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Merged
Shnatsel merged 3 commits into from
Oct 19, 2025
Merged

Do not assume --crate-name and --out-dir are present in the rustc com… #228

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863de9b
Do not assume --crate-name and --out-dir are present in the rustc com…
Shnatsel Oct 18, 2025
b0e2bef
Satisfy clippy
Shnatsel Oct 18, 2025
ddb6551
Out out of unhelpful clippy lint
Shnatsel Oct 18, 2025
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172 changes: 100 additions & 72 deletions cargo-auditable/src/rustc_wrapper.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -14,78 +14,10 @@ use crate::{
use std::io::BufRead;

pub fn main(rustc_path: &OsStr) {
let mut command = rustc_command(rustc_path);

// Binaries and C dynamic libraries are not built as non-primary packages,
// so this should not cause issues with Cargo caches.
if env::var_os("CARGO_PRIMARY_PACKAGE").is_some() {
let args = rustc_arguments::parse_args().unwrap(); // descriptive enough message
if should_embed_audit_data(&args) {
// Get the audit data to embed
let target_triple = args
.target
.clone()
.unwrap_or_else(|| rustc_host_target_triple(rustc_path));
let contents: Vec<u8> =
collect_audit_data::compressed_dependency_list(&args, &target_triple);
// write the audit info to an object file
let target_info = target_info::rustc_target_info(rustc_path, &target_triple);
let binfile = binary_file::create_binary_file(
&target_info,
&target_triple,
&contents,
"AUDITABLE_VERSION_INFO",
);
if let Some(file) = binfile {
// Place the audit data in the output dir.
// We can place it anywhere really, the only concern is clutter and name collisions,
// and the target dir is locked so we're probably good
let filename = format!(
"{}_audit_data.o",
args.crate_name
.as_ref()
.expect("rustc command is missing --crate-name")
);
let path = args
.out_dir
.as_ref()
.expect("rustc command is missing --out-dir")
.join(filename);
std::fs::write(&path, file).expect("Unable to write output file");

// Modify the rustc command to link the object file with audit data
let mut linker_command = OsString::from("-Clink-arg=");
linker_command.push(&path);
command.arg(linker_command);
// Prevent the symbol from being removed as unused by the linker
if is_apple(&target_info) {
if args.bare_linker() {
command.arg("-Clink-arg=-u,_AUDITABLE_VERSION_INFO");
} else {
command.arg("-Clink-arg=-Wl,-u,_AUDITABLE_VERSION_INFO");
}
} else if is_msvc(&target_info) {
command.arg("-Clink-arg=/INCLUDE:AUDITABLE_VERSION_INFO");
} else if is_wasm(&target_info) {
// We don't emit the symbol name in WASM, so nothing to do
} else {
// Unrecognized platform, assume it to be unix-like
#[allow(clippy::collapsible_else_if)]
if args.bare_linker() {
command.arg("-Clink-arg=--undefined=AUDITABLE_VERSION_INFO");
} else {
command.arg("-Clink-arg=-Wl,--undefined=AUDITABLE_VERSION_INFO");
}
}
} else {
// create_binary_file() returned None, indicating an unsupported architecture
eprintln!(
"WARNING: target '{target_triple}' is not supported by 'cargo auditable'!\n\
The build will continue, but no audit data will be injected into the binary."
);
}
}
}
let mut command = match rustc_command_with_audit_data(rustc_path) {
Some(cmd) => cmd,
None => rustc_command(rustc_path), // could not construct command that injects audit data, skip it
};

// Invoke rustc
let results = command.status().unwrap_or_else(|err| {
Expand Down Expand Up @@ -127,3 +59,99 @@ fn rustc_host_target_triple(rustc_path: &OsStr) -> String {
.map(|l| l[6..].to_string())
.expect("Failed to parse rustc output to determine the current platform. Please report this bug!")
}

fn rustc_command_with_audit_data(rustc_path: &OsStr) -> Option<Command> {
let mut command = rustc_command(rustc_path);

// Only inject audit data if CARGO_PRIMARY_PACKAGE is set.
// This allows linking audit data only in toplevel binaries, not intermediate artifacts.
//
// Binaries and C dynamic libraries are not built as non-primary packages,
// so this should not cause issues with Cargo caches.
#[allow(clippy::question_mark)]
if env::var_os("CARGO_PRIMARY_PACKAGE").is_none() {
return None;
}
let args = rustc_arguments::parse_args().unwrap(); // descriptive enough message
if !should_embed_audit_data(&args) {
return None;
}
// Get the audit data to embed
let target_triple = args
.target
.clone()
.unwrap_or_else(|| rustc_host_target_triple(rustc_path));
let contents: Vec<u8> = collect_audit_data::compressed_dependency_list(&args, &target_triple);

// write the audit info to an object file
let target_info = target_info::rustc_target_info(rustc_path, &target_triple);
let binfile = binary_file::create_binary_file(
&target_info,
&target_triple,
&contents,
"AUDITABLE_VERSION_INFO",
);
if let Some(file) = binfile {
// Place the audit data in the output dir.
// We can place it anywhere really, the only concern is clutter and name collisions,
// and the target dir is locked so we're probably good
let crate_name = match args.crate_name.as_deref() {
Some(name) => name,
None => {
eprintln!(
"WARNING: cargo-auditable: rustc command is missing --crate-name\n\
Please double-check that the audit data was injected into the binary.\n\
If it wasn't, please report a bug."
);
return None;
}
};
let out_dir = match args.out_dir.as_deref() {
Some(name) => name,
None => {
eprintln!(
"WARNING: cargo-auditable: rustc command is missing --out-dir\n\
Please double-check that the audit data was injected into the binary.\n\
If it wasn't, please report a bug."
);
return None;
}
};
let filename = format!("{crate_name}_audit_data.o");
let path = out_dir.join(filename);
std::fs::write(&path, file).expect("Unable to write output file");

// Modify the rustc command to link the object file with audit data
let mut linker_command = OsString::from("-Clink-arg=");
linker_command.push(&path);
command.arg(linker_command);
// Prevent the symbol from being removed as unused by the linker
if is_apple(&target_info) {
if args.bare_linker() {
command.arg("-Clink-arg=-u,_AUDITABLE_VERSION_INFO");
} else {
command.arg("-Clink-arg=-Wl,-u,_AUDITABLE_VERSION_INFO");
}
} else if is_msvc(&target_info) {
command.arg("-Clink-arg=/INCLUDE:AUDITABLE_VERSION_INFO");
} else if is_wasm(&target_info) {
// We don't emit the symbol name in WASM, so nothing to do
} else {
// Unrecognized platform, assume it to be unix-like
#[allow(clippy::collapsible_else_if)]
if args.bare_linker() {
command.arg("-Clink-arg=--undefined=AUDITABLE_VERSION_INFO");
} else {
command.arg("-Clink-arg=-Wl,--undefined=AUDITABLE_VERSION_INFO");
}
}
Some(command)
} else {
// create_binary_file() returned None, indicating an unsupported architecture
eprintln!(
"WARNING: cargo-auditable: target '{target_triple}' is not supported!\n\
The build will continue, but no audit data will be injected into the binary."
);
None
}
}
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