llvm/test/CodeGen/WebAssembly/exception.ll

; RUN: not llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-keep-registers -exception-model=wasm
; 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 }

@_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
}

; CHECK-LABEL: test_rethrow:
; CHECK:     rethrow
; CHECK-NOT: unreachable
define void @test_rethrow(i8* %p) {
  call void @llvm.wasm.rethrow()
  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:     block
; CHECK:       try
; CHECK:         call      foo
; CHECK:         br        0
; CHECK:       catch     $[[EXCEPT_REF:[0-9]+]]=
; CHECK:         global.set  __stack_pointer
; CHECK:         block i32
; CHECK:           br_on_exn 0, __cpp_exception, $[[EXCEPT_REF]]
; CHECK:           rethrow
; 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:         i32.call  $drop=, _Unwind_CallPersonality, $[[EXN]]
; CHECK:         block
; CHECK:           br_if     0
; CHECK:           i32.call  $drop=, __cxa_begin_catch
; CHECK:           call      __cxa_end_catch
; CHECK:           br        1
; CHECK:         end_block
; CHECK:         call      __cxa_rethrow
; CHECK:       end_try
; CHECK:     end_block
define void @test_catch() 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* 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
  call void @__cxa_rethrow() [ "funclet"(token %1) ]
  unreachable

try.cont:                                         ; preds = %entry, %catch
  ret void
}

; Destructor (cleanup) test
;
; void foo();
; struct Temp {
;   ~Temp() {}
; };
; void test_cleanup() {
;   Temp t;
;   foo();
; }

; CHECK-LABEL: test_cleanup:
; CHECK: block
; CHECK:   try
; CHECK:     call      foo
; CHECK:     br        0
; CHECK:   catch
; CHECK:     global.set  __stack_pointer
; CHECK:     i32.call  $drop=, _ZN4TempD2Ev
; CHECK:     rethrow
; CHECK:   end_try
; CHECK: end_block
define void @test_cleanup() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
  %t = alloca %struct.Temp, align 1
  invoke void @foo()
          to label %invoke.cont unwind label %ehcleanup

invoke.cont:                                      ; preds = %entry
  %call = call %struct.Temp* @_ZN4TempD2Ev(%struct.Temp* %t)
  ret void

ehcleanup:                                        ; preds = %entry
  %0 = cleanuppad within none []
  %call1 = call %struct.Temp* @_ZN4TempD2Ev(%struct.Temp* %t) [ "funclet"(token %0) ]
  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: block
; CHECK:   try
; CHECK:     call      foo
; CHECK:     br        0
; CHECK:   catch
; CHECK:     i32.call  $drop=, __cxa_begin_catch
; CHECK:     block
; CHECK:       try
; CHECK:         call      foo
; CHECK:         br        0
; CHECK:       catch
; CHECK:         block
; CHECK:           try
; CHECK:             call      __cxa_end_catch
; CHECK:             br        0
; CHECK:           catch
; CHECK:             block     i32
; CHECK:               br_on_exn   0, __cpp_exception
; CHECK:               call      __clang_call_terminate, 0
; CHECK:               unreachable
; CHECK:             end_block
; CHECK:             call      __clang_call_terminate
; CHECK:             unreachable
; CHECK:           end_try
; CHECK:         end_block
; CHECK:         rethrow
; CHECK:       end_try
; CHECK:     end_block
; CHECK:     call      __cxa_end_catch
; CHECK:   end_try
; CHECK: end_block
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

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)
  %4 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
  invoke void @foo() [ "funclet"(token %1) ]
          to label %invoke.cont1 unwind label %ehcleanup

invoke.cont1:                                     ; preds = %catch.start
  call void @__cxa_end_catch() [ "funclet"(token %1) ]
  catchret from %1 to label %try.cont

try.cont:                                         ; preds = %entry, %invoke.cont1
  ret void

ehcleanup:                                        ; preds = %catch.start
  %5 = cleanuppad within %1 []
  invoke void @__cxa_end_catch() [ "funclet"(token %5) ]
          to label %invoke.cont2 unwind label %terminate

invoke.cont2:                                     ; preds = %ehcleanup
  cleanupret from %5 unwind to caller

terminate:                                        ; preds = %ehcleanup
  %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:     block
; CHECK:       try
; CHECK:         call      foo
; CHECK:         br        0
; CHECK:       catch
; CHECK-NOT:     global.get  $push{{.+}}=, __stack_pointer
; CHECK:         global.set  __stack_pointer
; CHECK:         block
; CHECK:           block
; CHECK:             br_if     0
; CHECK:             i32.call  $drop=, __cxa_begin_catch
; CHECK:             try
; CHECK:               call      foo
; CHECK:               br        2
; 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
; CHECK:           call      __cxa_rethrow
; CHECK:         end_block
; CHECK-NOT:     global.set  __stack_pointer, $pop{{.+}}
; CHECK:         call      __cxa_end_catch
; CHECK:       end_try
; CHECK:     end_block
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
  call void @__cxa_rethrow() [ "funclet"(token %1) ]
  unreachable

try.cont:                                         ; preds = %entry, %invoke.cont1
  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:     block
; CHECK:       try
; CHECK:         call      foo
; CHECK:         br        0
; CHECK:       catch
; CHECK:         i32.call  $drop=, __cxa_begin_catch
; CHECK:         call      __cxa_end_catch
; CHECK:       end_try
; CHECK:     end_block
; 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)
  %4 = call i8* @__cxa_begin_catch(i8* %2) #2 [ "funclet"(token %1) ]
  call void @__cxa_end_catch() [ "funclet"(token %1) ]
  catchret from %1 to label %try.cont

try.cont:                                         ; preds = %entry, %catch.start
  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

try.cont:                                         ; preds = %entry, %catch.start
  ret void
}

declare void @foo()
declare void @bar(i32*)
declare i32 @__gxx_wasm_personality_v0(...)
declare void @llvm.wasm.throw(i32, i8*)
declare void @llvm.wasm.rethrow()
declare i8* @llvm.wasm.get.exception(token)
declare i32 @llvm.wasm.get.ehselector(token)
declare i32 @llvm.eh.typeid.for(i8*)
declare i8* @__cxa_begin_catch(i8*)
declare void @__cxa_end_catch()
declare void @__cxa_rethrow()
declare void @__clang_call_terminate(i8*)
declare %struct.Temp* @_ZN4TempD2Ev(%struct.Temp* returned)

; CHECK: __cpp_exception:
; CHECK: .eventtype  __cpp_exception i32