Summary:
In D80061 we added warning for exception specifications with types (such
as `throw(int)`), but it was enabled every time the target was wasm,
which means it warned (and ignored) exception specifications even if
wasm EH was not used. This fixes it and we only have the warning when we
enable `-fwasm-exceptions`.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D80362
Summary:
Wasm currently does not fully handle exception specifications. Rather
than crashing,
- This treats `throw()` in the same way as `noexcept`.
- This ignores and prints a warning for `throw(type, ..)`, for a
temporary measure. This warning is controlled by
`-Wwasm-exception-spec`, which is on by default. You can suppress the
warning by using `-Wno-wasm-exception-spec`.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D80061
This reverts commit bca347508c.
This broke clang/test/Misc/warning-flags.c, because the newly added
warning option in this commit didn't have a matching flag.
Summary:
Wasm currently does not fully handle exception specifications. Rather
than crashing, this treats `throw()` in the same way as `noexcept`, and
ignores and prints a warning for `throw(type, ..)`, for a temporary
measure.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D79655
D67208 added a new test line to wasm-eh.cpp that invokes the LLVM
backend and this test fails on bots that don't have WebAssembly target.
This makes wasm-eh.cpp explicitly require WebAssembly so this will be
skipped on those targets.
llvm-svn: 371711
Summary:
This adds `-fwasm-exceptions` (in similar fashion with
`-fdwarf-exceptions` or `-fsjlj-exceptions`) that turns on everything
with wasm exception handling from the frontend to the backend.
We currently have `-mexception-handling` in clang frontend, but this is
only about the architecture capability and does not turn on other
necessary options such as the exception model in the backend. (This can
be turned on with `llc -exception-model=wasm`, but llc is not invoked
separately as a command line tool, so this option has to be transferred
from clang.)
Turning on `-fwasm-exceptions` in clang also turns on
`-mexception-handling` if not specified, and will error out if
`-mno-exception-handling` is specified.
Reviewers: dschuff, tlively, sbc100
Subscribers: aprantl, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67208
llvm-svn: 371708
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.
Also modifies the parser to accept IR in that form for obvious reasons.
llvm-svn: 367755
Summary:
Because in wasm we merge all catch clauses into one big catchpad, in
case none of the types in catch handlers matches after we test against
each of them, we should unwind to the next EH enclosing scope. For this,
we should NOT use a call to `__cxa_rethrow` but rather a call to our own
rethrow intrinsic, because what we're trying to do here is just to
transfer the control flow into the next enclosing EH pad (or the
caller). Calls to `__cxa_rethrow` should only be used after a call to
`__cxa_begin_catch`.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D59353
llvm-svn: 356317
Summary:
clang's current wasm EH implementation is a non-MVP feature in progress.
We had a `-mexception-handling` wasm feature but were not using it. This
patch hides the non-MVP wasm EH behind a flag, so it does not affect
other code for now.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Differential Revision: https://reviews.llvm.org/D47614
llvm-svn: 333716
Summary:
Because wasm control flow needs to be structured, using WinEH
instructions to support wasm EH brings several benefits. This patch
makes wasm EH uses Windows EH instructions, with some changes:
1. Because wasm uses a single catch block to catch all C++ exceptions,
this merges all catch clauses into a single catchpad, within which we
test the EH selector as in Itanium EH.
2. Generates a call to `__clang_call_terminate` in case a cleanup
throws. Wasm does not have a runtime to handle this.
3. In case there is no catch-all clause, inserts a call to
`__cxa_rethrow` at the end of a catchpad in order to unwind to an
enclosing EH scope.
Reviewers: majnemer, dschuff
Subscribers: jfb, sbc100, jgravelle-google, sunfish, cfe-commits
Differential Revision: https://reviews.llvm.org/D44931
llvm-svn: 333703
Heejin Ahn