ghostty/src/terminal/parse_table.zig
Qwerasd 846b3421e6 terminal: replace utf8 decoding with custom decoder in stream.zig
(Completely removed utf8 handling from Parser.zig)
2024-02-05 23:20:47 -05:00

390 lines
13 KiB
Zig

//! The primary export of this file is "table", which contains a
//! comptime-generated state transition table for VT emulation.
//!
//! This is based on the vt100.net state machine:
//! https://vt100.net/emu/dec_ansi_parser
//! But has some modifications:
//!
//! * csi_param accepts the colon character (':') since the SGR command
//! accepts colon as a valid parameter value.
//!
const std = @import("std");
const builtin = @import("builtin");
const parser = @import("Parser.zig");
const State = parser.State;
const Action = parser.TransitionAction;
/// The state transition table. The type is [u8][State]Transition but
/// comptime-generated to be exactly-sized.
pub const table = genTable();
/// Table is the type of the state table. This is dynamically (comptime)
/// generated to be exactly sized.
pub const Table = genTableType(false);
/// OptionalTable is private to this file. We use this to accumulate and
/// detect invalid transitions created.
const OptionalTable = genTableType(true);
// Transition is the transition to take within the table
pub const Transition = struct {
state: State,
action: Action,
};
/// Table is the type of the state transition table.
fn genTableType(comptime optional: bool) type {
const max_u8 = std.math.maxInt(u8);
const stateInfo = @typeInfo(State);
const max_state = stateInfo.Enum.fields.len;
const Elem = if (optional) ?Transition else Transition;
return [max_u8 + 1][max_state]Elem;
}
/// Function to generate the full state transition table for VT emulation.
fn genTable() Table {
@setEvalBranchQuota(20000);
// We accumulate using an "optional" table so we can detect duplicates.
var result: OptionalTable = undefined;
for (0..result.len) |i| {
for (0..result[0].len) |j| {
result[i][j] = null;
}
}
// anywhere transitions
const stateInfo = @typeInfo(State);
inline for (stateInfo.Enum.fields) |field| {
const source: State = @enumFromInt(field.value);
// anywhere => ground
single(&result, 0x18, source, .ground, .execute);
single(&result, 0x1A, source, .ground, .execute);
range(&result, 0x80, 0x8F, source, .ground, .execute);
range(&result, 0x91, 0x97, source, .ground, .execute);
single(&result, 0x99, source, .ground, .execute);
single(&result, 0x9A, source, .ground, .execute);
single(&result, 0x9C, source, .ground, .none);
// anywhere => escape
single(&result, 0x1B, source, .escape, .none);
// anywhere => sos_pm_apc_string
single(&result, 0x98, source, .sos_pm_apc_string, .none);
single(&result, 0x9E, source, .sos_pm_apc_string, .none);
single(&result, 0x9F, source, .sos_pm_apc_string, .none);
// anywhere => csi_entry
single(&result, 0x9B, source, .csi_entry, .none);
// anywhere => dcs_entry
single(&result, 0x90, source, .dcs_entry, .none);
// anywhere => osc_string
single(&result, 0x9D, source, .osc_string, .none);
}
// ground
{
// events
single(&result, 0x19, .ground, .ground, .execute);
range(&result, 0, 0x17, .ground, .ground, .execute);
range(&result, 0x1C, 0x1F, .ground, .ground, .execute);
range(&result, 0x20, 0x7F, .ground, .ground, .print);
}
// escape_intermediate
{
const source = State.escape_intermediate;
single(&result, 0x19, source, source, .execute);
range(&result, 0, 0x17, source, source, .execute);
range(&result, 0x1C, 0x1F, source, source, .execute);
range(&result, 0x20, 0x2F, source, source, .collect);
single(&result, 0x7F, source, source, .ignore);
// => ground
range(&result, 0x30, 0x7E, source, .ground, .esc_dispatch);
}
// sos_pm_apc_string
{
const source = State.sos_pm_apc_string;
// events
single(&result, 0x19, source, source, .apc_put);
range(&result, 0, 0x17, source, source, .apc_put);
range(&result, 0x1C, 0x1F, source, source, .apc_put);
range(&result, 0x20, 0x7F, source, source, .apc_put);
}
// escape
{
const source = State.escape;
// events
single(&result, 0x19, source, source, .execute);
range(&result, 0, 0x17, source, source, .execute);
range(&result, 0x1C, 0x1F, source, source, .execute);
single(&result, 0x7F, source, source, .ignore);
// => ground
range(&result, 0x30, 0x4F, source, .ground, .esc_dispatch);
range(&result, 0x51, 0x57, source, .ground, .esc_dispatch);
range(&result, 0x60, 0x7E, source, .ground, .esc_dispatch);
single(&result, 0x59, source, .ground, .esc_dispatch);
single(&result, 0x5A, source, .ground, .esc_dispatch);
single(&result, 0x5C, source, .ground, .esc_dispatch);
// => escape_intermediate
range(&result, 0x20, 0x2F, source, .escape_intermediate, .collect);
// => sos_pm_apc_string
single(&result, 0x58, source, .sos_pm_apc_string, .none);
single(&result, 0x5E, source, .sos_pm_apc_string, .none);
single(&result, 0x5F, source, .sos_pm_apc_string, .none);
// => dcs_entry
single(&result, 0x50, source, .dcs_entry, .none);
// => csi_entry
single(&result, 0x5B, source, .csi_entry, .none);
// => osc_string
single(&result, 0x5D, source, .osc_string, .none);
}
// dcs_entry
{
const source = State.dcs_entry;
// events
single(&result, 0x19, source, source, .ignore);
range(&result, 0, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
single(&result, 0x7F, source, source, .ignore);
// => dcs_intermediate
range(&result, 0x20, 0x2F, source, .dcs_intermediate, .collect);
// => dcs_ignore
single(&result, 0x3A, source, .dcs_ignore, .none);
// => dcs_param
range(&result, 0x30, 0x39, source, .dcs_param, .param);
single(&result, 0x3B, source, .dcs_param, .param);
range(&result, 0x3C, 0x3F, source, .dcs_param, .collect);
// => dcs_passthrough
range(&result, 0x40, 0x7E, source, .dcs_passthrough, .none);
}
// dcs_intermediate
{
const source = State.dcs_intermediate;
// events
single(&result, 0x19, source, source, .ignore);
range(&result, 0, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
range(&result, 0x20, 0x2F, source, source, .collect);
single(&result, 0x7F, source, source, .ignore);
// => dcs_ignore
range(&result, 0x30, 0x3F, source, .dcs_ignore, .none);
// => dcs_passthrough
range(&result, 0x40, 0x7E, source, .dcs_passthrough, .none);
}
// dcs_ignore
{
const source = State.dcs_ignore;
// events
single(&result, 0x19, source, source, .ignore);
range(&result, 0, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
}
// dcs_param
{
const source = State.dcs_param;
// events
single(&result, 0x19, source, source, .ignore);
range(&result, 0, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
range(&result, 0x30, 0x39, source, source, .param);
single(&result, 0x3B, source, source, .param);
single(&result, 0x7F, source, source, .ignore);
// => dcs_ignore
single(&result, 0x3A, source, .dcs_ignore, .none);
range(&result, 0x3C, 0x3F, source, .dcs_ignore, .none);
// => dcs_intermediate
range(&result, 0x20, 0x2F, source, .dcs_intermediate, .collect);
// => dcs_passthrough
range(&result, 0x40, 0x7E, source, .dcs_passthrough, .none);
}
// dcs_passthrough
{
const source = State.dcs_passthrough;
// events
single(&result, 0x19, source, source, .put);
range(&result, 0, 0x17, source, source, .put);
range(&result, 0x1C, 0x1F, source, source, .put);
range(&result, 0x20, 0x7E, source, source, .put);
single(&result, 0x7F, source, source, .ignore);
}
// csi_param
{
const source = State.csi_param;
// events
single(&result, 0x19, source, source, .execute);
range(&result, 0, 0x17, source, source, .execute);
range(&result, 0x1C, 0x1F, source, source, .execute);
range(&result, 0x30, 0x39, source, source, .param);
single(&result, 0x3A, source, source, .param);
single(&result, 0x3B, source, source, .param);
single(&result, 0x7F, source, source, .ignore);
// => ground
range(&result, 0x40, 0x7E, source, .ground, .csi_dispatch);
// => csi_ignore
range(&result, 0x3C, 0x3F, source, .csi_ignore, .none);
// => csi_intermediate
range(&result, 0x20, 0x2F, source, .csi_intermediate, .collect);
}
// csi_ignore
{
const source = State.csi_ignore;
// events
single(&result, 0x19, source, source, .execute);
range(&result, 0, 0x17, source, source, .execute);
range(&result, 0x1C, 0x1F, source, source, .execute);
range(&result, 0x20, 0x3F, source, source, .ignore);
single(&result, 0x7F, source, source, .ignore);
// => ground
range(&result, 0x40, 0x7E, source, .ground, .none);
}
// csi_intermediate
{
const source = State.csi_intermediate;
// events
single(&result, 0x19, source, source, .execute);
range(&result, 0, 0x17, source, source, .execute);
range(&result, 0x1C, 0x1F, source, source, .execute);
range(&result, 0x20, 0x2F, source, source, .collect);
single(&result, 0x7F, source, source, .ignore);
// => ground
range(&result, 0x40, 0x7E, source, .ground, .csi_dispatch);
// => csi_ignore
range(&result, 0x30, 0x3F, source, .csi_ignore, .none);
}
// csi_entry
{
const source = State.csi_entry;
// events
single(&result, 0x19, source, source, .execute);
range(&result, 0, 0x17, source, source, .execute);
range(&result, 0x1C, 0x1F, source, source, .execute);
single(&result, 0x7F, source, source, .ignore);
// => ground
range(&result, 0x40, 0x7E, source, .ground, .csi_dispatch);
// => csi_ignore
single(&result, 0x3A, source, .csi_ignore, .none);
// => csi_intermediate
range(&result, 0x20, 0x2F, source, .csi_intermediate, .collect);
// => csi_param
range(&result, 0x30, 0x39, source, .csi_param, .param);
single(&result, 0x3B, source, .csi_param, .param);
range(&result, 0x3C, 0x3F, source, .csi_param, .collect);
}
// osc_string
{
const source = State.osc_string;
// events
single(&result, 0x19, source, source, .ignore);
range(&result, 0, 0x06, source, source, .ignore);
range(&result, 0x08, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
range(&result, 0x20, 0xFF, source, source, .osc_put);
// XTerm accepts either BEL or ST for terminating OSC
// sequences, and when returning information, uses the same
// terminator used in a query.
single(&result, 0x07, source, .ground, .none);
}
// Create our immutable version
var final: Table = undefined;
for (0..final.len) |i| {
for (0..final[0].len) |j| {
final[i][j] = result[i][j] orelse transition(@enumFromInt(j), .none);
}
}
return final;
}
fn single(t: *OptionalTable, c: u8, s0: State, s1: State, a: Action) void {
const s0_int = @intFromEnum(s0);
// TODO: enable this but it thinks we're in runtime right now
// if (t[c][s0_int]) |existing| {
// @compileLog(c);
// @compileLog(s0);
// @compileLog(s1);
// @compileLog(existing);
// @compileError("transition set multiple times");
// }
t[c][s0_int] = transition(s1, a);
}
fn range(t: *OptionalTable, from: u8, to: u8, s0: State, s1: State, a: Action) void {
var i = from;
while (i <= to) : (i += 1) {
single(t, i, s0, s1, a);
// If 'to' is 0xFF, our next pass will overflow. Return early to prevent
// the loop from executing it's continue expression
if (i == to) break;
}
}
fn transition(state: State, action: Action) Transition {
return .{ .state = state, .action = action };
}
test {
// This forces comptime-evaluation of table, so we're just testing
// that it succeeds in creation.
_ = table;
}