https://github.com/rust-lang/rust http://git.dreamy.place/mirrors/rust/atom?h=1.3.0 2015-07-21T23:08:11+00:00 2015-07-21T23:08:11+00:00 Alex Crichton alex@alexcrichton.com 2015-07-20T20:27:38+00:00 urn:sha1:c35b2bd226736925961ca6853b2ef29e8094cd90 This commit moves the IR files in the distribution, rust_try.ll, rust_try_msvc_64.ll, and rust_try_msvc_32.ll into the compiler from the main distribution. There's a few reasons for this change: * LLVM changes its IR syntax from time to time, so it's very difficult to have these files build across many LLVM versions simultaneously. We'll likely want to retain this ability for quite some time into the future. * The implementation of these files is closely tied to the compiler and runtime itself, so it makes sense to fold it into a location which can do more platform-specific checks for various implementation details (such as MSVC 32 vs 64-bit). * This removes LLVM as a build-time dependency of the standard library. This may end up becoming very useful if we move towards building the standard library with Cargo. In the immediate future, however, this commit should restore compatibility with LLVM 3.5 and 3.6. 2015-06-25T16:33:15+00:00 Alex Crichton alex@alexcrichton.com 2015-06-19T21:57:06+00:00 urn:sha1:91d799eab0d7f6784fb4366182b5007cf055519d Now that LLVM has been updated, the only remaining roadblock to implementing unwinding for MSVC is to fill out the runtime support in `std::rt::unwind::seh`. This commit does precisely that, fixing up some other bits and pieces along the way: * The `seh` unwinding module now uses `RaiseException` to initiate a panic. * The `rust_try.ll` file was rewritten for MSVC (as it's quite different) and is located at `rust_try_msvc_64.ll`, only included on MSVC builds for now. * The personality function for all landing pads generated by LLVM is hard-wired to `__C_specific_handler` instead of the standard `rust_eh_personality` lang item. This is required to get LLVM to emit SEH unwinding information instead of DWARF unwinding information. This also means that on MSVC the `rust_eh_personality` function is entirely unused (but is defined as it's a lang item). More details about how panicking works on SEH can be found in the `rust_try_msvc_64.ll` or `seh.rs` files, but I'm always open to adding more comments! A key aspect of this PR is missing, however, which is that **unwinding is still turned off by default for MSVC**. There is a [bug in llvm][llvm-bug] which causes optimizations to inline enough landing pads that LLVM chokes. If the compiler is optimized at `-O1` (where inlining isn't enabled) then it can bootstrap with unwinding enabled, but when optimized at `-O2` (inlining is enabled) then it hits a fatal LLVM error. [llvm-bug]: https://llvm.org/bugs/show_bug.cgi?id=23884 2015-05-19T17:53:07+00:00 Alex Crichton alex@alexcrichton.com 2015-05-12T04:09:07+00:00 urn:sha1:f5222fb892be00f2b3e4dd8b83c5277e94ebbbba At this time unwinding support is not implemented for MSVC as `libgcc_s_seh-1.dll` is not available by default (and this is used on MinGW), but this should be investigated soon. For now this change is just aimed at getting the compiler far enough to bootstrap everything instead of successfully running tests. This commit refactors the `std::rt::unwind` module a bit to prepare for SEH support eventually by moving all GCC-specific functionality to its own submodule and defining the interface needed.