditions.checkState(isHeader || isTextualInclude);
 
     if (ccToolchain.shouldProcessHeaders(featureConfiguration) && !isTextualInclude) {
-      compilationUnitSources.add(CppSource.create(privateHeader, label, CppSource.Type.HEADER));
+      compilationUnitSources.put(
+          privateHeader, CppSource.create(privateHeader, label, CppSource.Type.HEADER));
     }
+    
     this.privateHeaders.add(privateHeader);
     return this;
   }
@@ -464,7 +466,8 @@ public final class CcCompilationHelper {
     if (isTextualInclude || !isHeader || !ccToolchain.shouldProcessHeaders(featureConfiguration)) {
       return;
     }
-    compilationUnitSources.add(CppSource.create(header, label, CppSource.Type.HEADER));
+
+    compilationUnitSources.put(header, CppSource.create(header, label, CppSource.Type.HEADER));
   }
 
   /** Adds a header to {@code publicHeaders}, but not to this target's module map. */
@@ -497,7 +500,7 @@ public final class CcCompilationHelper {
     } else {
       type = CppSource.Type.SOURCE;
     }
-    compilationUnitSources.add(CppSource.create(source, label, type));
+    compilationUnitSources.put(source, CppSource.create(source, label, type));
   }
 
   /**
@@ -507,7 +510,7 @@ public final class CcCompilationHelper {
    * compilation.
    */
   public ImmutableSet<CppSource> getCompilationUnitSources() {
-    return ImmutableSet.copyOf(this.compilationUnitSources);
+    return ImmutableSet.copyOf(this.compilationUnitSources.values());
   }
 
   /**
@@ -1232,7 +1235,7 @@ public final class CcCompilationHelper {
    * for all artifacts.
    */
   private ImmutableMap<Artifact, String> calculateOutputNameMapByType(
-      Set<CppSource> sources, String prefixDir) {
+      Map<Artifact, CppSource> sources, String prefixDir) {
     ImmutableMap.Builder<Artifact, String> builder = ImmutableMap.builder();
     builder.putAll(
         calculateOutputNameMap(
@@ -1248,13 +1251,15 @@ public final class CcCompilationHelper {
   }
 
   private NestedSet<Artifact> getSourceArtifactsByType(
-    Set<CppSource> sources, CppSource.Type type) {
+      Map<Artifact, CppSource> sources, CppSource.Type type) {
     NestedSetBuilder<Artifact> result = NestedSetBuilder.stableOrder();
-    result.addAll(sources
-        .stream()
-        .filter(source -> source.getType().equals(type))
-        .map(CppSource::getSource)
-        .collect(Collectors.toList()));
+    result.addAll(
+        sources
+            .values()
+            .stream()
+            .filter(source -> source.getType().equals(type))
+            .map(CppSource::getSource)
+            .collect(Collectors.toList()));
     return result.build();
   }
 
@@ -1299,7 +1304,7 @@ public final class CcCompilationHelper {
       outputNameMap = calculateOutputNameMapByType(compilationUnitSources, outputNamePrefixDir);
     }
 
-    for (CppSource source : compilationUnitSources) {
+    for (CppSource source : compilationUnitSources.values()) {
       Artifact sourceArtifact = source.getSource();
       Label sourceLabel = source.getLabel();
       CppCompileActionBuilder builder = initializeCompileAction(sourceArtifact);