Use include guard instead of pragma once.
PiperOrigin-RevId: 672718959
Change-Id: Ie0dd3e2f37d6c2f421bba14bcc7b3a994340a257
diff --git a/cc_bindings_from_rs/bindings.rs b/cc_bindings_from_rs/bindings.rs
index de8f624..964e7cd 100644
--- a/cc_bindings_from_rs/bindings.rs
+++ b/cc_bindings_from_rs/bindings.rs
@@ -80,6 +80,9 @@
#[input]
fn no_thunk_name_mangling(&self) -> bool;
+ #[input]
+ fn h_out_include_guard(&self) -> IncludeGuard;
+
fn support_header(&self, suffix: &'tcx str) -> CcInclude;
fn repr_attrs(&self, did: DefId) -> Rc<[rustc_attr::ReprAttr]>;
@@ -112,6 +115,12 @@
pub struct Database;
}
+#[derive(Clone, Debug)]
+pub enum IncludeGuard {
+ PragmaOnce,
+ Guard(String),
+}
+
fn support_header<'tcx>(db: &dyn BindingsGenerator<'tcx>, suffix: &'tcx str) -> CcInclude {
CcInclude::support_lib_header(db.crubit_support_path_format(), suffix.into())
}
@@ -121,6 +130,29 @@
pub rs_body: TokenStream,
}
+fn add_include_guard(db: &dyn BindingsGenerator<'_>, h_body: TokenStream) -> Result<TokenStream> {
+ match db.h_out_include_guard() {
+ IncludeGuard::PragmaOnce => Ok(quote! {
+ __HASH_TOKEN__ pragma once __NEWLINE__
+ __NEWLINE__
+
+ #h_body
+ }),
+ IncludeGuard::Guard(include_guard_str) => {
+ let include_guard = format_cc_ident(include_guard_str.as_str())?;
+ Ok(quote! {
+ __HASH_TOKEN__ ifndef #include_guard __NEWLINE__
+ __HASH_TOKEN__ define #include_guard __NEWLINE__
+ __NEWLINE__
+
+ #h_body
+
+ __HASH_TOKEN__ endif __COMMENT__ #include_guard_str __NEWLINE__
+ })
+ }
+ }
+}
+
pub fn generate_bindings(db: &Database) -> Result<Output> {
let tcx = db.tcx();
@@ -151,14 +183,10 @@
let src = quote! { __COMMENT__ #txt };
Output { h_body: src.clone(), rs_body: src }
});
-
+ let h_body = add_include_guard(db, h_body)?;
let h_body = quote! {
#top_comment
- // TODO(b/251445877): Replace `#pragma once` with include guards.
- __HASH_TOKEN__ pragma once __NEWLINE__
- __NEWLINE__
-
#h_body
};
@@ -9586,6 +9614,7 @@
/* crate_name_to_features= */ Default::default(),
/* errors = */ Rc::new(IgnoreErrors),
/* no_thunk_name_mangling= */ false,
+ /* include_guard */ IncludeGuard::PragmaOnce,
)
}
diff --git a/cc_bindings_from_rs/cc_bindings_from_rs.rs b/cc_bindings_from_rs/cc_bindings_from_rs.rs
index a2ff39f..476ef3c 100644
--- a/cc_bindings_from_rs/cc_bindings_from_rs.rs
+++ b/cc_bindings_from_rs/cc_bindings_from_rs.rs
@@ -15,7 +15,7 @@
use std::path::Path;
use std::rc::Rc;
-use bindings::Database;
+use bindings::{Database, IncludeGuard};
use cmdline::Cmdline;
use code_gen_utils::CcInclude;
use error_report::{ErrorReport, ErrorReporting, IgnoreErrors};
@@ -25,7 +25,10 @@
};
fn turn_off_clang_format(mut h_body: String) -> String {
- h_body.insert_str(h_body.find("#pragma once").unwrap(), "// clang-format off\n");
+ h_body.insert_str(
+ h_body.find("#ifndef").unwrap_or_else(|| h_body.find("#pragma once").unwrap()),
+ "// clang-format off\n",
+ );
h_body
}
@@ -54,7 +57,11 @@
crate_name_to_features.entry(crate_name.as_str().into()).or_default();
*accumulated_features |= *features
}
-
+ let include_guard = if let Some(include_guard) = &cmdline.h_out_include_guard {
+ IncludeGuard::Guard(include_guard.clone())
+ } else {
+ IncludeGuard::PragmaOnce
+ };
Database::new(
tcx,
crubit_support_path_format,
@@ -62,6 +69,7 @@
crate_name_to_features.into(),
errors,
cmdline.no_thunk_name_mangling,
+ include_guard,
)
}
@@ -159,6 +167,7 @@
extra_rustc_args: Vec<String>,
tempdir: TempDir,
+ include_guard: Option<String>,
}
/// Result of `TestArgs::run` that helps tests access test outputs (e.g. the
@@ -180,6 +189,7 @@
panic_mechanism: "abort".to_string(),
extra_rustc_args: vec![],
tempdir: tempdir()?,
+ include_guard: None,
})
}
@@ -223,6 +233,11 @@
self
}
+ fn with_include_guard(mut self, include_guard: &str) -> Self {
+ self.include_guard = Some(include_guard.to_string());
+ self
+ }
+
/// Invokes `super::run_with_cmdline_args` with default `test_crate.rs`
/// input (and with other default args + args gathered by
/// `self`).
@@ -269,6 +284,11 @@
error_report_out_path.as_ref().unwrap().display()
));
}
+
+ if let Some(include_guard) = &self.include_guard {
+ args.push(format!("--h-out-include-guard={include_guard}"));
+ }
+
args.extend(self.extra_crubit_args.iter().cloned());
args.extend([
"--".to_string(),
@@ -361,6 +381,55 @@
}
#[test]
+ fn test_with_include_guard() -> Result<()> {
+ let test_args =
+ TestArgs::default_args()?.with_include_guard("CRUBIT_GENERATED_HEADER_FOR_test_crate_");
+ let test_result = test_args.run().expect("Customized include guard should succeed");
+
+ assert!(test_result.h_path.exists());
+ let temp_dir_str = test_args.tempdir.path().to_str().unwrap();
+ let h_body = std::fs::read_to_string(&test_result.h_path)?;
+ #[rustfmt::skip]
+ assert_body_matches(
+ &h_body,
+ &format!(
+ "{}\n{}\n{}",
+r#"// Automatically @generated C++ bindings for the following Rust crate:
+// test_crate
+// Features: <none>
+
+// clang-format off
+#ifndef CRUBIT_GENERATED_HEADER_FOR_test_crate_
+#define CRUBIT_GENERATED_HEADER_FOR_test_crate_
+
+namespace test_crate {
+
+namespace public_module {
+"#,
+ // TODO(b/261185414): Avoid assuming that all source code paths are google3 paths.
+format!("// Generated from: google3/{temp_dir_str}/test_crate.rs;l=2"),
+r#"void public_function();
+
+namespace __crubit_internal {
+extern "C" void
+__crubit_thunk__ANY_IDENTIFIER_CHARACTERS();
+}
+inline void public_function() {
+ return __crubit_internal::
+ __crubit_thunk__ANY_IDENTIFIER_CHARACTERS();
+}
+
+} // namespace public_module
+
+} // namespace test_crate
+#endif // CRUBIT_GENERATED_HEADER_FOR_test_crate_
+"#
+ ),
+ );
+ Ok(())
+ }
+
+ #[test]
fn test_happy_path() -> Result<()> {
let test_args = TestArgs::default_args()?;
let test_result = test_args.run().expect("Default args should succeed");
diff --git a/cc_bindings_from_rs/cmdline.rs b/cc_bindings_from_rs/cmdline.rs
index f792695..4282254 100644
--- a/cc_bindings_from_rs/cmdline.rs
+++ b/cc_bindings_from_rs/cmdline.rs
@@ -22,6 +22,10 @@
#[clap(long, value_parser, value_name = "FILE")]
pub h_out: PathBuf,
+ /// Include guard for the C++ header file with bindings.
+ #[clap(long, value_parser, value_name = "STRING")]
+ pub h_out_include_guard: Option<String>,
+
/// Output path for Rust implementation of the bindings.
#[clap(long, value_parser, value_name = "FILE")]
pub rs_out: PathBuf,
@@ -259,6 +263,9 @@
--h-out <FILE>
Output path for C++ header file with bindings
+ --h-out-include-guard <STRING>
+ Include guard for the C++ header file with bindings
+
--rs-out <FILE>
Output path for Rust implementation of the bindings
