WIP: objc include_prefix/strip_include_prefix

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

@@ -401,15 +401,17 @@ public String getPurpose() {
      * of all of its attributes.
      */
     public Builder mergeDependentCcCompilationContext(
-        CcCompilationContext otherCcCompilationContext) {
+        CcCompilationContext otherCcCompilationContext, boolean mergeDelcaredIncludeSrcs) {
       Preconditions.checkNotNull(otherCcCompilationContext);
       compilationPrerequisites.addAll(
           otherCcCompilationContext.getTransitiveCompilationPrerequisites());
       includeDirs.addAll(otherCcCompilationContext.getIncludeDirs());
       quoteIncludeDirs.addAll(otherCcCompilationContext.getQuoteIncludeDirs());
       systemIncludeDirs.addAll(otherCcCompilationContext.getSystemIncludeDirs());
       declaredIncludeDirs.addTransitive(otherCcCompilationContext.getDeclaredIncludeDirs());
-      declaredIncludeSrcs.addTransitive(otherCcCompilationContext.getDeclaredIncludeSrcs());
+      if (mergeDelcaredIncludeSrcs) {
+        declaredIncludeSrcs.addTransitive(otherCcCompilationContext.getDeclaredIncludeSrcs());
+      }
       transitiveHeaderInfo.addTransitive(otherCcCompilationContext.transitiveHeaderInfos);
       transitiveModules.addTransitive(otherCcCompilationContext.transitiveModules);
       if (otherCcCompilationContext.headerInfo.headerModule != null) {
@@ -439,7 +441,7 @@ public Builder mergeDependentCcCompilationContext(
      */
     public Builder mergeDependentCcCompilationContexts(Iterable<CcCompilationContext> targets) {
       for (CcCompilationContext target : targets) {
-        mergeDependentCcCompilationContext(target);
+        mergeDependentCcCompilationContext(target, /* mergeDeclaredIncludeSrcs= */ true);
       }
       return this;
     }

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

@@ -481,7 +481,7 @@ private CcCompilationHelper addPrivateHeader(Artifact privateHeader, Label label
       compilationUnitSources.put(
           privateHeader, CppSource.create(privateHeader, label, CppSource.Type.HEADER));
     }
-    
+
     this.privateHeaders.add(privateHeader);
     return this;
   }
@@ -2098,12 +2098,13 @@ private static void mergeToolchainDependentCcCompilationContext(
               "Unable to merge the STL '" + stl.getLabel() + "' and toolchain contexts");
           return;
         }
-        ccCompilationContextBuilder.mergeDependentCcCompilationContext(ccCompilationContext);
+        ccCompilationContextBuilder.mergeDependentCcCompilationContext(ccCompilationContext,
+            /* mergeDeclaredIncludeSrcs= */ true);
       }
     }
     if (toolchain != null) {
       ccCompilationContextBuilder.mergeDependentCcCompilationContext(
-          toolchain.getCcCompilationContext());
+          toolchain.getCcCompilationContext(), /* mergeDeclaredIncludeSrcs= */ true);
     }
   }
 }

src/main/java/com/google/devtools/build/lib/rules/objc/CompilationAttributes.java

@@ -55,6 +55,8 @@ static class Builder {
     private final NestedSetBuilder<SdkFramework> weakSdkFrameworks = NestedSetBuilder.stableOrder();
     private final NestedSetBuilder<String> sdkDylibs = NestedSetBuilder.stableOrder();
     private Optional<PathFragment> packageFragment = Optional.absent();
+    private String includePrefix = null;
+    private String stripIncludePrefix = null;
     private boolean enableModules;
 
     /**
@@ -173,6 +175,22 @@ public Builder enableModules() {
       return this;
     }
 
+    /**
+     * Sets the include_prefix attribute.
+     */
+    public Builder setIncludePrefix(String includePrefix) {
+      this.includePrefix = includePrefix;
+      return this;
+    }
+
+    /**
+     * Sets the strip_include_prefix attribute.
+     */
+    public Builder setStripIncludePrefix(String stripIncludePrefix) {
+      this.stripIncludePrefix = stripIncludePrefix;
+      return this;
+    }
+
     /**
      * Builds a {@code CompilationAttributes} object.
      */
@@ -189,6 +207,8 @@ public CompilationAttributes build() {
           this.copts.build(),
           this.linkopts.build(),
           this.moduleMapsForDirectDeps.build(),
+          this.includePrefix,
+          this.stripIncludePrefix,
           this.enableModules);
     }
 
@@ -224,6 +244,18 @@ private static void addIncludesFromRuleContext(Builder builder, RuleContext rule
                 PathFragment::create));
         builder.addSdkIncludes(sdkIncludes.build());
       }
+
+      if (ruleContext.getRule().isAttrDefined("include_prefix", Type.STRING)
+        && ruleContext.attributes().isAttributeValueExplicitlySpecified("include_prefix")) {
+        builder.setIncludePrefix(
+            ruleContext.attributes().get("include_prefix", Type.STRING));
+      }
+
+      if (ruleContext.getRule().isAttrDefined("strip_include_prefix", Type.STRING)
+          && ruleContext.attributes().isAttributeValueExplicitlySpecified("strip_include_prefix")) {
+        builder.setStripIncludePrefix(
+            ruleContext.attributes().get("strip_include_prefix", Type.STRING));
+      }
     }
 
     private static void addSdkAttributesFromRuleContext(Builder builder, RuleContext ruleContext) {
@@ -302,6 +334,8 @@ private static void addModuleOptionsFromRuleContext(Builder builder, RuleContext
   private final ImmutableList<String> copts;
   private final ImmutableList<String> linkopts;
   private final NestedSet<CppModuleMap> moduleMapsForDirectDeps;
+  private final String includePrefix;
+  private final String stripIncludePrefix;
   private final boolean enableModules;
 
   private CompilationAttributes(
@@ -316,6 +350,8 @@ private CompilationAttributes(
       ImmutableList<String> copts,
       ImmutableList<String> linkopts,
       NestedSet<CppModuleMap> moduleMapsForDirectDeps,
+      String includePrefix,
+      String stripIncludePrefix,
       boolean enableModules) {
     this.hdrs = hdrs;
     this.textualHdrs = textualHdrs;
@@ -328,6 +364,8 @@ private CompilationAttributes(
     this.copts = copts;
     this.linkopts = linkopts;
     this.moduleMapsForDirectDeps = moduleMapsForDirectDeps;
+    this.includePrefix = includePrefix;
+    this.stripIncludePrefix = stripIncludePrefix;
     this.enableModules = enableModules;
   }
 
@@ -424,6 +462,16 @@ public NestedSet<CppModuleMap> moduleMapsForDirectDeps() {
     return this.moduleMapsForDirectDeps;
   }
 
+  /**
+   * Returns the include_prefix attribute
+   */
+  public String getIncludePrefix() { return this.includePrefix; }
+
+  /**
+   * Returns the strip_include_prefix attribute
+   */
+  public String getStripIncludePrefix() { return this.stripIncludePrefix; }
+
   /**
    * Returns whether this target uses language features that require clang modules, such as
    * {@literal @}import.

src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java

@@ -307,6 +307,8 @@ private CompilationInfo compile(
       Collection<Artifact> privateHdrs,
       Collection<Artifact> publicHdrs,
       Artifact pchHdr,
+      String includePrefix,
+      String stripIncludePrefix,
       // TODO(b/70777494): Find out how deps get used and remove if not needed.
       Iterable<? extends TransitiveInfoCollection> deps,
       ObjcCppSemantics semantics,
@@ -341,6 +343,8 @@ private CompilationInfo compile(
                             .getCoptsForCompilationMode())
                     .addAll(extraCompileArgs)
                     .build())
+            .setIncludePrefix(includePrefix)
+            .setStripIncludePrefix(stripIncludePrefix)
             .addIncludeDirs(priorityHeaders)
             .addIncludeDirs(objcProvider.get(INCLUDE))
             .addSystemIncludeDirs(objcProvider.get(INCLUDE_SYSTEM))
@@ -405,6 +409,8 @@ private CompilationInfo compile(
             privateHdrs,
             publicHdrs,
             pchHdr,
+            attributes.getIncludePrefix(),
+            attributes.getStripIncludePrefix(),
             deps,
             semantics,
             purpose);
@@ -424,6 +430,8 @@ private CompilationInfo compile(
             privateHdrs,
             publicHdrs,
             pchHdr,
+            attributes.getIncludePrefix(),
+            attributes.getStripIncludePrefix(),
             deps,
             semantics,
             purpose);
@@ -464,8 +472,10 @@ private CompilationInfo compile(
     compilationOutputsBuilder.merge(objcArcCompilationInfo.getCcCompilationOutputs());
     compilationOutputsBuilder.merge(nonObjcArcCompilationInfo.getCcCompilationOutputs());
 
+    CcCompilationContext mergedCcCompilationContext = ccCompilationContextBuilder.build();
     LinkingInfo linkingInfo =
-        resultLink.link(compilationOutputsBuilder.build(), ccCompilationContextBuilder.build());
+        resultLink.link(compilationOutputsBuilder.build(), mergedCcCompilationContext);
+    ccCompilationContext = mergedCcCompilationContext;
 
     Map<String, NestedSet<Artifact>> mergedOutputGroups =
         CcCommon.mergeOutputGroups(
@@ -690,6 +700,7 @@ static Iterable<String> commonFrameworkNames(
   private final Map<String, NestedSet<Artifact>> outputGroupCollector;
   private final ImmutableList.Builder<Artifact> objectFilesCollector;
   private final CcToolchainProvider toolchain;
+  private CcCompilationContext ccCompilationContext;
   private final boolean isTestRule;
   private final boolean usePch;
 
@@ -743,6 +754,8 @@ private CompilationSupport(
     }
   }
 
+  public CcCompilationContext getCcCompilationContext() { return this.ccCompilationContext; }
+
   /** Builder for {@link CompilationSupport} */
   public static class Builder {
     private RuleContext ruleContext;

src/main/java/com/google/devtools/build/lib/rules/objc/ObjcLibrary.java

@@ -34,6 +34,7 @@
 import com.google.devtools.build.lib.rules.cpp.LinkerInputs.LibraryToLink;
 import com.google.devtools.build.lib.rules.objc.ObjcCommon.ResourceAttributes;
 import com.google.devtools.build.lib.syntax.Type;
+import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
 import java.util.Map;
 import java.util.TreeMap;
@@ -96,6 +97,8 @@ public ConfiguredTarget create(RuleContext ruleContext)
     J2ObjcEntryClassProvider j2ObjcEntryClassProvider = new J2ObjcEntryClassProvider.Builder()
       .addTransitive(ruleContext.getPrerequisites("deps", Mode.TARGET,
           J2ObjcEntryClassProvider.class)).build();
+    CcCompilationContext mergedCcCompilationContext = compilationSupport.getCcCompilationContext();
+
     CcCompilationContext ccCompilationContext =
         new CcCompilationContext.Builder(ruleContext)
             .addDeclaredIncludeSrcs(
@@ -105,9 +108,11 @@ public ConfiguredTarget create(RuleContext ruleContext)
                     .toCollection())
             .addTextualHdrs(common.getTextualHdrs())
             .addDeclaredIncludeSrcs(common.getTextualHdrs())
+            .mergeDependentCcCompilationContext(mergedCcCompilationContext,
+                /* mergeDeclaredIncludeSrcs= */ false)
             .build();
 
-    CcCompilationInfo.Builder ccCompilationInfoBuilder = CcCompilationInfo.Builder.create();
+        CcCompilationInfo.Builder ccCompilationInfoBuilder = CcCompilationInfo.Builder.create();
     ccCompilationInfoBuilder.setCcCompilationContext(ccCompilationContext);
 
     CcLinkParams ccLinkParams = buildCcLinkParams(common);

src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java

@@ -684,6 +684,31 @@ Enables clang module support (via -fmodules).
           provided module map to the compiler.
           <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
           .add(attr("module_map", LABEL).allowedFileTypes(FileType.of(".modulemap")))
+
+          /* <!-- #BLAZE_RULE($objc_compiling_rule).ATTRIBUTE(strip_include_prefix) -->
+          The prefix to strip from the paths of the headers of this rule.
+
+          <p>When set, the headers in the <code>hdrs</code> attribute of this rule are accessible
+          at their path with this prefix cut off.
+
+          <p>If it's a relative path, it's taken as a package-relative one. If it's an absolute one,
+          it's understood as a repository-relative path.
+
+          <p>The prefix in the <code>include_prefix</code> attribute is added after this prefix is
+          stripped.
+          <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+          .add(attr("strip_include_prefix", STRING))
+          /* <!-- #BLAZE_RULE($objc_compiling_rule).ATTRIBUTE(include_prefix) -->
+          The prefix to add to the paths of the headers of this rule.
+
+          <p>When set, the headers in the <code>hdrs</code> attribute of this rule are accessible
+          at is the value of this attribute prepended to their repository-relative path.
+
+          <p>The prefix in the <code>strip_include_prefix</code> attribute is removed before this
+          prefix is added.
+          <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+          .add(attr("include_prefix", STRING))
+
           /* Provides the label for header_scanner tool that is used to scan inclusions for ObjC
           sources and provide a list of required headers via a .header_list file.
 

src/test/shell/bazel/apple/bazel_objc_test.sh

@@ -117,4 +117,61 @@ EOF
       fail "Timestamp of contents of archive file should be zero"
 }
 
+function test_objc_library_include_prefix_external_repository() {
+  r="$TEST_TMPDIR/r"
+  mkdir -p "$TEST_TMPDIR/r/foo/v1"
+  touch "$TEST_TMPDIR/r/WORKSPACE"
+  echo "#define FOO 42" > "$TEST_TMPDIR/r/foo/v1/foo.h"
+  cat > "$TEST_TMPDIR/r/foo/BUILD" <<EOF
+objc_library(
+  name = "foo",
+  hdrs = ["v1/foo.h"],
+  include_prefix = "foolib",
+  strip_include_prefix = "v1",
+  visibility = ["//visibility:public"],
+)
+EOF
+
+  cat > WORKSPACE <<EOF
+local_repository(
+  name = "foo",
+  path = "$TEST_TMPDIR/r",
+)
+EOF
+
+  cat > BUILD <<EOF
+objc_library(
+  name = "ok",
+  srcs = ["ok.m"],
+  deps = ["@foo//foo"],
+)
+
+objc_library(
+  name = "bad",
+  srcs = ["bad.m"],
+  deps = ["@foo//foo"],
+)
+EOF
+
+  cat > ok.m <<EOF
+#include <stdio.h>
+#include "foolib/foo.h"
+int main() {
+  printf("FOO is %d\n", FOO);
+}
+EOF
+
+  cat > bad.m <<EOF
+#include <stdio.h>
+#include "foo/v1/foo.h"
+int main() {
+  printf("FOO is %d\n", FOO);
+}
+EOF
+
+  bazel build --sandbox_debug --verbose_failures -s :bad && fail "Should not have found include at repository-relative path"
+  bazel build --sandbox_debug --verbose_failures -s :ok || fail "Should have found include at synthetic path"
+}
+
+
 run_suite "objc/ios test suite"