jak-project/decompiler/Function/ExpressionStack.cpp

112 lines
2.9 KiB
C++

#include "third-party/fmt/core.h"
#include "ExpressionStack.h"
namespace decompiler {
std::string ExpressionStack::StackEntry::print(LinkedObjectFile& file) {
return fmt::format("d: {} s: {} | {} <- {}", display, sequence_point,
destination.has_value() ? destination.value().to_charp() : "N/A",
source->print(file));
}
std::string ExpressionStack::print(LinkedObjectFile& file) {
std::string result;
for (auto& x : m_stack) {
result += x.print(file);
result += '\n';
}
return result;
}
void ExpressionStack::set(Register reg, std::shared_ptr<IR> value, bool sequence_point) {
StackEntry entry;
entry.display = true; // by default, we should display everything!
entry.sequence_point = sequence_point;
entry.destination = reg;
entry.source = std::move(value);
m_stack.push_back(entry);
}
bool ExpressionStack::is_single_expression() {
int count = 0;
for (auto& e : m_stack) {
if (e.display) {
count++;
}
}
return count == 1;
}
void ExpressionStack::add_no_set(std::shared_ptr<IR> value, bool sequence_point) {
StackEntry entry;
entry.display = true;
entry.destination = std::nullopt;
entry.source = value;
entry.sequence_point = sequence_point;
m_stack.push_back(entry);
}
/*!
* "Remove" an entry from the stack. Cannot cross a sequence point.
* Internally, the entry is still stored. It is just flagged with display=false.
*/
std::shared_ptr<IR> ExpressionStack::get(Register reg) {
for (size_t i = m_stack.size(); i-- > 0;) {
auto& entry = m_stack.at(i);
if (entry.display) {
if (entry.destination == reg) {
entry.display = false;
return entry.source;
} else {
// we didn't match
if (entry.sequence_point) {
// and it's a sequence point! can't look any more back than this.
return std::make_shared<IR_Register>(reg, -1);
}
}
}
}
return std::make_shared<IR_Register>(reg, -1);
}
/*!
* Convert the stack into a sequence of compacted expressions.
* This is final result of the expression compaction algorithm.
*/
std::vector<std::shared_ptr<IR>> ExpressionStack::get_result() {
std::vector<std::shared_ptr<IR>> result;
for (auto& e : m_stack) {
if (!e.display) {
continue;
}
if (e.destination.has_value()) {
auto dst_reg = std::make_shared<IR_Register>(e.destination.value(), -1);
auto op = std::make_shared<IR_Set>(IR_Set::EXPR, dst_reg, e.source);
result.push_back(op);
} else {
result.push_back(e.source);
}
}
return result;
}
bool ExpressionStack::display_stack_empty() {
for (auto& e : m_stack) {
if (e.display) {
return false;
}
}
return true;
}
ExpressionStack::StackEntry& ExpressionStack::get_display_stack_top() {
for (size_t i = m_stack.size(); i-- > 0;) {
auto& entry = m_stack.at(i);
if (entry.display) {
return entry;
}
}
assert(false);
}
} // namespace decompiler