Fix for raw-dylib when linking with MinGW BFD

.github/workflows/ci.yml

@@ -537,6 +537,18 @@ jobs:
           - name: dist-x86_64-linux
             os: ubuntu-latest-xl
             env: {}
+          - name: dist-i686-mingw
+            env:
+              RUST_CONFIGURE_ARGS: "--build=i686-pc-windows-gnu"
+              SCRIPT: python x.py dist
+              CUSTOM_MINGW: 1
+            os: windows-latest-xl
+          - name: dist-x86_64-mingw
+            env:
+              SCRIPT: python x.py dist
+              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu"
+              CUSTOM_MINGW: 1
+            os: windows-latest-xl
     timeout-minutes: 600
     runs-on: "${{ matrix.os }}"
     steps:

compiler/rustc_codegen_llvm/src/back/archive.rs

@@ -1,6 +1,7 @@
 //! A helper class for dealing with static archives
 
-use std::ffi::{CStr, CString};
+use std::env;
+use std::ffi::{CStr, CString, OsString};
 use std::io;
 use std::mem;
 use std::path::{Path, PathBuf};
@@ -158,55 +159,102 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
             output_path.with_extension("lib")
         };
 
-        // we've checked for \0 characters in the library name already
-        let dll_name_z = CString::new(lib_name).unwrap();
+        // BFD doesn't work properly with short imports
+        let mingw_gnu_toolchain = self.config.sess.target.llvm_target.ends_with("pc-windows-gnu");
+
         // All import names are Rust identifiers and therefore cannot contain \0 characters.
         // FIXME: when support for #[link_name] implemented, ensure that import.name values don't
         // have any \0 characters
         let import_name_vector: Vec<CString> = dll_imports
             .iter()
             .map(|import: &DllImport| {
                 if self.config.sess.target.arch == "x86" {
-                    LlvmArchiveBuilder::i686_decorated_name(import)
+                    LlvmArchiveBuilder::i686_decorated_name(import, mingw_gnu_toolchain)
                 } else {
                     CString::new(import.name.to_string()).unwrap()
                 }
             })
             .collect();
 
-        let output_path_z = rustc_fs_util::path_to_c_string(&output_path);
+        if mingw_gnu_toolchain {
+            let mut def_file_path = tmpdir.as_ref().to_path_buf();
+            def_file_path.push(format!("{}_imports", lib_name));
+            def_file_path.with_extension("def");
+
+            let def_file_content = format!(
+                "EXPORTS\n{}",
+                import_name_vector
+                    .iter()
+                    .map(|cstring| cstring.to_str().unwrap())
+                    .intersperse("\n")
+                    .collect::<String>()
+            );
+            std::fs::write(&def_file_path, def_file_content).unwrap();
+
+            let dlltool = find_dlltool(self.config.sess);
+            let result = std::process::Command::new(dlltool)
+                .args([
+                    "-d",
+                    def_file_path.to_str().unwrap(),
+                    "-D",
+                    lib_name,
+                    "-l",
+                    output_path.to_str().unwrap(),
+                ])
+                .output();
+
+            match result {
+                Err(e) => {
+                    self.config.sess.fatal(&format!("Error calling dlltool: {}", e.to_string()))
+                }
+                Ok(output) if !output.status.success() => self.config.sess.fatal(&format!(
+                    "Dlltool could not create import library: {}\n{}",
+                    String::from_utf8_lossy(&output.stdout),
+                    String::from_utf8_lossy(&output.stderr)
+                )),
+                _ => {}
+            }
+        } else {
+            // we've checked for \0 characters in the library name already
+            let dll_name_z = CString::new(lib_name).unwrap();
+            let output_path_z = rustc_fs_util::path_to_c_string(&output_path);
+
+            tracing::trace!("invoking LLVMRustWriteImportLibrary");
+            tracing::trace!("  dll_name {:#?}", dll_name_z);
+            tracing::trace!("  output_path {}", output_path.display());
+            tracing::trace!(
+                "  import names: {}",
+                dll_imports
+                    .iter()
+                    .map(|import| import.name.to_string())
+                    .collect::<Vec<_>>()
+                    .join(", "),
+            );
 
-        tracing::trace!("invoking LLVMRustWriteImportLibrary");
-        tracing::trace!("  dll_name {:#?}", dll_name_z);
-        tracing::trace!("  output_path {}", output_path.display());
-        tracing::trace!(
-            "  import names: {}",
-            dll_imports.iter().map(|import| import.name.to_string()).collect::<Vec<_>>().join(", "),
-        );
+            let ffi_exports: Vec<LLVMRustCOFFShortExport> = import_name_vector
+                .iter()
+                .map(|name_z| LLVMRustCOFFShortExport::from_name(name_z.as_ptr()))
+                .collect();
+            let result = unsafe {
+                crate::llvm::LLVMRustWriteImportLibrary(
+                    dll_name_z.as_ptr(),
+                    output_path_z.as_ptr(),
+                    ffi_exports.as_ptr(),
+                    ffi_exports.len(),
+                    llvm_machine_type(&self.config.sess.target.arch) as u16,
+                    !self.config.sess.target.is_like_msvc,
+                )
+            };
 
-        let ffi_exports: Vec<LLVMRustCOFFShortExport> = import_name_vector
-            .iter()
-            .map(|name_z| LLVMRustCOFFShortExport::from_name(name_z.as_ptr()))
-            .collect();
-        let result = unsafe {
-            crate::llvm::LLVMRustWriteImportLibrary(
-                dll_name_z.as_ptr(),
-                output_path_z.as_ptr(),
-                ffi_exports.as_ptr(),
-                ffi_exports.len(),
-                llvm_machine_type(&self.config.sess.target.arch) as u16,
-                !self.config.sess.target.is_like_msvc,
-            )
+            if result == crate::llvm::LLVMRustResult::Failure {
+                self.config.sess.fatal(&format!(
+                    "Error creating import library for {}: {}",
+                    lib_name,
+                    llvm::last_error().unwrap_or("unknown LLVM error".to_string())
+                ));
+            }
         };
 
-        if result == crate::llvm::LLVMRustResult::Failure {
-            self.config.sess.fatal(&format!(
-                "Error creating import library for {}: {}",
-                lib_name,
-                llvm::last_error().unwrap_or("unknown LLVM error".to_string())
-            ));
-        }
-
         self.add_archive(&output_path, |_| false).unwrap_or_else(|e| {
             self.config.sess.fatal(&format!(
                 "failed to add native library {}: {}",
@@ -332,13 +380,17 @@ impl<'a> LlvmArchiveBuilder<'a> {
         }
     }
 
-    fn i686_decorated_name(import: &DllImport) -> CString {
+    fn i686_decorated_name(import: &DllImport, mingw: bool) -> CString {
         let name = import.name;
+        // MinGW doesn't want `_` prefix for `.def` file
+        let prefix = if mingw { "" } else { "_" };
         // We verified during construction that `name` does not contain any NULL characters, so the
         // conversion to CString is guaranteed to succeed.
         CString::new(match import.calling_convention {
-            DllCallingConvention::C => format!("_{}", name),
-            DllCallingConvention::Stdcall(arg_list_size) => format!("_{}@{}", name, arg_list_size),
+            DllCallingConvention::C => format!("{}{}", prefix, name),
+            DllCallingConvention::Stdcall(arg_list_size) => {
+                format!("{}{}@{}", prefix, name, arg_list_size)
+            }
             DllCallingConvention::Fastcall(arg_list_size) => format!("@{}@{}", name, arg_list_size),
             DllCallingConvention::Vectorcall(arg_list_size) => {
                 format!("{}@@{}", name, arg_list_size)
@@ -351,3 +403,26 @@ impl<'a> LlvmArchiveBuilder<'a> {
 fn string_to_io_error(s: String) -> io::Error {
     io::Error::new(io::ErrorKind::Other, format!("bad archive: {}", s))
 }
+
+fn find_dlltool(sess: &Session) -> OsString {
+    // When cross-compiling first try binary prefixed with target triple
+    if sess.host.llvm_target != sess.target.llvm_target {
+        let prefixed_dlltool = if sess.target.arch == "x86" {
+            "i686-w64-mingw32-dlltool"
+        } else {
+            "x86_64-w64-mingw32-dlltool"
+        };
+        let prefixed_dlltool = if cfg!(windows) {
+            [prefixed_dlltool, "exe"].concat()
+        } else {
+            prefixed_dlltool.to_string()
+        };
+        for dir in env::split_paths(&env::var_os("PATH").unwrap_or_default()) {
+            let full_path = dir.join(&prefixed_dlltool);
+            if full_path.is_file() {
+                return full_path.into_os_string();
+            }
+        }
+    }
+    OsString::from("dlltool")
+}

src/ci/github-actions/ci.yml

@@ -14,7 +14,6 @@
 # step CI will fail.
 
 ---
-
 ###############################
 #   YAML Anchors Definition   #
 ###############################
@@ -30,7 +29,6 @@
 # The expand-yaml-anchors tool will automatically remove this block from the
 # output YAML file.
 x--expand-yaml-anchors--remove:
-
   - &shared-ci-variables
     CI_JOB_NAME: ${{ matrix.name }}
 
@@ -77,7 +75,7 @@ x--expand-yaml-anchors--remove:
     <<: *base-job
 
   - &job-macos-xl
-    os: macos-latest  # We don't have an XL builder for this
+    os: macos-latest # We don't have an XL builder for this
     <<: *base-job
 
   - &job-windows-xl
@@ -669,6 +667,18 @@ jobs:
       matrix:
         include:
           - *dist-x86_64-linux
+          - name: dist-i686-mingw
+            env:
+              RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu
+              SCRIPT: python x.py dist
+              CUSTOM_MINGW: 1
+            <<: *job-windows-xl
+          - name: dist-x86_64-mingw
+            env:
+              SCRIPT: python x.py dist
+              RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-gnu
+              CUSTOM_MINGW: 1
+            <<: *job-windows-xl
 
   master:
     name: master

src/test/run-make/raw-dylib-alt-calling-convention/Makefile

@@ -1,12 +1,12 @@
 # Test the behavior of #[link(.., kind = "raw-dylib")] with alternative calling conventions.
 
-# only-i686-pc-windows-msvc
+# only-i686-pc-windows-gnu
 
 -include ../../run-make-fulldeps/tools.mk
 
 all:
 	$(call COMPILE_OBJ,"$(TMPDIR)"/extern.obj,extern.c)
-	$(CC) "$(TMPDIR)"/extern.obj -link -dll -out:"$(TMPDIR)"/extern.dll
+	$(CC) "$(TMPDIR)"/extern.obj -shared -o "$(TMPDIR)"/extern.dll
 	$(RUSTC) --crate-type lib --crate-name raw_dylib_alt_calling_convention_test lib.rs
 	$(RUSTC) --crate-type bin driver.rs -L "$(TMPDIR)"
 	"$(TMPDIR)"/driver > "$(TMPDIR)"/output.txt

src/test/run-make/raw-dylib-c/Makefile

@@ -1,14 +1,14 @@
 # Test the behavior of #[link(.., kind = "raw-dylib")] on windows-msvc
 
-# only-windows-msvc
+# only-windows-gnu
 
 -include ../../run-make-fulldeps/tools.mk
 
 all:
 	$(call COMPILE_OBJ,"$(TMPDIR)"/extern_1.obj,extern_1.c)
 	$(call COMPILE_OBJ,"$(TMPDIR)"/extern_2.obj,extern_2.c)
-	$(CC) "$(TMPDIR)"/extern_1.obj -link -dll -out:"$(TMPDIR)"/extern_1.dll
-	$(CC) "$(TMPDIR)"/extern_2.obj -link -dll -out:"$(TMPDIR)"/extern_2.dll
+	$(CC) "$(TMPDIR)"/extern_1.obj -shared -o "$(TMPDIR)"/extern_1.dll
+	$(CC) "$(TMPDIR)"/extern_2.obj -shared -o "$(TMPDIR)"/extern_2.dll
 	$(RUSTC) --crate-type lib --crate-name raw_dylib_test lib.rs
 	$(RUSTC) --crate-type bin driver.rs -L "$(TMPDIR)"
 	"$(TMPDIR)"/driver > "$(TMPDIR)"/output.txt