hammer/src/parsers/charset.c
2013-05-23 23:27:07 +02:00

109 lines
3.4 KiB
C

#include <assert.h>
#include <string.h>
#include "../internal.h"
#include "parser_internal.h"
static HParseResult* parse_charset(void *env, HParseState *state) {
uint8_t in = h_read_bits(&state->input_stream, 8, false);
HCharset cs = (HCharset)env;
if (charset_isset(cs, in)) {
HParsedToken *tok = a_new(HParsedToken, 1);
tok->token_type = TT_UINT; tok->uint = in;
return make_result(state->arena, tok);
} else
return NULL;
}
static HCFChoice* desugar_charset(HAllocator *mm__, void *env) {
HCFChoice *ret = h_new(HCFChoice, 1);
ret->type = HCF_CHARSET;
ret->charset = (HCharset)env;
ret->action = NULL;
return ret;
}
static bool h_svm_action_ch(HArena *arena, HSVMContext *ctx, void* env) {
// BUG: relies un undefined behaviour: int64_t is a signed uint64_t; not necessarily true on 32-bit
HParsedToken *top = ctx->stack[ctx->stack_count-1];
assert(top->token_type == TT_BYTES);
uint64_t res = 0;
for (size_t i = 0; i < top->bytes.len; i++)
res = (res << 8) | top->bytes.token[i]; // TODO: Handle other endiannesses.
top->uint = res; // possibly cast to signed through union
top->token_type = TT_UINT;
return true;
}
// FUTURE: this is horribly inefficient
static bool cs_ctrvm(HRVMProg *prog, void *env) {
HCharset cs = (HCharset)env;
h_rvm_insert_insn(prog, RVM_PUSH, 0);
uint16_t start = h_rvm_get_ip(prog);
for (size_t i=0; i<256; ++i) {
// TODO: merge ranges.
if (charset_isset(cs, i)) {
uint16_t insn = h_rvm_insert_insn(prog, RVM_FORK, 0);
h_rvm_insert_insn(prog, RVM_MATCH, i | i << 8);
h_rvm_insert_insn(prog, RVM_GOTO, 0);
h_rvm_patch_arg(prog, insn, h_rvm_get_ip(prog));
}
}
h_rvm_insert_insn(prog, RVM_MATCH, 0x00FF);
uint16_t jump = h_rvm_insert_insn(prog, RVM_STEP, 0);
for (size_t i=start; i<jump; ++i) {
if (RVM_GOTO == prog->insns[i].op)
h_rvm_patch_arg(prog, i, jump);
}
h_rvm_insert_insn(prog, RVM_CAPTURE, 0);
h_rvm_insert_insn(prog, RVM_ACTION, h_rvm_create_action(prog, h_svm_action_ch, env));
return true;
}
static const HParserVtable charset_vt = {
.parse = parse_charset,
.isValidRegular = h_true,
.isValidCF = h_true,
.desugar = desugar_charset,
.compile_to_rvm = cs_ctrvm,
};
HParser* h_ch_range(const uint8_t lower, const uint8_t upper) {
return h_ch_range__m(&system_allocator, lower, upper);
}
HParser* h_ch_range__m(HAllocator* mm__, const uint8_t lower, const uint8_t upper) {
HCharset cs = new_charset(mm__);
for (int i = 0; i < 256; i++)
charset_set(cs, i, (lower <= i) && (i <= upper));
return h_new_parser(mm__, &charset_vt, cs);
}
static HParser* h_in_or_not__m(HAllocator* mm__, const uint8_t *options, size_t count, int val) {
HCharset cs = new_charset(mm__);
for (size_t i = 0; i < 256; i++)
charset_set(cs, i, 1-val);
for (size_t i = 0; i < count; i++)
charset_set(cs, options[i], val);
return h_new_parser(mm__, &charset_vt, cs);
}
HParser* h_in(const uint8_t *options, size_t count) {
return h_in_or_not__m(&system_allocator, options, count, 1);
}
HParser* h_in__m(HAllocator* mm__, const uint8_t *options, size_t count) {
return h_in_or_not__m(mm__, options, count, 1);
}
HParser* h_not_in(const uint8_t *options, size_t count) {
return h_in_or_not__m(&system_allocator, options, count, 0);
}
HParser* h_not_in__m(HAllocator* mm__, const uint8_t *options, size_t count) {
return h_in_or_not__m(mm__, options, count, 0);
}