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ruby--ruby/ext/psych/yaml/loader.c
2021-03-30 23:41:21 +09:00

544 lines
14 KiB
C

#include "yaml_private.h"
/*
* API functions.
*/
YAML_DECLARE(int)
yaml_parser_load(yaml_parser_t *parser, yaml_document_t *document);
/*
* Error handling.
*/
static int
yaml_parser_set_composer_error(yaml_parser_t *parser,
const char *problem, yaml_mark_t problem_mark);
static int
yaml_parser_set_composer_error_context(yaml_parser_t *parser,
const char *context, yaml_mark_t context_mark,
const char *problem, yaml_mark_t problem_mark);
/*
* Alias handling.
*/
static int
yaml_parser_register_anchor(yaml_parser_t *parser,
int index, yaml_char_t *anchor);
/*
* Clean up functions.
*/
static void
yaml_parser_delete_aliases(yaml_parser_t *parser);
/*
* Document loading context.
*/
struct loader_ctx {
int *start;
int *end;
int *top;
};
/*
* Composer functions.
*/
static int
yaml_parser_load_nodes(yaml_parser_t *parser, struct loader_ctx *ctx);
static int
yaml_parser_load_document(yaml_parser_t *parser, yaml_event_t *event);
static int
yaml_parser_load_alias(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx);
static int
yaml_parser_load_scalar(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx);
static int
yaml_parser_load_sequence(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx);
static int
yaml_parser_load_mapping(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx);
static int
yaml_parser_load_sequence_end(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx);
static int
yaml_parser_load_mapping_end(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx);
/*
* Load the next document of the stream.
*/
YAML_DECLARE(int)
yaml_parser_load(yaml_parser_t *parser, yaml_document_t *document)
{
yaml_event_t event;
assert(parser); /* Non-NULL parser object is expected. */
assert(document); /* Non-NULL document object is expected. */
memset(document, 0, sizeof(yaml_document_t));
if (!STACK_INIT(parser, document->nodes, yaml_node_t*))
goto error;
if (!parser->stream_start_produced) {
if (!yaml_parser_parse(parser, &event)) goto error;
assert(event.type == YAML_STREAM_START_EVENT);
/* STREAM-START is expected. */
}
if (parser->stream_end_produced) {
return 1;
}
if (!yaml_parser_parse(parser, &event)) goto error;
if (event.type == YAML_STREAM_END_EVENT) {
return 1;
}
if (!STACK_INIT(parser, parser->aliases, yaml_alias_data_t*))
goto error;
parser->document = document;
if (!yaml_parser_load_document(parser, &event)) goto error;
yaml_parser_delete_aliases(parser);
parser->document = NULL;
return 1;
error:
yaml_parser_delete_aliases(parser);
yaml_document_delete(document);
parser->document = NULL;
return 0;
}
/*
* Set composer error.
*/
static int
yaml_parser_set_composer_error(yaml_parser_t *parser,
const char *problem, yaml_mark_t problem_mark)
{
parser->error = YAML_COMPOSER_ERROR;
parser->problem = problem;
parser->problem_mark = problem_mark;
return 0;
}
/*
* Set composer error with context.
*/
static int
yaml_parser_set_composer_error_context(yaml_parser_t *parser,
const char *context, yaml_mark_t context_mark,
const char *problem, yaml_mark_t problem_mark)
{
parser->error = YAML_COMPOSER_ERROR;
parser->context = context;
parser->context_mark = context_mark;
parser->problem = problem;
parser->problem_mark = problem_mark;
return 0;
}
/*
* Delete the stack of aliases.
*/
static void
yaml_parser_delete_aliases(yaml_parser_t *parser)
{
while (!STACK_EMPTY(parser, parser->aliases)) {
yaml_free(POP(parser, parser->aliases).anchor);
}
STACK_DEL(parser, parser->aliases);
}
/*
* Compose a document object.
*/
static int
yaml_parser_load_document(yaml_parser_t *parser, yaml_event_t *event)
{
struct loader_ctx ctx = { NULL, NULL, NULL };
assert(event->type == YAML_DOCUMENT_START_EVENT);
/* DOCUMENT-START is expected. */
parser->document->version_directive
= event->data.document_start.version_directive;
parser->document->tag_directives.start
= event->data.document_start.tag_directives.start;
parser->document->tag_directives.end
= event->data.document_start.tag_directives.end;
parser->document->start_implicit
= event->data.document_start.implicit;
parser->document->start_mark = event->start_mark;
if (!STACK_INIT(parser, ctx, int*)) return 0;
if (!yaml_parser_load_nodes(parser, &ctx)) {
STACK_DEL(parser, ctx);
return 0;
}
STACK_DEL(parser, ctx);
return 1;
}
/*
* Compose a node tree.
*/
static int
yaml_parser_load_nodes(yaml_parser_t *parser, struct loader_ctx *ctx)
{
yaml_event_t event;
do {
if (!yaml_parser_parse(parser, &event)) return 0;
switch (event.type) {
case YAML_ALIAS_EVENT:
if (!yaml_parser_load_alias(parser, &event, ctx)) return 0;
break;
case YAML_SCALAR_EVENT:
if (!yaml_parser_load_scalar(parser, &event, ctx)) return 0;
break;
case YAML_SEQUENCE_START_EVENT:
if (!yaml_parser_load_sequence(parser, &event, ctx)) return 0;
break;
case YAML_SEQUENCE_END_EVENT:
if (!yaml_parser_load_sequence_end(parser, &event, ctx))
return 0;
break;
case YAML_MAPPING_START_EVENT:
if (!yaml_parser_load_mapping(parser, &event, ctx)) return 0;
break;
case YAML_MAPPING_END_EVENT:
if (!yaml_parser_load_mapping_end(parser, &event, ctx))
return 0;
break;
default:
assert(0); /* Could not happen. */
return 0;
case YAML_DOCUMENT_END_EVENT:
break;
}
} while (event.type != YAML_DOCUMENT_END_EVENT);
parser->document->end_implicit = event.data.document_end.implicit;
parser->document->end_mark = event.end_mark;
return 1;
}
/*
* Add an anchor.
*/
static int
yaml_parser_register_anchor(yaml_parser_t *parser,
int index, yaml_char_t *anchor)
{
yaml_alias_data_t data;
yaml_alias_data_t *alias_data;
if (!anchor) return 1;
data.anchor = anchor;
data.index = index;
data.mark = parser->document->nodes.start[index-1].start_mark;
for (alias_data = parser->aliases.start;
alias_data != parser->aliases.top; alias_data ++) {
if (strcmp((char *)alias_data->anchor, (char *)anchor) == 0) {
yaml_free(anchor);
return yaml_parser_set_composer_error_context(parser,
"found duplicate anchor; first occurrence",
alias_data->mark, "second occurrence", data.mark);
}
}
if (!PUSH(parser, parser->aliases, data)) {
yaml_free(anchor);
return 0;
}
return 1;
}
/*
* Compose node into its parent in the stree.
*/
static int
yaml_parser_load_node_add(yaml_parser_t *parser, struct loader_ctx *ctx,
int index)
{
struct yaml_node_s *parent;
int parent_index;
if (STACK_EMPTY(parser, *ctx)) {
/* This is the root node, there's no tree to add it to. */
return 1;
}
parent_index = *((*ctx).top - 1);
parent = &parser->document->nodes.start[parent_index-1];
switch (parent->type) {
case YAML_SEQUENCE_NODE:
if (!STACK_LIMIT(parser, parent->data.sequence.items, INT_MAX-1))
return 0;
if (!PUSH(parser, parent->data.sequence.items, index))
return 0;
break;
case YAML_MAPPING_NODE: {
yaml_node_pair_t pair;
if (!STACK_EMPTY(parser, parent->data.mapping.pairs)) {
yaml_node_pair_t *p = parent->data.mapping.pairs.top - 1;
if (p->key != 0 && p->value == 0) {
p->value = index;
break;
}
}
pair.key = index;
pair.value = 0;
if (!STACK_LIMIT(parser, parent->data.mapping.pairs, INT_MAX-1))
return 0;
if (!PUSH(parser, parent->data.mapping.pairs, pair))
return 0;
break;
}
default:
assert(0); /* Could not happen. */
return 0;
}
return 1;
}
/*
* Compose a node corresponding to an alias.
*/
static int
yaml_parser_load_alias(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx)
{
yaml_char_t *anchor = event->data.alias.anchor;
yaml_alias_data_t *alias_data;
for (alias_data = parser->aliases.start;
alias_data != parser->aliases.top; alias_data ++) {
if (strcmp((char *)alias_data->anchor, (char *)anchor) == 0) {
yaml_free(anchor);
return yaml_parser_load_node_add(parser, ctx, alias_data->index);
}
}
yaml_free(anchor);
return yaml_parser_set_composer_error(parser, "found undefined alias",
event->start_mark);
}
/*
* Compose a scalar node.
*/
static int
yaml_parser_load_scalar(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx)
{
yaml_node_t node;
int index;
yaml_char_t *tag = event->data.scalar.tag;
if (!STACK_LIMIT(parser, parser->document->nodes, INT_MAX-1)) goto error;
if (!tag || strcmp((char *)tag, "!") == 0) {
yaml_free(tag);
tag = yaml_strdup((yaml_char_t *)YAML_DEFAULT_SCALAR_TAG);
if (!tag) goto error;
}
SCALAR_NODE_INIT(node, tag, event->data.scalar.value,
event->data.scalar.length, event->data.scalar.style,
event->start_mark, event->end_mark);
if (!PUSH(parser, parser->document->nodes, node)) goto error;
index = (int)(parser->document->nodes.top - parser->document->nodes.start);
if (!yaml_parser_register_anchor(parser, index,
event->data.scalar.anchor)) return 0;
return yaml_parser_load_node_add(parser, ctx, index);
error:
yaml_free(tag);
yaml_free(event->data.scalar.anchor);
yaml_free(event->data.scalar.value);
return 0;
}
/*
* Compose a sequence node.
*/
static int
yaml_parser_load_sequence(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx)
{
yaml_node_t node;
struct {
yaml_node_item_t *start;
yaml_node_item_t *end;
yaml_node_item_t *top;
} items = { NULL, NULL, NULL };
int index;
yaml_char_t *tag = event->data.sequence_start.tag;
if (!STACK_LIMIT(parser, parser->document->nodes, INT_MAX-1)) goto error;
if (!tag || strcmp((char *)tag, "!") == 0) {
yaml_free(tag);
tag = yaml_strdup((yaml_char_t *)YAML_DEFAULT_SEQUENCE_TAG);
if (!tag) goto error;
}
if (!STACK_INIT(parser, items, yaml_node_item_t*)) goto error;
SEQUENCE_NODE_INIT(node, tag, items.start, items.end,
event->data.sequence_start.style,
event->start_mark, event->end_mark);
if (!PUSH(parser, parser->document->nodes, node)) goto error;
index = (int)(parser->document->nodes.top - parser->document->nodes.start);
if (!yaml_parser_register_anchor(parser, index,
event->data.sequence_start.anchor)) return 0;
if (!yaml_parser_load_node_add(parser, ctx, index)) return 0;
if (!STACK_LIMIT(parser, *ctx, INT_MAX-1)) return 0;
if (!PUSH(parser, *ctx, index)) return 0;
return 1;
error:
yaml_free(tag);
yaml_free(event->data.sequence_start.anchor);
return 0;
}
static int
yaml_parser_load_sequence_end(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx)
{
int index;
assert(((*ctx).top - (*ctx).start) > 0);
index = *((*ctx).top - 1);
assert(parser->document->nodes.start[index-1].type == YAML_SEQUENCE_NODE);
parser->document->nodes.start[index-1].end_mark = event->end_mark;
(void)POP(parser, *ctx);
return 1;
}
/*
* Compose a mapping node.
*/
static int
yaml_parser_load_mapping(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx)
{
yaml_node_t node;
struct {
yaml_node_pair_t *start;
yaml_node_pair_t *end;
yaml_node_pair_t *top;
} pairs = { NULL, NULL, NULL };
int index;
yaml_char_t *tag = event->data.mapping_start.tag;
if (!STACK_LIMIT(parser, parser->document->nodes, INT_MAX-1)) goto error;
if (!tag || strcmp((char *)tag, "!") == 0) {
yaml_free(tag);
tag = yaml_strdup((yaml_char_t *)YAML_DEFAULT_MAPPING_TAG);
if (!tag) goto error;
}
if (!STACK_INIT(parser, pairs, yaml_node_pair_t*)) goto error;
MAPPING_NODE_INIT(node, tag, pairs.start, pairs.end,
event->data.mapping_start.style,
event->start_mark, event->end_mark);
if (!PUSH(parser, parser->document->nodes, node)) goto error;
index = (int)(parser->document->nodes.top - parser->document->nodes.start);
if (!yaml_parser_register_anchor(parser, index,
event->data.mapping_start.anchor)) return 0;
if (!yaml_parser_load_node_add(parser, ctx, index)) return 0;
if (!STACK_LIMIT(parser, *ctx, INT_MAX-1)) return 0;
if (!PUSH(parser, *ctx, index)) return 0;
return 1;
error:
yaml_free(tag);
yaml_free(event->data.mapping_start.anchor);
return 0;
}
static int
yaml_parser_load_mapping_end(yaml_parser_t *parser, yaml_event_t *event,
struct loader_ctx *ctx)
{
int index;
assert(((*ctx).top - (*ctx).start) > 0);
index = *((*ctx).top - 1);
assert(parser->document->nodes.start[index-1].type == YAML_MAPPING_NODE);
parser->document->nodes.start[index-1].end_mark = event->end_mark;
(void)POP(parser, *ctx);
return 1;
}