jak-project/decompiler/Function/Function.cpp
water111 4a97e15b40
[Decompiler] Remove most IR1 Analysis (#207)
* temp

* remove some of ir1
2021-01-22 22:03:58 -05:00

752 lines
25 KiB
C++

#include <cassert>
#include <vector>
#include "Function.h"
#include "common/log/log.h"
#include "decompiler/Disasm/InstructionMatching.h"
#include "decompiler/ObjectFile/LinkedObjectFile.h"
#include "decompiler/util/DecompilerTypeSystem.h"
#include "TypeInspector.h"
#include "decompiler/IR/IR.h"
namespace decompiler {
namespace {
std::vector<Register> gpr_backups = {make_gpr(Reg::GP), make_gpr(Reg::S5), make_gpr(Reg::S4),
make_gpr(Reg::S3), make_gpr(Reg::S2), make_gpr(Reg::S1),
make_gpr(Reg::S0)};
std::vector<Register> fpr_backups = {make_fpr(30), make_fpr(28), make_fpr(26),
make_fpr(24), make_fpr(22), make_fpr(20)};
Register get_expected_gpr_backup(int n, int total) {
assert(total <= int(gpr_backups.size()));
assert(n < total);
return gpr_backups.at((total - 1) - n);
}
Register get_expected_fpr_backup(int n, int total) {
assert(total <= int(fpr_backups.size()));
assert(n < total);
return fpr_backups.at((total - 1) - n);
}
uint32_t align16(uint32_t in) {
return (in + 15) & (~15);
}
uint32_t align8(uint32_t in) {
return (in + 7) & (~7);
}
uint32_t align4(uint32_t in) {
return (in + 3) & (~3);
}
} // namespace
Function::Function(int _start_word, int _end_word) : start_word(_start_word), end_word(_end_word) {}
/*!
* Remove the function prologue from the first basic block and populate this->prologue with info.
*/
void Function::analyze_prologue(const LinkedObjectFile& file) {
int idx = 1;
// first we look for daddiu sp, sp, -x to determine how much stack is used
if (is_gpr_2_imm_int(instructions.at(idx), InstructionKind::DADDIU, make_gpr(Reg::SP),
make_gpr(Reg::SP), {})) {
prologue.total_stack_usage = -instructions.at(idx).get_imm_src_int();
idx++;
} else {
prologue.total_stack_usage = 0;
}
// don't include type tag
prologue_end = 1;
// if we use the stack, we may back up some registers onto it
if (prologue.total_stack_usage) {
// heuristics to detect asm functions
{
auto& instr = instructions.at(idx);
// storing stack pointer on the stack is done by some ASM kernel functions
if (instr.kind == InstructionKind::SW && instr.get_src(0).get_reg() == make_gpr(Reg::SP)) {
printf("[Warning] %s Suspected ASM function based on this instruction in prologue: %s\n",
guessed_name.to_string().c_str(), instr.to_string(file.labels).c_str());
warnings += ";; Flagged as ASM function because of " + instr.to_string(file.labels) + "\n";
suspected_asm = true;
return;
}
}
// ra backup is always first
if (is_no_link_gpr_store(instructions.at(idx), 8, Register(Reg::GPR, Reg::RA), {},
Register(Reg::GPR, Reg::SP))) {
prologue.ra_backed_up = true;
prologue.ra_backup_offset = get_gpr_store_offset_as_int(instructions.at(idx));
assert(prologue.ra_backup_offset == 0);
idx++;
}
{
auto& instr = instructions.at(idx);
// storing s7 on the stack is done by interrupt handlers, which we probably don't want to
// support
if (instr.kind == InstructionKind::SD && instr.get_src(0).get_reg() == make_gpr(Reg::S7)) {
lg::warn("{} Suspected ASM function based on this instruction in prologue: {}\n",
guessed_name.to_string(), instr.to_string(file.labels));
warnings += ";; Flagged as ASM function because of " + instr.to_string(file.labels) + "\n";
suspected_asm = true;
return;
}
}
// next is fp backup
if (is_no_link_gpr_store(instructions.at(idx), 8, Register(Reg::GPR, Reg::FP), {},
Register(Reg::GPR, Reg::SP))) {
prologue.fp_backed_up = true;
prologue.fp_backup_offset = get_gpr_store_offset_as_int(instructions.at(idx));
// in Jak 1 like we never backup fp unless ra is also backed up, so the offset is always 8.
// but it seems like it could be possible to do one without the other?
assert(prologue.fp_backup_offset == 8);
idx++;
// after backing up fp, we always set it to t9.
prologue.fp_set = is_gpr_3(instructions.at(idx), InstructionKind::OR, make_gpr(Reg::FP),
make_gpr(Reg::T9), make_gpr(Reg::R0));
assert(prologue.fp_set);
idx++;
}
// next is gpr backups. these are in reverse order, so we should first find the length
// GOAL will always do the exact same thing when the same number of gprs needs to be backed up
// so we just need to determine the number of GPR backups, and we have all the info we need
int n_gpr_backups = 0;
int gpr_idx = idx;
bool expect_nothing_after_gprs = false;
while (is_no_link_gpr_store(instructions.at(gpr_idx), 16, {}, {}, make_gpr(Reg::SP))) {
auto store_reg = instructions.at(gpr_idx).get_src(0).get_reg();
// sometimes stack memory is zeroed immediately after gpr backups, and this fools the previous
// check.
if (store_reg == make_gpr(Reg::R0)) {
printf(
"[Warning] %s Stack Zeroing Detected in Function::analyze_prologue, prologue may be "
"wrong\n",
guessed_name.to_string().c_str());
warnings += ";; Stack Zeroing Detected, prologue may be wrong\n";
expect_nothing_after_gprs = true;
break;
}
// this also happens a few times per game. this a0/r0 check seems to be all that's needed to
// avoid false positives here!
if (store_reg == make_gpr(Reg::A0)) {
suspected_asm = true;
printf(
"[Warning] %s Suspected ASM function because register $a0 was stored on the stack!\n",
guessed_name.to_string().c_str());
warnings += ";; a0 on stack detected, flagging as asm\n";
return;
}
n_gpr_backups++;
gpr_idx++;
}
if (n_gpr_backups) {
prologue.gpr_backup_offset = get_gpr_store_offset_as_int(instructions.at(idx));
for (int i = 0; i < n_gpr_backups; i++) {
int this_offset = get_gpr_store_offset_as_int(instructions.at(idx + i));
auto this_reg = instructions.at(idx + i).get_src(0).get_reg();
assert(this_offset == prologue.gpr_backup_offset + 16 * i);
if (this_reg != get_expected_gpr_backup(i, n_gpr_backups)) {
suspected_asm = true;
printf("[Warning] %s Suspected asm function that isn't flagged due to stack store %s\n",
guessed_name.to_string().c_str(),
instructions.at(idx + i).to_string(file.labels).c_str());
warnings += ";; Suspected asm function due to stack store: " +
instructions.at(idx + i).to_string(file.labels) + "\n";
return;
}
}
}
prologue.n_gpr_backup = n_gpr_backups;
idx = gpr_idx;
int n_fpr_backups = 0;
int fpr_idx = idx;
if (!expect_nothing_after_gprs) {
// FPR backups
while (is_no_ll_fpr_store(instructions.at(fpr_idx), {}, {}, make_gpr(Reg::SP))) {
// auto store_reg = instructions.at(gpr_idx).get_src(0).get_reg();
n_fpr_backups++;
fpr_idx++;
}
if (n_fpr_backups) {
prologue.fpr_backup_offset = instructions.at(idx).get_src(1).get_imm();
for (int i = 0; i < n_fpr_backups; i++) {
int this_offset = instructions.at(idx + i).get_src(1).get_imm();
auto this_reg = instructions.at(idx + i).get_src(0).get_reg();
assert(this_offset == prologue.fpr_backup_offset + 4 * i);
if (this_reg != get_expected_fpr_backup(i, n_fpr_backups)) {
suspected_asm = true;
printf("[Warning] %s Suspected asm function that isn't flagged due to stack store %s\n",
guessed_name.to_string().c_str(),
instructions.at(idx + i).to_string(file.labels).c_str());
warnings += ";; Suspected asm function due to stack store: " +
instructions.at(idx + i).to_string(file.labels) + "\n";
return;
}
}
}
}
prologue.n_fpr_backup = n_fpr_backups;
idx = fpr_idx;
prologue_start = 1;
prologue_end = idx;
prologue.stack_var_offset = 0;
if (prologue.ra_backed_up) {
prologue.stack_var_offset = 8;
}
if (prologue.fp_backed_up) {
prologue.stack_var_offset = 16;
}
if (n_gpr_backups == 0 && n_fpr_backups == 0) {
prologue.n_stack_var_bytes = prologue.total_stack_usage - prologue.stack_var_offset;
} else if (n_gpr_backups == 0) {
// fprs only
prologue.n_stack_var_bytes = prologue.fpr_backup_offset - prologue.stack_var_offset;
} else if (n_fpr_backups == 0) {
// gprs only
prologue.n_stack_var_bytes = prologue.gpr_backup_offset - prologue.stack_var_offset;
} else {
// both, use gprs
assert(prologue.fpr_backup_offset > prologue.gpr_backup_offset);
prologue.n_stack_var_bytes = prologue.gpr_backup_offset - prologue.stack_var_offset;
}
assert(prologue.n_stack_var_bytes >= 0);
// check that the stack lines up by going in order
// RA backup
int total_stack = 0;
if (prologue.ra_backed_up) {
total_stack = align8(total_stack);
assert(prologue.ra_backup_offset == total_stack);
total_stack += 8;
}
if (!prologue.ra_backed_up && prologue.fp_backed_up) {
// GOAL does this for an unknown reason.
total_stack += 8;
}
// FP backup
if (prologue.fp_backed_up) {
total_stack = align8(total_stack);
assert(prologue.fp_backup_offset == total_stack);
total_stack += 8;
assert(prologue.fp_set);
}
// Stack Variables
if (prologue.n_stack_var_bytes) {
// no alignment because we don't know how the stack vars are aligned.
// stack var padding counts toward this section.
assert(prologue.stack_var_offset == total_stack);
total_stack += prologue.n_stack_var_bytes;
}
// GPRS
if (prologue.n_gpr_backup) {
total_stack = align16(total_stack);
assert(prologue.gpr_backup_offset == total_stack);
total_stack += 16 * prologue.n_gpr_backup;
}
// FPRS
if (prologue.n_fpr_backup) {
total_stack = align4(total_stack);
assert(prologue.fpr_backup_offset == total_stack);
total_stack += 4 * prologue.n_fpr_backup;
}
total_stack = align16(total_stack);
// End!
assert(prologue.total_stack_usage == total_stack);
}
// it's fine to have the entire first basic block be the prologue - you could loop back to the
// first instruction past the prologue.
assert(basic_blocks.at(0).end_word >= prologue_end);
basic_blocks.at(0).start_word = prologue_end;
prologue.decoded = true;
check_epilogue(file);
}
/*!
* Print info about the prologue and stack.
*/
std::string Function::Prologue::to_string(int indent) const {
char buff[512];
char* buff_ptr = buff;
std::string indent_str(indent, ' ');
if (!decoded) {
return indent_str + ";BAD PROLOGUE";
}
buff_ptr += sprintf(buff_ptr, "%s;stack: total 0x%02x, fp? %d ra? %d ep? %d", indent_str.c_str(),
total_stack_usage, fp_set, ra_backed_up, epilogue_ok);
if (n_stack_var_bytes) {
buff_ptr += sprintf(buff_ptr, "\n%s;stack_vars: %d bytes at %d", indent_str.c_str(),
n_stack_var_bytes, stack_var_offset);
}
if (n_gpr_backup) {
buff_ptr += sprintf(buff_ptr, "\n%s;gprs:", indent_str.c_str());
for (int i = 0; i < n_gpr_backup; i++) {
buff_ptr += sprintf(buff_ptr, " %s", gpr_backups.at(i).to_string().c_str());
}
}
if (n_fpr_backup) {
buff_ptr += sprintf(buff_ptr, "\n%s;fprs:", indent_str.c_str());
for (int i = 0; i < n_fpr_backup; i++) {
buff_ptr += sprintf(buff_ptr, " %s", fpr_backups.at(i).to_string().c_str());
}
}
return {buff};
}
/*!
* Check that the epilogue matches the prologue.
*/
void Function::check_epilogue(const LinkedObjectFile& file) {
(void)file;
if (!prologue.decoded || suspected_asm) {
printf("not decoded, or suspected asm, skipping epilogue\n");
return;
}
// start at the end and move up.
int idx = int(instructions.size()) - 1;
// seek past alignment nops
while (is_nop(instructions.at(idx))) {
idx--;
}
epilogue_end = idx;
// stack restore
if (prologue.total_stack_usage) {
// hack - sometimes an asm function has a compiler inserted jr ra/daddu sp sp r0 that follows
// the "true" return. We really should have this function flagged as asm, but for now, we can
// simply skip over the compiler-generated jr ra/daddu sp sp r0.
if (is_gpr_3(instructions.at(idx), InstructionKind::DADDU, make_gpr(Reg::SP), make_gpr(Reg::SP),
make_gpr(Reg::R0))) {
idx--;
assert(is_jr_ra(instructions.at(idx)));
idx--;
printf(
"[Warning] %s Double Return Epilogue Hack! This is probably an ASM function in "
"disguise\n",
guessed_name.to_string().c_str());
warnings += ";; Double Return Epilogue - this is probably an ASM function\n";
}
// delay slot should be daddiu sp, sp, offset
assert(is_gpr_2_imm_int(instructions.at(idx), InstructionKind::DADDIU, make_gpr(Reg::SP),
make_gpr(Reg::SP), prologue.total_stack_usage));
idx--;
} else {
// delay slot is always daddu sp, sp, r0...
assert(is_gpr_3(instructions.at(idx), InstructionKind::DADDU, make_gpr(Reg::SP),
make_gpr(Reg::SP), make_gpr(Reg::R0)));
idx--;
}
// jr ra
assert(is_jr_ra(instructions.at(idx)));
idx--;
// restore gprs
for (int i = 0; i < prologue.n_gpr_backup; i++) {
int gpr_idx = prologue.n_gpr_backup - (1 + i);
const auto& expected_reg = gpr_backups.at(gpr_idx);
auto expected_offset = prologue.gpr_backup_offset + 16 * i;
assert(is_no_ll_gpr_load(instructions.at(idx), 16, true, expected_reg, expected_offset,
make_gpr(Reg::SP)));
idx--;
}
// restore fprs
for (int i = 0; i < prologue.n_fpr_backup; i++) {
int fpr_idx = prologue.n_fpr_backup - (1 + i);
const auto& expected_reg = fpr_backups.at(fpr_idx);
auto expected_offset = prologue.fpr_backup_offset + 4 * i;
assert(
is_no_ll_fpr_load(instructions.at(idx), expected_reg, expected_offset, make_gpr(Reg::SP)));
idx--;
}
// restore fp
if (prologue.fp_backed_up) {
assert(is_no_ll_gpr_load(instructions.at(idx), 8, true, make_gpr(Reg::FP),
prologue.fp_backup_offset, make_gpr(Reg::SP)));
idx--;
}
// restore ra
if (prologue.ra_backed_up) {
assert(is_no_ll_gpr_load(instructions.at(idx), 8, true, make_gpr(Reg::RA),
prologue.ra_backup_offset, make_gpr(Reg::SP)));
idx--;
}
assert(!basic_blocks.empty());
assert(idx + 1 >= basic_blocks.back().start_word);
basic_blocks.back().end_word = idx + 1;
prologue.epilogue_ok = true;
epilogue_start = idx + 1;
}
/*!
* Look through all blocks in this function for storing the address of a function into a symbol.
* This indicates the stored function address belongs to a global function with the same name as
* the symbol.
*
* Updates the guessed_name of the function and updates type_info
*/
void Function::find_global_function_defs(LinkedObjectFile& file, DecompilerTypeSystem& dts) {
int state = 0;
int label_id = -1;
Register reg;
for (const auto& instr : instructions) {
// look for LUIs always
if (instr.kind == InstructionKind::LUI && instr.get_src(0).kind == InstructionAtom::LABEL) {
state = 1;
reg = instr.get_dst(0).get_reg();
label_id = instr.get_src(0).get_label();
assert(label_id != -1);
continue;
}
if (state == 1) {
// Look for ORI
if (instr.kind == InstructionKind::ORI && instr.get_src(0).get_reg() == reg &&
instr.get_src(1).get_label() == label_id) {
state = 2;
reg = instr.get_dst(0).get_reg();
continue;
} else {
state = 0;
}
}
if (state == 2) {
// Look for SW
if (instr.kind == InstructionKind::SW && instr.get_src(0).get_reg() == reg &&
instr.get_src(2).get_reg() == make_gpr(Reg::S7)) {
// done!
std::string name = instr.get_src(1).get_sym();
if (!file.label_points_to_code(label_id)) {
// printf("discard as not code: %s\n", name.c_str());
} else {
auto& func = file.get_function_at_label(label_id);
assert(func.guessed_name.empty());
func.guessed_name.set_as_global(name);
dts.add_symbol(name, "function");
;
// todo - inform function.
}
} else {
state = 0;
}
}
}
}
/*!
* Look through this function to find calls to method-set! which define methods.
* Updates the guessed_name of the function and updates type_info.
*/
void Function::find_method_defs(LinkedObjectFile& file, DecompilerTypeSystem& dts) {
(void)dts;
int state = 0;
int label_id = -1;
int method_id = -1;
Register lui_reg;
std::string type_name;
for (const auto& instr : instructions) {
// look for lw t9, method-set!(s7)
if (instr.kind == InstructionKind::LW && instr.get_dst(0).get_reg() == make_gpr(Reg::T9) &&
instr.get_src(0).kind == InstructionAtom::IMM_SYM &&
instr.get_src(0).get_sym() == "method-set!" &&
instr.get_src(1).get_reg() == make_gpr(Reg::S7)) {
state = 1;
continue;
}
if (state == 1) {
// look for lw a0, type-name(s7)
if (instr.kind == InstructionKind::LW && instr.get_dst(0).get_reg() == make_gpr(Reg::A0) &&
instr.get_src(0).kind == InstructionAtom::IMM_SYM &&
instr.get_src(1).get_reg() == make_gpr(Reg::S7)) {
type_name = instr.get_src(0).get_sym();
state = 2;
continue;
} else {
state = 0;
}
}
if (state == 2) {
// look for addiu a1, r0, x
if (instr.kind == InstructionKind::ADDIU && instr.get_dst(0).get_reg() == make_gpr(Reg::A1) &&
instr.get_src(0).get_reg() == make_gpr(Reg::R0)) {
method_id = instr.get_src(1).get_imm();
state = 3;
continue;
} else {
state = 0;
}
}
if (state == 3) {
// look for lui
if (instr.kind == InstructionKind::LUI && instr.get_src(0).kind == InstructionAtom::LABEL) {
state = 4;
lui_reg = instr.get_dst(0).get_reg();
label_id = instr.get_src(0).get_label();
assert(label_id != -1);
continue;
} else {
state = 0;
}
}
if (state == 4) {
if (instr.kind == InstructionKind::ORI && instr.get_src(0).get_reg() == lui_reg &&
instr.get_src(1).get_label() == label_id) {
state = 5;
lui_reg = instr.get_dst(0).get_reg();
continue;
} else {
state = 0;
}
}
if (state == 5) {
if (instr.kind == InstructionKind::JALR && instr.get_dst(0).get_reg() == make_gpr(Reg::RA) &&
instr.get_src(0).get_reg() == make_gpr(Reg::T9)) {
auto& func = file.get_function_at_label(label_id);
assert(func.guessed_name.empty());
func.guessed_name.set_as_method(type_name, method_id);
func.method_of_type = type_name;
if (method_id == GOAL_INSPECT_METHOD) {
func.is_inspect_method = true;
}
state = 0;
continue;
}
}
}
}
void Function::find_type_defs(LinkedObjectFile& file, DecompilerTypeSystem& dts) {
int state = 0;
Register temp_reg;
std::string type_name;
std::string parent_type;
int label_idx = -1;
for (const auto& instr : instructions) {
// look for lw xx, type(s7)
if (instr.kind == InstructionKind::LW && instr.get_src(0).kind == InstructionAtom::IMM_SYM &&
instr.get_src(0).get_sym() == "type" && instr.get_src(1).get_reg() == make_gpr(Reg::S7)) {
state = 1;
temp_reg = instr.get_dst(0).get_reg();
continue;
}
if (state == 1) {
// look for lwu t9, 16, v1
if (instr.kind == InstructionKind::LWU && instr.get_dst(0).get_reg() == make_gpr(Reg::T9) &&
instr.get_src(0).get_imm() == 16 && instr.get_src(1).get_reg() == temp_reg) {
state = 2;
continue;
} else {
state = 0;
}
}
if (state == 2) {
// look for daddiu a0, s7, name-of-type
if (instr.kind == InstructionKind::DADDIU &&
instr.get_dst(0).get_reg() == make_gpr(Reg::A0) &&
instr.get_src(0).get_reg() == make_gpr(Reg::S7) && instr.get_src(1).is_sym()) {
state = 3;
type_name = instr.get_src(1).get_sym();
continue;
} else {
state = 0;
}
}
if (state == 3) {
// look for lw a1, parent-type(s7)
if (instr.kind == InstructionKind::LW && instr.get_dst(0).get_reg() == make_gpr(Reg::A1) &&
instr.get_src(0).kind == InstructionAtom::IMM_SYM &&
instr.get_src(1).get_reg() == make_gpr(Reg::S7)) {
state = 4;
parent_type = instr.get_src(0).get_sym();
continue;
} else {
state = 0;
}
}
if (state == 4) {
// look for ld a2, LXX(fp)
if (instr.kind == InstructionKind::LD && instr.get_dst(0).get_reg() == make_gpr(Reg::A2) &&
instr.get_src(0).is_label() && instr.get_src(1).get_reg() == make_gpr(Reg::FP)) {
state = 5;
label_idx = instr.get_src(0).get_label();
continue;
} else {
state = 0;
}
}
if (state == 5) {
if (instr.kind == InstructionKind::JALR && instr.get_dst(0).get_reg() == make_gpr(Reg::RA) &&
instr.get_src(0).get_reg() == make_gpr(Reg::T9)) {
state = 6;
continue;
} else {
state = 0;
}
}
if (state == 6) {
// look for sll v0, ra, 0
if (instr.kind == InstructionKind::SLL && instr.get_dst(0).get_reg() == make_gpr(Reg::V0) &&
instr.get_src(0).get_reg() == make_gpr(Reg::RA) && instr.get_src(1).get_imm() == 0) {
// done!
// fmt::print("Got type {} parent {}\n", type_name, parent_type);
dts.add_type_parent(type_name, parent_type);
DecompilerLabel flag_label = file.labels.at(label_idx);
u64 word = file.read_data_word(flag_label);
flag_label.offset += 4;
u64 word2 = file.read_data_word(flag_label);
word |= (word2 << 32);
dts.add_type_flags(type_name, word);
// fmt::print("Flags are 0x{:x}\n", word);
state = 0;
continue;
}
} else {
state = 0;
}
}
}
void Function::add_basic_op(std::shared_ptr<IR_Atomic> op, int start_instr, int end_instr) {
op->is_basic_op = true;
assert(end_instr > start_instr);
for (int i = start_instr; i < end_instr; i++) {
instruction_to_basic_op[i] = basic_ops.size();
}
basic_op_to_instruction[basic_ops.size()] = start_instr;
basic_ops.push_back(op);
}
bool Function::instr_starts_basic_op(int idx) {
auto op = instruction_to_basic_op.find(idx);
if (op != instruction_to_basic_op.end()) {
auto start_instr = basic_op_to_instruction.at(op->second);
return start_instr == idx;
}
return false;
}
std::shared_ptr<IR_Atomic> Function::get_basic_op_at_instr(int idx) {
return basic_ops.at(instruction_to_basic_op.at(idx));
}
bool Function::instr_starts_atomic_op(int idx) {
auto op = ir2.atomic_ops->instruction_to_atomic_op.find(idx);
if (op != ir2.atomic_ops->instruction_to_atomic_op.end()) {
auto start_instr = ir2.atomic_ops->atomic_op_to_instruction.at(op->second);
return start_instr == idx;
}
return false;
}
const AtomicOp& Function::get_atomic_op_at_instr(int idx) {
return *ir2.atomic_ops->ops.at(ir2.atomic_ops->instruction_to_atomic_op.at(idx));
}
int Function::get_basic_op_count() {
return basic_ops.size();
}
int Function::get_failed_basic_op_count() {
int count = 0;
for (auto& x : basic_ops) {
if (dynamic_cast<IR_Failed*>(x.get())) {
count++;
}
}
return count;
}
/*!
* Topological sort of basic blocks.
* Returns a valid ordering + a list of blocks that you can't reach and therefore
* aren't in the ordering.
*/
BlockTopologicalSort Function::bb_topo_sort() {
BlockTopologicalSort result;
std::unordered_set<int> visit_set;
std::vector<int> visit_queue;
if (basic_blocks.empty()) {
assert(false);
}
visit_queue.push_back(0);
while (!visit_queue.empty()) {
// let's visit the most recently added:
auto to_visit = visit_queue.back();
visit_queue.pop_back();
result.vist_order.push_back(to_visit);
auto& block = basic_blocks.at(to_visit);
for (auto next : {block.succ_branch, block.succ_ft}) {
if (next != -1 && visit_set.find(next) == visit_set.end()) {
visit_set.insert(next);
visit_queue.push_back(next);
}
}
}
for (int i = 0; i < int(basic_blocks.size()); i++) {
if (visit_set.find(i) == visit_set.end()) {
result.unreachable.insert(i);
}
}
return result;
}
} // namespace decompiler