llvm-project/llvm/test/CodeGen/WebAssembly/exception.ll

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; RUN: not --crash llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-keep-registers -exception-model=wasm
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -exception-model=wasm -mattr=+exception-handling -verify-machineinstrs | FileCheck -allow-deprecated-dag-overlap %s
; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-keep-registers -exception-model=wasm -mattr=+exception-handling
target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
target triple = "wasm32-unknown-unknown"
%struct.Temp = type { i8 }
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
@_ZTIi = external constant i8*
; CHECK-LABEL: test_throw:
; CHECK: throw __cpp_exception, $0
; CHECK-NOT: unreachable
define void @test_throw(i8* %p) {
call void @llvm.wasm.throw(i32 0, i8* %p)
ret void
}
; Simple test with a try-catch
;
; void foo();
; void test_catch() {
; try {
; foo();
; } catch (int) {
; }
; }
; CHECK-LABEL: test_catch:
; CHECK: global.get ${{.+}}=, __stack_pointer
; CHECK: try
; CHECK: call foo
; CHECK: catch $[[EXNREF:[0-9]+]]=
; CHECK: global.set __stack_pointer
; CHECK: block i32
; CHECK: br_on_exn 0, __cpp_exception, $[[EXNREF]]
; CHECK: rethrow $[[EXNREF]]
; CHECK: end_block
; CHECK: extract_exception $[[EXN:[0-9]+]]=
; CHECK-DAG: i32.store __wasm_lpad_context
; CHECK-DAG: i32.store __wasm_lpad_context+4
; CHECK: call $drop=, _Unwind_CallPersonality, $[[EXN]]
; CHECK: block
; CHECK: br_if 0
; CHECK: call $drop=, __cxa_begin_catch
; CHECK: call __cxa_end_catch
; CHECK: br 1
; CHECK: end_block
; CHECK: rethrow $[[EXNREF]]
; CHECK: end_try
define void @test_catch() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
entry:
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* bitcast (i8** @_ZTIi to i8*)]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
%4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*))
%matches = icmp eq i32 %3, %4
br i1 %matches, label %catch, label %rethrow
catch: ; preds = %catch.start
%5 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont
rethrow: ; preds = %catch.start
[WebAssembly] Make rethrow take an except_ref type argument Summary: In the new wasm EH proposal, `rethrow` takes an `except_ref` argument. This change was missing in r352598. This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an intrinsic that's gonna eventually be lowered to wasm `rethrow` instruction, but this intrinsic can appear only within a catchpad or a cleanuppad scope. Also this intrinsic needs to be invokable - otherwise EH pad successor for it will not be correctly generated in clang. This also adds lowering logic for this intrinsic in `SelectionDAGBuilder::visitInvoke`. This routine is basically a specialized and simplified version of `SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it because if is only for `CallInst`s. This deletes the previous `llvm.wasm.rethrow` intrinsic and related tests, which was meant to be used within a `__cxa_rethrow` library function. Turned out this needs some more logic, so the intrinsic for this purpose will be added later. LateEHPrepare takes a result value of `catch` and inserts it into matching `rethrow` as an argument. `RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between `llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To generate a `rethrow` instruction, we need an `except_ref` argument, which is generated from `catch` instruction. But `catch` instrutions are added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes no argument, until we are able to correctly lower it to `rethrow` in LateEHPrepare. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59352 llvm-svn: 356316
2019-03-16 13:38:57 +08:00
call void @llvm.wasm.rethrow.in.catch() [ "funclet"(token %1) ]
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
unreachable
[WebAssembly] Fix a bug in finding matching EH pad Summary: `getMatchingEHPad()` in LateEHPrepare is a function to find the nearest EH pad that dominates the given instruction. This intends to be lightweight so it does not use full WebAssemblyException scope analysis or dominator analysis. It simply does backward BFS to its predecessors and stops at the first EH pad each search path encounters. All search should end up at the same EH pad, and if not, it returns null. But it didn't take into account that when there are inner scopes within the current scope, some path in BFS can hit an inner EH pad first. For example, in the given diagram, `Inst` belongs to the outer scope and `getMathingEHPad()` should return 'EHPad 1', but some search path can go into the inner scope and end up with 'EHPad 2'. The search will return null because different paths end up with different EH pads. ``` --- EHPad 1 --- | - EHPad 2 - | | | | | | ----------- | | Inst | --------------- ``` So far this was OK because we haven't tested a case in which a given instruction is far from its EH pad. Also, this bug does not happen when the inner EH scope is a cleanup scope, because a cleanup scope ends with a `cleanupret` whose successor is an EH pad, so the search encounters that EH pad first before going into the child scope. But this can happen when the child scope is a catch scope that ends with `catchret`. So this patch, when doing backward BFS, does not search predecessors that ends with `catchret`. Because `catchret`s are replaced with `br`s during this pass, this records BBs that have `catchret`s in the beginning, before doing any other transformations. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D80571
2020-05-25 16:35:35 +08:00
try.cont: ; preds = %catch, %entry
ret void
}
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
; Destructor (cleanup) test
;
; void foo();
; struct Temp {
; ~Temp() {}
; };
; void test_cleanup() {
; Temp t;
; foo();
; }
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
; CHECK-LABEL: test_cleanup:
; CHECK: try
; CHECK: call foo
; CHECK: catch $[[EXNREF:[0-9]+]]=
; CHECK: global.set __stack_pointer
; CHECK: call $drop=, _ZN4TempD2Ev
; CHECK: rethrow $[[EXNREF]]
; CHECK: end_try
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
define void @test_cleanup() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
%t = alloca %struct.Temp, align 1
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
invoke void @foo()
to label %invoke.cont unwind label %ehcleanup
invoke.cont: ; preds = %entry
%call = call %struct.Temp* @_ZN4TempD2Ev(%struct.Temp* %t)
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
ret void
ehcleanup: ; preds = %entry
%0 = cleanuppad within none []
%call1 = call %struct.Temp* @_ZN4TempD2Ev(%struct.Temp* %t) [ "funclet"(token %0) ]
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
cleanupret from %0 unwind to caller
}
; Calling a function that may throw within a 'catch (...)' generates a
; temrinatepad, because __cxa_end_catch() also can throw within 'catch (...)'.
;
; void foo();
; void test_terminatepad() {
; try {
; foo();
; } catch (...) {
; foo();
; }
; }
; CHECK-LABEL: test_terminatepad
; CHECK: try
; CHECK: call foo
; CHECK: catch
; CHECK: call $drop=, __cxa_begin_catch
; CHECK: try
; CHECK: call foo
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
; CHECK: catch
; CHECK: try
; CHECK: call __cxa_end_catch
; CHECK: catch
; CHECK: block i32
; CHECK: br_on_exn 0, __cpp_exception
; CHECK: i32.const ${{.*}}=, 0
; CHECK: call __clang_call_terminate
; CHECK: unreachable
; CHECK: end_block
; CHECK: call __clang_call_terminate
; CHECK: unreachable
; CHECK: end_try
; CHECK: rethrow
; CHECK: end_try
; CHECK: call __cxa_end_catch
; CHECK: end_try
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
define void @test_terminatepad() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
%1 = catchpad within %0 [i8* null]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
%4 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
invoke void @foo() [ "funclet"(token %1) ]
to label %invoke.cont1 unwind label %ehcleanup
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
invoke.cont1: ; preds = %catch.start
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont
[WebAssembly] Fix a bug in finding matching EH pad Summary: `getMatchingEHPad()` in LateEHPrepare is a function to find the nearest EH pad that dominates the given instruction. This intends to be lightweight so it does not use full WebAssemblyException scope analysis or dominator analysis. It simply does backward BFS to its predecessors and stops at the first EH pad each search path encounters. All search should end up at the same EH pad, and if not, it returns null. But it didn't take into account that when there are inner scopes within the current scope, some path in BFS can hit an inner EH pad first. For example, in the given diagram, `Inst` belongs to the outer scope and `getMathingEHPad()` should return 'EHPad 1', but some search path can go into the inner scope and end up with 'EHPad 2'. The search will return null because different paths end up with different EH pads. ``` --- EHPad 1 --- | - EHPad 2 - | | | | | | ----------- | | Inst | --------------- ``` So far this was OK because we haven't tested a case in which a given instruction is far from its EH pad. Also, this bug does not happen when the inner EH scope is a cleanup scope, because a cleanup scope ends with a `cleanupret` whose successor is an EH pad, so the search encounters that EH pad first before going into the child scope. But this can happen when the child scope is a catch scope that ends with `catchret`. So this patch, when doing backward BFS, does not search predecessors that ends with `catchret`. Because `catchret`s are replaced with `br`s during this pass, this records BBs that have `catchret`s in the beginning, before doing any other transformations. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D80571
2020-05-25 16:35:35 +08:00
try.cont: ; preds = %invoke.cont1, %entry
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
ret void
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
ehcleanup: ; preds = %catch.start
%5 = cleanuppad within %1 []
invoke void @__cxa_end_catch() [ "funclet"(token %5) ]
to label %invoke.cont2 unwind label %terminate
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
invoke.cont2: ; preds = %ehcleanup
cleanupret from %5 unwind to caller
terminate: ; preds = %ehcleanup
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
%6 = cleanuppad within %5 []
%7 = call i8* @llvm.wasm.get.exception(token %6)
call void @__clang_call_terminate(i8* %7) [ "funclet"(token %6) ]
unreachable
}
; Tests prologues and epilogues are not generated within EH scopes.
; They should not be treated as funclets; BBs starting with a catch instruction
; should not have a prologue, and BBs ending with a catchret/cleanupret should
; not have an epilogue. This is separate from __stack_pointer restoring
; instructions after a catch instruction.
;
; void bar(int) noexcept;
; void test_no_prolog_epilog_in_ehpad() {
; int stack_var = 0;
; bar(stack_var);
; try {
; foo();
; } catch (int) {
; foo();
; }
; }
; CHECK-LABEL: test_no_prolog_epilog_in_ehpad
; CHECK: try
; CHECK: call foo
; CHECK: catch
; CHECK-NOT: global.get $push{{.+}}=, __stack_pointer
; CHECK: global.set __stack_pointer
; CHECK: block
; CHECK: block
; CHECK: br_if 0
; CHECK: call $drop=, __cxa_begin_catch
; CHECK: try
; CHECK: call foo
; CHECK: catch
; CHECK-NOT: global.get $push{{.+}}=, __stack_pointer
; CHECK: global.set __stack_pointer
; CHECK: call __cxa_end_catch
; CHECK: rethrow
; CHECK-NOT: global.set __stack_pointer, $pop{{.+}}
; CHECK: end_try
; CHECK: end_block
[WebAssembly] Make rethrow take an except_ref type argument Summary: In the new wasm EH proposal, `rethrow` takes an `except_ref` argument. This change was missing in r352598. This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an intrinsic that's gonna eventually be lowered to wasm `rethrow` instruction, but this intrinsic can appear only within a catchpad or a cleanuppad scope. Also this intrinsic needs to be invokable - otherwise EH pad successor for it will not be correctly generated in clang. This also adds lowering logic for this intrinsic in `SelectionDAGBuilder::visitInvoke`. This routine is basically a specialized and simplified version of `SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it because if is only for `CallInst`s. This deletes the previous `llvm.wasm.rethrow` intrinsic and related tests, which was meant to be used within a `__cxa_rethrow` library function. Turned out this needs some more logic, so the intrinsic for this purpose will be added later. LateEHPrepare takes a result value of `catch` and inserts it into matching `rethrow` as an argument. `RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between `llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To generate a `rethrow` instruction, we need an `except_ref` argument, which is generated from `catch` instruction. But `catch` instrutions are added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes no argument, until we are able to correctly lower it to `rethrow` in LateEHPrepare. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59352 llvm-svn: 356316
2019-03-16 13:38:57 +08:00
; CHECK: rethrow
; CHECK: end_block
; CHECK-NOT: global.set __stack_pointer, $pop{{.+}}
; CHECK: call __cxa_end_catch
; CHECK: end_try
define void @test_no_prolog_epilog_in_ehpad() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
%stack_var = alloca i32, align 4
call void @bar(i32* %stack_var)
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* bitcast (i8** @_ZTIi to i8*)]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
%4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*))
%matches = icmp eq i32 %3, %4
br i1 %matches, label %catch, label %rethrow
catch: ; preds = %catch.start
%5 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
%6 = bitcast i8* %5 to float*
%7 = load float, float* %6, align 4
invoke void @foo() [ "funclet"(token %1) ]
to label %invoke.cont1 unwind label %ehcleanup
invoke.cont1: ; preds = %catch
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont
rethrow: ; preds = %catch.start
[WebAssembly] Make rethrow take an except_ref type argument Summary: In the new wasm EH proposal, `rethrow` takes an `except_ref` argument. This change was missing in r352598. This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an intrinsic that's gonna eventually be lowered to wasm `rethrow` instruction, but this intrinsic can appear only within a catchpad or a cleanuppad scope. Also this intrinsic needs to be invokable - otherwise EH pad successor for it will not be correctly generated in clang. This also adds lowering logic for this intrinsic in `SelectionDAGBuilder::visitInvoke`. This routine is basically a specialized and simplified version of `SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it because if is only for `CallInst`s. This deletes the previous `llvm.wasm.rethrow` intrinsic and related tests, which was meant to be used within a `__cxa_rethrow` library function. Turned out this needs some more logic, so the intrinsic for this purpose will be added later. LateEHPrepare takes a result value of `catch` and inserts it into matching `rethrow` as an argument. `RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between `llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To generate a `rethrow` instruction, we need an `except_ref` argument, which is generated from `catch` instruction. But `catch` instrutions are added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes no argument, until we are able to correctly lower it to `rethrow` in LateEHPrepare. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59352 llvm-svn: 356316
2019-03-16 13:38:57 +08:00
call void @llvm.wasm.rethrow.in.catch() [ "funclet"(token %1) ]
unreachable
[WebAssembly] Fix a bug in finding matching EH pad Summary: `getMatchingEHPad()` in LateEHPrepare is a function to find the nearest EH pad that dominates the given instruction. This intends to be lightweight so it does not use full WebAssemblyException scope analysis or dominator analysis. It simply does backward BFS to its predecessors and stops at the first EH pad each search path encounters. All search should end up at the same EH pad, and if not, it returns null. But it didn't take into account that when there are inner scopes within the current scope, some path in BFS can hit an inner EH pad first. For example, in the given diagram, `Inst` belongs to the outer scope and `getMathingEHPad()` should return 'EHPad 1', but some search path can go into the inner scope and end up with 'EHPad 2'. The search will return null because different paths end up with different EH pads. ``` --- EHPad 1 --- | - EHPad 2 - | | | | | | ----------- | | Inst | --------------- ``` So far this was OK because we haven't tested a case in which a given instruction is far from its EH pad. Also, this bug does not happen when the inner EH scope is a cleanup scope, because a cleanup scope ends with a `cleanupret` whose successor is an EH pad, so the search encounters that EH pad first before going into the child scope. But this can happen when the child scope is a catch scope that ends with `catchret`. So this patch, when doing backward BFS, does not search predecessors that ends with `catchret`. Because `catchret`s are replaced with `br`s during this pass, this records BBs that have `catchret`s in the beginning, before doing any other transformations. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D80571
2020-05-25 16:35:35 +08:00
try.cont: ; preds = %invoke.cont1, %entry
ret void
ehcleanup: ; preds = %catch
%8 = cleanuppad within %1 []
call void @__cxa_end_catch() [ "funclet"(token %8) ]
cleanupret from %8 unwind to caller
}
; When a function does not have stack-allocated objects, it does not need to
; store SP back to __stack_pointer global at the epilog.
;
; void foo();
; void test_no_sp_writeback() {
; try {
; foo();
; } catch (...) {
; }
; }
; CHECK-LABEL: test_no_sp_writeback
; CHECK: try
; CHECK: call foo
; CHECK: catch
; CHECK: call $drop=, __cxa_begin_catch
; CHECK: call __cxa_end_catch
; CHECK: end_try
; CHECK-NOT: global.set __stack_pointer
; CHECK: return
define void @test_no_sp_writeback() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* null]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
[WebAssembly] Fix a bug in finding matching EH pad Summary: `getMatchingEHPad()` in LateEHPrepare is a function to find the nearest EH pad that dominates the given instruction. This intends to be lightweight so it does not use full WebAssemblyException scope analysis or dominator analysis. It simply does backward BFS to its predecessors and stops at the first EH pad each search path encounters. All search should end up at the same EH pad, and if not, it returns null. But it didn't take into account that when there are inner scopes within the current scope, some path in BFS can hit an inner EH pad first. For example, in the given diagram, `Inst` belongs to the outer scope and `getMathingEHPad()` should return 'EHPad 1', but some search path can go into the inner scope and end up with 'EHPad 2'. The search will return null because different paths end up with different EH pads. ``` --- EHPad 1 --- | - EHPad 2 - | | | | | | ----------- | | Inst | --------------- ``` So far this was OK because we haven't tested a case in which a given instruction is far from its EH pad. Also, this bug does not happen when the inner EH scope is a cleanup scope, because a cleanup scope ends with a `cleanupret` whose successor is an EH pad, so the search encounters that EH pad first before going into the child scope. But this can happen when the child scope is a catch scope that ends with `catchret`. So this patch, when doing backward BFS, does not search predecessors that ends with `catchret`. Because `catchret`s are replaced with `br`s during this pass, this records BBs that have `catchret`s in the beginning, before doing any other transformations. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D80571
2020-05-25 16:35:35 +08:00
%4 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont
[WebAssembly] Fix a bug in finding matching EH pad Summary: `getMatchingEHPad()` in LateEHPrepare is a function to find the nearest EH pad that dominates the given instruction. This intends to be lightweight so it does not use full WebAssemblyException scope analysis or dominator analysis. It simply does backward BFS to its predecessors and stops at the first EH pad each search path encounters. All search should end up at the same EH pad, and if not, it returns null. But it didn't take into account that when there are inner scopes within the current scope, some path in BFS can hit an inner EH pad first. For example, in the given diagram, `Inst` belongs to the outer scope and `getMathingEHPad()` should return 'EHPad 1', but some search path can go into the inner scope and end up with 'EHPad 2'. The search will return null because different paths end up with different EH pads. ``` --- EHPad 1 --- | - EHPad 2 - | | | | | | ----------- | | Inst | --------------- ``` So far this was OK because we haven't tested a case in which a given instruction is far from its EH pad. Also, this bug does not happen when the inner EH scope is a cleanup scope, because a cleanup scope ends with a `cleanupret` whose successor is an EH pad, so the search encounters that EH pad first before going into the child scope. But this can happen when the child scope is a catch scope that ends with `catchret`. So this patch, when doing backward BFS, does not search predecessors that ends with `catchret`. Because `catchret`s are replaced with `br`s during this pass, this records BBs that have `catchret`s in the beginning, before doing any other transformations. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D80571
2020-05-25 16:35:35 +08:00
try.cont: ; preds = %catch.start, %entry
ret void
}
; When the result of @llvm.wasm.get.exception is not used. This is created to
; fix a bug in LateEHPrepare and this should not crash.
define void @test_get_exception_wo_use() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* null]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
catchret from %1 to label %try.cont
[WebAssembly] Fix a bug in finding matching EH pad Summary: `getMatchingEHPad()` in LateEHPrepare is a function to find the nearest EH pad that dominates the given instruction. This intends to be lightweight so it does not use full WebAssemblyException scope analysis or dominator analysis. It simply does backward BFS to its predecessors and stops at the first EH pad each search path encounters. All search should end up at the same EH pad, and if not, it returns null. But it didn't take into account that when there are inner scopes within the current scope, some path in BFS can hit an inner EH pad first. For example, in the given diagram, `Inst` belongs to the outer scope and `getMathingEHPad()` should return 'EHPad 1', but some search path can go into the inner scope and end up with 'EHPad 2'. The search will return null because different paths end up with different EH pads. ``` --- EHPad 1 --- | - EHPad 2 - | | | | | | ----------- | | Inst | --------------- ``` So far this was OK because we haven't tested a case in which a given instruction is far from its EH pad. Also, this bug does not happen when the inner EH scope is a cleanup scope, because a cleanup scope ends with a `cleanupret` whose successor is an EH pad, so the search encounters that EH pad first before going into the child scope. But this can happen when the child scope is a catch scope that ends with `catchret`. So this patch, when doing backward BFS, does not search predecessors that ends with `catchret`. Because `catchret`s are replaced with `br`s during this pass, this records BBs that have `catchret`s in the beginning, before doing any other transformations. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D80571
2020-05-25 16:35:35 +08:00
try.cont: ; preds = %catch.start, %entry
ret void
}
; Tests a case when a cleanup region (cleanuppad ~ clanupret) contains another
; catchpad
define void @test_complex_cleanup_region() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
invoke void @foo()
to label %invoke.cont unwind label %ehcleanup
invoke.cont: ; preds = %entry
ret void
[WebAssembly] Fix a bug in finding matching EH pad Summary: `getMatchingEHPad()` in LateEHPrepare is a function to find the nearest EH pad that dominates the given instruction. This intends to be lightweight so it does not use full WebAssemblyException scope analysis or dominator analysis. It simply does backward BFS to its predecessors and stops at the first EH pad each search path encounters. All search should end up at the same EH pad, and if not, it returns null. But it didn't take into account that when there are inner scopes within the current scope, some path in BFS can hit an inner EH pad first. For example, in the given diagram, `Inst` belongs to the outer scope and `getMathingEHPad()` should return 'EHPad 1', but some search path can go into the inner scope and end up with 'EHPad 2'. The search will return null because different paths end up with different EH pads. ``` --- EHPad 1 --- | - EHPad 2 - | | | | | | ----------- | | Inst | --------------- ``` So far this was OK because we haven't tested a case in which a given instruction is far from its EH pad. Also, this bug does not happen when the inner EH scope is a cleanup scope, because a cleanup scope ends with a `cleanupret` whose successor is an EH pad, so the search encounters that EH pad first before going into the child scope. But this can happen when the child scope is a catch scope that ends with `catchret`. So this patch, when doing backward BFS, does not search predecessors that ends with `catchret`. Because `catchret`s are replaced with `br`s during this pass, this records BBs that have `catchret`s in the beginning, before doing any other transformations. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D80571
2020-05-25 16:35:35 +08:00
ehcleanup: ; preds = %entry
%0 = cleanuppad within none []
invoke void @foo() [ "funclet"(token %0) ]
to label %ehcleanupret unwind label %catch.dispatch
catch.dispatch: ; preds = %ehcleanup
%1 = catchswitch within %0 [label %catch.start] unwind label %ehcleanup.1
catch.start: ; preds = %catch.dispatch
%2 = catchpad within %1 [i8* null]
%3 = call i8* @llvm.wasm.get.exception(token %2)
%4 = call i32 @llvm.wasm.get.ehselector(token %2)
catchret from %2 to label %ehcleanupret
ehcleanup.1: ; preds = %catch.dispatch
%5 = cleanuppad within %0 []
unreachable
ehcleanupret: ; preds = %catch.start, %ehcleanup
cleanupret from %0 unwind to caller
}
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
declare void @foo()
declare void @bar(i32*)
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
declare i32 @__gxx_wasm_personality_v0(...)
[WebAssembly] Exception handling: Switch to the new proposal Summary: This switches the EH implementation to the new proposal: https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md (The previous proposal was https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md) - Instruction changes - Now we have one single `catch` instruction that returns a except_ref value - `throw` now can take variable number of operations - `rethrow` does not have 'depth' argument anymore - `br_on_exn` queries an except_ref to see if it matches the tag and branches to the given label if true. - `extract_exception` is a pseudo instruction that simulates popping values from wasm stack. This is to make `br_on_exn`, a very special instruction, work: `br_on_exn` puts values onto the stack only if it is taken, and the # of values can vay depending on the tag. - Now there's only one `catch` per `try`, this patch removes all special handling for terminate pad with a call to `__clang_call_terminate`. Before it was the only case there are two catch clauses (a normal `catch` and `catch_all` per `try`). - Make `rethrow` act as a terminator like `throw`. This splits BB after `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable` after `rethrow` in LateEHPrepare. - Now we stop at all catchpads (because we add wasm `catch` instruction that catches all exceptions), this creates new `findWasmUnwindDestinations` function in SelectionDAGBuilder. - Now we use `br_on_exn` instrution to figure out if an except_ref matches the current tag or not, LateEHPrepare generates this sequence for catch pads: ``` catch block i32 br_on_exn $__cpp_exception end_block extract_exception ``` - Branch analysis for `br_on_exn` in WebAssemblyInstrInfo - Other various misc. changes to switch to the new proposal. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D57134 llvm-svn: 352598
2019-01-30 11:21:57 +08:00
declare void @llvm.wasm.throw(i32, i8*)
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
declare i8* @llvm.wasm.get.exception(token)
declare i32 @llvm.wasm.get.ehselector(token)
[WebAssembly] Make rethrow take an except_ref type argument Summary: In the new wasm EH proposal, `rethrow` takes an `except_ref` argument. This change was missing in r352598. This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an intrinsic that's gonna eventually be lowered to wasm `rethrow` instruction, but this intrinsic can appear only within a catchpad or a cleanuppad scope. Also this intrinsic needs to be invokable - otherwise EH pad successor for it will not be correctly generated in clang. This also adds lowering logic for this intrinsic in `SelectionDAGBuilder::visitInvoke`. This routine is basically a specialized and simplified version of `SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it because if is only for `CallInst`s. This deletes the previous `llvm.wasm.rethrow` intrinsic and related tests, which was meant to be used within a `__cxa_rethrow` library function. Turned out this needs some more logic, so the intrinsic for this purpose will be added later. LateEHPrepare takes a result value of `catch` and inserts it into matching `rethrow` as an argument. `RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between `llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To generate a `rethrow` instruction, we need an `except_ref` argument, which is generated from `catch` instruction. But `catch` instrutions are added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes no argument, until we are able to correctly lower it to `rethrow` in LateEHPrepare. Reviewers: dschuff Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59352 llvm-svn: 356316
2019-03-16 13:38:57 +08:00
declare void @llvm.wasm.rethrow.in.catch()
[WebAssembly] Support instruction selection for catching exceptions Summary: This lowers exception catching-related instructions: 1. Lowers `wasm.catch` intrinsic to `catch` instruction 2. Removes `catchpad` and `cleanuppad` instructions; they are not necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or `MachineBasicBlock::isEHPad()` can be used instead.) 3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret` and `cleanupret` instructions in isel, which will be replaced with other instructions in `WebAssemblyExceptionPrepare` pass. 4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various transformation for EH. Currently this pass only replaces `catchret` and `cleanupret` instructions into appropriate wasm instructions to make this patch successfully run until the end. Currently this does not handle lowering of intrinsics related to LSDA info generation (`wasm.landingpad.index` and `wasm.lsda`), because they cannot be tested without implementing `EHStreamer`'s wasm-specific handlers. They are marked as TODO, which is needed to make isel pass. Also this does not generate `try` and `end_try` markers yet, which will be handled in later patches. This patch is based on the first wasm EH proposal. (https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md) Reviewers: dschuff, majnemer Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D44090 llvm-svn: 333705
2018-06-01 06:25:54 +08:00
declare i32 @llvm.eh.typeid.for(i8*)
declare i8* @__cxa_begin_catch(i8*)
declare void @__cxa_end_catch()
declare void @__clang_call_terminate(i8*)
declare %struct.Temp* @_ZN4TempD2Ev(%struct.Temp* returned)
; CHECK: __cpp_exception:
; CHECK: .eventtype __cpp_exception i32