commit 29c88a91da1aac43a837ef39e7b5d4556d8e2c73 Author: Nicolas Vigier <boklm@torproject.org> Date: Sun Sep 19 09:25:39 2021 +0200 Bug 28240: switch from SJLJ exception handling to Dwarf2 in mingw for win32 --- projects/mingw-w64/build | 2 +- projects/mingw-w64/config | 2 +- projects/rust/build | 10 --- projects/rust/config | 2 - projects/rust/unwind.patch | 163 --------------------------------------------- 5 files changed, 2 insertions(+), 177 deletions(-) diff --git a/projects/mingw-w64/build b/projects/mingw-w64/build index 155c531..2d8e8e2 100644 --- a/projects/mingw-w64/build +++ b/projects/mingw-w64/build @@ -26,7 +26,7 @@ tar xJf $rootdir/gcc-[% c("var/gcc_version") %].tar.xz # CFLAGS_FOR_TARGET. export CFLAGS_FOR_TARGET="-Wl,--nxcompat -Wl,--dynamicbase -Wl,--no-insert-timestamp [% c('var/flag_noSEH') %]" # Rust requires enabling pthreads -gcc-[% c("var/gcc_version") %]/configure --prefix=$distdir --target=[% c("arch") %]-w64-mingw32 --with-gnu-ld --with-gnu-as --disable-multilib --enable-threads=posix --enable-languages=c,c++ +gcc-[% c("var/gcc_version") %]/configure --prefix=$distdir --target=[% c("arch") %]-w64-mingw32 --with-gnu-ld --with-gnu-as --disable-multilib --enable-threads=posix --enable-languages=c,c++[% IF c("var/windows-i686") %] --disable-sjlj-exceptions --with-dwarf2[% END %] make -j[% c("buildconf/num_procs") %] all-gcc make install-gcc diff --git a/projects/mingw-w64/config b/projects/mingw-w64/config index c5dde82..6758997 100644 --- a/projects/mingw-w64/config +++ b/projects/mingw-w64/config @@ -19,7 +19,7 @@ var: targets: windows-i686: var: - libgcc_dll: libgcc_s_sjlj-1.dll + libgcc_dll: libgcc_s_dw2-1.dll arch_deps: - g++-mingw-w64-i686 windows-x86_64: diff --git a/projects/rust/build b/projects/rust/build index 722aacc..69bd0f4 100644 --- a/projects/rust/build +++ b/projects/rust/build @@ -58,16 +58,6 @@ cd /var/tmp/build/rustc-[% c('version') %]-src patch -p1 < $rootdir/fix-build-1.53.0.patch [% END %] -[% IF c("var/windows-i686") %] - # Cross-compiling for Windows 32bit is currently not possible without any - # patches. The reason for that is libstd expecting DWARF unwinding while most - # toolchains on Linux, targeting Windows 32bit, use SjLj unwinding. - # See: https://github.com/rust-lang/rust/issues/12859 for discussion about - # that and https://github.com/rust-lang/rust/pull/49633 for a newer attempt to - # fix this problem. We apply the patch from neersighted. - patch -p1 < $rootdir/unwind.patch -[% END %] - mkdir build cd build ../configure --prefix=$distdir --disable-docs --disable-compiler-docs [% c("var/configure_opt") %] diff --git a/projects/rust/config b/projects/rust/config index 1e79687..01e1843 100644 --- a/projects/rust/config +++ b/projects/rust/config @@ -99,8 +99,6 @@ input_files: - project: python name: python enable: '[% c("var/linux") %]' - - filename: unwind.patch - enable: '[% c("var/windows-i686") %]' - filename: 43909.patch name: 43909 enable: '[% ! c("var/ff91esr") %]' diff --git a/projects/rust/unwind.patch b/projects/rust/unwind.patch deleted file mode 100644 index 65c51f9..0000000 --- a/projects/rust/unwind.patch +++ /dev/null @@ -1,163 +0,0 @@ -From 90ddcca6235b5f24c57df6a648e8d489c7e3eae5 Mon Sep 17 00:00:00 2001 -From: Bjorn Neergaard <bjorn@neersighted.com> -Date: Sat, 9 Feb 2019 19:39:23 +0000 -Subject: [PATCH] Fix cross-compiling i686-pc-windows-gnu from Linux - -This is still very rough and serves as a proof-of-concept for fixing -Linux -> 32-bit MinGW cross compilation workflow. Currently, clang and -GCC's MinGW targets both only support DW2 (DWARF) or SJLJ (Set Jump Long -Jump) unwinding on 32-bit Windows. - -The default for GCC (and the way it is shipped on every major distro) is -to use SJLJ on Windows, as DWARF cannot traverse non-DWARF frames. This -would work fine, except for the fact that libgcc (our C runtime on the -MinGW platform) exports symbols under a different name when configured -to use SJLJ-style unwinding, and uses a preprocessor macro internally to -alias them. - -Because of this, we have to detect this scenario and link to the correct -symbols ourselves. Linking has been tested with a full bootstrap on both -x86_64-unknown-linux-gnu and i686-pc-windows-gnu, as well as -cross-compilation of some of my own projects. - -Obviously, the detection is a bit unrefined. Right now we -unconditionally use SJLJ when compiling Linux -> MinGW. I'd like to add -feature detection using compiler build flags or autotools-style -compilation and object analysis. Input on the best way to proceed here -is welcome. - -Also, currently there is copy-pasted/duplicated code in libunwind. -Ideally, this could be reduced, but this would likely require a -rethinking of how iOS is special-cased above, to avoid further -duplication. Input on how to best structure this file is requested. - -diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs -index 65a00db3394..e821507c341 100644 ---- a/src/bootstrap/compile.rs -+++ b/src/bootstrap/compile.rs -@@ -207,6 +207,11 @@ pub fn std_cargo(builder: &Builder<'_>, target: Interned<String>, cargo: &mut Ca - let mut features = builder.std_features(); - features.push_str(&compiler_builtins_c_feature); - -+ // FIXME: Temporary detection of SJLJ MinGW compilers. -+ if builder.config.build.contains("linux") && target == "i686-pc-windows-gnu" { -+ features.push_str(" sjlj_eh"); -+ } -+ - cargo - .arg("--features") - .arg(features) -diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml -index b147aa55b2a..cad4d88caa2 100644 ---- a/src/libstd/Cargo.toml -+++ b/src/libstd/Cargo.toml -@@ -68,6 +68,7 @@ panic_immediate_abort = ["core/panic_immediate_abort"] - # https://github.com/rust-lang/stdarch/blob/master/crates/std_detect/Cargo.tom... - std_detect_file_io = [] - std_detect_dlsym_getauxval = [] -+sjlj_eh = ["unwind/sjlj_eh"] - - [package.metadata.fortanix-sgx] - # Maximum possible number of threads when testing -diff --git a/src/libtest/Cargo.toml b/src/libtest/Cargo.toml -index 170fbb984cf..b1b0be71067 100644 ---- a/src/libtest/Cargo.toml -+++ b/src/libtest/Cargo.toml -@@ -29,3 +29,4 @@ llvm-libunwind = ["std/llvm-libunwind"] - panic-unwind = ["std/panic_unwind"] - panic_immediate_abort = ["std/panic_immediate_abort"] - profiler = ["std/profiler"] -+sjlj_eh = ["std/sjlj_eh"] -diff --git a/src/libunwind/Cargo.toml b/src/libunwind/Cargo.toml -index 77bcfffd506..9d9fc5fbff5 100644 ---- a/src/libunwind/Cargo.toml -+++ b/src/libunwind/Cargo.toml -@@ -26,3 +26,4 @@ cc = { version = "1.0.1" } - - [features] - llvm-libunwind = [] -+sjlj_eh = [] -diff --git a/src/libunwind/libunwind.rs b/src/libunwind/libunwind.rs -index 0c57861f70a..44c767ebfc5 100644 ---- a/src/libunwind/libunwind.rs -+++ b/src/libunwind/libunwind.rs -@@ -79,8 +79,8 @@ pub type _Unwind_Exception_Cleanup_Fn = - link(name = "unwind", kind = "static") - )] - extern "C" { -- #[unwind(allowed)] -- pub fn _Unwind_Resume(exception: *mut _Unwind_Exception) -> !; -+ #[cfg_attr(stage0, unwind)] -+ #[cfg_attr(not(stage0), unwind(allowed))] - pub fn _Unwind_DeleteException(exception: *mut _Unwind_Exception); - pub fn _Unwind_GetLanguageSpecificData(ctx: *mut _Unwind_Context) -> *mut c_void; - pub fn _Unwind_GetRegionStart(ctx: *mut _Unwind_Context) -> _Unwind_Ptr; -@@ -222,32 +222,50 @@ if #[cfg(all(any(target_os = "ios", target_os = "netbsd", not(target_arch = "arm - } // cfg_if! - - cfg_if::cfg_if! { --if #[cfg(not(all(target_os = "ios", target_arch = "arm")))] { -- // Not 32-bit iOS -- #[cfg_attr(all(feature = "llvm-libunwind", -- any(target_os = "fuchsia", target_os = "linux")), -- link(name = "unwind", kind = "static"))] -+if #[cfg(all(target_os = "ios", target_arch = "arm"))] { -+ // 32-bit iOS uses SjLj and does not provide _Unwind_Backtrace() - extern "C" { -- #[unwind(allowed)] -- pub fn _Unwind_RaiseException(exception: *mut _Unwind_Exception) -> _Unwind_Reason_Code; -+ #[cfg_attr(stage0, unwind)] -+ #[cfg_attr(not(stage0), unwind(allowed))] -+ pub fn _Unwind_Resume(exception: *mut _Unwind_Exception) -> !; -+ pub fn _Unwind_SjLj_RaiseException(e: *mut _Unwind_Exception) -> _Unwind_Reason_Code; -+ } -+ -+ #[inline] -+ pub unsafe fn _Unwind_RaiseException(exc: *mut _Unwind_Exception) -> _Unwind_Reason_Code { -+ _Unwind_SjLj_RaiseException(exc) -+ } -+ -+} else if #[cfg(feature = "sjlj_eh")] { -+ extern "C" { -+ #[cfg_attr(stage0, unwind)] -+ #[cfg_attr(not(stage0), unwind(allowed))] -+ pub fn _Unwind_SjLj_Resume(e: *mut _Unwind_Exception) -> !; -+ pub fn _Unwind_SjLj_RaiseException(e: *mut _Unwind_Exception) -> _Unwind_Reason_Code; - pub fn _Unwind_Backtrace(trace: _Unwind_Trace_Fn, - trace_argument: *mut c_void) - -> _Unwind_Reason_Code; - } --} else { -- // 32-bit iOS uses SjLj and does not provide _Unwind_Backtrace() -- #[cfg_attr(all(feature = "llvm-libunwind", -- any(target_os = "fuchsia", target_os = "linux")), -- link(name = "unwind", kind = "static"))] -- extern "C" { -- #[unwind(allowed)] -- pub fn _Unwind_SjLj_RaiseException(e: *mut _Unwind_Exception) -> _Unwind_Reason_Code; -+ -+ #[inline] -+ pub unsafe fn _Unwind_Resume(exc: *mut _Unwind_Exception) -> ! { -+ _Unwind_SjLj_Resume(exc) - } - - #[inline] - pub unsafe fn _Unwind_RaiseException(exc: *mut _Unwind_Exception) -> _Unwind_Reason_Code { - _Unwind_SjLj_RaiseException(exc) - } -+} else { -+ extern "C" { -+ #[cfg_attr(stage0, unwind)] -+ #[cfg_attr(not(stage0), unwind(allowed))] -+ pub fn _Unwind_Resume(exception: *mut _Unwind_Exception) -> !; -+ pub fn _Unwind_RaiseException(exception: *mut _Unwind_Exception) -> _Unwind_Reason_Code; -+ pub fn _Unwind_Backtrace(trace: _Unwind_Trace_Fn, -+ trace_argument: *mut c_void) -+ -> _Unwind_Reason_Code; -+ } - } - } // cfg_if! - --- -2.28.0 -