motiejus/zig
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implement cancel

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all behavior tests passing in this branch
This commit is contained in:
Andrew Kelley
2019-08-07 00:52:56 -04:00
parent 1afbb53661
commit 7e1fcb55b3
7 changed files with 216 additions and 134 deletions
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109
src/codegen.cpp
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@@ -911,11 +911,13 @@ static Buf *panic_msg_buf(PanicMsgId msg_id) {
case PanicMsgIdBadResume:
return buf_create_from_str("resumed an async function which already returned");
case PanicMsgIdBadAwait:
return buf_create_from_str("async function awaited twice");
return buf_create_from_str("async function awaited/canceled twice");
case PanicMsgIdBadReturn:
return buf_create_from_str("async function returned twice");
case PanicMsgIdResumedAnAwaitingFn:
return buf_create_from_str("awaiting function resumed");
case PanicMsgIdResumedACancelingFn:
return buf_create_from_str("canceling function resumed");
case PanicMsgIdFrameTooSmall:
return buf_create_from_str("frame too small");
case PanicMsgIdResumedFnPendingAwait:
@@ -2189,12 +2191,12 @@ static void gen_assert_resume_id(CodeGen *g, IrInstruction *source_instr, Resume
if (end_bb == nullptr) end_bb = LLVMAppendBasicBlock(g->cur_fn_val, "OkResume");
LLVMValueRef ok_bit;
if (resume_id == ResumeIdAwaitEarlyReturn) {
LLVMValueRef last_value = LLVMBuildSub(g->builder, LLVMConstAllOnes(usize_type_ref),
LLVMConstInt(usize_type_ref, ResumeIdAwaitEarlyReturn, false), "");
LLVMValueRef last_value = LLVMConstSub(LLVMConstAllOnes(usize_type_ref),
LLVMConstInt(usize_type_ref, ResumeIdAwaitEarlyReturn, false));
ok_bit = LLVMBuildICmp(g->builder, LLVMIntULT, LLVMGetParam(g->cur_fn_val, 1), last_value, "");
} else {
LLVMValueRef expected_value = LLVMBuildSub(g->builder, LLVMConstAllOnes(usize_type_ref),
LLVMConstInt(usize_type_ref, resume_id, false), "");
LLVMValueRef expected_value = LLVMConstSub(LLVMConstAllOnes(usize_type_ref),
LLVMConstInt(usize_type_ref, resume_id, false));
ok_bit = LLVMBuildICmp(g->builder, LLVMIntEQ, LLVMGetParam(g->cur_fn_val, 1), expected_value, "");
}
LLVMBuildCondBr(g->builder, ok_bit, end_bb, bad_resume_block);
@@ -2210,11 +2212,13 @@ static LLVMValueRef gen_resume(CodeGen *g, LLVMValueRef fn_val, LLVMValueRef tar
{
LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
if (fn_val == nullptr) {
if (g->anyframe_fn_type == nullptr) {
(void)get_llvm_type(g, get_any_frame_type(g, nullptr));
}
LLVMValueRef fn_ptr_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr, coro_fn_ptr_index, "");
fn_val = LLVMBuildLoad(g->builder, fn_ptr_ptr, "");
LLVMValueRef fn_val_typed = LLVMBuildLoad(g->builder, fn_ptr_ptr, "");
LLVMValueRef as_int = LLVMBuildPtrToInt(g->builder, fn_val_typed, usize_type_ref, "");
LLVMValueRef one = LLVMConstInt(usize_type_ref, 1, false);
LLVMValueRef mask_val = LLVMConstNot(one);
LLVMValueRef as_int_masked = LLVMBuildAnd(g->builder, as_int, mask_val, "");
fn_val = LLVMBuildIntToPtr(g->builder, as_int_masked, LLVMTypeOf(fn_val_typed), "");
}
if (arg_val == nullptr) {
arg_val = LLVMBuildSub(g->builder, LLVMConstAllOnes(usize_type_ref),
@@ -2226,6 +2230,17 @@ static LLVMValueRef gen_resume(CodeGen *g, LLVMValueRef fn_val, LLVMValueRef tar
return ZigLLVMBuildCall(g->builder, fn_val, args, 2, LLVMFastCallConv, ZigLLVM_FnInlineAuto, "");
}
static LLVMBasicBlockRef gen_suspend_begin(CodeGen *g, const char *name_hint) {
LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
LLVMBasicBlockRef resume_bb = LLVMAppendBasicBlock(g->cur_fn_val, name_hint);
size_t new_block_index = g->cur_resume_block_count;
g->cur_resume_block_count += 1;
LLVMValueRef new_block_index_val = LLVMConstInt(usize_type_ref, new_block_index, false);
LLVMAddCase(g->cur_async_switch_instr, new_block_index_val, resume_bb);
LLVMBuildStore(g->builder, new_block_index_val, g->cur_async_resume_index_ptr);
return resume_bb;
}
static LLVMValueRef ir_render_return_begin(CodeGen *g, IrExecutable *executable,
IrInstructionReturnBegin *instruction)
{
@@ -2245,12 +2260,7 @@ static LLVMValueRef ir_render_return_begin(CodeGen *g, IrExecutable *executable,
}
// Prepare to be suspended. We might end up not having to suspend though.
LLVMBasicBlockRef resume_bb = LLVMAppendBasicBlock(g->cur_fn_val, "ReturnResume");
size_t new_block_index = g->cur_resume_block_count;
g->cur_resume_block_count += 1;
LLVMValueRef new_block_index_val = LLVMConstInt(usize_type_ref, new_block_index, false);
LLVMAddCase(g->cur_async_switch_instr, new_block_index_val, resume_bb);
LLVMBuildStore(g->builder, new_block_index_val, g->cur_async_resume_index_ptr);
LLVMBasicBlockRef resume_bb = gen_suspend_begin(g, "ReturnResume");
LLVMValueRef zero = LLVMConstNull(usize_type_ref);
LLVMValueRef all_ones = LLVMConstAllOnes(usize_type_ref);
@@ -2335,7 +2345,10 @@ static LLVMValueRef ir_render_return(CodeGen *g, IrExecutable *executable, IrIns
// We need to resume the caller by tail calling them.
ZigType *any_frame_type = get_any_frame_type(g, ret_type);
LLVMValueRef their_frame_ptr = LLVMBuildIntToPtr(g->builder, g->cur_async_prev_val,
LLVMValueRef one = LLVMConstInt(usize_type_ref, 1, false);
LLVMValueRef mask_val = LLVMConstNot(one);
LLVMValueRef masked_prev_val = LLVMBuildAnd(g->builder, g->cur_async_prev_val, mask_val, "");
LLVMValueRef their_frame_ptr = LLVMBuildIntToPtr(g->builder, masked_prev_val,
get_llvm_type(g, any_frame_type), "");
LLVMValueRef call_inst = gen_resume(g, nullptr, their_frame_ptr, ResumeIdReturn, nullptr);
ZigLLVMSetTailCall(call_inst);
@@ -3945,13 +3958,7 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
} else if (callee_is_async) {
ZigType *ptr_result_type = get_pointer_to_type(g, src_return_type, true);
LLVMBasicBlockRef call_bb = LLVMAppendBasicBlock(g->cur_fn_val, "CallResume");
size_t new_block_index = g->cur_resume_block_count;
g->cur_resume_block_count += 1;
LLVMValueRef new_block_index_val = LLVMConstInt(usize_type_ref, new_block_index, false);
LLVMAddCase(g->cur_async_switch_instr, new_block_index_val, call_bb);
LLVMBuildStore(g->builder, new_block_index_val, g->cur_async_resume_index_ptr);
LLVMBasicBlockRef call_bb = gen_suspend_begin(g, "CallResume");
LLVMValueRef call_inst = gen_resume(g, fn_val, frame_result_loc, ResumeIdCall, nullptr);
ZigLLVMSetTailCall(call_inst);
@@ -4672,10 +4679,6 @@ static LLVMValueRef ir_render_error_return_trace(CodeGen *g, IrExecutable *execu
return cur_err_ret_trace_val;
}
static LLVMValueRef ir_render_cancel(CodeGen *g, IrExecutable *executable, IrInstructionCancel *instruction) {
zig_panic("TODO cancel");
}
static LLVMAtomicOrdering to_LLVMAtomicOrdering(AtomicOrder atomic_order) {
switch (atomic_order) {
case AtomicOrderUnordered: return LLVMAtomicOrderingUnordered;
@@ -5416,13 +5419,7 @@ static LLVMValueRef ir_render_assert_non_null(CodeGen *g, IrExecutable *executab
static LLVMValueRef ir_render_suspend_begin(CodeGen *g, IrExecutable *executable,
IrInstructionSuspendBegin *instruction)
{
LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
instruction->resume_bb = LLVMAppendBasicBlock(g->cur_fn_val, "SuspendResume");
size_t new_block_index = g->cur_resume_block_count;
g->cur_resume_block_count += 1;
LLVMValueRef new_block_index_val = LLVMConstInt(usize_type_ref, new_block_index, false);
LLVMAddCase(g->cur_async_switch_instr, new_block_index_val, instruction->resume_bb);
LLVMBuildStore(g->builder, new_block_index_val, g->cur_async_resume_index_ptr);
instruction->resume_bb = gen_suspend_begin(g, "SuspendResume");
return nullptr;
}
@@ -5436,6 +5433,43 @@ static LLVMValueRef ir_render_suspend_finish(CodeGen *g, IrExecutable *executabl
return nullptr;
}
static LLVMValueRef ir_render_cancel(CodeGen *g, IrExecutable *executable, IrInstructionCancel *instruction) {
LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
LLVMValueRef zero = LLVMConstNull(usize_type_ref);
LLVMValueRef all_ones = LLVMConstAllOnes(usize_type_ref);
LLVMValueRef one = LLVMConstInt(usize_type_ref, 1, false);
LLVMValueRef target_frame_ptr = ir_llvm_value(g, instruction->frame);
LLVMBasicBlockRef resume_bb = gen_suspend_begin(g, "CancelResume");
LLVMValueRef awaiter_val = LLVMBuildPtrToInt(g->builder, g->cur_frame_ptr, usize_type_ref, "");
LLVMValueRef awaiter_ored_val = LLVMBuildOr(g->builder, awaiter_val, one, "");
LLVMValueRef awaiter_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr, coro_awaiter_index, "");
LLVMValueRef prev_val = LLVMBuildAtomicRMW(g->builder, LLVMAtomicRMWBinOpXchg, awaiter_ptr, awaiter_ored_val,
LLVMAtomicOrderingRelease, g->is_single_threaded);
LLVMBasicBlockRef complete_suspend_block = LLVMAppendBasicBlock(g->cur_fn_val, "CancelSuspend");
LLVMBasicBlockRef early_return_block = LLVMAppendBasicBlock(g->cur_fn_val, "EarlyReturn");
LLVMValueRef switch_instr = LLVMBuildSwitch(g->builder, prev_val, resume_bb, 2);
LLVMAddCase(switch_instr, zero, complete_suspend_block);
LLVMAddCase(switch_instr, all_ones, early_return_block);
LLVMPositionBuilderAtEnd(g->builder, complete_suspend_block);
LLVMBuildRetVoid(g->builder);
LLVMPositionBuilderAtEnd(g->builder, early_return_block);
LLVMValueRef call_inst = gen_resume(g, nullptr, target_frame_ptr, ResumeIdAwaitEarlyReturn, awaiter_ored_val);
ZigLLVMSetTailCall(call_inst);
LLVMBuildRetVoid(g->builder);
LLVMPositionBuilderAtEnd(g->builder, resume_bb);
gen_assert_resume_id(g, &instruction->base, ResumeIdReturn, PanicMsgIdResumedACancelingFn, nullptr);
return nullptr;
}
static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInstructionAwaitGen *instruction) {
LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
LLVMValueRef zero = LLVMConstNull(usize_type_ref);
@@ -5444,12 +5478,7 @@ static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInst
ZigType *ptr_result_type = get_pointer_to_type(g, result_type, true);
// Prepare to be suspended
LLVMBasicBlockRef resume_bb = LLVMAppendBasicBlock(g->cur_fn_val, "AwaitResume");
size_t new_block_index = g->cur_resume_block_count;
g->cur_resume_block_count += 1;
LLVMValueRef new_block_index_val = LLVMConstInt(usize_type_ref, new_block_index, false);
LLVMAddCase(g->cur_async_switch_instr, new_block_index_val, resume_bb);
LLVMBuildStore(g->builder, new_block_index_val, g->cur_async_resume_index_ptr);
LLVMBasicBlockRef resume_bb = gen_suspend_begin(g, "AwaitResume");
// At this point resuming the function will do the correct thing.
// This code is as if it is running inside the suspend block.