Merge remote-tracking branch 'gk/bug_25849_v3'

  # 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.

  [% IF !c("input_file_var/unwind_128") %]

    patch -p1 < $rootdir/unwind.patch

  [% ELSE %]

    patch -p1 < $rootdir/unwind_128.patch

  [% END %]

[% END %]

[% IF c("var/android") %]

    file_gpg_id: 1

    gpg_keyring: rust.gpg

  - filename: unwind.patch

    enable: '[% c("var/windows-i686") %]'

    enable: '[% c("var/windows-i686") && !c("input_file_var/unwind_128") %]'

  - filename: unwind_128.patch

    enable: '[% c("input_file_var/unwind_128") %]'

  - filename: 0001-Make-sure-dl_iterate_phdr-is-undefined-on-Android.patch

    enable: '[% c("var/android") %]'

  - filename: replace_pagesize_in_mmap.patch

From 0a186eafebf26ca01879827a4cc95cc274791334 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 11d9154ba6..bd8ff844f7 100644

--- a/src/bootstrap/compile.rs

+++ b/src/bootstrap/compile.rs

@@ -154,6 +154,11 @@ pub fn std_cargo(builder: &Builder,

     } else {

         let mut features = builder.std_features();

+        // FIXME: Temporary detection of SJLJ MinGW compilers.

+        if builder.config.build.contains("linux") && target == "i686-pc-windows-gnu" {

+            features.push_str(" sjlj_eh");

+        }

+

         // When doing a local rebuild we tell cargo that we're stage1 rather than

         // stage0. This works fine if the local rust and being-built rust have the

         // same view of what the default allocator is, but fails otherwise. Since

diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml

index 5a2dce5930..e1c876f503 100644

--- a/src/libstd/Cargo.toml

+++ b/src/libstd/Cargo.toml

@@ -50,3 +50,4 @@ force_alloc_system = []

 panic-unwind = ["panic_unwind"]

 profiler = ["profiler_builtins"]

 wasm_syscall = []

+sjlj_eh = ["unwind/sjlj_eh"]

diff --git a/src/libunwind/Cargo.toml b/src/libunwind/Cargo.toml

index 4760461df6..27c7303604 100644

--- a/src/libunwind/Cargo.toml

+++ b/src/libunwind/Cargo.toml

@@ -15,3 +15,6 @@ doc = false

 core = { path = "../libcore" }

 libc = { path = "../rustc/libc_shim" }

 compiler_builtins = { path = "../rustc/compiler_builtins_shim" }

+

+[features]

+sjlj_eh = []

diff --git a/src/libunwind/libunwind.rs b/src/libunwind/libunwind.rs

index 73a259bd44..ff3404864f 100644

--- a/src/libunwind/libunwind.rs

+++ b/src/libunwind/libunwind.rs

@@ -10,11 +10,6 @@

 #![allow(bad_style)]

-macro_rules! cfg_if {

-    ( $( if #[cfg( $meta:meta )] { $($it1:item)* } else { $($it2:item)* } )* ) =>

-        ( $( $( #[cfg($meta)] $it1)* $( #[cfg(not($meta))] $it2)* )* )

-}

-

 use libc::{c_int, c_void, uintptr_t};

 #[repr(C)]

@@ -83,8 +78,8 @@ pub enum _Unwind_Context {}

 pub type _Unwind_Exception_Cleanup_Fn = extern "C" fn(unwind_code: _Unwind_Reason_Code,

                                                       exception: *mut _Unwind_Exception);

 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;

@@ -216,26 +211,52 @@ if #[cfg(all(any(target_os = "ios", target_os = "netbsd", not(target_arch = "arm

         pc

     }

 }

+} // cfg_if!

-if #[cfg(not(all(target_os = "ios", target_arch = "arm")))] {

-    // Not 32-bit iOS

+cfg_if! {

+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()

-    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!

-- 

2.20.1

tar -C /var/tmp/dist -xf [% c('input_files_by_name/openssl') %]

tar -C /var/tmp/dist -xf [% c('input_files_by_name/libevent') %]

[% IF (c("var/linux") || c("var/osx")) && c("var/nightly") %]

[% IF !c("var/android") && c("var/nightly") %]

  tar -C /var/tmp/dist -xf [% c('input_files_by_name/rust') %]

  export PATH=/var/tmp/dist/rust/bin:$PATH

[% END %]

openssldir=/var/tmp/dist/openssl

[% IF c("var/windows") %]

  [% IF ("var/nightly") %]

    # We are compiling Tor with Rust enabled for nightlies.

    export TOR_RUST_TARGET=[% c("arch") %]-pc-windows-gnu

  [% END %]

  tar -C /var/tmp/build -xf [% c('input_files_by_name/zlib') %]

  zlibdir=/var/tmp/build/zlib

  mingwlibs=/var/tmp/dist/mingw-w64/[% c("arch") %]-w64-mingw32/bin/

echo '"[% c("abbrev", { abbrev_length => 16 }) %]"' > micro-revision.i

./autogen.sh

find -type f -print0 | xargs -0 [% c("var/touch") %]

[% IF (c("var/linux") || c("var/osx")) && c("var/nightly") %]TOR_RUST_DEPENDENCIES=`pwd`/src/ext/rust/crates[% END %] ./configure --disable-asciidoc --with-libevent-dir="$libeventdir" --with-openssl-dir="$openssldir" \

[% IF !c("var/android") && c("var/nightly") %]TOR_RUST_DEPENDENCIES=`pwd`/src/ext/rust/crates[% END %] ./configure --disable-asciidoc --with-libevent-dir="$libeventdir" --with-openssl-dir="$openssldir" \

    [% IF c("var/asan") %]--enable-fragile-hardening[% END %] \

    [% IF c("var/windows") %]--with-zlib-dir="$zlibdir"[% END %] \

    [% IF c("var/osx") %]--enable-static-openssl[% END %] \

    [% IF (c("var/linux") || c("var/osx")) && c("var/nightly") %]--enable-rust[% END %] \

    [% IF !c("var/android") && c("var/nightly") %]--enable-rust[% END %] \

    --prefix="$distdir" [% c("var/configure_opt") %]

[% IF c("var/osx") || c("var/windows") -%]

  export LD_PRELOAD=[% c("var/faketime_path") %]

    input_file_var:

      rust_version: 1.28.0

      prev_version: 1.27.2

    enable: '[% (c("var/linux") || c("var/osx")) && c("var/nightly") %]'

      unwind_128: '[% c("var/windows-i686") %]'

    enable: '[% !c("var/android") && c("var/nightly") %]'