transpile: tests: cross-transpile

.github/workflows/ci.yml

@@ -32,9 +32,17 @@ jobs:
 
       - name: Install Python Packages
         run: |
+          uv python install 3.14
+          uv run python -V
+
           uv venv
           uv pip install -r ./scripts/requirements.txt
 
+          # `zig cc` needed for cross-compilation
+          uv tool install ziglang
+          ln -s $(which python-zig) $(dirname $(which python-zig))/zig
+          zig version
+
       # rust-cache very carefully caches toolchains and target directories,
       # based on the job and toolchain and other factors. See
       # https://github.com/Swatinem/rust-cache#cache-details for what gets
@@ -47,6 +55,17 @@ jobs:
       # Run after `rust-cache` so that this is cached.
       - run: rustup component add rustfmt rustc-dev
 
+      - name: Install generated Rust targets
+        run: |
+          rustup +nightly-2023-04-15 target add \
+            x86_64-unknown-linux-gnu \
+            x86_64-apple-darwin \
+            aarch64-unknown-linux-gnu \
+            aarch64-apple-darwin \
+            i686-unknown-linux-gnu \
+            armv7-unknown-linux-gnueabihf \
+            riscv64gc-unknown-linux-gnu
+
       - name: cargo fmt --check
         run: |
           export RUSTFLAGS="$RUSTFLAGS -D warnings"
@@ -98,7 +117,6 @@ jobs:
           # It's important that we keep `RUSTFLAGS` consistent between different steps
           # so that we don't have to rebuild everything.
           echo "RUSTFLAGS=-Clink-arg=-L/opt/homebrew/lib -Clink-arg=-Wl,-rpath,/opt/homebrew/lib" >> $GITHUB_ENV
-
 
       - name: cargo build --release
         run: |

c2rust-transpile/Cargo.toml

@@ -45,3 +45,4 @@ llvm-static = ["c2rust-ast-exporter/llvm-static"]
 
 [dev-dependencies]
 insta = { version = "1.43.2", features = ["glob"] }
+shell-words = "1.1.0"

c2rust-transpile/src/build_files/mod.rs

@@ -2,7 +2,8 @@ use std::collections::BTreeMap;
 use std::fs::{self, File};
 use std::io::Write;
 use std::path::{Path, PathBuf};
-use std::str::FromStr;
+use std::slice;
+use std::str::{from_utf8, FromStr};
 
 use handlebars::Handlebars;
 use pathdiff::diff_paths;
@@ -225,7 +226,7 @@ fn emit_build_rs(
     });
     let output = reg.render("build.rs", &json).unwrap();
     let output_path = build_dir.join("build.rs");
-    maybe_write_to_file(&output_path, output, tcfg.overwrite_existing)
+    maybe_write_to_file(&output_path, &output, tcfg.overwrite_existing)
 }
 
 /// Emit lib.rs (main.rs) for a library (binary). Returns `Some(path)`
@@ -253,15 +254,68 @@ fn emit_lib_rs(
     let output_path = build_dir.join(file_name);
     let output = reg.render("lib.rs", &json).unwrap();
 
-    maybe_write_to_file(&output_path, output, tcfg.overwrite_existing)
+    maybe_write_to_file(&output_path, &output, tcfg.overwrite_existing)
 }
 
+pub const GENERATED_RUST_TOOLCHAIN_TOML: &str = include_str!("generated-rust-toolchain.toml");
+pub const GENERATED_RUST_TOOLCHAIN: &str = {
+    const fn find_substring(s: &str, sub: &str, start: usize) -> usize {
+        let s = s.as_bytes();
+        let sub = sub.as_bytes();
+        assert!(sub.len() + start <= s.len());
+        let n = s.len() - sub.len();
+        let mut i = start;
+        while i < n {
+            let mut j = 0;
+            let mut eq = true;
+            while j < sub.len() {
+                if s[i + j] != sub[j] {
+                    eq = false;
+                    break;
+                }
+                j += 1;
+            }
+            if eq {
+                return i;
+            }
+            i += 1;
+        }
+        assert!(false);
+        return 0;
+    }
+
+    let toml = GENERATED_RUST_TOOLCHAIN_TOML;
+    let prefix = "\nchannel = \"";
+    let suffix = "\"";
+    let prefix_start = find_substring(toml, prefix, 0);
+    let start = prefix_start + prefix.len();
+    let end = find_substring(toml, suffix, start);
+
+    let toml = toml.as_bytes();
+    let len = end - start;
+    assert!(start + len <= toml.len());
+    // `const` slicing.
+    // SAFETY: Above `assert!`.
+    let toolchain = unsafe {
+        let ptr = toml.as_ptr().add(start);
+        slice::from_raw_parts(ptr, len)
+    };
+    let toolchain = match from_utf8(toolchain) {
+        Ok(toolchain) => toolchain,
+        Err(_) => panic!(),
+    };
+    toolchain
+};
+
 /// If we translate variadic functions, the output will only compile
 /// on a nightly toolchain until the `c_variadics` feature is stable.
 fn emit_rust_toolchain(tcfg: &TranspilerConfig, build_dir: &Path) {
     let output_path = build_dir.join("rust-toolchain.toml");
-    let output = include_str!("generated-rust-toolchain.toml").to_string();
-    maybe_write_to_file(&output_path, output, tcfg.overwrite_existing);
+    maybe_write_to_file(
+        &output_path,
+        GENERATED_RUST_TOOLCHAIN_TOML,
+        tcfg.overwrite_existing,
+    );
 }
 
 fn emit_cargo_toml<'lcmd>(
@@ -306,10 +360,10 @@ fn emit_cargo_toml<'lcmd>(
     let file_name = "Cargo.toml";
     let output_path = build_dir.join(file_name);
     let output = reg.render(file_name, &json).unwrap();
-    maybe_write_to_file(&output_path, output, tcfg.overwrite_existing);
+    maybe_write_to_file(&output_path, &output, tcfg.overwrite_existing);
 }
 
-fn maybe_write_to_file(output_path: &Path, output: String, overwrite: bool) -> Option<PathBuf> {
+fn maybe_write_to_file(output_path: &Path, output: &str, overwrite: bool) -> Option<PathBuf> {
     if output_path.exists() && !overwrite {
         eprintln!("Skipping existing file {}", output_path.display());
         return None;

c2rust-transpile/src/lib.rs

@@ -27,15 +27,15 @@ use regex::Regex;
 use serde_derive::Serialize;
 pub use tempfile::TempDir;
 
+use crate::build_files::{emit_build_files, get_build_dir, CrateConfig};
+pub use crate::build_files::{GENERATED_RUST_TOOLCHAIN, GENERATED_RUST_TOOLCHAIN_TOML};
 use crate::c_ast::Printer;
 use crate::c_ast::*;
-pub use crate::diagnostics::Diagnostic;
-use c2rust_ast_exporter as ast_exporter;
-
-use crate::build_files::{emit_build_files, get_build_dir, CrateConfig};
 use crate::compile_cmds::get_compile_commands;
 use crate::convert_type::RESERVED_NAMES;
+pub use crate::diagnostics::Diagnostic;
 pub use crate::translator::ReplaceMode;
+use c2rust_ast_exporter as ast_exporter;
 use std::prelude::v1::Vec;
 
 type PragmaVec = Vec<(&'static str, Vec<&'static str>)>;