authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2019-08-04 18:24:10-04:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2019-08-04 18:24:10-04:00
logfa30ebfbe5949fc63aee9853d66932facfd1d168
tree170145ae5e992a7920d6288d76d8675c1b5af321
parent12924477a50d37bf055fd5fc1cdf0fd77684a472
signaturelock-open Commit is signed but in an unrecognized format.

suspension points inside branching control flow

6 files changed, 160 insertions(+), 82 deletions(-)

BRANCH_TODO-1
......@@ -1,4 +1,3 @@
1 * suspension points inside branching control flow
21 * go over the commented out tests
32 * error return tracing
43 * compile error for error: expected anyframe->T, found 'anyframe'
src/all_types.hpp+11-4
......@@ -1716,6 +1716,9 @@ struct CodeGen {
17161716 ZigLLVMDIFile *dummy_di_file;
17171717 LLVMValueRef cur_ret_ptr;
17181718 LLVMValueRef cur_fn_val;
1719 LLVMValueRef cur_async_switch_instr;
1720 LLVMValueRef cur_async_resume_index_ptr;
1721 LLVMValueRef cur_async_awaiter_ptr;
17191722 LLVMValueRef cur_err_ret_trace_val_arg;
17201723 LLVMValueRef cur_err_ret_trace_val_stack;
17211724 LLVMValueRef memcpy_fn_val;
......@@ -2166,8 +2169,8 @@ struct IrBasicBlock {
21662169 size_t ref_count;
21672170 // index into the basic block list
21682171 size_t index;
2169 // for async functions, the split function which corresponds to this block
2170 LLVMValueRef split_llvm_fn;
2172 // for async functions, the resume index which corresponds to this block
2173 size_t resume_index;
21712174 LLVMBasicBlockRef llvm_block;
21722175 LLVMBasicBlockRef llvm_exit_block;
21732176 // The instruction that referenced this basic block and caused us to
......@@ -3703,8 +3706,12 @@ static const size_t err_union_payload_index = 1;
37033706
37043707// label (grep this): [coro_frame_struct_layout]
37053708static const size_t coro_fn_ptr_index = 0;
3706static const size_t coro_awaiter_index = 1;
3707static const size_t coro_arg_start = 2;
3709static const size_t coro_resume_index = 1;
3710static const size_t coro_awaiter_index = 2;
3711static const size_t coro_arg_start = 3;
3712
3713// one for the Entry block, resume blocks are indexed after that.
3714static const size_t coro_extra_resume_block_count = 1;
37083715
37093716// TODO call graph analysis to find out what this number needs to be for every function
37103717// MUST BE A POWER OF TWO.
src/analyze.cpp+27-8
......@@ -5215,6 +5215,9 @@ static Error resolve_coro_frame(CodeGen *g, ZigType *frame_type) {
52155215 field_names.append("fn_ptr");
52165216 field_types.append(fn_type);
52175217
5218 field_names.append("resume_index");
5219 field_types.append(g->builtin_types.entry_usize);
5220
52185221 field_names.append("awaiter");
52195222 field_types.append(g->builtin_types.entry_usize);
52205223
......@@ -7532,9 +7535,10 @@ static void resolve_llvm_types_any_frame(CodeGen *g, ZigType *any_frame_type, Re
75327535 // label (grep this): [coro_frame_struct_layout]
75337536 LLVMTypeRef field_types[] = {
75347537 ptr_result_type, // fn_ptr
7538 usize_type_ref, // resume_index
75357539 usize_type_ref, // awaiter
75367540 };
7537 LLVMStructSetBody(frame_header_type, field_types, 2, false);
7541 LLVMStructSetBody(frame_header_type, field_types, 3, false);
75387542
75397543 ZigLLVMDIType *di_element_types[] = {
75407544 ZigLLVMCreateDebugMemberType(g->dbuilder,
......@@ -7545,12 +7549,19 @@ static void resolve_llvm_types_any_frame(CodeGen *g, ZigType *any_frame_type, Re
75457549 8*LLVMOffsetOfElement(g->target_data_ref, frame_header_type, 0),
75467550 ZigLLVM_DIFlags_Zero, usize_di_type),
75477551 ZigLLVMCreateDebugMemberType(g->dbuilder,
7548 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "awaiter",
7552 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "resume_index",
75497553 di_file, line,
75507554 8*LLVMABISizeOfType(g->target_data_ref, field_types[1]),
75517555 8*LLVMABIAlignmentOfType(g->target_data_ref, field_types[1]),
75527556 8*LLVMOffsetOfElement(g->target_data_ref, frame_header_type, 1),
75537557 ZigLLVM_DIFlags_Zero, usize_di_type),
7558 ZigLLVMCreateDebugMemberType(g->dbuilder,
7559 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "awaiter",
7560 di_file, line,
7561 8*LLVMABISizeOfType(g->target_data_ref, field_types[2]),
7562 8*LLVMABIAlignmentOfType(g->target_data_ref, field_types[2]),
7563 8*LLVMOffsetOfElement(g->target_data_ref, frame_header_type, 2),
7564 ZigLLVM_DIFlags_Zero, usize_di_type),
75547565 };
75557566 ZigLLVMDIType *replacement_di_type = ZigLLVMCreateDebugStructType(g->dbuilder,
75567567 compile_unit_scope, buf_ptr(name),
......@@ -7558,7 +7569,7 @@ static void resolve_llvm_types_any_frame(CodeGen *g, ZigType *any_frame_type, Re
75587569 8*LLVMABISizeOfType(g->target_data_ref, frame_header_type),
75597570 8*LLVMABIAlignmentOfType(g->target_data_ref, frame_header_type),
75607571 ZigLLVM_DIFlags_Zero,
7561 nullptr, di_element_types, 2, 0, nullptr, "");
7572 nullptr, di_element_types, 3, 0, nullptr, "");
75627573
75637574 ZigLLVMReplaceTemporary(g->dbuilder, frame_header_di_type, replacement_di_type);
75647575 } else {
......@@ -7566,11 +7577,12 @@ static void resolve_llvm_types_any_frame(CodeGen *g, ZigType *any_frame_type, Re
75667577 // label (grep this): [coro_frame_struct_layout]
75677578 LLVMTypeRef field_types[] = {
75687579 LLVMPointerType(fn_type, 0), // fn_ptr
7580 usize_type_ref, // resume_index
75697581 usize_type_ref, // awaiter
75707582 get_llvm_type(g, ptr_result_type), // result_ptr
75717583 get_llvm_type(g, result_type), // result
75727584 };
7573 LLVMStructSetBody(frame_header_type, field_types, 4, false);
7585 LLVMStructSetBody(frame_header_type, field_types, 5, false);
75747586
75757587 ZigLLVMDIType *di_element_types[] = {
75767588 ZigLLVMCreateDebugMemberType(g->dbuilder,
......@@ -7588,18 +7600,25 @@ static void resolve_llvm_types_any_frame(CodeGen *g, ZigType *any_frame_type, Re
75887600 8*LLVMOffsetOfElement(g->target_data_ref, frame_header_type, 1),
75897601 ZigLLVM_DIFlags_Zero, usize_di_type),
75907602 ZigLLVMCreateDebugMemberType(g->dbuilder,
7591 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "result_ptr",
7603 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "awaiter",
75927604 di_file, line,
75937605 8*LLVMABISizeOfType(g->target_data_ref, field_types[2]),
75947606 8*LLVMABIAlignmentOfType(g->target_data_ref, field_types[2]),
75957607 8*LLVMOffsetOfElement(g->target_data_ref, frame_header_type, 2),
7596 ZigLLVM_DIFlags_Zero, get_llvm_di_type(g, ptr_result_type)),
7608 ZigLLVM_DIFlags_Zero, usize_di_type),
75977609 ZigLLVMCreateDebugMemberType(g->dbuilder,
7598 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "result",
7610 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "result_ptr",
75997611 di_file, line,
76007612 8*LLVMABISizeOfType(g->target_data_ref, field_types[3]),
76017613 8*LLVMABIAlignmentOfType(g->target_data_ref, field_types[3]),
76027614 8*LLVMOffsetOfElement(g->target_data_ref, frame_header_type, 3),
7615 ZigLLVM_DIFlags_Zero, get_llvm_di_type(g, ptr_result_type)),
7616 ZigLLVMCreateDebugMemberType(g->dbuilder,
7617 ZigLLVMTypeToScope(any_frame_type->llvm_di_type), "result",
7618 di_file, line,
7619 8*LLVMABISizeOfType(g->target_data_ref, field_types[4]),
7620 8*LLVMABIAlignmentOfType(g->target_data_ref, field_types[4]),
7621 8*LLVMOffsetOfElement(g->target_data_ref, frame_header_type, 4),
76037622 ZigLLVM_DIFlags_Zero, get_llvm_di_type(g, result_type)),
76047623 };
76057624 ZigLLVMDIType *replacement_di_type = ZigLLVMCreateDebugStructType(g->dbuilder,
......@@ -7608,7 +7627,7 @@ static void resolve_llvm_types_any_frame(CodeGen *g, ZigType *any_frame_type, Re
76087627 8*LLVMABISizeOfType(g->target_data_ref, frame_header_type),
76097628 8*LLVMABIAlignmentOfType(g->target_data_ref, frame_header_type),
76107629 ZigLLVM_DIFlags_Zero,
7611 nullptr, di_element_types, 2, 0, nullptr, "");
7630 nullptr, di_element_types, 5, 0, nullptr, "");
76127631
76137632 ZigLLVMReplaceTemporary(g->dbuilder, frame_header_di_type, replacement_di_type);
76147633 }
src/codegen.cpp+95-68
......@@ -1997,7 +1997,9 @@ static LLVMValueRef ir_render_save_err_ret_addr(CodeGen *g, IrExecutable *execut
19971997 return call_instruction;
19981998}
19991999
2000static LLVMValueRef ir_render_return(CodeGen *g, IrExecutable *executable, IrInstructionReturn *return_instruction) {
2000static LLVMValueRef ir_render_return(CodeGen *g, IrExecutable *executable,
2001 IrInstructionReturn *return_instruction)
2002{
20012003 if (fn_is_async(g->cur_fn)) {
20022004 LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
20032005 LLVMValueRef locals_ptr = g->cur_ret_ptr;
......@@ -2006,12 +2008,10 @@ static LLVMValueRef ir_render_return(CodeGen *g, IrExecutable *executable, IrIns
20062008 ZigType *ret_type = ret_type_has_bits ? return_instruction->value->value.type : nullptr;
20072009
20082010 if (ir_want_runtime_safety(g, &return_instruction->base)) {
2009 LLVMValueRef resume_index_ptr = LLVMBuildStructGEP(g->builder, locals_ptr, coro_fn_ptr_index, "");
2010 LLVMValueRef new_resume_fn = g->cur_fn->resume_blocks.last()->split_llvm_fn;
2011 LLVMBuildStore(g->builder, new_resume_fn, resume_index_ptr);
2011 LLVMValueRef new_resume_index = LLVMConstAllOnes(usize_type_ref);
2012 LLVMBuildStore(g->builder, new_resume_index, g->cur_async_resume_index_ptr);
20122013 }
20132014
2014 LLVMValueRef awaiter_ptr = LLVMBuildStructGEP(g->builder, locals_ptr, coro_awaiter_index, "");
20152015 LLVMValueRef result_ptr_as_usize;
20162016 if (ret_type_has_bits) {
20172017 LLVMValueRef result_ptr_ptr = LLVMBuildStructGEP(g->builder, locals_ptr, coro_arg_start, "");
......@@ -2029,8 +2029,8 @@ static LLVMValueRef ir_render_return(CodeGen *g, IrExecutable *executable, IrIns
20292029 }
20302030 LLVMValueRef zero = LLVMConstNull(usize_type_ref);
20312031 LLVMValueRef all_ones = LLVMConstAllOnes(usize_type_ref);
2032 LLVMValueRef prev_val = LLVMBuildAtomicRMW(g->builder, LLVMAtomicRMWBinOpXchg, awaiter_ptr,
2033 all_ones, LLVMAtomicOrderingSequentiallyConsistent, g->is_single_threaded);
2032 LLVMValueRef prev_val = LLVMBuildAtomicRMW(g->builder, LLVMAtomicRMWBinOpXchg, g->cur_async_awaiter_ptr,
2033 all_ones, LLVMAtomicOrderingMonotonic, g->is_single_threaded);
20342034
20352035 LLVMBasicBlockRef bad_return_block = LLVMAppendBasicBlock(g->cur_fn_val, "BadReturn");
20362036 LLVMBasicBlockRef early_return_block = LLVMAppendBasicBlock(g->cur_fn_val, "EarlyReturn");
......@@ -3453,7 +3453,6 @@ static void render_async_spills(CodeGen *g) {
34533453}
34543454
34553455static void render_async_var_decls(CodeGen *g, Scope *scope) {
3456 render_async_spills(g);
34573456 for (;;) {
34583457 switch (scope->id) {
34593458 case ScopeIdCImport:
......@@ -3573,6 +3572,14 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
35733572 if (instruction->is_async || callee_is_async) {
35743573 assert(frame_result_loc != nullptr);
35753574
3575 LLVMValueRef fn_ptr_ptr = LLVMBuildStructGEP(g->builder, frame_result_loc, coro_fn_ptr_index, "");
3576 LLVMValueRef bitcasted_fn_val = LLVMBuildBitCast(g->builder, fn_val,
3577 LLVMGetElementType(LLVMTypeOf(fn_ptr_ptr)), "");
3578 LLVMBuildStore(g->builder, bitcasted_fn_val, fn_ptr_ptr);
3579
3580 LLVMValueRef resume_index_ptr = LLVMBuildStructGEP(g->builder, frame_result_loc, coro_resume_index, "");
3581 LLVMBuildStore(g->builder, zero, resume_index_ptr);
3582
35763583 if (prefix_arg_err_ret_stack) {
35773584 zig_panic("TODO");
35783585 }
......@@ -3652,23 +3659,24 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
36523659 return nullptr;
36533660 } else if (callee_is_async) {
36543661 ZigType *ptr_result_type = get_pointer_to_type(g, src_return_type, true);
3655 LLVMValueRef split_llvm_fn = make_fn_llvm_value(g, g->cur_fn);
3656 LLVMValueRef fn_ptr_ptr = LLVMBuildStructGEP(g->builder, g->cur_ret_ptr, coro_fn_ptr_index, "");
3657 LLVMBuildStore(g->builder, split_llvm_fn, fn_ptr_ptr);
3662
3663 LLVMBasicBlockRef call_bb = LLVMAppendBasicBlock(g->cur_fn_val, "CallResume");
3664 size_t new_block_index = g->cur_fn->resume_blocks.length + coro_extra_resume_block_count;
3665 g->cur_fn->resume_blocks.append(nullptr);
3666 LLVMValueRef new_block_index_val = LLVMConstInt(usize_type_ref, new_block_index, false);
3667 LLVMAddCase(g->cur_async_switch_instr, new_block_index_val, call_bb);
3668
3669 LLVMBuildStore(g->builder, new_block_index_val, g->cur_async_resume_index_ptr);
36583670 LLVMValueRef args[] = {frame_result_loc, LLVMGetUndef(usize_type_ref)};
36593671 LLVMValueRef call_inst = ZigLLVMBuildCall(g->builder, fn_val, args, 2, llvm_cc, fn_inline, "");
36603672 ZigLLVMSetTailCall(call_inst);
36613673 LLVMBuildRetVoid(g->builder);
36623674
3663 g->cur_fn_val = split_llvm_fn;
3664 g->cur_ret_ptr = LLVMGetParam(split_llvm_fn, 0);
3665 LLVMBasicBlockRef call_bb = LLVMAppendBasicBlock(split_llvm_fn, "CallResume");
36663675 LLVMPositionBuilderAtEnd(g->builder, call_bb);
3667
36683676 if (ir_want_runtime_safety(g, &instruction->base)) {
3669 LLVMBasicBlockRef bad_resume_block = LLVMAppendBasicBlock(split_llvm_fn, "BadResume");
3670 LLVMBasicBlockRef ok_resume_block = LLVMAppendBasicBlock(split_llvm_fn, "OkResume");
3671 LLVMValueRef arg_val = LLVMGetParam(split_llvm_fn, 1);
3677 LLVMBasicBlockRef bad_resume_block = LLVMAppendBasicBlock(g->cur_fn_val, "BadResume");
3678 LLVMBasicBlockRef ok_resume_block = LLVMAppendBasicBlock(g->cur_fn_val, "OkResume");
3679 LLVMValueRef arg_val = LLVMGetParam(g->cur_fn_val, 1);
36723680 LLVMValueRef all_ones = LLVMConstAllOnes(usize_type_ref);
36733681 LLVMValueRef ok_bit = LLVMBuildICmp(g->builder, LLVMIntNE, arg_val, all_ones, "");
36743682 LLVMBuildCondBr(g->builder, ok_bit, ok_resume_block, bad_resume_block);
......@@ -5144,10 +5152,9 @@ static LLVMValueRef ir_render_assert_non_null(CodeGen *g, IrExecutable *executab
51445152static LLVMValueRef ir_render_suspend_begin(CodeGen *g, IrExecutable *executable,
51455153 IrInstructionSuspendBegin *instruction)
51465154{
5147 LLVMValueRef locals_ptr = g->cur_ret_ptr;
5148 LLVMValueRef fn_ptr_ptr = LLVMBuildStructGEP(g->builder, locals_ptr, coro_fn_ptr_index, "");
5149 LLVMValueRef new_fn_ptr = instruction->resume_block->split_llvm_fn;
5150 LLVMBuildStore(g->builder, new_fn_ptr, fn_ptr_ptr);
5155 LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
5156 LLVMValueRef new_resume_index = LLVMConstInt(usize_type_ref, instruction->resume_block->resume_index, false);
5157 LLVMBuildStore(g->builder, new_resume_index, g->cur_async_resume_index_ptr);
51515158 return nullptr;
51525159}
51535160
......@@ -5159,19 +5166,22 @@ static LLVMValueRef ir_render_suspend_br(CodeGen *g, IrExecutable *executable,
51595166}
51605167
51615168static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInstructionAwait *instruction) {
5169 LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
51625170 LLVMValueRef target_frame_ptr = ir_llvm_value(g, instruction->frame);
51635171 ZigType *result_type = instruction->base.value.type;
51645172 ZigType *ptr_result_type = get_pointer_to_type(g, result_type, true);
51655173
51665174 // Prepare to be suspended
5167 LLVMValueRef split_llvm_fn = make_fn_llvm_value(g, g->cur_fn);
5168 LLVMValueRef fn_ptr_ptr = LLVMBuildStructGEP(g->builder, g->cur_ret_ptr, coro_fn_ptr_index, "");
5169 LLVMBuildStore(g->builder, split_llvm_fn, fn_ptr_ptr);
5175 LLVMBasicBlockRef resume_bb = LLVMAppendBasicBlock(g->cur_fn_val, "AwaitResume");
5176 size_t new_block_index = g->cur_fn->resume_blocks.length + coro_extra_resume_block_count;
5177 g->cur_fn->resume_blocks.append(nullptr);
5178 LLVMValueRef new_block_index_val = LLVMConstInt(usize_type_ref, new_block_index, false);
5179 LLVMAddCase(g->cur_async_switch_instr, new_block_index_val, resume_bb);
5180 LLVMBuildStore(g->builder, new_block_index_val, g->cur_async_resume_index_ptr);
51705181
51715182 // At this point resuming the function will do the correct thing.
51725183 // This code is as if it is running inside the suspend block.
51735184
5174 LLVMTypeRef usize_type_ref = g->builtin_types.entry_usize->llvm_type;
51755185 // caller's own frame pointer
51765186 LLVMValueRef awaiter_init_val = LLVMBuildPtrToInt(g->builder, g->cur_ret_ptr, usize_type_ref, "");
51775187 LLVMValueRef awaiter_ptr = LLVMBuildStructGEP(g->builder, target_frame_ptr, coro_awaiter_index, "");
......@@ -5184,18 +5194,20 @@ static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInst
51845194 result_ptr_as_usize = LLVMGetUndef(usize_type_ref);
51855195 }
51865196 LLVMValueRef prev_val = LLVMBuildAtomicRMW(g->builder, LLVMAtomicRMWBinOpXchg, awaiter_ptr, awaiter_init_val,
5187 LLVMAtomicOrderingSequentiallyConsistent, g->is_single_threaded);
5197 LLVMAtomicOrderingMonotonic, g->is_single_threaded);
51885198
51895199 LLVMBasicBlockRef bad_await_block = LLVMAppendBasicBlock(g->cur_fn_val, "BadAwait");
51905200 LLVMBasicBlockRef complete_suspend_block = LLVMAppendBasicBlock(g->cur_fn_val, "CompleteSuspend");
5191 LLVMBasicBlockRef early_return_block = LLVMAppendBasicBlock(g->cur_fn_val, "EarlyReturn");
51925201
51935202 LLVMValueRef zero = LLVMConstNull(usize_type_ref);
51945203 LLVMValueRef all_ones = LLVMConstAllOnes(usize_type_ref);
51955204 LLVMValueRef switch_instr = LLVMBuildSwitch(g->builder, prev_val, bad_await_block, 2);
5205 LLVMBasicBlockRef predecessor_bb = LLVMGetInsertBlock(g->builder);
51965206
51975207 LLVMAddCase(switch_instr, zero, complete_suspend_block);
5198 LLVMAddCase(switch_instr, all_ones, early_return_block);
5208
5209 // Early return: The async function has already completed. No need to suspend.
5210 LLVMAddCase(switch_instr, all_ones, resume_bb);
51995211
52005212 // We discovered that another awaiter was already here.
52015213 LLVMPositionBuilderAtEnd(g->builder, bad_await_block);
......@@ -5205,25 +5217,18 @@ static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInst
52055217 LLVMPositionBuilderAtEnd(g->builder, complete_suspend_block);
52065218 LLVMBuildRetVoid(g->builder);
52075219
5208 // The async function has already completed. So we use a tail call to resume ourselves.
5209 LLVMPositionBuilderAtEnd(g->builder, early_return_block);
5210 LLVMValueRef args[] = {g->cur_ret_ptr, result_ptr_as_usize};
5211 LLVMValueRef call_inst = ZigLLVMBuildCall(g->builder, split_llvm_fn, args, 2, LLVMFastCallConv,
5212 ZigLLVM_FnInlineAuto, "");
5213 ZigLLVMSetTailCall(call_inst);
5214 LLVMBuildRetVoid(g->builder);
5215
5216 g->cur_fn_val = split_llvm_fn;
5217 g->cur_ret_ptr = LLVMGetParam(split_llvm_fn, 0);
5218 LLVMBasicBlockRef call_bb = LLVMAppendBasicBlock(split_llvm_fn, "AwaitResume");
5219 LLVMPositionBuilderAtEnd(g->builder, call_bb);
5220 LLVMPositionBuilderAtEnd(g->builder, resume_bb);
5221 // We either got here from Entry (function call) or from the switch above
5222 LLVMValueRef spilled_result_ptr = LLVMBuildPhi(g->builder, usize_type_ref, "");
5223 LLVMValueRef incoming_values[] = { LLVMGetParam(g->cur_fn_val, 1), result_ptr_as_usize };
5224 LLVMBasicBlockRef incoming_blocks[] = { g->cur_fn->preamble_llvm_block, predecessor_bb };
5225 LLVMAddIncoming(spilled_result_ptr, incoming_values, incoming_blocks, 2);
52205226
52215227 if (ir_want_runtime_safety(g, &instruction->base)) {
5222 LLVMBasicBlockRef bad_resume_block = LLVMAppendBasicBlock(split_llvm_fn, "BadResume");
5223 LLVMBasicBlockRef ok_resume_block = LLVMAppendBasicBlock(split_llvm_fn, "OkResume");
5224 LLVMValueRef arg_val = LLVMGetParam(split_llvm_fn, 1);
5228 LLVMBasicBlockRef bad_resume_block = LLVMAppendBasicBlock(g->cur_fn_val, "BadResume");
5229 LLVMBasicBlockRef ok_resume_block = LLVMAppendBasicBlock(g->cur_fn_val, "OkResume");
52255230 LLVMValueRef all_ones = LLVMConstAllOnes(usize_type_ref);
5226 LLVMValueRef ok_bit = LLVMBuildICmp(g->builder, LLVMIntNE, arg_val, all_ones, "");
5231 LLVMValueRef ok_bit = LLVMBuildICmp(g->builder, LLVMIntNE, spilled_result_ptr, all_ones, "");
52275232 LLVMBuildCondBr(g->builder, ok_bit, ok_resume_block, bad_resume_block);
52285233
52295234 LLVMPositionBuilderAtEnd(g->builder, bad_resume_block);
......@@ -5235,7 +5240,6 @@ static LLVMValueRef ir_render_await(CodeGen *g, IrExecutable *executable, IrInst
52355240 render_async_var_decls(g, instruction->base.scope);
52365241
52375242 if (type_has_bits(result_type)) {
5238 LLVMValueRef spilled_result_ptr = LLVMGetParam(g->cur_fn_val, 1);
52395243 LLVMValueRef casted_spilled_result_ptr = LLVMBuildIntToPtr(g->builder, spilled_result_ptr,
52405244 get_llvm_type(g, ptr_result_type), "");
52415245 return get_handle_value(g, casted_spilled_result_ptr, result_type, ptr_result_type);
......@@ -5547,13 +5551,18 @@ static void ir_render(CodeGen *g, ZigFn *fn_entry) {
55475551
55485552 IrExecutable *executable = &fn_entry->analyzed_executable;
55495553 assert(executable->basic_block_list.length > 0);
5554
5555 if (fn_is_async(fn_entry)) {
5556 IrBasicBlock *entry_block = executable->basic_block_list.at(0);
5557 LLVMPositionBuilderAtEnd(g->builder, entry_block->llvm_block);
5558 render_async_var_decls(g, entry_block->instruction_list.at(0)->scope);
5559 }
5560
55505561 for (size_t block_i = 0; block_i < executable->basic_block_list.length; block_i += 1) {
55515562 IrBasicBlock *current_block = executable->basic_block_list.at(block_i);
55525563 assert(current_block->llvm_block);
55535564 LLVMPositionBuilderAtEnd(g->builder, current_block->llvm_block);
5554 if (current_block->split_llvm_fn != nullptr) {
5555 g->cur_fn_val = current_block->split_llvm_fn;
5556 g->cur_ret_ptr = LLVMGetParam(g->cur_fn_val, 0);
5565 if (current_block->resume_index != 0) {
55575566 render_async_var_decls(g, current_block->instruction_list.at(0)->scope);
55585567 }
55595568 for (size_t instr_i = 0; instr_i < current_block->instruction_list.length; instr_i += 1) {
......@@ -6416,17 +6425,19 @@ static void build_all_basic_blocks(CodeGen *g, ZigFn *fn) {
64166425 IrExecutable *executable = &fn->analyzed_executable;
64176426 assert(executable->basic_block_list.length > 0);
64186427 LLVMValueRef fn_val = fn_llvm_value(g, fn);
6428 LLVMBasicBlockRef first_bb = nullptr;
6429 if (fn_is_async(fn)) {
6430 first_bb = LLVMAppendBasicBlock(fn_val, "AsyncSwitch");
6431 fn->preamble_llvm_block = first_bb;
6432 }
64196433 for (size_t block_i = 0; block_i < executable->basic_block_list.length; block_i += 1) {
64206434 IrBasicBlock *bb = executable->basic_block_list.at(block_i);
6421 if (bb->split_llvm_fn != nullptr) {
6422 assert(bb->split_llvm_fn == reinterpret_cast<LLVMValueRef>(0x1));
6423 fn_val = make_fn_llvm_value(g, fn);
6424 bb->split_llvm_fn = fn_val;
6425 }
64266435 bb->llvm_block = LLVMAppendBasicBlock(fn_val, bb->name_hint);
64276436 }
6428 IrBasicBlock *entry_bb = executable->basic_block_list.at(0);
6429 LLVMPositionBuilderAtEnd(g->builder, entry_bb->llvm_block);
6437 if (first_bb == nullptr) {
6438 first_bb = executable->basic_block_list.at(0)->llvm_block;
6439 }
6440 LLVMPositionBuilderAtEnd(g->builder, first_bb);
64306441}
64316442
64326443static void gen_global_var(CodeGen *g, ZigVar *var, LLVMValueRef init_val,
......@@ -6636,9 +6647,7 @@ static void do_code_gen(CodeGen *g) {
66366647 g->cur_err_ret_trace_val_stack = nullptr;
66376648 }
66386649
6639 if (is_async) {
6640 render_async_spills(g);
6641 } else {
6650 if (!is_async) {
66426651 // allocate temporary stack data
66436652 for (size_t alloca_i = 0; alloca_i < fn_table_entry->alloca_gen_list.length; alloca_i += 1) {
66446653 IrInstructionAllocaGen *instruction = fn_table_entry->alloca_gen_list.at(alloca_i);
......@@ -6752,17 +6761,35 @@ static void do_code_gen(CodeGen *g) {
67526761 LLVMValueRef size_val = LLVMConstInt(usize_type_ref, fn_table_entry->frame_type->abi_size, false);
67536762 ZigLLVMFunctionSetPrefixData(fn_table_entry->llvm_value, size_val);
67546763
6755 if (ir_want_runtime_safety_scope(g, fn_table_entry->child_scope)) {
6756 IrBasicBlock *bad_resume_block = allocate<IrBasicBlock>(1);
6757 bad_resume_block->name_hint = "BadResume";
6758 bad_resume_block->split_llvm_fn = make_fn_llvm_value(g, fn_table_entry);
6759
6760 LLVMBasicBlockRef llvm_block = LLVMAppendBasicBlock(bad_resume_block->split_llvm_fn, "BadResume");
6761 LLVMPositionBuilderAtEnd(g->builder, llvm_block);
6762 gen_safety_crash(g, PanicMsgIdBadResume);
6764 if (!g->strip_debug_symbols) {
6765 AstNode *source_node = fn_table_entry->proto_node;
6766 ZigLLVMSetCurrentDebugLocation(g->builder, (int)source_node->line + 1,
6767 (int)source_node->column + 1, get_di_scope(g, fn_table_entry->child_scope));
6768 }
6769 IrExecutable *executable = &fn_table_entry->analyzed_executable;
6770 LLVMBasicBlockRef bad_resume_block = LLVMAppendBasicBlock(g->cur_fn_val, "BadResume");
6771 LLVMPositionBuilderAtEnd(g->builder, bad_resume_block);
6772 gen_assertion_scope(g, PanicMsgIdBadResume, fn_table_entry->child_scope);
67636773
6764 fn_table_entry->resume_blocks.append(bad_resume_block);
6774 LLVMPositionBuilderAtEnd(g->builder, fn_table_entry->preamble_llvm_block);
6775 render_async_spills(g);
6776 g->cur_async_awaiter_ptr = LLVMBuildStructGEP(g->builder, g->cur_ret_ptr, coro_awaiter_index, "");
6777 LLVMValueRef resume_index_ptr = LLVMBuildStructGEP(g->builder, g->cur_ret_ptr, coro_resume_index, "");
6778 g->cur_async_resume_index_ptr = resume_index_ptr;
6779 LLVMValueRef resume_index = LLVMBuildLoad(g->builder, resume_index_ptr, "");
6780 LLVMValueRef switch_instr = LLVMBuildSwitch(g->builder, resume_index, bad_resume_block,
6781 fn_table_entry->resume_blocks.length + coro_extra_resume_block_count);
6782 g->cur_async_switch_instr = switch_instr;
6783
6784 LLVMValueRef zero = LLVMConstNull(usize_type_ref);
6785 LLVMAddCase(switch_instr, zero, executable->basic_block_list.at(0)->llvm_block);
6786
6787 for (size_t resume_i = 0; resume_i < fn_table_entry->resume_blocks.length; resume_i += 1) {
6788 IrBasicBlock *resume_block = fn_table_entry->resume_blocks.at(resume_i);
6789 LLVMValueRef case_value = LLVMConstInt(usize_type_ref, resume_block->resume_index, false);
6790 LLVMAddCase(switch_instr, case_value, resume_block->llvm_block);
67656791 }
6792
67666793 } else {
67676794 // create debug variable declarations for parameters
67686795 // rely on the first variables in the variable_list being parameters.
src/ir.cpp+1-1
......@@ -24474,7 +24474,7 @@ static IrInstruction *ir_analyze_instruction_suspend_br(IrAnalyze *ira, IrInstru
2447424474 ZigFn *fn_entry = exec_fn_entry(ira->new_irb.exec);
2447524475 ir_assert(fn_entry != nullptr, &instruction->base);
2447624476
24477 new_bb->split_llvm_fn = reinterpret_cast<LLVMValueRef>(0x1);
24477 new_bb->resume_index = fn_entry->resume_blocks.length + coro_extra_resume_block_count;
2447824478
2447924479 fn_entry->resume_blocks.append(new_bb);
2448024480 if (fn_entry->inferred_async_node == nullptr) {
test/stage1/behavior/coroutines.zig+26
......@@ -419,3 +419,29 @@ test "async function call return value" {
419419 };
420420 S.doTheTest();
421421}
422
423test "suspension points inside branching control flow" {
424 const S = struct {
425 var global_result: i32 = 10;
426
427 fn doTheTest() void {
428 expect(10 == global_result);
429 var frame = async func(true);
430 expect(10 == global_result);
431 resume frame;
432 expect(11 == global_result);
433 resume frame;
434 expect(12 == global_result);
435 resume frame;
436 expect(13 == global_result);
437 }
438
439 fn func(b: bool) void {
440 while (b) {
441 suspend;
442 global_result += 1;
443 }
444 }
445 };
446 S.doTheTest();
447}