Make virtual include paths shorter

Fixes #18683

RELNOTES[INC]: Virtual include header files are linked under `bin/_v_inc/<hash of target path>` instead of `bin/<target package path>/_virtual_include/<target name>`. This shortens the virtual include paths which is critical for mitigating long path issue with MSVC on Windows.

Closes #26005.

PiperOrigin-RevId: 754930166
Change-Id: Ie1e5bad06a9f945c0cf71c5e122d444e527f7ca6

Author: meteorcloudy

src/main/java/com/google/devtools/build/lib/analysis/test/InstrumentedFilesInfo.java

@@ -116,8 +116,8 @@ public ImmutableMap<String, String> getCoverageEnvironment() {
    *
    * <p>This is useful for virtual include paths in C++, which get reported at the include location
    * and not the real source path. For example, the reported include source file can be
-   * "bazel-out/k8-fastbuild/bin/include/common/_virtual_includes/strategy/strategy.h", but its
-   * actual source path is "include/common/strategy.h".
+   * "bazel-out/k8-fastbuild/_virtual_includes/XXXXXXXX/strategy.h", but its actual source path is
+   * "include/common/strategy.h".
    */
   NestedSet<Tuple> getReportedToActualSources() {
     return reportedToActualSources;

src/main/java/com/google/devtools/build/lib/rules/cpp/CcCompilationContext.java

@@ -88,17 +88,19 @@ public final class CcCompilationContext implements CcCompilationContextApi<Artif
   // Each pair maps the Bazel generated paths of virtual include headers back to their original path
   // relative to the workspace directory.
   // For example it can map
-  // "bazel-out/k8-fastbuild/bin/include/common/_virtual_includes/strategy/strategy.h"
+  // "bazel-out/k8-fastbuild/_virtual_includes/XXXXXXXX/strategy.h"
   // back to the path of the header in the workspace directory "include/common/strategy.h".
   // This is needed only when code coverage collection is enabled, to report the actual source file
   // name in the coverage output file.
   private final NestedSet<Tuple> virtualToOriginalHeaders;
+
   /**
    * Caches the actual number of transitive headers reachable through transitiveHeaderInfos. We need
    * to create maps to store these and so caching this count can substantially help with memory
    * allocations.
    */
   private int transitiveHeaderCount;
+
   /** Aftifacts generated by the header validation actions. */
   private final NestedSet<Artifact> headerTokens;
 

src/main/starlark/builtins_bzl/common/cc/compile/cc_compilation_helper.bzl

@@ -111,7 +111,7 @@ def _compute_public_headers(
 
     module_map_headers = []
     virtual_to_original_headers_list = []
-    virtual_include_dir = paths.join(paths.join(package_source_root(label.workspace_name, label.package, is_sibling_repository_layout), _VIRTUAL_INCLUDES_DIR), label.name)
+    virtual_include_dir = paths.join(_VIRTUAL_INCLUDES_DIR, "%x" % hash(paths.join(cc_helper.package_source_root(label.workspace_name, label.package, is_sibling_repository_layout), label.name)))
     for original_header in public_headers_artifacts:
         repo_relative_path = _repo_relative_path(original_header)
         if not repo_relative_path.startswith(strip_prefix):

src/test/java/com/google/devtools/build/lib/rules/cpp/CcCommonTest.java

@@ -18,6 +18,7 @@
 import static com.google.devtools.build.lib.actions.util.ActionsTestUtil.baseArtifactNames;
 import static com.google.devtools.build.lib.actions.util.ActionsTestUtil.baseNamesOf;
 
+import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 import com.google.common.truth.IterableSubject;
 import com.google.devtools.build.lib.actions.Action;
@@ -1071,12 +1072,12 @@ public void testIncludeManglingSmoke() throws Exception {
     ConfiguredTarget lib = getConfiguredTarget("//third_party/a");
     CcCompilationContext ccCompilationContext = lib.get(CcInfo.PROVIDER).getCcCompilationContext();
     assertThat(ActionsTestUtil.prettyArtifactNames(ccCompilationContext.getDeclaredIncludeSrcs()))
-        .containsExactly("third_party/a/_virtual_includes/a/lib/b/c.h", "third_party/a/v1/b/c.h");
+        .containsExactly("_virtual_includes/207132b2/lib/b/c.h", "third_party/a/v1/b/c.h");
     assertThat(ccCompilationContext.getIncludeDirs())
         .containsExactly(
             getTargetConfiguration()
                 .getBinFragment(RepositoryName.MAIN)
-                .getRelative("third_party/a/_virtual_includes/a"));
+                .getRelative("_virtual_includes/207132b2"));
   }
 
   @Test
@@ -1148,10 +1149,9 @@ public void testAbsoluteAndRelativeStripPrefix() throws Exception {
             .getCcCompilationContext();
 
     assertThat(ActionsTestUtil.prettyArtifactNames(relative.getDeclaredIncludeSrcs()))
-        .containsExactly("third_party/a/_virtual_includes/relative/b.h", "third_party/a/v1/b.h");
+        .containsExactly("_virtual_includes/6665bb5b/b.h", "third_party/a/v1/b.h");
     assertThat(ActionsTestUtil.prettyArtifactNames(absolute.getDeclaredIncludeSrcs()))
-        .containsExactly(
-            "third_party/a/_virtual_includes/absolute/a/v1/b.h", "third_party/a/v1/b.h");
+        .containsExactly("_virtual_includes/ee72ce06/a/v1/b.h", "third_party/a/v1/b.h");
   }
 
   @Test
@@ -1205,8 +1205,12 @@ public void testSymlinkActionIsNotRegisteredWhenIncludePrefixDoesntChangePath()
 
     CcCompilationContext ccCompilationContext =
         getConfiguredTarget("//third_party:a").get(CcInfo.PROVIDER).getCcCompilationContext();
-    assertThat(ActionsTestUtil.prettyArtifactNames(ccCompilationContext.getDeclaredIncludeSrcs()))
-        .doesNotContain("third_party/_virtual_includes/a/third_party/a.h");
+    assertThat(
+            Joiner.on(" ")
+                .join(
+                    ActionsTestUtil.prettyArtifactNames(
+                        ccCompilationContext.getDeclaredIncludeSrcs())))
+        .doesNotContainMatch("_virtual_includes/[a-z0-9]{8}/third_party/a.h");
   }
 
   @Test

src/test/java/com/google/devtools/build/lib/rules/cpp/CompileBuildVariablesTest.java

@@ -432,7 +432,7 @@ public void testExternalIncludePathsVariable() throws Exception {
     ImmutableList.Builder<String> entries =
         ImmutableList.<String>builder()
             .add(
-                "/k8-fastbuild/bin/external/pkg+/_virtual_includes/foo2",
+                "/k8-fastbuild/bin/_virtual_includes/8a060f18",
                 "external/pkg+",
                 "/k8-fastbuild/bin/external/pkg+");
     if (analysisMock.isThisBazel()) {

src/test/java/com/google/devtools/build/lib/rules/cpp/StarlarkCcCommonTest.java

@@ -5849,8 +5849,7 @@ public void testIncludePrefix() throws Exception {
     assertThat(target).isNotNull();
     CcInfo ccInfo = target.get(CcInfo.PROVIDER);
     assertThat(artifactsToStrings(ccInfo.getCcCompilationContext().getDirectPublicHdrs()))
-        .contains(
-            "bin third_party/bar/_virtual_includes/starlark_lib_suffix/prefix/starlark_lib.h");
+        .contains("bin _virtual_includes/c203db2d/prefix/starlark_lib.h");
   }
 
   @Test
@@ -5873,7 +5872,7 @@ public void testStripIncludePrefix() throws Exception {
     assertThat(target).isNotNull();
     CcInfo ccInfo = target.get(CcInfo.PROVIDER);
     assertThat(artifactsToStrings(ccInfo.getCcCompilationContext().getDirectPublicHdrs()))
-        .contains("bin third_party/bar/_virtual_includes/starlark_lib_suffix/starlark_lib.h");
+        .contains("bin _virtual_includes/c203db2d/starlark_lib.h");
   }
 
   @Test
@@ -5900,7 +5899,7 @@ public void testStripIncludePrefixIncludePath() throws Exception {
         .containsExactly(
             getTargetConfiguration()
                 .getBinFragment(RepositoryName.MAIN)
-                .getRelative("third_party/bar/_virtual_includes/starlark_lib_suffix"));
+                .getRelative("_virtual_includes/c203db2d"));
   }
 
   @Test
@@ -5925,8 +5924,7 @@ public void testStripIncludePrefixAndIncludePrefix() throws Exception {
     assertThat(target).isNotNull();
     CcInfo ccInfo = target.get(CcInfo.PROVIDER);
     assertThat(artifactsToStrings(ccInfo.getCcCompilationContext().getDirectPublicHdrs()))
-        .contains(
-            "bin third_party/bar/_virtual_includes/starlark_lib_suffix/prefix/starlark_lib.h");
+        .contains("bin _virtual_includes/c203db2d/prefix/starlark_lib.h");
   }
 
   @Test
@@ -5951,7 +5949,7 @@ public void testStripIncludePrefixAndIncludePrefixIncludePath() throws Exception
         .containsExactly(
             getTargetConfiguration()
                 .getBinFragment(RepositoryName.MAIN)
-                .getRelative("third_party/bar/_virtual_includes/starlark_lib_suffix"));
+                .getRelative("_virtual_includes/c203db2d"));
   }
 
   @Test

src/test/java/com/google/devtools/build/lib/rules/objc/ObjcLibraryTest.java

@@ -1436,8 +1436,7 @@ public void testIncludesDirsOfTransitiveCcIncDepsGetPassedToCompileAction() thro
     CommandAction compileAction = compileAction("//package:objc_lib", "b.o");
     // We remove spaces, since the crosstool rules do not use spaces for include paths.
     String compileActionArgs = Joiner.on("").join(compileAction.getArguments()).replace(" ", "");
-    assertThat(compileActionArgs)
-        .matches(".*-iquote.*/third_party/cc_lib/_virtual_includes/cc_lib.*");
+    assertThat(compileActionArgs).matches(".*-iquote.*/_virtual_includes/848637ee.*");
   }
 
   @Test