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await does not force async if callee is blocking

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closes #3067
This commit is contained in:
Andrew Kelley
2019-08-29 21:51:31 -04:00
parent 8e93991634
commit 03910925f0
7 changed files with 169 additions and 68 deletions
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78
src/codegen.cpp
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@@ -3924,7 +3924,7 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
LLVMBuildStore(g->builder, awaiter_init_val, awaiter_ptr);
if (ret_has_bits) {
LLVMValueRef ret_ptr = LLVMBuildStructGEP(g->builder, frame_result_loc, frame_ret_start + 2, "");
ret_ptr = LLVMBuildStructGEP(g->builder, frame_result_loc, frame_ret_start + 2, "");
LLVMValueRef ret_ptr_ptr = LLVMBuildStructGEP(g->builder, frame_result_loc, frame_ret_start, "");
LLVMBuildStore(g->builder, ret_ptr, ret_ptr_ptr);
@@ -4067,6 +4067,9 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
LLVMValueRef store_instr = LLVMBuildStore(g->builder, result, result_loc);
LLVMSetAlignment(store_instr, get_ptr_align(g, instruction->result_loc->value.type));
return result_loc;
} else if (!callee_is_async && instruction->is_async) {
LLVMBuildStore(g->builder, result, ret_ptr);
return result_loc;
} else {
return result;
}
@@ -5498,6 +5501,44 @@ static LLVMValueRef ir_render_suspend_finish(CodeGen *g, IrExecutable *executabl
return nullptr;
}
static LLVMValueRef gen_await_early_return(CodeGen *g, IrInstruction *source_instr,
LLVMValueRef target_frame_ptr, ZigType *result_type, ZigType *ptr_result_type,
LLVMValueRef result_loc, bool non_async)
{
LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
LLVMValueRef their_result_ptr = nullptr;
if (type_has_bits(result_type) && (non_async || result_loc != nullptr)) {
LLVMValueRef their_result_ptr_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr, frame_ret_start, "");
their_result_ptr = LLVMBuildLoad(g->builder, their_result_ptr_ptr, "");
if (result_loc != nullptr) {
LLVMTypeRef ptr_u8 = LLVMPointerType(LLVMInt8Type(), 0);
LLVMValueRef dest_ptr_casted = LLVMBuildBitCast(g->builder, result_loc, ptr_u8, "");
LLVMValueRef src_ptr_casted = LLVMBuildBitCast(g->builder, their_result_ptr, ptr_u8, "");
bool is_volatile = false;
uint32_t abi_align = get_abi_alignment(g, result_type);
LLVMValueRef byte_count_val = LLVMConstInt(usize_type_ref, type_size(g, result_type), false);
ZigLLVMBuildMemCpy(g->builder,
dest_ptr_casted, abi_align,
src_ptr_casted, abi_align, byte_count_val, is_volatile);
}
}
if (codegen_fn_has_err_ret_tracing_arg(g, result_type)) {
LLVMValueRef their_trace_ptr_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr,
frame_index_trace_arg(g, result_type), "");
LLVMValueRef src_trace_ptr = LLVMBuildLoad(g->builder, their_trace_ptr_ptr, "");
LLVMValueRef dest_trace_ptr = get_cur_err_ret_trace_val(g, source_instr->scope);
LLVMValueRef args[] = { dest_trace_ptr, src_trace_ptr };
ZigLLVMBuildCall(g->builder, get_merge_err_ret_traces_fn_val(g), args, 2,
get_llvm_cc(g, CallingConventionUnspecified), ZigLLVM_FnInlineAuto, "");
}
if (non_async && type_has_bits(result_type)) {
LLVMValueRef result_ptr = (result_loc == nullptr) ? their_result_ptr : result_loc;
return get_handle_value(g, result_ptr, result_type, ptr_result_type);
} else {
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);
@@ -5505,6 +5546,14 @@ static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInst
ZigType *result_type = instruction->base.value.type;
ZigType *ptr_result_type = get_pointer_to_type(g, result_type, true);
LLVMValueRef result_loc = (instruction->result_loc == nullptr) ?
nullptr : ir_llvm_value(g, instruction->result_loc);
if (instruction->target_fn != nullptr && !fn_is_async(instruction->target_fn)) {
return gen_await_early_return(g, &instruction->base, target_frame_ptr, result_type,
ptr_result_type, result_loc, true);
}
// Prepare to be suspended
LLVMBasicBlockRef resume_bb = gen_suspend_begin(g, "AwaitResume");
LLVMBasicBlockRef end_bb = LLVMAppendBasicBlock(g->cur_fn_val, "AwaitEnd");
@@ -5512,9 +5561,8 @@ static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInst
// At this point resuming the function will continue from resume_bb.
// This code is as if it is running inside the suspend block.
// supply the awaiter return pointer
LLVMValueRef result_loc = (instruction->result_loc == nullptr) ?
nullptr : ir_llvm_value(g, instruction->result_loc);
if (type_has_bits(result_type)) {
LLVMValueRef awaiter_ret_ptr_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr, frame_ret_start + 1, "");
if (result_loc == nullptr) {
@@ -5562,28 +5610,8 @@ static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInst
// Early return: The async function has already completed. We must copy the result and
// the error return trace if applicable.
LLVMPositionBuilderAtEnd(g->builder, early_return_block);
if (type_has_bits(result_type) && result_loc != nullptr) {
LLVMValueRef their_result_ptr_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr, frame_ret_start, "");
LLVMValueRef their_result_ptr = LLVMBuildLoad(g->builder, their_result_ptr_ptr, "");
LLVMTypeRef ptr_u8 = LLVMPointerType(LLVMInt8Type(), 0);
LLVMValueRef dest_ptr_casted = LLVMBuildBitCast(g->builder, result_loc, ptr_u8, "");
LLVMValueRef src_ptr_casted = LLVMBuildBitCast(g->builder, their_result_ptr, ptr_u8, "");
bool is_volatile = false;
uint32_t abi_align = get_abi_alignment(g, result_type);
LLVMValueRef byte_count_val = LLVMConstInt(usize_type_ref, type_size(g, result_type), false);
ZigLLVMBuildMemCpy(g->builder,
dest_ptr_casted, abi_align,
src_ptr_casted, abi_align, byte_count_val, is_volatile);
}
if (codegen_fn_has_err_ret_tracing_arg(g, result_type)) {
LLVMValueRef their_trace_ptr_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr,
frame_index_trace_arg(g, result_type), "");
LLVMValueRef src_trace_ptr = LLVMBuildLoad(g->builder, their_trace_ptr_ptr, "");
LLVMValueRef dest_trace_ptr = get_cur_err_ret_trace_val(g, instruction->base.scope);
LLVMValueRef args[] = { dest_trace_ptr, src_trace_ptr };
ZigLLVMBuildCall(g->builder, get_merge_err_ret_traces_fn_val(g), args, 2,
get_llvm_cc(g, CallingConventionUnspecified), ZigLLVM_FnInlineAuto, "");
}
gen_await_early_return(g, &instruction->base, target_frame_ptr, result_type, ptr_result_type,
result_loc, false);
LLVMBuildBr(g->builder, end_bb);
LLVMPositionBuilderAtEnd(g->builder, resume_bb);