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Merged
merged 2 commits into from
Sep 11, 2021
Merged

Allow returning void from void functions #2063

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43517d7
Allow returning void from void functions
dcodeIO Sep 11, 2021
d6663d7
nop fwiw
dcodeIO Sep 11, 2021
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32 changes: 18 additions & 14 deletions src/compiler.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -2825,14 +2825,6 @@ export class Compiler extends DiagnosticEmitter {

var valueExpression = statement.value;
if (valueExpression) {
if (returnType == Type.void) {
this.error(
DiagnosticCode.Type_0_is_not_assignable_to_type_1,
valueExpression.range, this.currentType.toString(), returnType.toString()
);
this.currentType = Type.void;
return module.unreachable();
}
let constraints = Constraints.CONV_IMPLICIT;
if (flow.actualFunction.is(CommonFlags.MODULE_EXPORT)) constraints |= Constraints.MUST_WRAP;

Expand All @@ -2857,15 +2849,27 @@ export class Compiler extends DiagnosticEmitter {

// Handle inline return
if (flow.isInline) {
return isLastInBody && expr != 0
? expr
: module.br(assert(flow.inlineReturnLabel), 0, expr);
return !expr
? isLastInBody
? module.nop()
: module.br(assert(flow.inlineReturnLabel))
: isLastInBody
? expr
: this.currentType == Type.void
? module.block(null, [ expr, module.br(assert(flow.inlineReturnLabel)) ])
: module.br(assert(flow.inlineReturnLabel), 0, expr);
}

// Otherwise emit a normal return
return isLastInBody && expr != 0
? expr
: module.return(expr);
return !expr
? isLastInBody
? module.nop()
: module.return()
: isLastInBody
? expr
: this.currentType == Type.void
? module.block(null, [ expr, module.return() ])
: module.return(expr);
}

private compileSwitchStatement(
Expand Down
4 changes: 4 additions & 0 deletions tests/compiler/return.json
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Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
{
"asc_flags": [
]
}
82 changes: 82 additions & 0 deletions tests/compiler/return.optimized.wat
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Original file line number Diff line number Diff line change
@@ -0,0 +1,82 @@
(module
(type $none_=>_none (func))
(type $i32_=>_none (func (param i32)))
(type $i32_i32_i32_i32_=>_none (func (param i32 i32 i32 i32)))
(type $i32_i32_=>_none (func (param i32 i32)))
(import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
(global $~lib/memory/__stack_pointer (mut i32) (i32.const 17452))
(memory $0 1)
(data (i32.const 1036) "\1c")
(data (i32.const 1048) "\03\00\00\00\08\00\00\00\01")
(table $0 2 funcref)
(elem $0 (i32.const 1) $start:return~anonymous|0)
(export "testVoidReturn" (func $return/testVoidReturn))
(export "memory" (memory $0))
(export "testVoidReturnFunction" (func $export:return/testVoidReturnFunction))
(start $~start)
(func $start:return~anonymous|0
nop
)
(func $return/testVoidReturn (param $0 i32)
nop
)
(func $~start
(local $0 i32)
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.sub
global.set $~lib/memory/__stack_pointer
global.get $~lib/memory/__stack_pointer
i32.const 1068
i32.lt_s
if
i32.const 17472
i32.const 17520
i32.const 1
i32.const 1
call $~lib/builtins/abort
unreachable
end
global.get $~lib/memory/__stack_pointer
local.tee $0
i32.const 0
i32.store
local.get $0
i32.const 1056
i32.store
i32.const 1056
i32.load
call_indirect $0 (type $none_=>_none)
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.add
global.set $~lib/memory/__stack_pointer
)
(func $export:return/testVoidReturnFunction (param $0 i32) (param $1 i32)
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.sub
global.set $~lib/memory/__stack_pointer
global.get $~lib/memory/__stack_pointer
i32.const 1068
i32.lt_s
if
i32.const 17472
i32.const 17520
i32.const 1
i32.const 1
call $~lib/builtins/abort
unreachable
end
global.get $~lib/memory/__stack_pointer
local.get $1
i32.store
local.get $1
i32.load
call_indirect $0 (type $none_=>_none)
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.add
global.set $~lib/memory/__stack_pointer
)
)
16 changes: 16 additions & 0 deletions tests/compiler/return.ts
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@@ -0,0 +1,16 @@
function nop(): void {}

export function testVoidReturn(cond: bool): void {
if (cond) {
return nop();
}
return nop();
}

export function testVoidReturnFunction(cond: bool, fn: () => void): void {
if (cond) {
return fn();
}
return fn();
}
testVoidReturnFunction(true, () => nop());
105 changes: 105 additions & 0 deletions tests/compiler/return.untouched.wat
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@@ -0,0 +1,105 @@
(module
(type $none_=>_none (func))
(type $i32_i32_=>_none (func (param i32 i32)))
(type $i32_=>_none (func (param i32)))
(type $i32_i32_i32_i32_=>_none (func (param i32 i32 i32 i32)))
(import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
(global $~argumentsLength (mut i32) (i32.const 0))
(global $~lib/memory/__data_end i32 (i32.const 44))
(global $~lib/memory/__stack_pointer (mut i32) (i32.const 16428))
(global $~lib/memory/__heap_base i32 (i32.const 16428))
(memory $0 1)
(data (i32.const 12) "\1c\00\00\00\00\00\00\00\00\00\00\00\03\00\00\00\08\00\00\00\01\00\00\00\00\00\00\00\00\00\00\00")
(table $0 2 funcref)
(elem $0 (i32.const 1) $start:return~anonymous|0)
(export "testVoidReturn" (func $return/testVoidReturn))
(export "memory" (memory $0))
(export "testVoidReturnFunction" (func $export:return/testVoidReturnFunction))
(start $~start)
(func $return/nop
nop
)
(func $start:return~anonymous|0
call $return/nop
)
(func $return/testVoidReturnFunction (param $0 i32) (param $1 i32)
local.get $0
if
i32.const 0
global.set $~argumentsLength
local.get $1
i32.load
call_indirect $0 (type $none_=>_none)
return
end
i32.const 0
global.set $~argumentsLength
local.get $1
i32.load
call_indirect $0 (type $none_=>_none)
)
(func $return/testVoidReturn (param $0 i32)
local.get $0
if
call $return/nop
return
end
call $return/nop
)
(func $~start
call $start:return
)
(func $~stack_check
global.get $~lib/memory/__stack_pointer
global.get $~lib/memory/__data_end
i32.lt_s
if
i32.const 16448
i32.const 16496
i32.const 1
i32.const 1
call $~lib/builtins/abort
unreachable
end
)
(func $start:return
(local $0 i32)
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.sub
global.set $~lib/memory/__stack_pointer
call $~stack_check
global.get $~lib/memory/__stack_pointer
i32.const 0
i32.store
i32.const 1
i32.const 32
local.set $0
global.get $~lib/memory/__stack_pointer
local.get $0
i32.store
local.get $0
call $return/testVoidReturnFunction
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.add
global.set $~lib/memory/__stack_pointer
)
(func $export:return/testVoidReturnFunction (param $0 i32) (param $1 i32)
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.sub
global.set $~lib/memory/__stack_pointer
call $~stack_check
global.get $~lib/memory/__stack_pointer
local.get $1
i32.store
local.get $0
local.get $1
call $return/testVoidReturnFunction
global.get $~lib/memory/__stack_pointer
i32.const 4
i32.add
global.set $~lib/memory/__stack_pointer
)
)