From cefadf05f9319f01b0245de72f4e5941a046b0e9 Mon Sep 17 00:00:00 2001
From: Simonas Kazlauskas <git@kazlauskas.me>
Date: Tue, 29 Sep 2015 01:01:48 +0300
Subject: [PATCH 1/2] Enable and make stage0 landing pads optional

---
 configure  | 1 +
 mk/main.mk | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/configure b/configure
index fa2117dcc1d..6dfa31bc3fd 100755
--- a/configure
+++ b/configure
@@ -578,6 +578,7 @@ opt ccache 0 "invoke gcc/clang via ccache to reuse object files between builds"
 opt local-rust 0 "use an installed rustc rather than downloading a snapshot"
 opt llvm-static-stdcpp 0 "statically link to libstdc++ for LLVM"
 opt rpath 0 "build rpaths into rustc itself"
+opt stage0-landing-pads 1 "enable landing pads during bootstrap with stage0"
 # This is used by the automation to produce single-target nightlies
 opt dist-host-only 0 "only install bins for the host architecture"
 opt inject-std-version 1 "inject the current compiler version of libstd into programs"
diff --git a/mk/main.mk b/mk/main.mk
index fa6d8097150..dedf4ec57ea 100644
--- a/mk/main.mk
+++ b/mk/main.mk
@@ -170,7 +170,10 @@ RUST_LIB_FLAGS_ST3 += -C prefer-dynamic
 
 # Landing pads require a lot of codegen. We can get through bootstrapping faster
 # by not emitting them.
-RUSTFLAGS_STAGE0 += -Z no-landing-pads
+
+ifdef CFG_DISABLE_STAGE0_LANDING_PADS
+  RUSTFLAGS_STAGE0 += -Z no-landing-pads
+endif
 
 # Enable MIR to "always build" for crates where this works. This is
 # just temporary while MIR is being actively built up -- it's just a

From a7f2a7881dc724fd9e36e31c8bf969225f72f792 Mon Sep 17 00:00:00 2001
From: Simonas Kazlauskas <git@kazlauskas.me>
Date: Fri, 2 Oct 2015 22:19:51 +0300
Subject: [PATCH 2/2] Fix MSVC stage0 with landing pads enabled

---
 src/libstd/sys/common/unwind/mod.rs | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/libstd/sys/common/unwind/mod.rs b/src/libstd/sys/common/unwind/mod.rs
index c06d7886a75..3978aeb39bc 100644
--- a/src/libstd/sys/common/unwind/mod.rs
+++ b/src/libstd/sys/common/unwind/mod.rs
@@ -81,8 +81,18 @@ use sys_common::mutex::Mutex;
 #[path = "seh.rs"] #[doc(hidden)]
 pub mod imp;
 
+// SNAP: i686-pc-windows-gnu
+#[cfg(all(stage0, windows, target_arch = "x86_64", target_env = "gnu"))]
+#[path = "seh64_gnu.rs"] #[doc(hidden)]
+pub mod imp;
+
+// SNAP: x86_64-pc-windows-msvc
+#[cfg(all(stage0, windows, target_arch = "x86_64", target_env = "msvc"))]
+#[path = "seh.rs"] #[doc(hidden)]
+pub mod imp;
+
 // x86_64-pc-windows-*
-#[cfg(all(windows, target_arch = "x86_64"))]
+#[cfg(all(not(stage0), windows, target_arch = "x86_64"))]
 #[path = "seh64_gnu.rs"] #[doc(hidden)]
 pub mod imp;