From bd4d4ee51efebb79ed7b563a10eec992a71220fd Mon Sep 17 00:00:00 2001 From: Andrew Kelley Date: Sun, 27 Nov 2016 00:14:19 -0500 Subject: IR: detect error for exceeding branch quota --- src/ir.cpp | 60 ++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 34 insertions(+), 26 deletions(-) (limited to 'src/ir.cpp') diff --git a/src/ir.cpp b/src/ir.cpp index 569de611a8..f74ed39e7a 100644 --- a/src/ir.cpp +++ b/src/ir.cpp @@ -2957,8 +2957,24 @@ static void ir_finish_bb(IrAnalyze *ira) { } } -static void ir_inline_bb(IrAnalyze *ira, IrBasicBlock *old_bb) { +static TypeTableEntry *ir_unreach_error(IrAnalyze *ira) { + ira->block_queue_index = SIZE_MAX; + ira->new_irb.exec->invalid = true; + return ira->codegen->builtin_types.entry_unreachable; +} + +static TypeTableEntry *ir_inline_bb(IrAnalyze *ira, IrInstruction *source_instruction, IrBasicBlock *old_bb) { + if (old_bb->debug_id <= ira->old_irb.current_basic_block->debug_id) { + ira->new_irb.exec->backward_branch_count += 1; + if (ira->new_irb.exec->backward_branch_count > ira->new_irb.exec->backward_branch_quota) { + add_node_error(ira->codegen, source_instruction->source_node, + buf_sprintf("evaluation exceeded %zu backwards branches", ira->new_irb.exec->backward_branch_quota)); + return ir_unreach_error(ira); + } + } + ir_start_bb(ira, old_bb, ira->old_irb.current_basic_block); + return ira->codegen->builtin_types.entry_unreachable; } static TypeTableEntry *ir_finish_anal(IrAnalyze *ira, TypeTableEntry *result_type) { @@ -3439,12 +3455,12 @@ static TypeTableEntry *ir_analyze_instruction_return(IrAnalyze *ira, { IrInstruction *value = return_instruction->value->other; if (value->type_entry->id == TypeTableEntryIdInvalid) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); ira->implicit_return_type_list.append(value); IrInstruction *casted_value = ir_get_casted_value(ira, value, ira->explicit_return_type); if (casted_value == ira->codegen->invalid_instruction) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); ir_build_return_from(&ira->new_irb, &return_instruction->base, casted_value); return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); @@ -4302,11 +4318,8 @@ static TypeTableEntry *ir_analyze_instruction_un_op(IrAnalyze *ira, IrInstructio static TypeTableEntry *ir_analyze_instruction_br(IrAnalyze *ira, IrInstructionBr *br_instruction) { IrBasicBlock *old_dest_block = br_instruction->dest_block; - // TODO detect backward jumps - if (br_instruction->is_inline || old_dest_block->ref_count == 1) { - ir_inline_bb(ira, old_dest_block); - return ira->codegen->builtin_types.entry_unreachable; + return ir_inline_bb(ira, &br_instruction->base, old_dest_block); } IrBasicBlock *new_bb = ir_get_new_bb(ira, old_dest_block); @@ -4317,28 +4330,24 @@ static TypeTableEntry *ir_analyze_instruction_br(IrAnalyze *ira, IrInstructionBr static TypeTableEntry *ir_analyze_instruction_cond_br(IrAnalyze *ira, IrInstructionCondBr *cond_br_instruction) { IrInstruction *condition = cond_br_instruction->condition->other; if (condition->type_entry->id == TypeTableEntryIdInvalid) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); - - // TODO detect backward jumps + return ir_unreach_error(ira); if (cond_br_instruction->is_inline || condition->static_value.special != ConstValSpecialRuntime) { bool cond_is_true; if (!ir_resolve_bool(ira, condition, &cond_is_true)) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); IrBasicBlock *old_dest_block = cond_is_true ? cond_br_instruction->then_block : cond_br_instruction->else_block; - if (cond_br_instruction->is_inline || old_dest_block->ref_count == 1) { - ir_inline_bb(ira, old_dest_block); - return ira->codegen->builtin_types.entry_unreachable; - } + if (cond_br_instruction->is_inline || old_dest_block->ref_count == 1) + return ir_inline_bb(ira, &cond_br_instruction->base, old_dest_block); } TypeTableEntry *bool_type = ira->codegen->builtin_types.entry_bool; IrInstruction *casted_condition = ir_get_casted_value(ira, condition, bool_type); if (casted_condition == ira->codegen->invalid_instruction) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); IrBasicBlock *new_then_block = ir_get_new_bb(ira, cond_br_instruction->then_block); IrBasicBlock *new_else_block = ir_get_new_bb(ira, cond_br_instruction->else_block); @@ -5418,9 +5427,7 @@ static TypeTableEntry *ir_analyze_instruction_switch_br(IrAnalyze *ira, { IrInstruction *target_value = switch_br_instruction->target_value->other; if (target_value->type_entry->id == TypeTableEntryIdInvalid) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); - - // TODO detect backward jumps + return ir_unreach_error(ira); size_t case_count = switch_br_instruction->case_count; bool is_inline = switch_br_instruction->is_inline; @@ -5428,27 +5435,26 @@ static TypeTableEntry *ir_analyze_instruction_switch_br(IrAnalyze *ira, if (is_inline || target_value->static_value.special != ConstValSpecialRuntime) { ConstExprValue *target_val = ir_resolve_const(ira, target_value); if (!target_val) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); for (size_t i = 0; i < case_count; i += 1) { IrInstructionSwitchBrCase *old_case = &switch_br_instruction->cases[i]; IrInstruction *case_value = old_case->value->other; if (case_value->type_entry->id == TypeTableEntryIdInvalid) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); IrInstruction *casted_case_value = ir_get_casted_value(ira, case_value, target_value->type_entry); if (casted_case_value->type_entry->id == TypeTableEntryIdInvalid) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); ConstExprValue *case_val = ir_resolve_const(ira, casted_case_value); if (!case_val) - return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable); + return ir_unreach_error(ira); if (const_values_equal(target_val, case_val, target_value->type_entry)) { IrBasicBlock *old_dest_block = old_case->block; if (is_inline || old_dest_block->ref_count == 1) { - ir_inline_bb(ira, old_dest_block); - return ira->codegen->builtin_types.entry_unreachable; + return ir_inline_bb(ira, &switch_br_instruction->base, old_dest_block); } else { IrBasicBlock *new_dest_block = ir_get_new_bb(ira, old_dest_block); ir_build_br_from(&ira->new_irb, &switch_br_instruction->base, new_dest_block); @@ -5840,7 +5846,9 @@ TypeTableEntry *ir_analyze(CodeGen *codegen, IrExecutable *old_exec, IrExecutabl ira->instruction_index += 1; } - if (ira->implicit_return_type_list.length == 0) { + if (new_exec->invalid) { + return ira->codegen->builtin_types.entry_invalid; + } else if (ira->implicit_return_type_list.length == 0) { return codegen->builtin_types.entry_unreachable; } else { return ir_resolve_peer_types(ira, expected_type_source_node, ira->implicit_return_type_list.items, -- cgit v1.2.3