rustc_trans: Disable landing pads on 32-bit MSVC

This is currently quite buggy in LLVM from what I can tell, so just disable it
entirely. This commit also adds preliminary support, however, to actually
target 32-bit MSVC by making sure the `rust_try_msvc_32.ll` file exists and
wiring up exceptions to `_except_handler3` instead of `__C_specific_handler`
(which doesn't exist on 32-bit).

1 files changed, 42 insertions, 0 deletions

diff --git a/src/rt/rust_try_msvc_32.ll b/src/rt/rust_try_msvc_32.ll
new file mode 100644
index 00000000000..bdee53b136e
--- /dev/null
+++ b/src/rt/rust_try_msvc_32.ll
@@ -0,0 +1,42 @@
+; Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+; file at the top-level directory of this distribution and at
+; http://rust-lang.org/COPYRIGHT.
+;
+; Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+; http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+; <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+; option. This file may not be copied, modified, or distributed
+; except according to those terms.
+
+; For more comments about what's going on here see rust_try_msvc_64.ll. The only
+; difference between that and this file is the personality function used as it's
+; different for 32-bit MSVC than it is for 64-bit.
+
+define i8* @rust_try(void (i8*)* %f, i8* %env)
+    personality i8* bitcast (i32 (...)* @_except_handler3 to i8*)
+{
+    invoke void %f(i8* %env)
+        to label %normal
+        unwind label %catch
+
+normal:
+    ret i8* null
+catch:
+    %vals = landingpad { i8*, i32 }
+              catch i8* bitcast (i32 (i8*, i8*)* @__rust_try_filter to i8*)
+    %ehptr = extractvalue { i8*, i32 } %vals, 0
+    %sel = extractvalue { i8*, i32 } %vals, 1
+    %filter_sel = call i32 @llvm.eh.typeid.for(i8* bitcast (i32 (i8*, i8*)* @__rust_try_filter to i8*))
+    %is_filter = icmp eq i32 %sel, %filter_sel
+    br i1 %is_filter, label %catch-return, label %catch-resume
+
+catch-return:
+    ret i8* %ehptr
+
+catch-resume:
+    resume { i8*, i32 } %vals
+}
+
+declare i32 @_except_handler3(...)
+declare i32 @__rust_try_filter(i8*, i8*)
+declare i32 @llvm.eh.typeid.for(i8*) readnone nounwind