Blaze: let a LinkerInput declare that it needs debug info in the executable

RELNOTES: None.
PiperOrigin-RevId: 185455486

3 files changed, 68 insertions, 10 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppLinkActionBuilder.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppLinkActionBuilder.java
index e0cd9a44d9..46c9d92a81 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppLinkActionBuilder.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppLinkActionBuilder.java
@@ -209,6 +209,7 @@ public class CppLinkActionBuilder {
   private boolean isNativeDeps;
   private boolean useTestOnlyFlags;
   private boolean wholeArchive;
+  private boolean mustKeepDebug = false;
   private LinkArtifactFactory linkArtifactFactory = CppLinkAction.DEFAULT_ARTIFACT_FACTORY;
 
   private boolean isLtoIndexing = false;
@@ -929,7 +930,8 @@ public class CppLinkActionBuilder {
                 // If we reached here, then allowLtoIndexing must be true (checked above).
                 /* allowLtoIndexing= */ true,
                 /* interfaceLibraryBuilder= */ null,
-                /* interfaceLibraryOutput= */ null)
+                /* interfaceLibraryOutput= */ null,
+                mustKeepDebug)
             : new CppLinkVariablesExtension(
                 configuration,
                 needWholeArchive,
@@ -943,7 +945,8 @@ public class CppLinkActionBuilder {
                 /* ltoOutputRootPrefix= */ PathFragment.EMPTY_FRAGMENT,
                 allowLtoIndexing,
                 toolchain.getInterfaceSoBuilder(),
-                interfaceOutput);
+                interfaceOutput,
+                mustKeepDebug);
     variablesExtension.addVariables(buildVariablesBuilder);
     for (VariablesExtension extraVariablesExtension : variablesExtensions) {
       extraVariablesExtension.addVariables(buildVariablesBuilder);
@@ -1314,6 +1317,9 @@ public class CppLinkActionBuilder {
     Preconditions.checkArgument(
         input.getArtifact().isTreeArtifact() || Link.OBJECT_FILETYPES.matches(name), name);
     this.objectFiles.add(input);
+    if (input.isMustKeepDebug()) {
+      this.mustKeepDebug = true;
+    }
   }
 
   /**
@@ -1383,6 +1389,9 @@ public class CppLinkActionBuilder {
   public CppLinkActionBuilder addLibrary(LibraryToLink input) {
     checkLibrary(input);
     libraries.add(input);
+    if (input.isMustKeepDebug()) {
+      mustKeepDebug = true;
+    }
     return this;
   }
 
@@ -1393,6 +1402,9 @@ public class CppLinkActionBuilder {
   public CppLinkActionBuilder addLibraries(NestedSet<LibraryToLink> inputs) {
     for (LibraryToLink input : inputs) {
       checkLibrary(input);
+      if (input.isMustKeepDebug()) {
+        mustKeepDebug = true;
+      }
     }
     this.libraries.addTransitive(inputs);
     return this;
@@ -1613,6 +1625,7 @@ public class CppLinkActionBuilder {
     private final Artifact thinltoMergedObjectFile;
     private final PathFragment ltoOutputRootPrefix;
     private final boolean allowLtoIndexing;
+    private final boolean mustKeepDebug;
 
     private final LinkArgCollector linkArgCollector = new LinkArgCollector();
 
@@ -1629,7 +1642,8 @@ public class CppLinkActionBuilder {
         PathFragment ltoOutputRootPrefix,
         boolean allowLtoIndexing,
         Artifact interfaceLibraryBuilder,
-        Artifact interfaceLibraryOutput) {
+        Artifact interfaceLibraryOutput,
+        boolean mustKeepDebug) {
       this.configuration = configuration;
       this.needWholeArchive = needWholeArchive;
       this.linkerInputs = linkerInputs;
@@ -1643,6 +1657,7 @@ public class CppLinkActionBuilder {
       this.thinltoMergedObjectFile = thinltoMergedObjectFile;
       this.ltoOutputRootPrefix = ltoOutputRootPrefix;
       this.allowLtoIndexing = allowLtoIndexing;
+      this.mustKeepDebug = mustKeepDebug;
 
       addInputFileLinkOptions(linkArgCollector);
     }
@@ -1661,7 +1676,7 @@ public class CppLinkActionBuilder {
         buildVariables.addStringVariable(FORCE_PIC_VARIABLE, "");
       }
 
-      if (cppConfiguration.shouldStripBinaries()) {
+      if (!mustKeepDebug && cppConfiguration.shouldStripBinaries()) {
         buildVariables.addStringVariable(STRIP_DEBUG_SYMBOLS_VARIABLE, "");
       }
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInput.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInput.java
index dacc11275c..3d07e1b89c 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInput.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInput.java
@@ -54,4 +54,9 @@ public interface LinkerInput {
    * legal to call this only when {@link #containsObjectFiles()} returns true.
    */
   Iterable<Artifact> getObjectFiles();
+
+  /**
+   * Returns whether we must keep debug symbols for this input.
+   */
+  boolean isMustKeepDebug();
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInputs.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInputs.java
index 70ab54de4f..808db7be7d 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInputs.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkerInputs.java
@@ -117,6 +117,11 @@ public abstract class LinkerInputs {
     public String toString() {
       return "SimpleLinkerInput(" + artifact + ")";
     }
+
+    @Override
+    public boolean isMustKeepDebug() {
+      return false;
+    }
   }
 
   /**
@@ -262,6 +267,11 @@ public abstract class LinkerInputs {
     public int hashCode() {
       return solibSymlinkArtifact.hashCode();
     }
+
+    @Override
+    public boolean isMustKeepDebug() {
+      return false;
+    }
   }
 
   /** This class represents a library that may contain object files. */
@@ -278,6 +288,7 @@ public abstract class LinkerInputs {
     private final Iterable<Artifact> objectFiles;
     private final ImmutableMap<Artifact, Artifact> ltoBitcodeFiles;
     private final ImmutableMap<Artifact, LtoBackendArtifacts> sharedNonLtoBackends;
+    private final boolean mustKeepDebug;
 
     @AutoCodec.Instantiator
     @VisibleForSerialization
@@ -287,13 +298,15 @@ public abstract class LinkerInputs {
         String libraryIdentifier,
         Iterable<Artifact> objectFiles,
         ImmutableMap<Artifact, Artifact> ltoBitcodeFiles,
-        ImmutableMap<Artifact, LtoBackendArtifacts> sharedNonLtoBackends) {
+        ImmutableMap<Artifact, LtoBackendArtifacts> sharedNonLtoBackends,
+        boolean mustKeepDebug) {
       this.libraryArtifact = libraryArtifact;
       this.category = category;
       this.libraryIdentifier = libraryIdentifier;
       this.objectFiles = objectFiles;
       this.ltoBitcodeFiles = ltoBitcodeFiles;
       this.sharedNonLtoBackends = sharedNonLtoBackends;
+      this.mustKeepDebug = mustKeepDebug;
     }
 
     private CompoundLibraryToLink(
@@ -303,7 +316,8 @@ public abstract class LinkerInputs {
         Iterable<Artifact> objectFiles,
         ImmutableMap<Artifact, Artifact> ltoBitcodeFiles,
         ImmutableMap<Artifact, LtoBackendArtifacts> sharedNonLtoBackends,
-        boolean allowArchiveTypeInAlwayslink) {
+        boolean allowArchiveTypeInAlwayslink,
+        boolean mustKeepDebug) {
       String basename = libraryArtifact.getFilename();
       switch (category) {
         case ALWAYSLINK_STATIC_LIBRARY:
@@ -332,6 +346,7 @@ public abstract class LinkerInputs {
       this.ltoBitcodeFiles =
           (ltoBitcodeFiles == null) ? ImmutableMap.<Artifact, Artifact>of() : ltoBitcodeFiles;
       this.sharedNonLtoBackends = sharedNonLtoBackends;
+      this.mustKeepDebug = mustKeepDebug;
     }
 
     @Override
@@ -402,6 +417,11 @@ public abstract class LinkerInputs {
     public int hashCode() {
       return libraryArtifact.hashCode();
     }
+
+    @Override
+    public boolean isMustKeepDebug() {
+      return this.mustKeepDebug;
+    }
   }
 
   //////////////////////////////////////////////////////////////////////////////////////
@@ -467,7 +487,8 @@ public abstract class LinkerInputs {
         /* objectFiles= */ null,
         /* ltoBitcodeFiles= */ null,
         /* sharedNonLtoBackends= */ null,
-        /* allowArchiveTypeInAlwayslink= */ false);
+        /* allowArchiveTypeInAlwayslink= */ false,
+        /* mustKeepDebug= */ false);
   }
 
   public static LibraryToLink opaqueLibraryToLink(
@@ -479,7 +500,8 @@ public abstract class LinkerInputs {
         /* objectFiles= */ null,
         /* ltoBitcodeFiles= */ null,
         /* sharedNonLtoBackends= */ null,
-        /* allowArchiveTypeInAlwayslink= */ false);
+        /* allowArchiveTypeInAlwayslink= */ false,
+        /* mustKeepDebug= */ false);
   }
 
   public static LibraryToLink opaqueLibraryToLink(
@@ -488,7 +510,22 @@ public abstract class LinkerInputs {
       String libraryIdentifier,
       boolean allowArchiveTypeInAlwayslink) {
     return new CompoundLibraryToLink(
-        artifact, category, libraryIdentifier, null, null, null, allowArchiveTypeInAlwayslink);
+        artifact, category, libraryIdentifier, null, null, null, allowArchiveTypeInAlwayslink,
+        /* mustKeepDebug= */ false);
+  }
+
+  public static LibraryToLink opaqueLibraryToLink(
+      Artifact artifact, ArtifactCategory category, String libraryIdentifier,
+      CppConfiguration.StripMode stripMode) {
+    return new CompoundLibraryToLink(
+        artifact,
+        category,
+        libraryIdentifier,
+        /* objectFiles= */ null,
+        /* ltoBitcodeFiles= */ null,
+        /* sharedNonLtoBackends= */ null,
+        /* allowArchiveTypeInAlwayslink= */ false,
+        /* mustKeepDebug= */ stripMode == CppConfiguration.StripMode.NEVER);
   }
 
   /** Creates a library to link with the specified object files. */
@@ -501,7 +538,8 @@ public abstract class LinkerInputs {
       ImmutableMap<Artifact, LtoBackendArtifacts> sharedNonLtoBackends) {
     return new CompoundLibraryToLink(
         library, category, libraryIdentifier, objectFiles, ltoBitcodeFiles, sharedNonLtoBackends,
-        /* allowArchiveTypeInAlwayslink= */ false);
+        /* allowArchiveTypeInAlwayslink= */ false,
+        /* mustKeepDebug= */ false);
   }
 
   public static Iterable<Artifact> toNonSolibArtifacts(Iterable<LibraryToLink> libraries) {