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Hugo Mårdbrink 2025-08-01 23:16:51 +02:00
commit 3e2b956786
6 changed files with 559 additions and 0 deletions

253
parser/parser.odin Normal file
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package parser
import "core:strings"
import "core:fmt"
import "core:mem"
import "core:slice"
import "core:log"
FORBIDDEN_TOKENS :: []string {
"&&",
"||",
"|",
">",
"&>",
"<",
"2>",
}
@private
ParseError :: enum {
None = 0,
MissingCommand,
MissingRedirect,
ForbiddenToken,
}
SequenceType :: enum {
Head,
Or,
And
}
Command :: struct {
name: cstring,
args: [dynamic]cstring,
}
PipeSequence :: struct {
rstdin: cstring,
rstdout: cstring,
rstderr: cstring,
is_background: bool,
commands: [dynamic]Command,
sequence_type: SequenceType,
}
CommandSequence :: struct {
pipe_sequences: [dynamic]PipeSequence,
}
ParserState :: struct {
cmd_seq: CommandSequence,
cur_pipe_seq: PipeSequence,
cur_cmd: Command,
tokens: []cstring,
token_idx: int,
}
@private
new_command :: proc() -> Command {
cmd := Command{ name = "" }
err: mem.Allocator_Error
cmd.args, err = make([dynamic]cstring, 0, 1, context.temp_allocator)
log.assertf(err == nil, "Memory allocation failed")
return cmd
}
@private
new_pipe_sequence :: proc(seq_type: SequenceType) -> PipeSequence {
pipe_seq := PipeSequence{ sequence_type = seq_type }
err: mem.Allocator_Error
pipe_seq.commands, err = make([dynamic]Command, 0, 1, context.temp_allocator)
log.assertf(err == nil, "Memory allocation failed")
return pipe_seq
}
@private
parse_token :: proc(parser_state: ^ParserState) -> ParseError {
token := parser_state.tokens[parser_state.token_idx]
switch(token) {
case "&":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
parser_state^.cur_pipe_seq.is_background = true
parser_state^.token_idx += 1
case "&&":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
_, mem_err := append(&parser_state^.cur_pipe_seq.commands, parser_state^.cur_cmd)
log.assertf(mem_err == nil, "Memory allocation failed")
_, mem_err = append(&parser_state^.cmd_seq.pipe_sequences, parser_state^.cur_pipe_seq)
log.assertf(mem_err == nil, "Memory allocation failed")
parser_state^.cur_pipe_seq = new_pipe_sequence(SequenceType.And)
parser_state^.cur_cmd = new_command()
parser_state^.token_idx += 1
case "||":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
_, mem_err := append(&parser_state^.cur_pipe_seq.commands, parser_state^.cur_cmd)
log.assertf(mem_err == nil, "Memory allocation failed")
_, mem_err = append(&parser_state^.cmd_seq.pipe_sequences, parser_state^.cur_pipe_seq)
log.assertf(mem_err == nil, "Memory allocation failed")
parser_state^.cur_pipe_seq = new_pipe_sequence(SequenceType.Or)
parser_state^.cur_cmd = new_command()
parser_state^.token_idx += 1
case "|":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
_, mem_err := append(&parser_state^.cur_pipe_seq.commands, parser_state^.cur_cmd)
log.assertf(mem_err == nil, "Memory allocation failed")
parser_state^.cur_cmd = new_command()
parser_state^.token_idx += 1
case ">":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
if len(parser_state^.cur_pipe_seq.commands) >= parser_state^.token_idx + 1 do return ParseError.MissingRedirect
next_token := parser_state.tokens[parser_state.token_idx + 1]
if slice.contains(FORBIDDEN_TOKENS, string(next_token)) do return ParseError.ForbiddenToken
parser_state^.cur_pipe_seq.rstdout = next_token
parser_state^.token_idx += 2
case "&>":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
if len(parser_state^.cur_pipe_seq.commands) >= parser_state^.token_idx + 1 do return ParseError.MissingRedirect
next_token := parser_state.tokens[parser_state.token_idx + 1]
if slice.contains(FORBIDDEN_TOKENS, string(next_token)) do return ParseError.ForbiddenToken
parser_state^.cur_pipe_seq.rstdout = next_token
parser_state^.cur_pipe_seq.rstderr = next_token
parser_state^.token_idx += 2
case "<":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
if len(parser_state^.cur_pipe_seq.commands) >= parser_state^.token_idx + 1 do return ParseError.MissingRedirect
next_token := parser_state.tokens[parser_state.token_idx + 1]
if slice.contains(FORBIDDEN_TOKENS, string(next_token)) do return ParseError.ForbiddenToken
parser_state^.cur_pipe_seq.rstdin = next_token
parser_state^.token_idx += 2
case "2>":
if parser_state^.cur_cmd.name == "" do return ParseError.MissingCommand
if len(parser_state^.cur_pipe_seq.commands) >= parser_state^.token_idx + 1 do return ParseError.MissingRedirect
next_token := parser_state.tokens[parser_state.token_idx + 1]
if slice.contains(FORBIDDEN_TOKENS, string(next_token)) do return ParseError.ForbiddenToken
parser_state^.cur_pipe_seq.rstderr = next_token
parser_state^.token_idx += 2
case:
if parser_state^.cur_cmd.name != "" {
_, mem_err := append(&parser_state^.cur_cmd.args, token)
log.assertf(mem_err == nil, "Memory allocation failed")
} else {
parser_state^.cur_cmd.name = token
}
parser_state^.token_idx += 1
}
return nil
}
get_cstring_tokens ::proc(input: string) -> []cstring {
tokens, mem_err := strings.fields(input, context.temp_allocator)
log.assertf(mem_err == nil, "Memory allocation failed")
c_tokens: []cstring
c_tokens, mem_err = make([]cstring, len(tokens), context.temp_allocator)
log.assertf(mem_err == nil, "Memory allocation failed")
for token, i in tokens {
c_tokens[i], mem_err = strings.clone_to_cstring(token, context.temp_allocator)
log.assertf(mem_err == nil, "Memory allocation failed")
}
return c_tokens
}
parse :: proc(input: string) -> (cmd_seq: CommandSequence, err: ParseError) {
mem_err: mem.Allocator_Error
cur_cmd_seq := CommandSequence{}
cur_cmd_seq.pipe_sequences, mem_err = make([dynamic]PipeSequence, 0, 1, context.temp_allocator)
log.assertf(mem_err == nil, "Memory allocation failed")
c_tokens := get_cstring_tokens(input)
cur_pipe_seq := new_pipe_sequence(SequenceType.Head)
cur_pipe_seq.commands, mem_err = make([dynamic]Command, 0, 1, context.temp_allocator)
log.assertf(mem_err == nil, "Memory allocation failed")
if len(c_tokens) == 0 {
return cmd_seq, nil
}
cur_cmd := Command{ name = c_tokens[0] }
cur_cmd.args, mem_err = make([dynamic]cstring, 0, 1, context.temp_allocator)
log.assertf(mem_err == nil, "Memory allocation failed")
parser_state := ParserState{
cmd_seq = cur_cmd_seq,
cur_pipe_seq = cur_pipe_seq,
cur_cmd = cur_cmd,
tokens = c_tokens,
token_idx = 1
}
for parser_state.token_idx < len(parser_state.tokens) {
parse_err := parse_token(&parser_state)
switch parse_err {
case .MissingRedirect:
fmt.printf("Error: Missing redirect target after '%s'\n", parser_state.tokens[parser_state.token_idx])
return cmd_seq, parse_err
case .MissingCommand:
fmt.printf("Error: Missing command before '%s'\n", parser_state.tokens[parser_state.token_idx])
return cmd_seq, parse_err
case .ForbiddenToken:
fmt.printf("Error: Forbidden '%s' after '%s'\n",
parser_state.tokens[parser_state.token_idx+1],
parser_state.tokens[parser_state.token_idx])
return cmd_seq, parse_err
case .None:
continue
}
}
if parser_state.cur_cmd.name != "" {
_, mem_err = append(&parser_state.cur_pipe_seq.commands, parser_state.cur_cmd)
log.assertf(mem_err == nil, "Memory allocation failed")
}
if len(parser_state.cur_pipe_seq.commands) > 0 {
_, mem_err = append(&parser_state.cmd_seq.pipe_sequences, parser_state.cur_pipe_seq)
log.assertf(mem_err == nil, "Memory allocation failed")
}
return parser_state.cmd_seq, nil
}