maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/clang/test/CodeGenCXX/wasm-eh.cpp

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

414 lines
16 KiB
C++
Raw Normal View History

[WebAssembly] Make wasm-eh.cpp requires WebAssembly 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
2019-09-12 14:52:24 +08:00
// REQUIRES: webassembly-registered-target
[clang][cli] Squash multiple cc1 -fxxx-exceptions flags into single -exception-model=xxx option This patch enables marshalling of the exception model options while enforcing their mutual exclusivity. The clang driver interface remains the same, this only affects the cc1 command line. Depends on D93215. Reviewed By: dexonsmith Differential Revision: https://reviews.llvm.org/D93216
2020-12-15 16:59:19 +08:00
// RUN: %clang_cc1 %s -triple wasm32-unknown-unknown -fms-extensions -fexceptions -fcxx-exceptions -exception-model=wasm -target-feature +exception-handling -emit-llvm -o - -std=c++11 | FileCheck %s
// RUN: %clang_cc1 %s -triple wasm64-unknown-unknown -fms-extensions -fexceptions -fcxx-exceptions -exception-model=wasm -target-feature +exception-handling -emit-llvm -o - -std=c++11 | FileCheck %s
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
void may_throw();
void dont_throw() noexcept;
struct Cleanup {
~Cleanup() { dont_throw(); }
};
// Multiple catch clauses w/o catch-all
void test0() {
try {
may_throw();
} catch (int) {
dont_throw();
} catch (double) {
dont_throw();
}
}
// CHECK-LABEL: define void @_Z5test0v() {{.*}} personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*)
// CHECK: %[[INT_ALLOCA:.*]] = alloca i32
// CHECK: invoke void @_Z9may_throwv()
// CHECK-NEXT: to label %[[NORMAL_BB:.*]] unwind label %[[CATCHDISPATCH_BB:.*]]
// CHECK: [[CATCHDISPATCH_BB]]:
// CHECK-NEXT: %[[CATCHSWITCH:.*]] = catchswitch within none [label %[[CATCHSTART_BB:.*]]] unwind to caller
// CHECK: [[CATCHSTART_BB]]:
// CHECK-NEXT: %[[CATCHPAD:.*]] = catchpad within %[[CATCHSWITCH]] [i8* bitcast (i8** @_ZTIi to i8*), i8* bitcast (i8** @_ZTId to i8*)]
// CHECK-NEXT: %[[EXN:.*]] = call i8* @llvm.wasm.get.exception(token %[[CATCHPAD]])
// CHECK-NEXT: store i8* %[[EXN]], i8** %exn.slot
// CHECK-NEXT: %[[SELECTOR:.*]] = call i32 @llvm.wasm.get.ehselector(token %[[CATCHPAD]])
// CHECK-NEXT: %[[TYPEID:.*]] = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) #2
// CHECK-NEXT: %[[MATCHES:.*]] = icmp eq i32 %[[SELECTOR]], %[[TYPEID]]
// CHECK-NEXT: br i1 %[[MATCHES]], label %[[CATCH_INT_BB:.*]], label %[[CATCH_FALLTHROUGH_BB:.*]]
// CHECK: [[CATCH_INT_BB]]:
// CHECK-NEXT: %[[EXN:.*]] = load i8*, i8** %exn.slot
// CHECK-NEXT: %[[ADDR:.*]] = call i8* @__cxa_begin_catch(i8* %[[EXN]]) {{.*}} [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: %[[ADDR_CAST:.*]] = bitcast i8* %[[ADDR]] to i32*
// CHECK-NEXT: %[[INT_VAL:.*]] = load i32, i32* %[[ADDR_CAST]]
// CHECK-NEXT: store i32 %[[INT_VAL]], i32* %[[INT_ALLOCA]]
// CHECK-NEXT: call void @_Z10dont_throwv() {{.*}} [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: call void @__cxa_end_catch() {{.*}} [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: catchret from %[[CATCHPAD]] to label %[[CATCHRET_DEST_BB0:.*]]
// CHECK: [[CATCHRET_DEST_BB0]]:
// CHECK-NEXT: br label %[[TRY_CONT_BB:.*]]
// CHECK: [[CATCH_FALLTHROUGH_BB]]
// CHECK-NEXT: %[[TYPEID:.*]] = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTId to i8*)) #2
// CHECK-NEXT: %[[MATCHES:.*]] = icmp eq i32 %[[SELECTOR]], %[[TYPEID]]
// CHECK-NEXT: br i1 %[[MATCHES]], label %[[CATCH_FLOAT_BB:.*]], label %[[RETHROW_BB:.*]]
// CHECK: [[CATCH_FLOAT_BB]]:
// CHECK: catchret from %[[CATCHPAD]] to label %[[CATCHRET_DEST_BB1:.*]]
// CHECK: [[CATCHRET_DEST_BB1]]:
// CHECK-NEXT: br label %[[TRY_CONT_BB]]
// CHECK: [[RETHROW_BB]]:
[WebAssembly] Rename wasm_rethrow_in_catch intrinsic/builtin `wasm_rethrow_in_catch` intrinsic and builtin are used in order to rethrow an exception when the exception is caught but there is no matching clause within the current `catch`. For example, ``` try { foo(); } catch (int n) { ... } ``` If the caught exception does not correspond to C++ `int` type, it should be rethrown. These intrinsic/builtin were renamed `rethrow_in_catch` because at the time I thought there would be another intrinsic for C++'s `throw` keyword, which rethrows an exception. It turned out that `throw` keyword doesn't require wasm's `rethrow` instruction, so we rename `rethrow_in_catch` to just `rethrow` here. Reviewed By: dschuff, tlively Differential Revision: https://reviews.llvm.org/D94038
2020-12-26 08:14:35 +08:00
// CHECK-NEXT: call void @llvm.wasm.rethrow() {{.*}} [ "funclet"(token %[[CATCHPAD]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK-NEXT: unreachable
// Single catch-all
void test1() {
try {
may_throw();
} catch (...) {
dont_throw();
}
}
// CATCH-LABEL: @_Z5test1v()
// CHECK: %[[CATCHSWITCH:.*]] = catchswitch within none [label %[[CATCHSTART_BB:.*]]] unwind to caller
// CHECK: [[CATCHSTART_BB]]:
// CHECK-NEXT: %[[CATCHPAD:.*]] = catchpad within %[[CATCHSWITCH]] [i8* null]
// CHECK: br label %[[CATCH_ALL_BB:.*]]
// CHECK: [[CATCH_ALL_BB]]:
// CHECK: catchret from %[[CATCHPAD]] to label
// Multiple catch clauses w/ catch-all
void test2() {
try {
may_throw();
} catch (int) {
dont_throw();
} catch (...) {
dont_throw();
}
}
// CHECK-LABEL: @_Z5test2v()
// CHECK: %[[CATCHSWITCH:.*]] = catchswitch within none [label %[[CATCHSTART_BB:.*]]] unwind to caller
// CHECK: [[CATCHSTART_BB]]:
// CHECK-NEXT: %[[CATCHPAD:.*]] = catchpad within %[[CATCHSWITCH]] [i8* bitcast (i8** @_ZTIi to i8*), i8* null]
// CHECK: br i1 %{{.*}}, label %[[CATCH_INT_BB:.*]], label %[[CATCH_ALL_BB:.*]]
// CHECK: [[CATCH_INT_BB]]:
// CHECK: catchret from %[[CATCHPAD]] to label
// CHECK: [[CATCH_ALL_BB]]:
// CHECK: catchret from %[[CATCHPAD]] to label
// Cleanup
void test3() {
Cleanup c;
may_throw();
}
// CHECK-LABEL: @_Z5test3v()
// CHECK: invoke void @_Z9may_throwv()
// CHECK-NEXT: to label {{.*}} unwind label %[[EHCLEANUP_BB:.*]]
// CHECK: [[EHCLEANUP_BB]]:
// CHECK-NEXT: %[[CLEANUPPAD:.*]] = cleanuppad within none []
[CodeGen] Apply 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments. * Adds 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments * Gates 'nonnull' on -f(no-)delete-null-pointer-checks * Introduces this-nonnull.cpp and microsoft-abi-this-nullable.cpp tests to explicitly test the behavior of this change * Refactors hundreds of over-constrained clang tests to permit these attributes, where needed * Updates Clang12 patch notes mentioning this change Reviewed-by: rsmith, jdoerfert Differential Revision: https://reviews.llvm.org/D17993
2020-11-17 07:04:55 +08:00
// CHECK-NEXT: call %struct.Cleanup* @_ZN7CleanupD1Ev(%struct.Cleanup* {{[^,]*}} %{{.*}}) {{.*}} [ "funclet"(token %[[CLEANUPPAD]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK-NEXT: cleanupret from %[[CLEANUPPAD]] unwind to caller
// Possibly throwing function call within a catch
void test4() {
try {
may_throw();
} catch (int) {
may_throw();
}
}
// CHECK-LABEL: @_Z5test4v()
// CHECK: %[[CATCHSWITCH]] = catchswitch within none [label %[[CATCHSTART_BB]]] unwind to caller
// CHECK: [[CATCHSTART_BB]]:
// CHECK: %[[CATCHPAD:.*]] = catchpad within %[[CATCHSWITCH]] [i8* bitcast (i8** @_ZTIi to i8*)]
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: to label %[[INVOKE_CONT_BB:.*]] unwind label %[[EHCLEANUP_BB:.*]]
// CHECK: [[INVOKE_CONT_BB]]:
// CHECK-NEXT: call void @__cxa_end_catch() {{.*}} [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: catchret from %[[CATCHPAD]] to label
// CHECK: [[EHCLEANUP_BB]]:
// CHECK-NEXT: %[[CLEANUPPAD:.*]] = cleanuppad within %[[CATCHPAD]] []
// CHECK-NEXT: call void @__cxa_end_catch() {{.*}} [ "funclet"(token %[[CLEANUPPAD]]) ]
// CHECK-NEXT: cleanupret from %[[CLEANUPPAD]] unwind to caller
// Possibly throwing function call within a catch-all
void test5() {
try {
may_throw();
} catch (...) {
may_throw();
}
}
// CHECK-LABEL: @_Z5test5v()
// CHECK: %[[CATCHSWITCH:.*]] = catchswitch within none [label %[[CATCHSTART_BB]]] unwind to caller
// CHECK: [[CATCHSTART_BB]]:
// CHECK: %[[CATCHPAD:.*]] = catchpad within %[[CATCHSWITCH]] [i8* null]
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: to label %[[INVOKE_CONT_BB0:.*]] unwind label %[[EHCLEANUP_BB:.*]]
// CHECK: [[INVOKE_CONT_BB0]]:
// CHECK-NEXT: call void @__cxa_end_catch() [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: catchret from %[[CATCHPAD]] to label
// CHECK: [[EHCLEANUP_BB]]:
// CHECK-NEXT: %[[CLEANUPPAD0:.*]] = cleanuppad within %[[CATCHPAD]] []
// CHECK-NEXT: invoke void @__cxa_end_catch() [ "funclet"(token %[[CLEANUPPAD0]]) ]
// CHECK-NEXT: to label %[[INVOKE_CONT_BB1:.*]] unwind label %[[TERMINATE_BB:.*]]
// CHECK: [[INVOKE_CONT_BB1]]:
// CHECK-NEXT: cleanupret from %[[CLEANUPPAD0]] unwind to caller
// CHECK: [[TERMINATE_BB]]:
// CHECK-NEXT: %[[CLEANUPPAD1:.*]] = cleanuppad within %[[CLEANUPPAD0]] []
[WebAssembly] Disable uses of __clang_call_terminate Background: Wasm EH, while using Windows EH (catchpad/cleanuppad based) IR, uses Itanium-based libraries and ABIs with some modifications. `__clang_call_terminate` is a wrapper generated in Clang's Itanium C++ ABI implementation. It contains this code, in C-style pseudocode: ``` void __clang_call_terminate(void *exn) { __cxa_begin_catch(exn); std::terminate(); } ``` So this function is a wrapper to call `__cxa_begin_catch` on the exception pointer before termination. In Itanium ABI, this function is called when another exception is thrown while processing an exception. The pointer for this second, violating exception is passed as the argument of this `__clang_call_terminate`, which calls `__cxa_begin_catch` with that pointer and calls `std::terminate` to terminate the program. The spec (https://libcxxabi.llvm.org/spec.html) for `__cxa_begin_catch` says, ``` When the personality routine encounters a termination condition, it will call __cxa_begin_catch() to mark the exception as handled and then call terminate(), which shall not return to its caller. ``` In wasm EH's Clang implementation, this function is called from cleanuppads that terminates the program, which we also call terminate pads. Cleanuppads normally don't access the thrown exception and the wasm backend converts them to `catch_all` blocks. But because we need the exception pointer in this cleanuppad, we generate `wasm.get.exception` intrinsic (which will eventually be lowered to `catch` instruction) as we do in the catchpads. But because terminate pads are cleanup pads and should run even when a foreign exception is thrown, so what we have been doing is: 1. In `WebAssemblyLateEHPrepare::ensureSingleBBTermPads()`, we make sure terminate pads are in this simple shape: ``` %exn = catch call @__clang_call_terminate(%exn) unreachable ``` 2. In `WebAssemblyHandleEHTerminatePads` pass at the end of the pipeline, we attach a `catch_all` to terminate pads, so they will be in this form: ``` %exn = catch call @__clang_call_terminate(%exn) unreachable catch_all call @std::terminate() unreachable ``` In `catch_all` part, we don't have the exception pointer, so we call `std::terminate()` directly. The reason we ran HandleEHTerminatePads at the end of the pipeline, separate from LateEHPrepare, was it was convenient to assume there was only a single `catch` part per `try` during CFGSort and CFGStackify. --- Problem: While it thinks terminate pads could have been possibly split or calls to `__clang_call_terminate` could have been duplicated, `WebAssemblyLateEHPrepare::ensureSingleBBTermPads()` assumes terminate pads contain no more than calls to `__clang_call_terminate` and `unreachable` instruction. I assumed that because in LLVM very limited forms of transformations are done to catchpads and cleanuppads to maintain the scoping structure. But it turned out to be incorrect; passes can merge cleanuppads into one, including terminate pads, as long as the new code has a correct scoping structure. One pass that does this I observed was `SimplifyCFG`, but there can be more. After this transformation, a single cleanuppad can contain any number of other instructions with the call to `__clang_call_terminate` and can span many BBs. It wouldn't be practical to duplicate all these BBs within the cleanuppad to generate the equivalent `catch_all` blocks, only with calls to `__clang_call_terminate` replaced by calls to `std::terminate`. Unless we do more complicated transformation to split those calls to `__clang_call_terminate` into a separate cleanuppad, it is tricky to solve. --- Solution (?): This CL just disables the generation and use of `__clang_call_terminate` and calls `std::terminate()` directly in its place. The possible downside of this approach can be, because the Itanium ABI intended to "mark" the violating exception handled, we don't do that anymore. What `__cxa_begin_catch` actually does is increment the exception's handler count and decrement the uncaught exception count, which in my opinion do not matter much given that we are about to terminate the program anyway. Also it does not affect info like stack traces that can be possibly shown to developers. And while we use a variant of Itanium EH ABI, we can make some deviations if we choose to; we are already different in that in the current version of the EH spec we don't support two-phase unwinding. We can possibly consider a more complicated transformation later to reenable this, but I don't think that has high priority. Changes in this CL contains: - In Clang, we don't generate a call to `wasm.get.exception()` intrinsic and `__clang_call_terminate` function in terminate pads anymore; we simply generate calls to `std::terminate()`, which is the default implementation of `CGCXXABI::emitTerminateForUnexpectedException`. - Remove `WebAssembly::ensureSingleBBTermPads() function and `WebAssemblyHandleEHTerminatePads` pass, because terminate pads are already `catch_all` now (because they don't need the exception pointer) and we don't need these transformations anymore. - Change tests to use `std::terminate` directly. Also removes tests that tested `LateEHPrepare::ensureSingleBBTermPads` and `HandleEHTerminatePads` pass. - Drive-by fix: Add some function attributes to EH intrinsic declarations Fixes https://github.com/emscripten-core/emscripten/issues/13582. Reviewed By: dschuff, tlively Differential Revision: https://reviews.llvm.org/D97834
2021-03-03 07:05:30 +08:00
// CHECK-NEXT: call void @_ZSt9terminatev() {{.*}} [ "funclet"(token %[[CLEANUPPAD1]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK-NEXT: unreachable
// Try-catch with cleanups
void test6() {
Cleanup c1;
try {
Cleanup c2;
may_throw();
} catch (int) {
Cleanup c3;
may_throw();
}
}
// CHECK-LABEL: @_Z5test6v()
// CHECK: invoke void @_Z9may_throwv()
// CHECK-NEXT: to label %{{.*}} unwind label %[[EHCLEANUP_BB0:.*]]
// CHECK: [[EHCLEANUP_BB0]]:
// CHECK-NEXT: %[[CLEANUPPAD0:.*]] = cleanuppad within none []
// CHECK-NEXT: call %struct.Cleanup* @_ZN7CleanupD1Ev(%struct.Cleanup* {{.*}}) {{.*}} [ "funclet"(token %[[CLEANUPPAD0]]) ]
// CHECK-NEXT: cleanupret from %[[CLEANUPPAD0]] unwind label %[[CATCH_DISPATCH_BB:.*]]
// CHECK: [[CATCH_DISPATCH_BB]]:
// CHECK-NEXT: %[[CATCHSWITCH:.*]] = catchswitch within none [label %[[CATCHSTART_BB:.*]]] unwind label %[[EHCLEANUP_BB1:.*]]
// CHECK: [[CATCHSTART_BB]]:
// CHECK-NEXT: %[[CATCHPAD:.*]] = catchpad within %[[CATCHSWITCH]] [i8* bitcast (i8** @_ZTIi to i8*)]
// CHECK: br i1 %{{.*}}, label %[[CATCH_INT_BB:.*]], label %[[RETHROW_BB:.*]]
// CHECK: [[CATCH_INT_BB]]:
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD]]) ]
// CHECK-NEXT: to label %[[INVOKE_CONT_BB:.*]] unwind label %[[EHCLEANUP_BB2:.*]]
// CHECK: [[INVOKE_CONT_BB]]:
// CHECK: catchret from %[[CATCHPAD]] to label %{{.*}}
// CHECK: [[RETHROW_BB]]:
[WebAssembly] Rename wasm_rethrow_in_catch intrinsic/builtin `wasm_rethrow_in_catch` intrinsic and builtin are used in order to rethrow an exception when the exception is caught but there is no matching clause within the current `catch`. For example, ``` try { foo(); } catch (int n) { ... } ``` If the caught exception does not correspond to C++ `int` type, it should be rethrown. These intrinsic/builtin were renamed `rethrow_in_catch` because at the time I thought there would be another intrinsic for C++'s `throw` keyword, which rethrows an exception. It turned out that `throw` keyword doesn't require wasm's `rethrow` instruction, so we rename `rethrow_in_catch` to just `rethrow` here. Reviewed By: dschuff, tlively Differential Revision: https://reviews.llvm.org/D94038
2020-12-26 08:14:35 +08:00
// CHECK-NEXT: invoke void @llvm.wasm.rethrow() {{.*}} [ "funclet"(token %[[CATCHPAD]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK-NEXT: to label %[[UNREACHABLE_BB:.*]] unwind label %[[EHCLEANUP_BB1:.*]]
// CHECK: [[EHCLEANUP_BB2]]:
// CHECK-NEXT: %[[CLEANUPPAD2:.*]] = cleanuppad within %[[CATCHPAD]] []
[CodeGen] Apply 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments. * Adds 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments * Gates 'nonnull' on -f(no-)delete-null-pointer-checks * Introduces this-nonnull.cpp and microsoft-abi-this-nullable.cpp tests to explicitly test the behavior of this change * Refactors hundreds of over-constrained clang tests to permit these attributes, where needed * Updates Clang12 patch notes mentioning this change Reviewed-by: rsmith, jdoerfert Differential Revision: https://reviews.llvm.org/D17993
2020-11-17 07:04:55 +08:00
// CHECK-NEXT: call %struct.Cleanup* @_ZN7CleanupD1Ev(%struct.Cleanup* {{[^,]*}} %{{.*}}) {{.*}} [ "funclet"(token %[[CLEANUPPAD2]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK-NEXT: cleanupret from %[[CLEANUPPAD2]] unwind label %[[EHCLEANUP_BB3:.*]]
// CHECK: [[EHCLEANUP_BB3]]:
// CHECK-NEXT: %[[CLEANUPPAD3:.*]] = cleanuppad within %[[CATCHPAD]] []
// CHECK: cleanupret from %[[CLEANUPPAD3]] unwind label %[[EHCLEANUP_BB1:.*]]
// CHECK: [[EHCLEANUP_BB1]]:
// CHECK-NEXT: %[[CLEANUPPAD1:.*]] = cleanuppad within none []
[CodeGen] Apply 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments. * Adds 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments * Gates 'nonnull' on -f(no-)delete-null-pointer-checks * Introduces this-nonnull.cpp and microsoft-abi-this-nullable.cpp tests to explicitly test the behavior of this change * Refactors hundreds of over-constrained clang tests to permit these attributes, where needed * Updates Clang12 patch notes mentioning this change Reviewed-by: rsmith, jdoerfert Differential Revision: https://reviews.llvm.org/D17993
2020-11-17 07:04:55 +08:00
// CHECK-NEXT: call %struct.Cleanup* @_ZN7CleanupD1Ev(%struct.Cleanup* {{[^,]*}} %{{.*}}) {{.*}} [ "funclet"(token %[[CLEANUPPAD1]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK-NEXT: cleanupret from %[[CLEANUPPAD1]] unwind to caller
// CHECK: [[UNREACHABLE_BB]]:
// CHECK-NEXT: unreachable
// Nested try-catches within a try with cleanups
void test7() {
Cleanup c1;
may_throw();
try {
Cleanup c2;
may_throw();
try {
Cleanup c3;
may_throw();
} catch (int) {
may_throw();
} catch (double) {
may_throw();
}
} catch (int) {
may_throw();
} catch (...) {
may_throw();
}
}
// CHECK-LABEL: @_Z5test7v()
// CHECK: invoke void @_Z9may_throwv()
// CHECK: invoke void @_Z9may_throwv()
// CHECK: invoke void @_Z9may_throwv()
// CHECK: %[[CLEANUPPAD0:.*]] = cleanuppad within none []
// CHECK: cleanupret from %[[CLEANUPPAD0]] unwind label
// CHECK: %[[CATCHSWITCH0:.*]] = catchswitch within none
// CHECK: %[[CATCHPAD0:.*]] = catchpad within %[[CATCHSWITCH0]] [i8* bitcast (i8** @_ZTIi to i8*), i8* bitcast (i8** @_ZTId to i8*)]
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD0]]) ]
// CHECK: catchret from %[[CATCHPAD0]] to label
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD0]]) ]
// CHECK: catchret from %[[CATCHPAD0]] to label
[WebAssembly] Rename wasm_rethrow_in_catch intrinsic/builtin `wasm_rethrow_in_catch` intrinsic and builtin are used in order to rethrow an exception when the exception is caught but there is no matching clause within the current `catch`. For example, ``` try { foo(); } catch (int n) { ... } ``` If the caught exception does not correspond to C++ `int` type, it should be rethrown. These intrinsic/builtin were renamed `rethrow_in_catch` because at the time I thought there would be another intrinsic for C++'s `throw` keyword, which rethrows an exception. It turned out that `throw` keyword doesn't require wasm's `rethrow` instruction, so we rename `rethrow_in_catch` to just `rethrow` here. Reviewed By: dschuff, tlively Differential Revision: https://reviews.llvm.org/D94038
2020-12-26 08:14:35 +08:00
// CHECK: invoke void @llvm.wasm.rethrow() {{.*}} [ "funclet"(token %[[CATCHPAD0]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK: %[[CLEANUPPAD1:.*]] = cleanuppad within %[[CATCHPAD0]] []
// CHECK: cleanupret from %[[CLEANUPPAD1]] unwind label
// CHECK: %[[CLEANUPPAD2:.*]] = cleanuppad within %[[CATCHPAD0]] []
// CHECK: cleanupret from %[[CLEANUPPAD2]] unwind label
// CHECK: %[[CLEANUPPAD3:.*]] = cleanuppad within none []
// CHECK: cleanupret from %[[CLEANUPPAD3]] unwind label
// CHECK: %[[CATCHSWITCH1:.*]] = catchswitch within none
// CHECK: %[[CATCHPAD1:.*]] = catchpad within %[[CATCHSWITCH1]] [i8* bitcast (i8** @_ZTIi to i8*), i8* null]
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD1]]) ]
// CHECK: catchret from %[[CATCHPAD1]] to label
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD1]]) ]
// CHECK: invoke void @__cxa_end_catch() [ "funclet"(token %[[CATCHPAD1]]) ]
// CHECK: catchret from %[[CATCHPAD1]] to label
// CHECK: %[[CLEANUPPAD4:.*]] = cleanuppad within %[[CATCHPAD1]] []
// CHECK: invoke void @__cxa_end_catch() [ "funclet"(token %[[CLEANUPPAD4]]) ]
// CHECK: cleanupret from %[[CLEANUPPAD4]] unwind label
// CHECK: %[[CLEANUPPAD5:.*]] = cleanuppad within %[[CATCHPAD1]] []
// CHECK: cleanupret from %[[CLEANUPPAD5]] unwind label
// CHECK: %[[CLEANUPPAD6:.*]] = cleanuppad within none []
// CHECK: cleanupret from %[[CLEANUPPAD6]] unwind to caller
// CHECK: unreachable
// CHECK: %[[CLEANUPPAD7:.*]] = cleanuppad within %[[CLEANUPPAD4]] []
[WebAssembly] Disable uses of __clang_call_terminate Background: Wasm EH, while using Windows EH (catchpad/cleanuppad based) IR, uses Itanium-based libraries and ABIs with some modifications. `__clang_call_terminate` is a wrapper generated in Clang's Itanium C++ ABI implementation. It contains this code, in C-style pseudocode: ``` void __clang_call_terminate(void *exn) { __cxa_begin_catch(exn); std::terminate(); } ``` So this function is a wrapper to call `__cxa_begin_catch` on the exception pointer before termination. In Itanium ABI, this function is called when another exception is thrown while processing an exception. The pointer for this second, violating exception is passed as the argument of this `__clang_call_terminate`, which calls `__cxa_begin_catch` with that pointer and calls `std::terminate` to terminate the program. The spec (https://libcxxabi.llvm.org/spec.html) for `__cxa_begin_catch` says, ``` When the personality routine encounters a termination condition, it will call __cxa_begin_catch() to mark the exception as handled and then call terminate(), which shall not return to its caller. ``` In wasm EH's Clang implementation, this function is called from cleanuppads that terminates the program, which we also call terminate pads. Cleanuppads normally don't access the thrown exception and the wasm backend converts them to `catch_all` blocks. But because we need the exception pointer in this cleanuppad, we generate `wasm.get.exception` intrinsic (which will eventually be lowered to `catch` instruction) as we do in the catchpads. But because terminate pads are cleanup pads and should run even when a foreign exception is thrown, so what we have been doing is: 1. In `WebAssemblyLateEHPrepare::ensureSingleBBTermPads()`, we make sure terminate pads are in this simple shape: ``` %exn = catch call @__clang_call_terminate(%exn) unreachable ``` 2. In `WebAssemblyHandleEHTerminatePads` pass at the end of the pipeline, we attach a `catch_all` to terminate pads, so they will be in this form: ``` %exn = catch call @__clang_call_terminate(%exn) unreachable catch_all call @std::terminate() unreachable ``` In `catch_all` part, we don't have the exception pointer, so we call `std::terminate()` directly. The reason we ran HandleEHTerminatePads at the end of the pipeline, separate from LateEHPrepare, was it was convenient to assume there was only a single `catch` part per `try` during CFGSort and CFGStackify. --- Problem: While it thinks terminate pads could have been possibly split or calls to `__clang_call_terminate` could have been duplicated, `WebAssemblyLateEHPrepare::ensureSingleBBTermPads()` assumes terminate pads contain no more than calls to `__clang_call_terminate` and `unreachable` instruction. I assumed that because in LLVM very limited forms of transformations are done to catchpads and cleanuppads to maintain the scoping structure. But it turned out to be incorrect; passes can merge cleanuppads into one, including terminate pads, as long as the new code has a correct scoping structure. One pass that does this I observed was `SimplifyCFG`, but there can be more. After this transformation, a single cleanuppad can contain any number of other instructions with the call to `__clang_call_terminate` and can span many BBs. It wouldn't be practical to duplicate all these BBs within the cleanuppad to generate the equivalent `catch_all` blocks, only with calls to `__clang_call_terminate` replaced by calls to `std::terminate`. Unless we do more complicated transformation to split those calls to `__clang_call_terminate` into a separate cleanuppad, it is tricky to solve. --- Solution (?): This CL just disables the generation and use of `__clang_call_terminate` and calls `std::terminate()` directly in its place. The possible downside of this approach can be, because the Itanium ABI intended to "mark" the violating exception handled, we don't do that anymore. What `__cxa_begin_catch` actually does is increment the exception's handler count and decrement the uncaught exception count, which in my opinion do not matter much given that we are about to terminate the program anyway. Also it does not affect info like stack traces that can be possibly shown to developers. And while we use a variant of Itanium EH ABI, we can make some deviations if we choose to; we are already different in that in the current version of the EH spec we don't support two-phase unwinding. We can possibly consider a more complicated transformation later to reenable this, but I don't think that has high priority. Changes in this CL contains: - In Clang, we don't generate a call to `wasm.get.exception()` intrinsic and `__clang_call_terminate` function in terminate pads anymore; we simply generate calls to `std::terminate()`, which is the default implementation of `CGCXXABI::emitTerminateForUnexpectedException`. - Remove `WebAssembly::ensureSingleBBTermPads() function and `WebAssemblyHandleEHTerminatePads` pass, because terminate pads are already `catch_all` now (because they don't need the exception pointer) and we don't need these transformations anymore. - Change tests to use `std::terminate` directly. Also removes tests that tested `LateEHPrepare::ensureSingleBBTermPads` and `HandleEHTerminatePads` pass. - Drive-by fix: Add some function attributes to EH intrinsic declarations Fixes https://github.com/emscripten-core/emscripten/issues/13582. Reviewed By: dschuff, tlively Differential Revision: https://reviews.llvm.org/D97834
2021-03-03 07:05:30 +08:00
// CHECK: call void @_ZSt9terminatev() {{.*}} [ "funclet"(token %[[CLEANUPPAD7]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK: unreachable
// Nested try-catches within a catch
void test8() {
try {
may_throw();
} catch (int) {
try {
may_throw();
} catch (int) {
may_throw();
}
}
}
// CHECK-LABEL: @_Z5test8v()
// CHECK: invoke void @_Z9may_throwv()
// CHECK: %[[CATCHSWITCH0:.*]] = catchswitch within none
// CHECK: %[[CATCHPAD0:.*]] = catchpad within %[[CATCHSWITCH0]] [i8* bitcast (i8** @_ZTIi to i8*)]
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD0]]) ]
// CHECK: %[[CATCHSWITCH1:.*]] = catchswitch within %[[CATCHPAD0]]
// CHECK: %[[CATCHPAD1:.*]] = catchpad within %[[CATCHSWITCH1]] [i8* bitcast (i8** @_ZTIi to i8*)]
// CHECK: invoke void @_Z9may_throwv() [ "funclet"(token %[[CATCHPAD1]]) ]
// CHECK: catchret from %[[CATCHPAD1]] to label
[WebAssembly] Rename wasm_rethrow_in_catch intrinsic/builtin `wasm_rethrow_in_catch` intrinsic and builtin are used in order to rethrow an exception when the exception is caught but there is no matching clause within the current `catch`. For example, ``` try { foo(); } catch (int n) { ... } ``` If the caught exception does not correspond to C++ `int` type, it should be rethrown. These intrinsic/builtin were renamed `rethrow_in_catch` because at the time I thought there would be another intrinsic for C++'s `throw` keyword, which rethrows an exception. It turned out that `throw` keyword doesn't require wasm's `rethrow` instruction, so we rename `rethrow_in_catch` to just `rethrow` here. Reviewed By: dschuff, tlively Differential Revision: https://reviews.llvm.org/D94038
2020-12-26 08:14:35 +08:00
// CHECK: invoke void @llvm.wasm.rethrow() {{.*}} [ "funclet"(token %[[CATCHPAD1]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK: catchret from %[[CATCHPAD0]] to label
[WebAssembly] Rename wasm_rethrow_in_catch intrinsic/builtin `wasm_rethrow_in_catch` intrinsic and builtin are used in order to rethrow an exception when the exception is caught but there is no matching clause within the current `catch`. For example, ``` try { foo(); } catch (int n) { ... } ``` If the caught exception does not correspond to C++ `int` type, it should be rethrown. These intrinsic/builtin were renamed `rethrow_in_catch` because at the time I thought there would be another intrinsic for C++'s `throw` keyword, which rethrows an exception. It turned out that `throw` keyword doesn't require wasm's `rethrow` instruction, so we rename `rethrow_in_catch` to just `rethrow` here. Reviewed By: dschuff, tlively Differential Revision: https://reviews.llvm.org/D94038
2020-12-26 08:14:35 +08:00
// CHECK: call void @llvm.wasm.rethrow() {{.*}} [ "funclet"(token %[[CATCHPAD0]]) ]
[WebAssembly] Use Windows EH instructions for Wasm EH 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
2018-06-01 06:18:13 +08:00
// CHECK: unreachable
// CHECK: %[[CLEANUPPAD0:.*]] = cleanuppad within %[[CATCHPAD1]] []
// CHECK: cleanupret from %[[CLEANUPPAD0]] unwind label
// CHECK: %[[CLEANUPPAD1:.*]] = cleanuppad within %[[CATCHPAD0]] []
// CHECK: cleanupret from %[[CLEANUPPAD1]] unwind to caller
// CHECK: unreachable
[WebAssembly] Add -fwasm-exceptions for wasm EH 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
2019-09-12 12:01:37 +08:00
[clang][cli] Squash multiple cc1 -fxxx-exceptions flags into single -exception-model=xxx option This patch enables marshalling of the exception model options while enforcing their mutual exclusivity. The clang driver interface remains the same, this only affects the cc1 command line. Depends on D93215. Reviewed By: dexonsmith Differential Revision: https://reviews.llvm.org/D93216
2020-12-15 16:59:19 +08:00
// RUN: %clang_cc1 %s -triple wasm32-unknown-unknown -fms-extensions -fexceptions -fcxx-exceptions -exception-model=wasm -target-feature +exception-handling -emit-llvm -o - -std=c++11 2>&1 | FileCheck %s --check-prefix=WARNING-DEFAULT
// RUN: %clang_cc1 %s -triple wasm32-unknown-unknown -fms-extensions -fexceptions -fcxx-exceptions -exception-model=wasm -target-feature +exception-handling -Wwasm-exception-spec -emit-llvm -o - -std=c++11 2>&1 | FileCheck %s --check-prefix=WARNING-ON
// RUN: %clang_cc1 %s -triple wasm32-unknown-unknown -fms-extensions -fexceptions -fcxx-exceptions -exception-model=wasm -target-feature +exception-handling -Wno-wasm-exception-spec -emit-llvm -o - -std=c++11 2>&1 | FileCheck %s --check-prefix=WARNING-OFF
[WebAssembly] Warn on exception spec for Emscripten EH It turns out we have not correctly supported exception spec all along in Emscripten EH. Emscripten EH supports `throw()` but not `throw` with types. See https://bugs.llvm.org/show_bug.cgi?id=50396. Wasm EH also only supports `throw()` but not `throw` with types, and we have been printing a warning message for the latter. This prints the same warning message for `throw` with types when Emscripten EH is used, or more precisely, when Wasm EH is not used. (So this will print the warning messsage even when `-fno-exceptions` is used but I think that should be fine. It's cumbersome to do a complilcated option checking in CGException.cpp and options checkings are mostly done in elsewhere.) Reviewed By: dschuff, kripken Differential Revision: https://reviews.llvm.org/D102791
2021-05-19 16:47:58 +08:00
// RUN: %clang_cc1 %s -triple wasm32-unknown-unknown -fexceptions -fcxx-exceptions -emit-llvm -o - -std=c++11 2>&1 | FileCheck %s --check-prefix=EM-EH-WARNING
[WebAssembly] Handle exception specifications 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
2020-05-09 07:19:46 +08:00
[WebAssembly] Warn on exception spec only when Wasm EH is used 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
2020-05-21 14:02:41 +08:00
// Wasm EH ignores dynamic exception specifications with types at the moment.
// This is controlled by -Wwasm-exception-spec, which is on by default. This
// warning can be suppressed with -Wno-wasm-exception-spec. Checks if a warning
// message is correctly printed or not printed depending on the options.
[WebAssembly] Handle exception specifications 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
2020-05-09 07:19:46 +08:00
void test9() throw(int) {
}
// WARNING-DEFAULT: warning: dynamic exception specifications with types are currently ignored in wasm
// WARNING-ON: warning: dynamic exception specifications with types are currently ignored in wasm
// WARNING-OFF-NOT: warning: dynamic exception specifications with types are currently ignored in wasm
[WebAssembly] Warn on exception spec for Emscripten EH It turns out we have not correctly supported exception spec all along in Emscripten EH. Emscripten EH supports `throw()` but not `throw` with types. See https://bugs.llvm.org/show_bug.cgi?id=50396. Wasm EH also only supports `throw()` but not `throw` with types, and we have been printing a warning message for the latter. This prints the same warning message for `throw` with types when Emscripten EH is used, or more precisely, when Wasm EH is not used. (So this will print the warning messsage even when `-fno-exceptions` is used but I think that should be fine. It's cumbersome to do a complilcated option checking in CGException.cpp and options checkings are mostly done in elsewhere.) Reviewed By: dschuff, kripken Differential Revision: https://reviews.llvm.org/D102791
2021-05-19 16:47:58 +08:00
// EM-EH-WARNING: warning: dynamic exception specifications with types are currently ignored in wasm
[WebAssembly] Handle exception specifications 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
2020-05-09 07:19:46 +08:00
// Wasm curremtly treats 'throw()' in the same way as 'noexept'. Check if the
// same warning message is printed as if when a 'noexcept' function throws.
void test10() throw() {
throw 3;
}
// WARNING-DEFAULT: warning: 'test10' has a non-throwing exception specification but can still throw
// WARNING-DEFAULT: function declared non-throwing here
[WebAssembly] Add -fwasm-exceptions for wasm EH 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
2019-09-12 12:01:37 +08:00
// Here we only check if the command enables wasm exception handling in the
// backend so that exception handling instructions can be generated in .s file.
[WebAssembly] Reenable end-to-end test in wasm-eh.cpp This was temporarily disabled while we were reimplementing the new spec. Reviewed By: tlively Differential Revision: https://reviews.llvm.org/D101735
2021-05-03 09:03:25 +08:00
// RUN: %clang_cc1 %s -triple wasm32-unknown-unknown -fms-extensions -fexceptions -fcxx-exceptions -exception-model=wasm -target-feature +exception-handling -S -o - -std=c++11 | FileCheck %s --check-prefix=ASSEMBLY
[WebAssembly] Handle exception specifications 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
2020-05-09 07:19:46 +08:00
[WebAssembly] Add -fwasm-exceptions for wasm EH 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
2019-09-12 12:01:37 +08:00
// ASSEMBLY: try
// ASSEMBLY: catch
// ASSEMBLY: rethrow
// ASSEMBLY: end_try