Migrate C++ link action .params files to the Blaze-standard ParameterFileWriteAction.

Performance changes:
- output files of actions require an extra system call
+ incremental builds no longer require re-writing the .param file (typically)

--
MOS_MIGRATED_REVID=95842983

1 files changed, 26 insertions, 11 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkCommandLine.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkCommandLine.java
index 99568c94a6..f8fc37e0a1 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkCommandLine.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/LinkCommandLine.java
@@ -74,7 +74,7 @@ public final class LinkCommandLine extends CommandLine {
   private final boolean nativeDeps;
   private final boolean useTestOnlyFlags;
   private final boolean needWholeArchive;
-  private final boolean supportsParamFiles;
+  private final PathFragment paramFileExecPath;
   @Nullable private final Artifact interfaceSoBuilder;
 
   private LinkCommandLine(
@@ -96,7 +96,7 @@ public final class LinkCommandLine extends CommandLine {
       boolean nativeDeps,
       boolean useTestOnlyFlags,
       boolean needWholeArchive,
-      boolean supportsParamFiles,
+      PathFragment paramFileFragment,
       Artifact interfaceSoBuilder) {
     Preconditions.checkArgument(linkTargetType != LinkTargetType.INTERFACE_DYNAMIC_LIBRARY,
         "you can't link an interface dynamic library directly");
@@ -143,7 +143,7 @@ public final class LinkCommandLine extends CommandLine {
     this.nativeDeps = nativeDeps;
     this.useTestOnlyFlags = useTestOnlyFlags;
     this.needWholeArchive = needWholeArchive;
-    this.supportsParamFiles = supportsParamFiles;
+    this.paramFileExecPath = paramFileFragment;
     // For now, silently ignore interfaceSoBuilder if we don't build an interface dynamic library.
     this.interfaceSoBuilder =
         ((linkTargetType == LinkTargetType.DYNAMIC_LIBRARY) && (interfaceOutput != null))
@@ -256,7 +256,7 @@ public final class LinkCommandLine extends CommandLine {
    * @throws IllegalStateException if the command-line cannot be split
    */
   @VisibleForTesting
-  final Pair<List<String>, List<String>> splitCommandline(PathFragment paramExecPath) {
+  final Pair<List<String>, List<String>> splitCommandline() {
     Preconditions.checkState(canBeSplit());
     List<String> args = getRawLinkArgv();
     if (linkTargetType.isStaticLibraryLink()) {
@@ -265,7 +265,7 @@ public final class LinkCommandLine extends CommandLine {
       List<String> commandlineArgs = new ArrayList<>();
       commandlineArgs.add(args.get(0));
 
-      commandlineArgs.add("@" + paramExecPath.getPathString());
+      commandlineArgs.add("@" + paramFileExecPath.getPathString());
       return Pair.of(commandlineArgs, paramFileArgs);
     } else {
       // Gcc link commands tend to generate humongous commandlines for some targets, which may
@@ -275,13 +275,28 @@ public final class LinkCommandLine extends CommandLine {
       List<String> commandlineArgs = new ArrayList<>();
       extractArgumentsForParamFile(args, commandlineArgs, paramFileArgs);
 
-      commandlineArgs.add("-Wl,@" + paramExecPath.getPathString());
+      commandlineArgs.add("-Wl,@" + paramFileExecPath.getPathString());
       return Pair.of(commandlineArgs, paramFileArgs);
     }
   }
 
+  /**
+   * Returns just the .params file portion of the command-line as a {@link CommandLine}.
+   *
+   * @throws IllegalStateException if the command-line cannot be split
+   */
+  CommandLine paramCmdLine() {
+    Preconditions.checkState(canBeSplit());
+    return new CommandLine() {
+      @Override
+      public Iterable<String> arguments() {
+        return splitCommandline().getSecond();
+      }
+    };
+  }
+
   boolean canBeSplit() {
-    if (!supportsParamFiles) {
+    if (paramFileExecPath == null) {
       return false;
     }
     switch (linkTargetType) {
@@ -931,7 +946,7 @@ public final class LinkCommandLine extends CommandLine {
     private boolean nativeDeps;
     private boolean useTestOnlyFlags;
     private boolean needWholeArchive;
-    private boolean supportsParamFiles;
+    private PathFragment paramFileFragment;
     @Nullable private Artifact interfaceSoBuilder;
 
     public Builder(BuildConfiguration configuration, ActionOwner owner) {
@@ -954,7 +969,7 @@ public final class LinkCommandLine extends CommandLine {
       return new LinkCommandLine(configuration, owner, output, interfaceOutput,
           symbolCountsOutput, buildInfoHeaderArtifacts, linkerInputs, runtimeInputs, linkTargetType,
           linkStaticness, linkopts, features, linkstamps, actualLinkstampCompileOptions,
-          runtimeSolibDir, nativeDeps, useTestOnlyFlags, needWholeArchive, supportsParamFiles,
+          runtimeSolibDir, nativeDeps, useTestOnlyFlags, needWholeArchive, paramFileFragment,
           interfaceSoBuilder);
     }
 
@@ -1116,8 +1131,8 @@ public final class LinkCommandLine extends CommandLine {
       return this;
     }
 
-    public Builder setSupportsParamFiles(boolean supportsParamFiles) {
-      this.supportsParamFiles = supportsParamFiles;
+    public Builder setParamFileFragment(PathFragment paramFragment) {
+      this.paramFileFragment = paramFragment;
       return this;
     }
   }