Modify Crubit to natively generate inline_cpp! and global_cpp!

PiperOrigin-RevId: 949213817

Author: andrewle10

Cargo.lock

@@ -30,6 +30,7 @@ clap.workspace = true
 itertools.workspace = true
 crubit_feature = { path = "../../../cargo/common/crubit_feature"}
 flagset.workspace = true
+quote.workspace = true
 rustversion.workspace = true
 [dev-dependencies]
 run_compiler_test_support = { path = "../../../cargo/cc_bindings_from_rs/run_compiler_test_support", package = "cc_bindings_from_rs_run_compiler_test_support"}

cargo/cc_bindings_from_rs/cpp_api_from_rust_lib/Cargo.toml

@@ -39,6 +39,7 @@ rust_library(
         "@crate_index//:clap",  # v4
         "@crate_index//:flagset",  # v0_4
         "@crate_index//:itertools",  # v0_13
+        "@crate_index//:quote",  # v1
     ],
 )
 

cc_bindings_from_rs/BUILD

@@ -73,13 +73,14 @@ def get_additional_cc_hdrs_and_srcs(aspect_hints):
     """Returns any additional C++ headers and sources that should be compiled with the generated bindings.
 
     Args:
-        aspect_ctx: The ctx from an aspect_hint.
+        aspect_hints: A list of aspect hints (Target list).
 
     Returns:
         A list of `File` and its module paths as specified by the `extra_rs_srcs`.
     """
     additional_cc_hdrs = []
     additional_cc_srcs = []
+
     for hint in aspect_hints:
         if CcBindingsFromRustLibraryConfigInfo in hint:
             for target in hint[CcBindingsFromRustLibraryConfigInfo].extra_cc_hdrs:

cc_bindings_from_rs/bazel_support/cc_bindings_from_rust_library_config_aspect_hint.bzl

@@ -261,6 +261,7 @@ def _generate_bindings(ctx, dep_bindings_infos, config, label, features, cli_fla
         crubit_args.add("--source-crate-name", self_crate_name)
         if self_rmeta != None:
             crubit_args.add("--extern={}={}".format(self_crate_name, self_rmeta.path))
+
     crubit_args.add("--enable-rmeta-interface")
     is_golden_test = is_golden_test_override if is_golden_test_override != None else ctx.attr._is_golden_test[BuildSettingInfo].value
     if is_golden_test:
@@ -393,6 +394,8 @@ def _cc_bindings_from_rust_aspect_impl(target, ctx):
 
     if CrateInfo not in target:
         return []
+    if CcBindingsFromRustInfo in target:
+        return []
     if str(target.label) in targets_to_remove:
         return []
 
@@ -486,6 +489,11 @@ def _cc_bindings_from_rust_aspect_impl(target, ctx):
         aspect_hints = ctx.rule.attr.aspect_hints,
         rust_infos = dep_bindings_infos,
     )
+    (extra_cc_hdrs, extra_cc_srcs) = get_additional_cc_hdrs_and_srcs(ctx.rule.attr.aspect_hints)
+    for hdr in extra_cc_hdrs:
+        if hdr.short_path.endswith("_extracted_cc.h"):
+            cli_flags.append("--extra-rs-srcs-include=" + hdr.short_path)
+
     bindings_info, features, config, output_depset = _generate_bindings(
         ctx,
         dep_bindings_infos = dep_bindings_infos,
@@ -504,8 +512,6 @@ def _cc_bindings_from_rust_aspect_impl(target, ctx):
 
     dep_variant_info = _compile_rs_out_file(ctx, ctx.rule.attr, bindings_info.rust_file, target[CrateInfo].name, [target])
 
-    (extra_cc_hdrs, extra_cc_srcs) = get_additional_cc_hdrs_and_srcs(ctx.rule.attr.aspect_hints)
-
     cc_info = _make_cc_info_for_h_out_file(
         ctx,
         bindings_info.h_file,

cc_bindings_from_rs/bazel_support/cc_bindings_from_rust_rule.bzl

@@ -141,6 +141,14 @@ pub struct Cmdline {
            value_name = "CRATE_NAME=RENAMED")]
     pub crate_rename: Vec<(String, String)>,
 
+    /// Extra headers to `#include` and re-export via IWYU in the generated C++ API header.
+    ///
+    /// Re-exports user headers required by embedded C++ declarations (such as `inline_cpp!`).
+    /// This ensures C++ callers using the generated C++ API header automatically receive
+    /// the necessary includes for those types without encountering missing symbol errors.
+    #[clap(long = "extra-rs-srcs-include", value_name = "FILE")]
+    pub extra_rs_srcs_includes: Vec<String>,
+
     /// The name of the crate to generate bindings for.
     ///
     /// If provided, this value must correspond to the name of an extern crate provided to the

cc_bindings_from_rs/cmdline.rs

@@ -19,7 +19,7 @@ use rustc_middle::ty::TyCtxt;
 use rustc_session::config::OptionsTargetModifiers;
 
 use arc_anyhow::{bail, Context, Result};
-use std::collections::{HashMap, HashSet};
+use std::collections::{BTreeSet, HashMap, HashSet};
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
 
@@ -121,11 +121,24 @@ fn run_with_tcx(cmdline: &Cmdline, tcx: TyCtxt) -> Result<()> {
         ErrorReport::new_rc_or_ignore(generate_error_report, SourceLanguage::Rust);
     let fatal_errors = Rc::new(FatalErrors::new());
 
-    let BindingsTokens { cc_api, cc_api_impl } = {
+    let BindingsTokens { mut cc_api, cc_api_impl } = {
         let db = new_db(cmdline, tcx, errors, fatal_errors.clone());
         generate_bindings(&db)?
     };
 
+    if !cmdline.extra_rs_srcs_includes.is_empty() {
+        let extra_includes: BTreeSet<CcInclude> = cmdline
+            .extra_rs_srcs_includes
+            .iter()
+            .map(|include| CcInclude::exported_user_header(include.as_str().into()))
+            .collect();
+        let extra_includes_tokens = code_gen_utils::format_cc_includes(&extra_includes);
+        cc_api = quote::quote! {
+            #extra_includes_tokens
+            #cc_api
+        };
+    }
+
     let fatal_error_message = fatal_errors.take_string();
     if !fatal_error_message.is_empty() {
         return Err(arc_anyhow::Error::msg(fatal_error_message));

cc_bindings_from_rs/lib.rs

@@ -959,6 +959,8 @@ pub enum CcInclude {
     /// format specifier for what comes after `#include` and path of the support
     /// library header.
     SupportLibHeader(Format<1>, Rc<str>),
+    /// Represents a user header which should be re-exported by IWYU.
+    ExportedUserHeader(Rc<str>),
 }
 
 impl CcInclude {
@@ -1043,6 +1045,11 @@ impl CcInclude {
         Self::UserHeader(path)
     }
 
+    /// Creates a user include: `#include "some/path/to/header.h" // IWYU pragma: export`
+    pub fn exported_user_header(path: Rc<str>) -> Self {
+        Self::ExportedUserHeader(path)
+    }
+
     /// Creates a `CcInclude` and detects whether it's a system header or a user
     /// header based on the path.
     ///
@@ -1074,6 +1081,9 @@ impl ToTokens for CcInclude {
             Self::UserHeader(path) => {
                 quote! { __HASH_TOKEN__ include #path __NEWLINE__ }.to_tokens(tokens)
             }
+            Self::ExportedUserHeader(path) => {
+                quote! { __HASH_TOKEN__ include #path __COMMENT__ "IWYU pragma: export" __NEWLINE__ }.to_tokens(tokens)
+            }
             Self::SupportLibHeader(format, path) => {
                 let full_path: TokenStream = format
                     .format(&[&*path])

common/code_gen_utils.rs

@@ -135,6 +135,10 @@ ABSL_FLAG(std::string, template_blocklist_path_regex, "",
           "If nonempty, do not instantiate templates defined in files with "
           "paths matching this llvm::Regex.");
 
+ABSL_FLAG(bool, carcinize, false,
+          "If true, enables the carcinize pipeline for automated porting, "
+          "which emits inline_cpp! blocks and modifies structure.");
+
 namespace crubit {
 
 namespace {
@@ -253,6 +257,7 @@ absl::StatusOr<Cmdline> Cmdline::FromFlags() {
       .do_not_bind_allowlist = absl::GetFlag(FLAGS_do_not_bind_allowlist),
       .template_blocklist_path_regex =
           absl::GetFlag(FLAGS_template_blocklist_path_regex),
+      .carcinize = absl::GetFlag(FLAGS_carcinize),
   };
 
   absl::Status parse_target_args_status =

rs_bindings_from_cc/cmdline.cc

@@ -59,6 +59,7 @@ struct CmdlineArgs {
   std::optional<std::vector<std::string>> do_not_bind_allowlist;
 
   std::string template_blocklist_path_regex;
+  bool carcinize = false;
 };
 
 // A valid command line invocation.