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#pragma once
#include <cstdint>
#include <filesystem>
#include <string>
#include <string_view>
#include <unordered_map>
#include <vector>
namespace Hsdbg
{
// one preprocessing token. whitespace is dropped during tokenising, so a run
// of tokens is rendered back to text with a small spacing heuristic. the hide
// set is the classic preprocessor "blue paint": the names of macros that must
// not expand this token again, which is what keeps a self-referential macro
// from unrolling forever
enum class PpKind : uint8_t
{
Identifier,
Number,
String,
Char,
Punct,
};
struct PpToken
{
PpKind kind = PpKind::Identifier;
std::string text;
std::vector<std::string> hide;
};
// a single #define, object-like (BUFFER) or function-like (MAX(a, b)). the
// body is the replacement list as significant tokens, with #, ## and the
// parameter names left in place for substitution time
struct MacroDef
{
std::string name;
bool function_like = false;
bool variadic = false;
std::vector<std::string> params;
std::vector<PpToken> body;
};
// the set of #defines visible in a source file. built by scanning the file
// for #define / #undef directives in order, optionally following local
// "quote" includes one project deep. system <...> includes are ignored on
// purpose: this is meant for a project's own macros, not libc's
class MacroTable
{
public:
auto clear() -> void;
// scan already-loaded lines as the primary file, then chase local quote
// includes relative to base_dir off disk. either argument may be empty
auto build(const std::vector<std::string>& lines,
const std::filesystem::path& base_dir) -> void;
auto find(std::string_view name) const -> const MacroDef*;
auto empty() const -> bool { return m_macros.empty(); }
auto size() const -> size_t { return m_macros.size(); }
// bumped every rebuild, so a consumer can tell its cached expansion is
// stale without comparing the whole table
auto revision() const -> uint64_t { return m_revision; }
private:
auto scan_lines(const std::vector<std::string>& lines,
const std::filesystem::path& base_dir, int depth,
std::vector<std::filesystem::path>& seen) -> void;
auto scan_path(const std::filesystem::path& path, int depth,
std::vector<std::filesystem::path>& seen) -> void;
std::unordered_map<std::string, MacroDef> m_macros;
uint64_t m_revision = 0;
};
// the result of unrolling an expression one macro layer at a time. levels[0]
// is the input as written, levels[i] is the text after i rounds of expansion,
// and levels.back() is the fixpoint where nothing expands any further
struct MacroExpansion
{
std::vector<std::string> levels;
// names of macros that were actually expanded going into each level, so
// levels_expanded[i] describes what turned levels[i-1] into levels[i].
// index 0 is always empty
std::vector<std::vector<std::string>> expanded;
auto fully_expanded() const -> bool { return m_reached_fixpoint; }
bool m_reached_fixpoint = true;
};
// unroll input against the table, capping the number of layers so a
// pathological macro cannot hang the ui
auto expand_stages(const MacroTable& table, std::string_view input,
int max_levels = 64) -> MacroExpansion;
}
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