0007-clang-subsystem.patch

diff -urN rustc-1.52.1-src.orig/compiler/rustc_target/src/spec/windows_gnu_base.rs rustc-1.52.1-src/compiler/rustc_target/src/spec/windows_gnu_base.rs
--- rustc-1.52.1-src.orig/compiler/rustc_target/src/spec/windows_gnu_base.rs	2021-05-09 04:52:39.000000000 +0200
+++ rustc-1.52.1-src/compiler/rustc_target/src/spec/windows_gnu_base.rs	2021-06-06 22:12:33.367953300 +0200
@@ -18,34 +18,13 @@
         ],
     );
 
-    let mut late_link_args = LinkArgs::new();
     let mut late_link_args_dynamic = LinkArgs::new();
     let mut late_link_args_static = LinkArgs::new();
-    // Order of `late_link_args*` was found through trial and error to work with various
-    // mingw-w64 versions (not tested on the CI). It's expected to change from time to time.
-    let mingw_libs = vec![
-        "-lmsvcrt".to_string(),
-        "-lmingwex".to_string(),
-        "-lmingw32".to_string(),
-        "-lgcc".to_string(), // alas, mingw* libraries above depend on libgcc
-        // mingw's msvcrt is a weird hybrid import library and static library.
-        // And it seems that the linker fails to use import symbols from msvcrt
-        // that are required from functions in msvcrt in certain cases. For example
-        // `_fmode` that is used by an implementation of `__p__fmode` in x86_64.
-        // The library is purposely listed twice to fix that.
-        //
-        // See https://github.com/rust-lang/rust/pull/47483 for some more details.
-        "-lmsvcrt".to_string(),
-        "-luser32".to_string(),
-        "-lkernel32".to_string(),
-    ];
-    late_link_args.insert(LinkerFlavor::Gcc, mingw_libs.clone());
-    late_link_args.insert(LinkerFlavor::Lld(LldFlavor::Ld), mingw_libs);
     let dynamic_unwind_libs = vec![
         // If any of our crates are dynamically linked then we need to use
         // the shared libgcc_s-dw2-1.dll. This is required to support
         // unwinding across DLL boundaries.
-        "-lgcc_s".to_string(),
+        "-l:libunwind.dll.a".to_string(),
     ];
     late_link_args_dynamic.insert(LinkerFlavor::Gcc, dynamic_unwind_libs.clone());
     late_link_args_dynamic.insert(LinkerFlavor::Lld(LldFlavor::Ld), dynamic_unwind_libs);
@@ -55,8 +34,7 @@
         // binaries to be redistributed without the libgcc_s-dw2-1.dll
         // dependency, but unfortunately break unwinding across DLL
         // boundaries when unwinding across FFI boundaries.
-        "-lgcc_eh".to_string(),
-        "-l:libpthread.a".to_string(),
+        "-l:libunwind.a".to_string(),
     ];
     late_link_args_static.insert(LinkerFlavor::Gcc, static_unwind_libs.clone());
     late_link_args_static.insert(LinkerFlavor::Lld(LldFlavor::Ld), static_unwind_libs);
@@ -66,7 +44,8 @@
         env: "gnu".to_string(),
         vendor: "pc".to_string(),
         // FIXME(#13846) this should be enabled for windows
-        function_sections: false,
+        function_sections: true,
+        no_default_libraries: false,
         linker: Some("gcc".to_string()),
         dynamic_linking: true,
         executables: true,
@@ -84,7 +63,6 @@
         pre_link_objects_fallback: crt_objects::pre_mingw_fallback(),
         post_link_objects_fallback: crt_objects::post_mingw_fallback(),
         crt_objects_fallback: Some(CrtObjectsFallback::Mingw),
-        late_link_args,
         late_link_args_dynamic,
         late_link_args_static,
         abi_return_struct_as_int: true,
diff -urN rustc-1.53.0-src/src/bootstrap/bootstrap.py.orig rustc-1.53.0-src/src/bootstrap/bootstrap.py
--- rustc-1.53.0-src/src/bootstrap/bootstrap.py.orig    2021-07-03 13:57:23.756296000 +0200
+++ rustc-1.53.0-src/src/bootstrap/bootstrap.py 2021-07-03 13:58:41.037817900 +0200
@@ -425,6 +425,12 @@
             with output(self.rustc_stamp(stage0)) as rust_stamp:
                 rust_stamp.write(key)

+            gcc_libs_hack = os.environ.get('GCC_LIBS_HACK')
+            gcc_libs_hack_dest = '{}/rustlib/{}/lib'.format(lib_dir, self.build)
+            shutil.copy(gcc_libs_hack + '/libgcc.a', gcc_libs_hack_dest)
+            shutil.copy(gcc_libs_hack + '/libgcc_eh.a', gcc_libs_hack_dest)
+            shutil.copy(gcc_libs_hack + '/libgcc_s.a', gcc_libs_hack_dest)
+
         if self.rustfmt() and self.rustfmt().startswith(bin_root) and (
             not os.path.exists(self.rustfmt())
             or self.program_out_of_date(self.rustfmt_stamp(), self.rustfmt_channel)