ctest: pass target to macro expansion

This also fixes missing `reg32` struct bugs on 32-bit FreeBSD.

Author: mbyx

ctest/src/generator.rs

@@ -14,7 +14,7 @@ use crate::template::{CTestTemplate, RustTestTemplate};
 use crate::translator::translate_primitive_type;
 use crate::{
     Const, Field, MapInput, Parameter, Result, Static, Struct, TranslationError, Type, Union,
-    VolatileItemKind, expand,
+    VolatileItemKind, expand, get_build_target,
 };
 
 /// A function that takes a mappable input and returns its mapping as `Some`, otherwise
@@ -961,7 +961,7 @@ impl TestGenerator {
         crate_path: impl AsRef<Path>,
         output_file_path: impl AsRef<Path>,
     ) -> Result<PathBuf, GenerationError> {
-        let expanded = expand(&crate_path, &self.cfg).map_err(|e| {
+        let expanded = expand(&crate_path, &self.cfg, get_build_target(self)?).map_err(|e| {
             GenerationError::MacroExpansion(crate_path.as_ref().to_path_buf(), e.to_string())
         })?;
         let ast = syn::parse_file(&expanded)

ctest/src/lib.rs

@@ -20,12 +20,16 @@ mod runner;
 mod template;
 mod translator;
 
+use std::env;
+
 pub use ast::{Abi, Const, Field, Fn, Parameter, Static, Struct, Type, Union};
 pub use generator::TestGenerator;
 pub use macro_expansion::expand;
 pub use runner::{__compile_test, __run_test, generate_test};
 pub use translator::TranslationError;
 
+use crate::generator::GenerationError;
+
 /// A possible error that can be encountered in our library.
 pub type Error = Box<dyn std::error::Error>;
 /// A type alias for `std::result::Result` that defaults to our error type.
@@ -74,6 +78,23 @@ pub(crate) enum MapInput<'a> {
     UnionFieldType(&'a Union, &'a Field),
 }
 
+/// Search for the target to build for, specified manually or through an environment variable.
+///
+/// This function will check the following places for the target name:
+/// - TestGenerator.target
+/// - TARGET environment variable.
+/// - TARGET_PLATFORM environment variable.
+fn get_build_target(generator: &TestGenerator) -> Result<String, GenerationError> {
+    generator
+        .target
+        .clone()
+        .or_else(|| env::var("TARGET").ok())
+        .or_else(|| env::var("TARGET_PLATFORM").ok())
+        .ok_or(GenerationError::EnvVarNotFound(
+            "TARGET, TARGET_PLATFORM".to_string(),
+        ))
+}
+
 /* The From impls make it easier to write code in the test templates. */
 
 impl<'a> From<&'a Const> for MapInput<'a> {

ctest/src/macro_expansion.rs

@@ -6,7 +6,11 @@ use std::process::Command;
 use crate::{EDITION, Result};
 
 /// Use rustc to expand all macros and pretty print the crate into a single file.
-pub fn expand<P: AsRef<Path>>(crate_path: P, cfg: &[(String, Option<String>)]) -> Result<String> {
+pub fn expand<P: AsRef<Path>>(
+    crate_path: P,
+    cfg: &[(String, Option<String>)],
+    target: String,
+) -> Result<String> {
     let rustc = env::var("RUSTC").unwrap_or_else(|_| String::from("rustc"));
 
     let mut cmd = Command::new(rustc);
@@ -16,6 +20,10 @@ pub fn expand<P: AsRef<Path>>(crate_path: P, cfg: &[(String, Option<String>)]) -
         .arg(EDITION) // By default, -Zunpretty=expanded uses 2015 edition.
         .arg(canonicalize(crate_path)?);
 
+    if !target.is_empty() {
+        cmd.arg("--target").arg(target);
+    }
+
     // `libc` uses non standard cfg flags as well, which have to be manually expanded.
     for (k, v) in cfg {
         match v {

ctest/src/runner.rs

@@ -7,7 +7,7 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 
 use crate::generator::GenerationError;
-use crate::{EDITION, Result, TestGenerator};
+use crate::{EDITION, Result, TestGenerator, get_build_target};
 
 /// Generate all tests for the given crate and output the Rust side to a file.
 #[doc(hidden)]
@@ -18,17 +18,7 @@ pub fn generate_test(
 ) -> Result<PathBuf, GenerationError> {
     let output_file_path = generator.generate_files(crate_path, output_file_path)?;
 
-    // Search for the target and host to build for if specified manually
-    // (generator.target, generator.host),
-    // via build script (TARGET, HOST), or for internal testing (TARGET_PLATFORM, HOST_PLATFORM).
-    let target = generator
-        .target
-        .clone()
-        .or_else(|| env::var("TARGET").ok())
-        .or_else(|| env::var("TARGET_PLATFORM").ok())
-        .ok_or(GenerationError::EnvVarNotFound(
-            "TARGET, TARGET_PLATFORM".to_string(),
-        ))?;
+    let target = get_build_target(generator)?;
     let host = env::var("HOST")
         .or_else(|_| env::var("HOST_PLATFORM"))
         .map_err(|_| GenerationError::EnvVarNotFound("HOST, HOST_PLATFORM".to_string()))?;