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IR: detect error for exceeding branch quota

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This commit is contained in:
Andrew Kelley 2016-11-27 00:14:19 -05:00
parent 1fba7f3696
commit bd4d4ee51e
3 changed files with 41 additions and 27 deletions
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2
src/all_types.hpp
View File

@ -36,6 +36,8 @@ struct IrExecutable {
ZigList<IrBasicBlock *> basic_block_list;
size_t mem_slot_count;
size_t next_debug_id;
size_t backward_branch_count;
size_t backward_branch_quota;
bool invalid;
ZigList<LabelTableEntry *> all_labels;
ZigList<AstNode *> goto_list;

6
src/analyze.cpp
View File

@ -17,6 +17,8 @@
#include "parser.hpp"
#include "zig_llvm.hpp"
static const size_t default_backward_branch_quota = 1000;
static void resolve_enum_type(CodeGen *g, ImportTableEntry *import, TypeTableEntry *enum_type);
static void resolve_struct_type(CodeGen *g, ImportTableEntry *import, TypeTableEntry *struct_type);
@ -836,7 +838,6 @@ static IrInstruction *analyze_const_value(CodeGen *g, BlockContext *scope, AstNo
TypeTableEntry *expected_type)
{
IrExecutable ir_executable = {0};
IrExecutable analyzed_executable = {0};
ir_gen(g, node, scope, &ir_executable);
if (ir_executable.invalid)
@ -849,6 +850,8 @@ static IrInstruction *analyze_const_value(CodeGen *g, BlockContext *scope, AstNo
ir_print(stderr, &ir_executable, 4);
fprintf(stderr, "}\n");
}
IrExecutable analyzed_executable = {0};
analyzed_executable.backward_branch_quota = default_backward_branch_quota;
TypeTableEntry *result_type = ir_analyze(g, &ir_executable, &analyzed_executable, expected_type, node);
if (result_type->id == TypeTableEntryIdInvalid)
return g->invalid_instruction;
@ -1514,6 +1517,7 @@ static void preview_fn_proto_instance(CodeGen *g, ImportTableEntry *import, AstN
}
FnTableEntry *fn_table_entry = allocate<FnTableEntry>(1);
fn_table_entry->analyzed_executable.backward_branch_quota = default_backward_branch_quota;
fn_table_entry->import_entry = import;
fn_table_entry->proto_node = proto_node;
fn_table_entry->fn_def_node = fn_def_node;

60
src/ir.cpp
View File

@ -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,