Implement proto_common.create_proto_info in Starlark.

There is some confusion in naming of the fields in ProtoInfo, for example:
```
  ImmutableList<ProtoSource> directSources; // in Starlark .proto_sources (added)
  ImmutableList<Artifact> directProtoSources; // in Starlark .sources (was there before)
```

We need to keep old names in Starlark and create some new. The naming opportunity for the new Starlark names clashed with what was already used natively.

PiperOrigin-RevId: 410502067

src/main/java/com/google/devtools/build/lib/rules/proto/BazelProtoCommon.java

@@ -14,16 +14,14 @@
 
 package com.google.devtools.build.lib.rules.proto;
 
-import com.google.devtools.build.lib.analysis.starlark.StarlarkRuleContext;
-import com.google.devtools.build.lib.cmdline.Label;
-import com.google.devtools.build.lib.packages.BazelModuleContext;
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.collect.nestedset.Depset;
 import com.google.devtools.build.lib.starlarkbuildapi.proto.ProtoCommonApi;
-import javax.annotation.Nullable;
+import com.google.devtools.build.lib.vfs.PathFragment;
 import net.starlark.java.annot.Param;
 import net.starlark.java.annot.StarlarkMethod;
 import net.starlark.java.eval.EvalException;
-import net.starlark.java.eval.Module;
-import net.starlark.java.eval.Starlark;
+import net.starlark.java.eval.StarlarkList;
 import net.starlark.java.eval.StarlarkThread;
 
 /** Protocol buffers support for Starlark. */
@@ -33,26 +31,66 @@ public class BazelProtoCommon implements ProtoCommonApi {
   protected BazelProtoCommon() {}
 
   @StarlarkMethod(
-      name = "create_proto_info",
+      name = "ProtoSource",
       documented = false,
-      parameters = {@Param(name = "ctx", doc = "The rule context")},
-      useStarlarkThread = true,
-      allowReturnNones = true)
-  @Nullable
-  public ProtoInfo createProtoInfo(StarlarkRuleContext ruleContext, StarlarkThread thread)
+      parameters = {
+        @Param(name = "source_file", doc = "The proto file."),
+        @Param(name = "original_source_file", doc = "Original proto file."),
+        @Param(name = "proto_path", doc = "Path to proto file."),
+      },
+      useStarlarkThread = true)
+  public ProtoSource protoSource(
+      Artifact sourceFile, Artifact originalSourceFile, String sourceRoot, StarlarkThread thread)
       throws EvalException {
-    Label label =
-        ((BazelModuleContext) Module.ofInnermostEnclosingStarlarkFunction(thread).getClientData())
-            .label();
-    if (!label.getPackageIdentifier().getRepository().toString().equals("@_builtins")) {
-      throw Starlark.errorf("Rule in '%s' cannot use private API", label.getPackageName());
-    }
+    ProtoCommon.checkPrivateStarlarkificationAllowlist(thread);
+    return new ProtoSource(sourceFile, originalSourceFile, PathFragment.create(sourceRoot));
+  }
 
-    return ProtoCommon.createProtoInfo(
-        ruleContext.getRuleContext(),
-        ruleContext
-            .getRuleContext()
-            .getFragment(ProtoConfiguration.class)
-            .generatedProtosInVirtualImports());
+  @StarlarkMethod(
+      name = "ProtoInfo",
+      documented = false,
+      parameters = {
+        @Param(name = "direct_sources", doc = "Direct sources."),
+        @Param(name = "proto_path", doc = "Proto path."),
+        @Param(name = "transitive_sources", doc = "Transitive sources."),
+        @Param(name = "transitive_proto_sources", doc = "Transitive proto sources."),
+        @Param(name = "transitive_proto_path", doc = "Transitive proto path."),
+        @Param(name = "check_deps_sources", doc = "Check deps sources."),
+        @Param(name = "direct_descriptor_set", doc = "Direct descriptor set."),
+        @Param(name = "transitive_descriptor_set", doc = "Transitive descriptor sets."),
+        @Param(name = "exported_sources", doc = "Exported sources"),
+        @Param(name = "strict_importable_sources", doc = "Strict importable sources."),
+        @Param(name = "public_import_protos", doc = "Public import protos."),
+      },
+      useStarlarkThread = true)
+  @SuppressWarnings("unchecked")
+  public ProtoInfo protoInfo(
+      StarlarkList<? extends ProtoSource> directSources,
+      String directProtoSourceRoot,
+      Depset transitiveProtoSources,
+      Depset transitiveSources,
+      Depset transitiveProtoSourceRoots,
+      Depset strictImportableProtoSourcesForDependents,
+      Artifact directDescriptorSet,
+      Depset transitiveDescriptorSets,
+      Depset exportedSources,
+      Depset strictImportableSources,
+      Depset publicImportSources,
+      StarlarkThread thread)
+      throws EvalException {
+    ProtoCommon.checkPrivateStarlarkificationAllowlist(thread);
+    return new ProtoInfo(
+        ((StarlarkList<ProtoSource>) directSources).getImmutableList(),
+        PathFragment.create(directProtoSourceRoot),
+        Depset.cast(transitiveSources, ProtoSource.class, "transitive_sources"),
+        Depset.cast(transitiveProtoSources, Artifact.class, "transitive_proto_sources"),
+        Depset.cast(transitiveProtoSourceRoots, String.class, "transitive_proto_path"),
+        Depset.cast(
+            strictImportableProtoSourcesForDependents, Artifact.class, "check_deps_sources"),
+        directDescriptorSet,
+        Depset.cast(transitiveDescriptorSets, Artifact.class, "transitive_descriptor_set"),
+        Depset.cast(exportedSources, ProtoSource.class, "exported_sources"),
+        Depset.cast(strictImportableSources, ProtoSource.class, "strict_importable_sources"),
+        Depset.cast(publicImportSources, ProtoSource.class, "public_import_protos"));
   }
 }

src/main/java/com/google/devtools/build/lib/rules/proto/ProtoConfiguration.java

@@ -285,6 +285,16 @@ public boolean strictPublicImports() {
     return options.experimentalJavaProtoAddAllowedPublicImports;
   }
 
+  @StarlarkMethod(
+      name = "generated_protos_in_virtual_imports",
+      useStarlarkThread = true,
+      documented = false)
+  public boolean generatedProtosInVirtualImportsForStarlark(StarlarkThread thread)
+      throws EvalException {
+    ProtoCommon.checkPrivateStarlarkificationAllowlist(thread);
+    return generatedProtosInVirtualImports();
+  }
+
   public boolean generatedProtosInVirtualImports() {
     return options.generatedProtosInVirtualImports;
   }

src/main/java/com/google/devtools/build/lib/rules/proto/ProtoInfo.java

@@ -209,6 +209,12 @@ public NestedSet<Artifact> getTransitiveDescriptorSets() {
     return transitiveDescriptorSets;
   }
 
+  @Override
+  public Depset getExportedSourcesForStarlark(StarlarkThread thread) throws EvalException {
+    ProtoCommon.checkPrivateStarlarkificationAllowlist(thread);
+    return Depset.of(ProtoSource.TYPE, getExportedSources());
+  }
+
   /**
    * Returns a set of {@code .proto} sources that may be imported by {@code proto_library} targets
    * directly depending on this {@code ProtoInfo}.

src/main/java/com/google/devtools/build/lib/rules/proto/ProtoSource.java

@@ -82,4 +82,9 @@ public PathFragment getImportPath() {
   public String toString() {
     return "ProtoSource('" + getImportPath() + "')";
   }
+
+  @Override
+  public boolean isImmutable() {
+    return true;
+  }
 }

src/main/java/com/google/devtools/build/lib/starlarkbuildapi/ProtoInfoApi.java

@@ -113,4 +113,7 @@ interface ProtoInfoProviderApi extends ProviderApi {
 
   @StarlarkMethod(name = "transitive_proto_sources", documented = false, useStarlarkThread = true)
   Depset getTransitiveSourcesForStarlark(StarlarkThread thread) throws EvalException;
+
+  @StarlarkMethod(name = "exported_sources", documented = false, useStarlarkThread = true)
+  Depset getExportedSourcesForStarlark(StarlarkThread thread) throws EvalException;
 }

src/main/starlark/builtins_bzl/common/proto/proto_common.bzl

@@ -17,8 +17,125 @@ Definition of proto_common module.
 """
 
 load(":common/proto/proto_semantics.bzl", "semantics")
+load(":common/paths.bzl", "paths")
 
 ProtoInfo = _builtins.toplevel.ProtoInfo
+native_proto_common = _builtins.toplevel.proto_common
+
+def _join(*path):
+    return "/".join([p for p in path if p != ""])
+
+def _create_proto_info(ctx):
+    srcs = ctx.files.srcs
+    deps = [dep[ProtoInfo] for dep in ctx.attr.deps]
+    exports = [dep[ProtoInfo] for dep in ctx.attr.exports]
+
+    import_prefix = ctx.attr.import_prefix if hasattr(ctx.attr, "import_prefix") else ""
+    if not paths.is_normalized(import_prefix):
+        fail("should be normalized (without uplevel references or '.' path segments)", attr = "import_prefix")
+
+    strip_import_prefix = ctx.attr.strip_import_prefix
+    if not paths.is_normalized(strip_import_prefix):
+        fail("should be normalized (without uplevel references or '.' path segments)", attr = "strip_import_prefix")
+    if strip_import_prefix.startswith("/"):
+        strip_import_prefix = strip_import_prefix[1:]
+    elif strip_import_prefix != "DO_NOT_STRIP":  # Relative to current package
+        strip_import_prefix = _join(ctx.label.package, strip_import_prefix)
+    else:
+        strip_import_prefix = ""
+
+    has_generated_sources = False
+    if ctx.fragments.proto.generated_protos_in_virtual_imports():
+        has_generated_sources = any([not src.is_source for src in srcs])
+
+    direct_sources = []
+    if import_prefix != "" or strip_import_prefix != "" or has_generated_sources:
+        # Use virtual source roots
+        if paths.is_absolute(import_prefix):
+            fail("should be a relative path", attr = "import_prefix")
+
+        virtual_imports = _join("_virtual_imports", ctx.label.name)
+        if ctx.label.workspace_name == "" or ctx.label.workspace_root.startswith(".."):  # siblingRepositoryLayout
+            proto_path = _join(ctx.genfiles_dir.path, ctx.label.package, virtual_imports)
+        else:
+            proto_path = _join(ctx.genfiles_dir.path, ctx.label.workspace_root, ctx.label.package, virtual_imports)
+
+        for src in srcs:
+            if ctx.label.workspace_name == "":
+                repository_relative_path = src.short_path
+            else:
+                repository_relative_path = paths.relativize(src.short_path, "../" + ctx.label.workspace_name)
+
+            if not repository_relative_path.startswith(strip_import_prefix):
+                fail(".proto file '%s' is not under the specified strip prefix '%s'" %
+                     (src.short_path, strip_import_prefix))
+            import_path = repository_relative_path[len(strip_import_prefix):]
+
+            virtual_src = ctx.actions.declare_file(_join(virtual_imports, import_prefix, import_path))
+            ctx.actions.symlink(
+                output = virtual_src,
+                target_file = src,
+                progress_message = "Symlinking virtual .proto sources for %{label}",
+            )
+            direct_sources.append(native_proto_common.ProtoSource(virtual_src, src, proto_path))
+
+    else:
+        # No virtual source roots
+        proto_path = "."
+        for src in srcs:
+            direct_sources.append(native_proto_common.ProtoSource(src, src, ctx.label.workspace_root + src.root.path))
+
+    # Construct ProtoInfo
+    transitive_proto_sources = depset(
+        direct = direct_sources,
+        transitive = [dep.transitive_proto_sources() for dep in deps],
+        order = "preorder",
+    )
+    transitive_sources = depset(
+        direct = [src.source_file() for src in direct_sources],
+        transitive = [dep.transitive_sources for dep in deps],
+        order = "preorder",
+    )
+    transitive_proto_path = depset(
+        direct = [proto_path],
+        transitive = [dep.transitive_proto_path for dep in deps],
+    )
+    if direct_sources:
+        check_deps_sources = depset(direct = [src.source_file() for src in direct_sources])
+    else:
+        check_deps_sources = depset(transitive = [dep.check_deps_sources for dep in deps])
+
+    direct_descriptor_set = ctx.actions.declare_file(ctx.label.name + "-descriptor-set.proto.bin")
+    transitive_descriptor_sets = depset(
+        direct = [direct_descriptor_set],
+        transitive = [dep.transitive_descriptor_sets for dep in deps],
+    )
+
+    # Layering checks.
+    if direct_sources:
+        exported_sources = depset(direct = direct_sources)
+        strict_importable_sources = depset(
+            direct = direct_sources,
+            transitive = [dep.exported_sources() for dep in deps],
+        )
+    else:
+        exported_sources = depset(transitive = [dep.exported_sources() for dep in deps])
+        strict_importable_sources = depset()
+    public_import_protos = depset(transitive = [export.exported_sources() for export in exports])
+
+    return native_proto_common.ProtoInfo(
+        direct_sources,
+        proto_path,
+        transitive_sources,
+        transitive_proto_sources,
+        transitive_proto_path,
+        check_deps_sources,
+        direct_descriptor_set,
+        transitive_descriptor_sets,
+        exported_sources,
+        strict_importable_sources,
+        public_import_protos,
+    )
 
 def _write_descriptor_set(ctx, proto_info):
     output = proto_info.direct_descriptor_set
@@ -83,5 +200,6 @@ def _ExpandImportArgsFn(proto_source):
     return "-I%s=%s" % (proto_source.import_path(), proto_source.source_file().path)
 
 proto_common = struct(
+    create_proto_info = _create_proto_info,
     write_descriptor_set = _write_descriptor_set,
 )

src/main/starlark/builtins_bzl/common/proto/proto_library.bzl

@@ -20,7 +20,6 @@ load(":common/proto/proto_semantics.bzl", "semantics")
 load(":common/proto/proto_common.bzl", "proto_common")
 
 ProtoInfo = _builtins.toplevel.ProtoInfo
-native_proto_common = _builtins.toplevel.proto_common
 
 def _check_srcs_package(target_package, srcs):
     """Makes sure the given srcs live in the given package."""
@@ -33,7 +32,7 @@ def _proto_library_impl(ctx):
 
     _check_srcs_package(ctx.label.package, ctx.attr.srcs)
 
-    proto_info = native_proto_common.create_proto_info(ctx)
+    proto_info = proto_common.create_proto_info(ctx)
 
     proto_common.write_descriptor_set(ctx, proto_info)
 
@@ -64,7 +63,7 @@ proto_library = rule(
         "exports": attr.label_list(
             providers = [ProtoInfo],
         ),
-        "strip_import_prefix": attr.string(),
+        "strip_import_prefix": attr.string(default = "DO_NOT_STRIP"),
         "data": attr.label_list(
             allow_files = True,
             flags = ["SKIP_CONSTRAINTS_OVERRIDE"],