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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
No known key found for this signature in database
GPG Key ID: 7C5F548F728501A9
7 changed files with 169 additions and 68 deletions
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4
src/all_types.hpp
View File

@ -36,6 +36,7 @@ struct IrInstruction;
struct IrInstructionCast;
struct IrInstructionAllocaGen;
struct IrInstructionCallGen;
struct IrInstructionAwaitGen;
struct IrBasicBlock;
struct ScopeDecls;
struct ZigWindowsSDK;
@ -1486,6 +1487,7 @@ struct ZigFn {
AstNode **param_source_nodes;
Buf **param_names;
IrInstruction *err_code_spill;
AstNode *assumed_non_async;
AstNode *fn_no_inline_set_node;
AstNode *fn_static_eval_set_node;
@ -1503,6 +1505,7 @@ struct ZigFn {
ZigList<GlobalExport> export_list;
ZigList<IrInstructionCallGen *> call_list;
ZigList<IrInstructionAwaitGen *> await_list;
LLVMValueRef valgrind_client_request_array;
@ -3717,6 +3720,7 @@ struct IrInstructionAwaitGen {
IrInstruction *frame;
IrInstruction *result_loc;
ZigFn *target_fn;
};
struct IrInstructionResume {

108
src/analyze.cpp
View File

@ -31,6 +31,7 @@ static void analyze_fn_body(CodeGen *g, ZigFn *fn_table_entry);
static void resolve_llvm_types(CodeGen *g, ZigType *type, ResolveStatus wanted_resolve_status);
static void preview_use_decl(CodeGen *g, TldUsingNamespace *using_namespace, ScopeDecls *dest_decls_scope);
static void resolve_use_decl(CodeGen *g, TldUsingNamespace *tld_using_namespace, ScopeDecls *dest_decls_scope);
static void analyze_fn_async(CodeGen *g, ZigFn *fn, bool resolve_frame);
// nullptr means not analyzed yet; this one means currently being analyzed
static const AstNode *inferred_async_checking = reinterpret_cast<AstNode *>(0x1);
@ -4196,6 +4197,54 @@ static void add_async_error_notes(CodeGen *g, ErrorMsg *msg, ZigFn *fn) {
}
}
// ErrorNone - not async
// ErrorIsAsync - yes async
// ErrorSemanticAnalyzeFail - compile error emitted result is invalid
static Error analyze_callee_async(CodeGen *g, ZigFn *fn, ZigFn *callee, AstNode *call_node,
bool must_not_be_async)
{
if (callee->type_entry->data.fn.fn_type_id.cc != CallingConventionUnspecified)
return ErrorNone;
if (callee->anal_state == FnAnalStateReady) {
analyze_fn_body(g, callee);
if (callee->anal_state == FnAnalStateInvalid) {
return ErrorSemanticAnalyzeFail;
}
}
bool callee_is_async;
if (callee->anal_state == FnAnalStateComplete) {
analyze_fn_async(g, callee, true);
if (callee->anal_state == FnAnalStateInvalid) {
return ErrorSemanticAnalyzeFail;
}
callee_is_async = fn_is_async(callee);
} else {
// If it's already been determined, use that value. Otherwise
// assume non-async, emit an error later if it turned out to be async.
if (callee->inferred_async_node == nullptr ||
callee->inferred_async_node == inferred_async_checking)
{
callee->assumed_non_async = call_node;
callee_is_async = false;
} else {
callee_is_async = callee->inferred_async_node != inferred_async_none;
}
}
if (callee_is_async) {
fn->inferred_async_node = call_node;
fn->inferred_async_fn = callee;
if (must_not_be_async) {
ErrorMsg *msg = add_node_error(g, fn->proto_node,
buf_sprintf("function with calling convention '%s' cannot be async",
calling_convention_name(fn->type_entry->data.fn.fn_type_id.cc)));
add_async_error_notes(g, msg, fn);
return ErrorSemanticAnalyzeFail;
}
return ErrorIsAsync;
}
return ErrorNone;
}
// This function resolves functions being inferred async.
static void analyze_fn_async(CodeGen *g, ZigFn *fn, bool resolve_frame) {
if (fn->inferred_async_node == inferred_async_checking) {
@ -4222,47 +4271,40 @@ static void analyze_fn_async(CodeGen *g, ZigFn *fn, bool resolve_frame) {
for (size_t i = 0; i < fn->call_list.length; i += 1) {
IrInstructionCallGen *call = fn->call_list.at(i);
ZigFn *callee = call->fn_entry;
if (callee == nullptr) {
if (call->fn_entry == nullptr) {
// TODO function pointer call here, could be anything
continue;
}
if (callee->type_entry->data.fn.fn_type_id.cc != CallingConventionUnspecified)
continue;
if (callee->anal_state == FnAnalStateReady) {
analyze_fn_body(g, callee);
if (callee->anal_state == FnAnalStateInvalid) {
switch (analyze_callee_async(g, fn, call->fn_entry, call->base.source_node, must_not_be_async)) {
case ErrorSemanticAnalyzeFail:
fn->anal_state = FnAnalStateInvalid;
return;
}
case ErrorNone:
continue;
case ErrorIsAsync:
if (resolve_frame) {
resolve_async_fn_frame(g, fn);
}
return;
default:
zig_unreachable();
}
if (callee->anal_state != FnAnalStateComplete) {
add_node_error(g, call->base.source_node,
buf_sprintf("call to function '%s' depends on itself", buf_ptr(&callee->symbol_name)));
fn->anal_state = FnAnalStateInvalid;
return;
}
analyze_fn_async(g, callee, true);
if (callee->anal_state == FnAnalStateInvalid) {
fn->anal_state = FnAnalStateInvalid;
return;
}
if (fn_is_async(callee)) {
fn->inferred_async_node = call->base.source_node;
fn->inferred_async_fn = callee;
if (must_not_be_async) {
ErrorMsg *msg = add_node_error(g, fn->proto_node,
buf_sprintf("function with calling convention '%s' cannot be async",
calling_convention_name(fn->type_entry->data.fn.fn_type_id.cc)));
add_async_error_notes(g, msg, fn);
}
for (size_t i = 0; i < fn->await_list.length; i += 1) {
IrInstructionAwaitGen *await = fn->await_list.at(i);
switch (analyze_callee_async(g, fn, await->target_fn, await->base.source_node, must_not_be_async)) {
case ErrorSemanticAnalyzeFail:
fn->anal_state = FnAnalStateInvalid;
return;
}
if (resolve_frame) {
resolve_async_fn_frame(g, fn);
}
return;
case ErrorNone:
continue;
case ErrorIsAsync:
if (resolve_frame) {
resolve_async_fn_frame(g, fn);
}
return;
default:
zig_unreachable();
}
}
fn->inferred_async_node = inferred_async_none;

78
src/codegen.cpp
View File

@ -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);

1
src/error.cpp
View File

@ -56,6 +56,7 @@ const char *err_str(Error err) {
case ErrorNoSpaceLeft: return "no space left";
case ErrorNoCCompilerInstalled: return "no C compiler installed";
case ErrorNotLazy: return "not lazy";
case ErrorIsAsync: return "is async";
}
return "(invalid error)";
}

35
src/ir.cpp
View File

@ -3268,7 +3268,7 @@ static IrInstruction *ir_build_await_src(IrBuilder *irb, Scope *scope, AstNode *
return &instruction->base;
}
static IrInstruction *ir_build_await_gen(IrAnalyze *ira, IrInstruction *source_instruction,
static IrInstructionAwaitGen *ir_build_await_gen(IrAnalyze *ira, IrInstruction *source_instruction,
IrInstruction *frame, ZigType *result_type, IrInstruction *result_loc)
{
IrInstructionAwaitGen *instruction = ir_build_instruction<IrInstructionAwaitGen>(&ira->new_irb,
@ -3280,7 +3280,7 @@ static IrInstruction *ir_build_await_gen(IrAnalyze *ira, IrInstruction *source_i
ir_ref_instruction(frame, ira->new_irb.current_basic_block);
if (result_loc != nullptr) ir_ref_instruction(result_loc, ira->new_irb.current_basic_block);
return &instruction->base;
return instruction;
}
static IrInstruction *ir_build_resume(IrBuilder *irb, Scope *scope, AstNode *source_node, IrInstruction *frame) {
@ -24763,18 +24763,22 @@ static IrInstruction *ir_analyze_instruction_suspend_finish(IrAnalyze *ira,
}
static IrInstruction *analyze_frame_ptr_to_anyframe_T(IrAnalyze *ira, IrInstruction *source_instr,
IrInstruction *frame_ptr)
IrInstruction *frame_ptr, ZigFn **target_fn)
{
if (type_is_invalid(frame_ptr->value.type))
return ira->codegen->invalid_instruction;
*target_fn = nullptr;
ZigType *result_type;
IrInstruction *frame;
if (frame_ptr->value.type->id == ZigTypeIdPointer &&
frame_ptr->value.type->data.pointer.ptr_len == PtrLenSingle &&
frame_ptr->value.type->data.pointer.child_type->id == ZigTypeIdFnFrame)
{
result_type = frame_ptr->value.type->data.pointer.child_type->data.frame.fn->type_entry->data.fn.fn_type_id.return_type;
ZigFn *func = frame_ptr->value.type->data.pointer.child_type->data.frame.fn;
result_type = func->type_entry->data.fn.fn_type_id.return_type;
*target_fn = func;
frame = frame_ptr;
} else {
frame = ir_get_deref(ira, source_instr, frame_ptr, nullptr);
@ -24782,7 +24786,9 @@ static IrInstruction *analyze_frame_ptr_to_anyframe_T(IrAnalyze *ira, IrInstruct
frame->value.type->data.pointer.ptr_len == PtrLenSingle &&
frame->value.type->data.pointer.child_type->id == ZigTypeIdFnFrame)
{
result_type = frame->value.type->data.pointer.child_type->data.frame.fn->type_entry->data.fn.fn_type_id.return_type;
ZigFn *func = frame->value.type->data.pointer.child_type->data.frame.fn;
result_type = func->type_entry->data.fn.fn_type_id.return_type;
*target_fn = func;
} else if (frame->value.type->id != ZigTypeIdAnyFrame ||
frame->value.type->data.any_frame.result_type == nullptr)
{
@ -24803,7 +24809,11 @@ static IrInstruction *analyze_frame_ptr_to_anyframe_T(IrAnalyze *ira, IrInstruct
}
static IrInstruction *ir_analyze_instruction_await(IrAnalyze *ira, IrInstructionAwaitSrc *instruction) {
IrInstruction *frame = analyze_frame_ptr_to_anyframe_T(ira, &instruction->base, instruction->frame->child);
IrInstruction *operand = instruction->frame->child;
if (type_is_invalid(operand->value.type))
return ira->codegen->invalid_instruction;
ZigFn *target_fn;
IrInstruction *frame = analyze_frame_ptr_to_anyframe_T(ira, &instruction->base, operand, &target_fn);
if (type_is_invalid(frame->value.type))
return ira->codegen->invalid_instruction;
@ -24812,8 +24822,11 @@ static IrInstruction *ir_analyze_instruction_await(IrAnalyze *ira, IrInstruction
ZigFn *fn_entry = exec_fn_entry(ira->new_irb.exec);
ir_assert(fn_entry != nullptr, &instruction->base);
if (fn_entry->inferred_async_node == nullptr) {
fn_entry->inferred_async_node = instruction->base.source_node;
// If it's not @Frame(func) then it's definitely a suspend point
if (target_fn == nullptr) {
if (fn_entry->inferred_async_node == nullptr) {
fn_entry->inferred_async_node = instruction->base.source_node;
}
}
if (type_can_fail(result_type)) {
@ -24830,8 +24843,10 @@ static IrInstruction *ir_analyze_instruction_await(IrAnalyze *ira, IrInstruction
result_loc = nullptr;
}
IrInstruction *result = ir_build_await_gen(ira, &instruction->base, frame, result_type, result_loc);
return ir_finish_anal(ira, result);
IrInstructionAwaitGen *result = ir_build_await_gen(ira, &instruction->base, frame, result_type, result_loc);
result->target_fn = target_fn;
fn_entry->await_list.append(result);
return ir_finish_anal(ira, &result->base);
}
static IrInstruction *ir_analyze_instruction_resume(IrAnalyze *ira, IrInstructionResume *instruction) {

1
src/userland.h
View File

@ -76,6 +76,7 @@ enum Error {
ErrorBrokenPipe,
ErrorNoSpaceLeft,
ErrorNotLazy,
ErrorIsAsync,
};
// ABI warning

10
test/stage1/behavior/async_fn.zig
View File

@ -844,3 +844,13 @@ test "cast fn to async fn when it is inferred to be async" {
resume S.frame;
expect(S.ok);
}
test "await does not force async if callee is blocking" {
const S = struct {
fn simple() i32 {
return 1234;
}
};
var x = async S.simple();
expect(await x == 1234);
}