mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-31 17:47:21 +02:00
Thomas Munro fixed a longstanding annoyance in pg_bsd_indent, that it would misformat lines containing IsA() macros on the assumption that the IsA() call should be treated like a cast. This improves some other cases involving field/variable names that match typedefs, too. The only places that get worse are a couple of uses of the OpenSSL macro STACK_OF(); we'll gladly take that trade-off. Discussion: https://postgr.es/m/20200114221814.GA19630@alvherre.pgsql
1133 lines
29 KiB
C
1133 lines
29 KiB
C
/*-------------------------------------------------------------------------
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*
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* jsonapi.c
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* JSON parser and lexer interfaces
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*
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* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* src/common/jsonapi.c
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef FRONTEND
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#include "postgres.h"
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#else
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#include "postgres_fe.h"
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#endif
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#include "common/jsonapi.h"
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#include "mb/pg_wchar.h"
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#ifdef FRONTEND
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#include "common/logging.h"
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#else
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#include "miscadmin.h"
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#endif
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#ifdef FRONTEND
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#define check_stack_depth()
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#define json_log_and_abort(...) \
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do { pg_log_fatal(__VA_ARGS__); exit(1); } while(0)
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#else
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#define json_log_and_abort(...) elog(ERROR, __VA_ARGS__)
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#endif
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/*
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* The context of the parser is maintained by the recursive descent
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* mechanism, but is passed explicitly to the error reporting routine
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* for better diagnostics.
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*/
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typedef enum /* contexts of JSON parser */
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{
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JSON_PARSE_VALUE, /* expecting a value */
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JSON_PARSE_STRING, /* expecting a string (for a field name) */
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JSON_PARSE_ARRAY_START, /* saw '[', expecting value or ']' */
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JSON_PARSE_ARRAY_NEXT, /* saw array element, expecting ',' or ']' */
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JSON_PARSE_OBJECT_START, /* saw '{', expecting label or '}' */
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JSON_PARSE_OBJECT_LABEL, /* saw object label, expecting ':' */
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JSON_PARSE_OBJECT_NEXT, /* saw object value, expecting ',' or '}' */
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JSON_PARSE_OBJECT_COMMA, /* saw object ',', expecting next label */
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JSON_PARSE_END /* saw the end of a document, expect nothing */
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} JsonParseContext;
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static inline JsonParseErrorType json_lex_string(JsonLexContext *lex);
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static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, char *s,
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bool *num_err, int *total_len);
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static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, JsonSemAction *sem);
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static JsonParseErrorType parse_object_field(JsonLexContext *lex, JsonSemAction *sem);
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static JsonParseErrorType parse_object(JsonLexContext *lex, JsonSemAction *sem);
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static JsonParseErrorType parse_array_element(JsonLexContext *lex, JsonSemAction *sem);
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static JsonParseErrorType parse_array(JsonLexContext *lex, JsonSemAction *sem);
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static JsonParseErrorType report_parse_error(JsonParseContext ctx, JsonLexContext *lex);
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static char *extract_token(JsonLexContext *lex);
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/* the null action object used for pure validation */
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JsonSemAction nullSemAction =
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{
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NULL, NULL, NULL, NULL, NULL,
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NULL, NULL, NULL, NULL, NULL
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};
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/* Recursive Descent parser support routines */
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/*
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* lex_peek
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*
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* what is the current look_ahead token?
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*/
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static inline JsonTokenType
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lex_peek(JsonLexContext *lex)
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{
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return lex->token_type;
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}
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/*
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* lex_expect
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*
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* move the lexer to the next token if the current look_ahead token matches
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* the parameter token. Otherwise, report an error.
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*/
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static inline JsonParseErrorType
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lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token)
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{
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if (lex_peek(lex) == token)
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return json_lex(lex);
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else
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return report_parse_error(ctx, lex);
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}
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/* chars to consider as part of an alphanumeric token */
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#define JSON_ALPHANUMERIC_CHAR(c) \
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(((c) >= 'a' && (c) <= 'z') || \
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((c) >= 'A' && (c) <= 'Z') || \
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((c) >= '0' && (c) <= '9') || \
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(c) == '_' || \
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IS_HIGHBIT_SET(c))
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/*
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* Utility function to check if a string is a valid JSON number.
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*
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* str is of length len, and need not be null-terminated.
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*/
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bool
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IsValidJsonNumber(const char *str, int len)
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{
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bool numeric_error;
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int total_len;
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JsonLexContext dummy_lex;
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if (len <= 0)
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return false;
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/*
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* json_lex_number expects a leading '-' to have been eaten already.
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*
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* having to cast away the constness of str is ugly, but there's not much
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* easy alternative.
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*/
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if (*str == '-')
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{
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dummy_lex.input = unconstify(char *, str) + 1;
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dummy_lex.input_length = len - 1;
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}
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else
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{
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dummy_lex.input = unconstify(char *, str);
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dummy_lex.input_length = len;
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}
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json_lex_number(&dummy_lex, dummy_lex.input, &numeric_error, &total_len);
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return (!numeric_error) && (total_len == dummy_lex.input_length);
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}
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/*
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* makeJsonLexContextCstringLen
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*
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* lex constructor, with or without StringInfo object for de-escaped lexemes.
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*
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* Without is better as it makes the processing faster, so only make one
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* if really required.
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*/
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JsonLexContext *
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makeJsonLexContextCstringLen(char *json, int len, int encoding, bool need_escapes)
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{
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JsonLexContext *lex = palloc0(sizeof(JsonLexContext));
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lex->input = lex->token_terminator = lex->line_start = json;
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lex->line_number = 1;
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lex->input_length = len;
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lex->input_encoding = encoding;
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if (need_escapes)
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lex->strval = makeStringInfo();
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return lex;
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}
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/*
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* pg_parse_json
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*
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* Publicly visible entry point for the JSON parser.
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*
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* lex is a lexing context, set up for the json to be processed by calling
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* makeJsonLexContext(). sem is a structure of function pointers to semantic
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* action routines to be called at appropriate spots during parsing, and a
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* pointer to a state object to be passed to those routines.
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*/
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JsonParseErrorType
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pg_parse_json(JsonLexContext *lex, JsonSemAction *sem)
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{
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JsonTokenType tok;
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JsonParseErrorType result;
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/* get the initial token */
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result = json_lex(lex);
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if (result != JSON_SUCCESS)
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return result;
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tok = lex_peek(lex);
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/* parse by recursive descent */
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switch (tok)
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{
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case JSON_TOKEN_OBJECT_START:
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result = parse_object(lex, sem);
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break;
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case JSON_TOKEN_ARRAY_START:
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result = parse_array(lex, sem);
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break;
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default:
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result = parse_scalar(lex, sem); /* json can be a bare scalar */
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}
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if (result == JSON_SUCCESS)
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result = lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END);
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return result;
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}
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/*
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* json_count_array_elements
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*
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* Returns number of array elements in lex context at start of array token
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* until end of array token at same nesting level.
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*
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* Designed to be called from array_start routines.
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*/
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JsonParseErrorType
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json_count_array_elements(JsonLexContext *lex, int *elements)
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{
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JsonLexContext copylex;
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int count;
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JsonParseErrorType result;
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/*
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* It's safe to do this with a shallow copy because the lexical routines
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* don't scribble on the input. They do scribble on the other pointers
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* etc, so doing this with a copy makes that safe.
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*/
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memcpy(©lex, lex, sizeof(JsonLexContext));
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copylex.strval = NULL; /* not interested in values here */
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copylex.lex_level++;
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count = 0;
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result = lex_expect(JSON_PARSE_ARRAY_START, ©lex,
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JSON_TOKEN_ARRAY_START);
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if (result != JSON_SUCCESS)
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return result;
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if (lex_peek(©lex) != JSON_TOKEN_ARRAY_END)
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{
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while (1)
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{
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count++;
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result = parse_array_element(©lex, &nullSemAction);
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if (result != JSON_SUCCESS)
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return result;
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if (copylex.token_type != JSON_TOKEN_COMMA)
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break;
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result = json_lex(©lex);
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if (result != JSON_SUCCESS)
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return result;
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}
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}
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result = lex_expect(JSON_PARSE_ARRAY_NEXT, ©lex,
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JSON_TOKEN_ARRAY_END);
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if (result != JSON_SUCCESS)
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return result;
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*elements = count;
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return JSON_SUCCESS;
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}
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/*
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* Recursive Descent parse routines. There is one for each structural
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* element in a json document:
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* - scalar (string, number, true, false, null)
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* - array ( [ ] )
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* - array element
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* - object ( { } )
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* - object field
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*/
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static inline JsonParseErrorType
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parse_scalar(JsonLexContext *lex, JsonSemAction *sem)
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{
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char *val = NULL;
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json_scalar_action sfunc = sem->scalar;
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JsonTokenType tok = lex_peek(lex);
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JsonParseErrorType result;
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/* a scalar must be a string, a number, true, false, or null */
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if (tok != JSON_TOKEN_STRING && tok != JSON_TOKEN_NUMBER &&
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tok != JSON_TOKEN_TRUE && tok != JSON_TOKEN_FALSE &&
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tok != JSON_TOKEN_NULL)
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return report_parse_error(JSON_PARSE_VALUE, lex);
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/* if no semantic function, just consume the token */
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if (sfunc == NULL)
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return json_lex(lex);
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/* extract the de-escaped string value, or the raw lexeme */
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if (lex_peek(lex) == JSON_TOKEN_STRING)
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{
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if (lex->strval != NULL)
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val = pstrdup(lex->strval->data);
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}
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else
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{
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int len = (lex->token_terminator - lex->token_start);
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val = palloc(len + 1);
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memcpy(val, lex->token_start, len);
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val[len] = '\0';
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}
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/* consume the token */
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result = json_lex(lex);
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if (result != JSON_SUCCESS)
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return result;
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/* invoke the callback */
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(*sfunc) (sem->semstate, val, tok);
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return JSON_SUCCESS;
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}
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static JsonParseErrorType
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parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
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{
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/*
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* An object field is "fieldname" : value where value can be a scalar,
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* object or array. Note: in user-facing docs and error messages, we
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* generally call a field name a "key".
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*/
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char *fname = NULL; /* keep compiler quiet */
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json_ofield_action ostart = sem->object_field_start;
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json_ofield_action oend = sem->object_field_end;
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bool isnull;
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JsonTokenType tok;
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JsonParseErrorType result;
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if (lex_peek(lex) != JSON_TOKEN_STRING)
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return report_parse_error(JSON_PARSE_STRING, lex);
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if ((ostart != NULL || oend != NULL) && lex->strval != NULL)
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fname = pstrdup(lex->strval->data);
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result = json_lex(lex);
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if (result != JSON_SUCCESS)
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return result;
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result = lex_expect(JSON_PARSE_OBJECT_LABEL, lex, JSON_TOKEN_COLON);
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if (result != JSON_SUCCESS)
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return result;
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tok = lex_peek(lex);
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isnull = tok == JSON_TOKEN_NULL;
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if (ostart != NULL)
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(*ostart) (sem->semstate, fname, isnull);
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switch (tok)
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{
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case JSON_TOKEN_OBJECT_START:
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result = parse_object(lex, sem);
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break;
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case JSON_TOKEN_ARRAY_START:
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result = parse_array(lex, sem);
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break;
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default:
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result = parse_scalar(lex, sem);
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}
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if (result != JSON_SUCCESS)
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return result;
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if (oend != NULL)
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(*oend) (sem->semstate, fname, isnull);
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return JSON_SUCCESS;
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}
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static JsonParseErrorType
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parse_object(JsonLexContext *lex, JsonSemAction *sem)
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{
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/*
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* an object is a possibly empty sequence of object fields, separated by
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* commas and surrounded by curly braces.
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*/
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json_struct_action ostart = sem->object_start;
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json_struct_action oend = sem->object_end;
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JsonTokenType tok;
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JsonParseErrorType result;
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check_stack_depth();
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if (ostart != NULL)
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(*ostart) (sem->semstate);
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/*
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* Data inside an object is at a higher nesting level than the object
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* itself. Note that we increment this after we call the semantic routine
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* for the object start and restore it before we call the routine for the
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* object end.
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*/
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lex->lex_level++;
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Assert(lex_peek(lex) == JSON_TOKEN_OBJECT_START);
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result = json_lex(lex);
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if (result != JSON_SUCCESS)
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return result;
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tok = lex_peek(lex);
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switch (tok)
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{
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case JSON_TOKEN_STRING:
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result = parse_object_field(lex, sem);
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while (result == JSON_SUCCESS && lex_peek(lex) == JSON_TOKEN_COMMA)
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{
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result = json_lex(lex);
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if (result != JSON_SUCCESS)
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break;
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result = parse_object_field(lex, sem);
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}
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break;
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case JSON_TOKEN_OBJECT_END:
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break;
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default:
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/* case of an invalid initial token inside the object */
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result = report_parse_error(JSON_PARSE_OBJECT_START, lex);
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}
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if (result != JSON_SUCCESS)
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return result;
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result = lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END);
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if (result != JSON_SUCCESS)
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return result;
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lex->lex_level--;
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if (oend != NULL)
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(*oend) (sem->semstate);
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return JSON_SUCCESS;
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}
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static JsonParseErrorType
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parse_array_element(JsonLexContext *lex, JsonSemAction *sem)
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{
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json_aelem_action astart = sem->array_element_start;
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json_aelem_action aend = sem->array_element_end;
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JsonTokenType tok = lex_peek(lex);
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JsonParseErrorType result;
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bool isnull;
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isnull = tok == JSON_TOKEN_NULL;
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if (astart != NULL)
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(*astart) (sem->semstate, isnull);
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/* an array element is any object, array or scalar */
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switch (tok)
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{
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case JSON_TOKEN_OBJECT_START:
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result = parse_object(lex, sem);
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break;
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case JSON_TOKEN_ARRAY_START:
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result = parse_array(lex, sem);
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break;
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default:
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result = parse_scalar(lex, sem);
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}
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if (result != JSON_SUCCESS)
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return result;
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if (aend != NULL)
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(*aend) (sem->semstate, isnull);
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return JSON_SUCCESS;
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}
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|
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static JsonParseErrorType
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parse_array(JsonLexContext *lex, JsonSemAction *sem)
|
|
{
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/*
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* an array is a possibly empty sequence of array elements, separated by
|
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* commas and surrounded by square brackets.
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*/
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json_struct_action astart = sem->array_start;
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json_struct_action aend = sem->array_end;
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JsonParseErrorType result;
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check_stack_depth();
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if (astart != NULL)
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(*astart) (sem->semstate);
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|
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/*
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* Data inside an array is at a higher nesting level than the array
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* itself. Note that we increment this after we call the semantic routine
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* for the array start and restore it before we call the routine for the
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* array end.
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*/
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lex->lex_level++;
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result = lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START);
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if (result == JSON_SUCCESS && lex_peek(lex) != JSON_TOKEN_ARRAY_END)
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{
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result = parse_array_element(lex, sem);
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while (result == JSON_SUCCESS && lex_peek(lex) == JSON_TOKEN_COMMA)
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{
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result = json_lex(lex);
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if (result != JSON_SUCCESS)
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break;
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result = parse_array_element(lex, sem);
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}
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}
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if (result != JSON_SUCCESS)
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return result;
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result = lex_expect(JSON_PARSE_ARRAY_NEXT, lex, JSON_TOKEN_ARRAY_END);
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if (result != JSON_SUCCESS)
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return result;
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lex->lex_level--;
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if (aend != NULL)
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(*aend) (sem->semstate);
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return JSON_SUCCESS;
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}
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|
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/*
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* Lex one token from the input stream.
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*/
|
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JsonParseErrorType
|
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json_lex(JsonLexContext *lex)
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|
{
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char *s;
|
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int len;
|
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JsonParseErrorType result;
|
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|
|
/* Skip leading whitespace. */
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s = lex->token_terminator;
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len = s - lex->input;
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while (len < lex->input_length &&
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(*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r'))
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{
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if (*s == '\n')
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++lex->line_number;
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++s;
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++len;
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}
|
|
lex->token_start = s;
|
|
|
|
/* Determine token type. */
|
|
if (len >= lex->input_length)
|
|
{
|
|
lex->token_start = NULL;
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s;
|
|
lex->token_type = JSON_TOKEN_END;
|
|
}
|
|
else
|
|
{
|
|
switch (*s)
|
|
{
|
|
/* Single-character token, some kind of punctuation mark. */
|
|
case '{':
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
lex->token_type = JSON_TOKEN_OBJECT_START;
|
|
break;
|
|
case '}':
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
lex->token_type = JSON_TOKEN_OBJECT_END;
|
|
break;
|
|
case '[':
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
lex->token_type = JSON_TOKEN_ARRAY_START;
|
|
break;
|
|
case ']':
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
lex->token_type = JSON_TOKEN_ARRAY_END;
|
|
break;
|
|
case ',':
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
lex->token_type = JSON_TOKEN_COMMA;
|
|
break;
|
|
case ':':
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
lex->token_type = JSON_TOKEN_COLON;
|
|
break;
|
|
case '"':
|
|
/* string */
|
|
result = json_lex_string(lex);
|
|
if (result != JSON_SUCCESS)
|
|
return result;
|
|
lex->token_type = JSON_TOKEN_STRING;
|
|
break;
|
|
case '-':
|
|
/* Negative number. */
|
|
result = json_lex_number(lex, s + 1, NULL, NULL);
|
|
if (result != JSON_SUCCESS)
|
|
return result;
|
|
lex->token_type = JSON_TOKEN_NUMBER;
|
|
break;
|
|
case '0':
|
|
case '1':
|
|
case '2':
|
|
case '3':
|
|
case '4':
|
|
case '5':
|
|
case '6':
|
|
case '7':
|
|
case '8':
|
|
case '9':
|
|
/* Positive number. */
|
|
result = json_lex_number(lex, s, NULL, NULL);
|
|
if (result != JSON_SUCCESS)
|
|
return result;
|
|
lex->token_type = JSON_TOKEN_NUMBER;
|
|
break;
|
|
default:
|
|
{
|
|
char *p;
|
|
|
|
/*
|
|
* We're not dealing with a string, number, legal
|
|
* punctuation mark, or end of string. The only legal
|
|
* tokens we might find here are true, false, and null,
|
|
* but for error reporting purposes we scan until we see a
|
|
* non-alphanumeric character. That way, we can report
|
|
* the whole word as an unexpected token, rather than just
|
|
* some unintuitive prefix thereof.
|
|
*/
|
|
for (p = s; p - s < lex->input_length - len && JSON_ALPHANUMERIC_CHAR(*p); p++)
|
|
/* skip */ ;
|
|
|
|
/*
|
|
* We got some sort of unexpected punctuation or an
|
|
* otherwise unexpected character, so just complain about
|
|
* that one character.
|
|
*/
|
|
if (p == s)
|
|
{
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
return JSON_INVALID_TOKEN;
|
|
}
|
|
|
|
/*
|
|
* We've got a real alphanumeric token here. If it
|
|
* happens to be true, false, or null, all is well. If
|
|
* not, error out.
|
|
*/
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = p;
|
|
if (p - s == 4)
|
|
{
|
|
if (memcmp(s, "true", 4) == 0)
|
|
lex->token_type = JSON_TOKEN_TRUE;
|
|
else if (memcmp(s, "null", 4) == 0)
|
|
lex->token_type = JSON_TOKEN_NULL;
|
|
else
|
|
return JSON_INVALID_TOKEN;
|
|
}
|
|
else if (p - s == 5 && memcmp(s, "false", 5) == 0)
|
|
lex->token_type = JSON_TOKEN_FALSE;
|
|
else
|
|
return JSON_INVALID_TOKEN;
|
|
|
|
}
|
|
} /* end of switch */
|
|
}
|
|
|
|
return JSON_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* The next token in the input stream is known to be a string; lex it.
|
|
*/
|
|
static inline JsonParseErrorType
|
|
json_lex_string(JsonLexContext *lex)
|
|
{
|
|
char *s;
|
|
int len;
|
|
int hi_surrogate = -1;
|
|
|
|
if (lex->strval != NULL)
|
|
resetStringInfo(lex->strval);
|
|
|
|
Assert(lex->input_length > 0);
|
|
s = lex->token_start;
|
|
len = lex->token_start - lex->input;
|
|
for (;;)
|
|
{
|
|
s++;
|
|
len++;
|
|
/* Premature end of the string. */
|
|
if (len >= lex->input_length)
|
|
{
|
|
lex->token_terminator = s;
|
|
return JSON_INVALID_TOKEN;
|
|
}
|
|
else if (*s == '"')
|
|
break;
|
|
else if ((unsigned char) *s < 32)
|
|
{
|
|
/* Per RFC4627, these characters MUST be escaped. */
|
|
/* Since *s isn't printable, exclude it from the context string */
|
|
lex->token_terminator = s;
|
|
return JSON_ESCAPING_REQUIRED;
|
|
}
|
|
else if (*s == '\\')
|
|
{
|
|
/* OK, we have an escape character. */
|
|
s++;
|
|
len++;
|
|
if (len >= lex->input_length)
|
|
{
|
|
lex->token_terminator = s;
|
|
return JSON_INVALID_TOKEN;
|
|
}
|
|
else if (*s == 'u')
|
|
{
|
|
int i;
|
|
int ch = 0;
|
|
|
|
for (i = 1; i <= 4; i++)
|
|
{
|
|
s++;
|
|
len++;
|
|
if (len >= lex->input_length)
|
|
{
|
|
lex->token_terminator = s;
|
|
return JSON_INVALID_TOKEN;
|
|
}
|
|
else if (*s >= '0' && *s <= '9')
|
|
ch = (ch * 16) + (*s - '0');
|
|
else if (*s >= 'a' && *s <= 'f')
|
|
ch = (ch * 16) + (*s - 'a') + 10;
|
|
else if (*s >= 'A' && *s <= 'F')
|
|
ch = (ch * 16) + (*s - 'A') + 10;
|
|
else
|
|
{
|
|
lex->token_terminator = s + pg_encoding_mblen(lex->input_encoding, s);
|
|
return JSON_UNICODE_ESCAPE_FORMAT;
|
|
}
|
|
}
|
|
if (lex->strval != NULL)
|
|
{
|
|
/*
|
|
* Combine surrogate pairs.
|
|
*/
|
|
if (is_utf16_surrogate_first(ch))
|
|
{
|
|
if (hi_surrogate != -1)
|
|
return JSON_UNICODE_HIGH_SURROGATE;
|
|
hi_surrogate = ch;
|
|
continue;
|
|
}
|
|
else if (is_utf16_surrogate_second(ch))
|
|
{
|
|
if (hi_surrogate == -1)
|
|
return JSON_UNICODE_LOW_SURROGATE;
|
|
ch = surrogate_pair_to_codepoint(hi_surrogate, ch);
|
|
hi_surrogate = -1;
|
|
}
|
|
|
|
if (hi_surrogate != -1)
|
|
return JSON_UNICODE_LOW_SURROGATE;
|
|
|
|
/*
|
|
* Reject invalid cases. We can't have a value above
|
|
* 0xFFFF here (since we only accepted 4 hex digits
|
|
* above), so no need to test for out-of-range chars.
|
|
*/
|
|
if (ch == 0)
|
|
{
|
|
/* We can't allow this, since our TEXT type doesn't */
|
|
return JSON_UNICODE_CODE_POINT_ZERO;
|
|
}
|
|
|
|
/*
|
|
* Add the represented character to lex->strval. In the
|
|
* backend, we can let pg_unicode_to_server() handle any
|
|
* required character set conversion; in frontend, we can
|
|
* only deal with trivial conversions.
|
|
*
|
|
* Note: pg_unicode_to_server() will throw an error for a
|
|
* conversion failure, rather than returning a failure
|
|
* indication. That seems OK.
|
|
*/
|
|
#ifndef FRONTEND
|
|
{
|
|
char cbuf[MAX_UNICODE_EQUIVALENT_STRING + 1];
|
|
|
|
pg_unicode_to_server(ch, (unsigned char *) cbuf);
|
|
appendStringInfoString(lex->strval, cbuf);
|
|
}
|
|
#else
|
|
if (lex->input_encoding == PG_UTF8)
|
|
{
|
|
/* OK, we can map the code point to UTF8 easily */
|
|
char utf8str[5];
|
|
int utf8len;
|
|
|
|
unicode_to_utf8(ch, (unsigned char *) utf8str);
|
|
utf8len = pg_utf_mblen((unsigned char *) utf8str);
|
|
appendBinaryStringInfo(lex->strval, utf8str, utf8len);
|
|
}
|
|
else if (ch <= 0x007f)
|
|
{
|
|
/* The ASCII range is the same in all encodings */
|
|
appendStringInfoChar(lex->strval, (char) ch);
|
|
}
|
|
else
|
|
return JSON_UNICODE_HIGH_ESCAPE;
|
|
#endif /* FRONTEND */
|
|
}
|
|
}
|
|
else if (lex->strval != NULL)
|
|
{
|
|
if (hi_surrogate != -1)
|
|
return JSON_UNICODE_LOW_SURROGATE;
|
|
|
|
switch (*s)
|
|
{
|
|
case '"':
|
|
case '\\':
|
|
case '/':
|
|
appendStringInfoChar(lex->strval, *s);
|
|
break;
|
|
case 'b':
|
|
appendStringInfoChar(lex->strval, '\b');
|
|
break;
|
|
case 'f':
|
|
appendStringInfoChar(lex->strval, '\f');
|
|
break;
|
|
case 'n':
|
|
appendStringInfoChar(lex->strval, '\n');
|
|
break;
|
|
case 'r':
|
|
appendStringInfoChar(lex->strval, '\r');
|
|
break;
|
|
case 't':
|
|
appendStringInfoChar(lex->strval, '\t');
|
|
break;
|
|
default:
|
|
/* Not a valid string escape, so signal error. */
|
|
lex->token_start = s;
|
|
lex->token_terminator = s + pg_encoding_mblen(lex->input_encoding, s);
|
|
return JSON_ESCAPING_INVALID;
|
|
}
|
|
}
|
|
else if (strchr("\"\\/bfnrt", *s) == NULL)
|
|
{
|
|
/*
|
|
* Simpler processing if we're not bothered about de-escaping
|
|
*
|
|
* It's very tempting to remove the strchr() call here and
|
|
* replace it with a switch statement, but testing so far has
|
|
* shown it's not a performance win.
|
|
*/
|
|
lex->token_start = s;
|
|
lex->token_terminator = s + pg_encoding_mblen(lex->input_encoding, s);
|
|
return JSON_ESCAPING_INVALID;
|
|
}
|
|
|
|
}
|
|
else if (lex->strval != NULL)
|
|
{
|
|
if (hi_surrogate != -1)
|
|
return JSON_UNICODE_LOW_SURROGATE;
|
|
|
|
appendStringInfoChar(lex->strval, *s);
|
|
}
|
|
|
|
}
|
|
|
|
if (hi_surrogate != -1)
|
|
return JSON_UNICODE_LOW_SURROGATE;
|
|
|
|
/* Hooray, we found the end of the string! */
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s + 1;
|
|
return JSON_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* The next token in the input stream is known to be a number; lex it.
|
|
*
|
|
* In JSON, a number consists of four parts:
|
|
*
|
|
* (1) An optional minus sign ('-').
|
|
*
|
|
* (2) Either a single '0', or a string of one or more digits that does not
|
|
* begin with a '0'.
|
|
*
|
|
* (3) An optional decimal part, consisting of a period ('.') followed by
|
|
* one or more digits. (Note: While this part can be omitted
|
|
* completely, it's not OK to have only the decimal point without
|
|
* any digits afterwards.)
|
|
*
|
|
* (4) An optional exponent part, consisting of 'e' or 'E', optionally
|
|
* followed by '+' or '-', followed by one or more digits. (Note:
|
|
* As with the decimal part, if 'e' or 'E' is present, it must be
|
|
* followed by at least one digit.)
|
|
*
|
|
* The 's' argument to this function points to the ostensible beginning
|
|
* of part 2 - i.e. the character after any optional minus sign, or the
|
|
* first character of the string if there is none.
|
|
*
|
|
* If num_err is not NULL, we return an error flag to *num_err rather than
|
|
* raising an error for a badly-formed number. Also, if total_len is not NULL
|
|
* the distance from lex->input to the token end+1 is returned to *total_len.
|
|
*/
|
|
static inline JsonParseErrorType
|
|
json_lex_number(JsonLexContext *lex, char *s,
|
|
bool *num_err, int *total_len)
|
|
{
|
|
bool error = false;
|
|
int len = s - lex->input;
|
|
|
|
/* Part (1): leading sign indicator. */
|
|
/* Caller already did this for us; so do nothing. */
|
|
|
|
/* Part (2): parse main digit string. */
|
|
if (len < lex->input_length && *s == '0')
|
|
{
|
|
s++;
|
|
len++;
|
|
}
|
|
else if (len < lex->input_length && *s >= '1' && *s <= '9')
|
|
{
|
|
do
|
|
{
|
|
s++;
|
|
len++;
|
|
} while (len < lex->input_length && *s >= '0' && *s <= '9');
|
|
}
|
|
else
|
|
error = true;
|
|
|
|
/* Part (3): parse optional decimal portion. */
|
|
if (len < lex->input_length && *s == '.')
|
|
{
|
|
s++;
|
|
len++;
|
|
if (len == lex->input_length || *s < '0' || *s > '9')
|
|
error = true;
|
|
else
|
|
{
|
|
do
|
|
{
|
|
s++;
|
|
len++;
|
|
} while (len < lex->input_length && *s >= '0' && *s <= '9');
|
|
}
|
|
}
|
|
|
|
/* Part (4): parse optional exponent. */
|
|
if (len < lex->input_length && (*s == 'e' || *s == 'E'))
|
|
{
|
|
s++;
|
|
len++;
|
|
if (len < lex->input_length && (*s == '+' || *s == '-'))
|
|
{
|
|
s++;
|
|
len++;
|
|
}
|
|
if (len == lex->input_length || *s < '0' || *s > '9')
|
|
error = true;
|
|
else
|
|
{
|
|
do
|
|
{
|
|
s++;
|
|
len++;
|
|
} while (len < lex->input_length && *s >= '0' && *s <= '9');
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check for trailing garbage. As in json_lex(), any alphanumeric stuff
|
|
* here should be considered part of the token for error-reporting
|
|
* purposes.
|
|
*/
|
|
for (; len < lex->input_length && JSON_ALPHANUMERIC_CHAR(*s); s++, len++)
|
|
error = true;
|
|
|
|
if (total_len != NULL)
|
|
*total_len = len;
|
|
|
|
if (num_err != NULL)
|
|
{
|
|
/* let the caller handle any error */
|
|
*num_err = error;
|
|
}
|
|
else
|
|
{
|
|
/* return token endpoint */
|
|
lex->prev_token_terminator = lex->token_terminator;
|
|
lex->token_terminator = s;
|
|
/* handle error if any */
|
|
if (error)
|
|
return JSON_INVALID_TOKEN;
|
|
}
|
|
|
|
return JSON_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* Report a parse error.
|
|
*
|
|
* lex->token_start and lex->token_terminator must identify the current token.
|
|
*/
|
|
static JsonParseErrorType
|
|
report_parse_error(JsonParseContext ctx, JsonLexContext *lex)
|
|
{
|
|
/* Handle case where the input ended prematurely. */
|
|
if (lex->token_start == NULL || lex->token_type == JSON_TOKEN_END)
|
|
return JSON_EXPECTED_MORE;
|
|
|
|
/* Otherwise choose the error type based on the parsing context. */
|
|
switch (ctx)
|
|
{
|
|
case JSON_PARSE_END:
|
|
return JSON_EXPECTED_END;
|
|
case JSON_PARSE_VALUE:
|
|
return JSON_EXPECTED_JSON;
|
|
case JSON_PARSE_STRING:
|
|
return JSON_EXPECTED_STRING;
|
|
case JSON_PARSE_ARRAY_START:
|
|
return JSON_EXPECTED_ARRAY_FIRST;
|
|
case JSON_PARSE_ARRAY_NEXT:
|
|
return JSON_EXPECTED_ARRAY_NEXT;
|
|
case JSON_PARSE_OBJECT_START:
|
|
return JSON_EXPECTED_OBJECT_FIRST;
|
|
case JSON_PARSE_OBJECT_LABEL:
|
|
return JSON_EXPECTED_COLON;
|
|
case JSON_PARSE_OBJECT_NEXT:
|
|
return JSON_EXPECTED_OBJECT_NEXT;
|
|
case JSON_PARSE_OBJECT_COMMA:
|
|
return JSON_EXPECTED_STRING;
|
|
}
|
|
|
|
/*
|
|
* We don't use a default: case, so that the compiler will warn about
|
|
* unhandled enum values. But this needs to be here anyway to cover the
|
|
* possibility of an incorrect input.
|
|
*/
|
|
json_log_and_abort("unexpected json parse state: %d", (int) ctx);
|
|
return JSON_SUCCESS; /* silence stupider compilers */
|
|
}
|
|
|
|
/*
|
|
* Construct a detail message for a JSON error.
|
|
*/
|
|
char *
|
|
json_errdetail(JsonParseErrorType error, JsonLexContext *lex)
|
|
{
|
|
switch (error)
|
|
{
|
|
case JSON_SUCCESS:
|
|
/* fall through to the error code after switch */
|
|
break;
|
|
case JSON_ESCAPING_INVALID:
|
|
return psprintf(_("Escape sequence \"\\%s\" is invalid."),
|
|
extract_token(lex));
|
|
case JSON_ESCAPING_REQUIRED:
|
|
return psprintf(_("Character with value 0x%02x must be escaped."),
|
|
(unsigned char) *(lex->token_terminator));
|
|
case JSON_EXPECTED_END:
|
|
return psprintf(_("Expected end of input, but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_EXPECTED_ARRAY_FIRST:
|
|
return psprintf(_("Expected array element or \"]\", but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_EXPECTED_ARRAY_NEXT:
|
|
return psprintf(_("Expected \",\" or \"]\", but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_EXPECTED_COLON:
|
|
return psprintf(_("Expected \":\", but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_EXPECTED_JSON:
|
|
return psprintf(_("Expected JSON value, but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_EXPECTED_MORE:
|
|
return _("The input string ended unexpectedly.");
|
|
case JSON_EXPECTED_OBJECT_FIRST:
|
|
return psprintf(_("Expected string or \"}\", but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_EXPECTED_OBJECT_NEXT:
|
|
return psprintf(_("Expected \",\" or \"}\", but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_EXPECTED_STRING:
|
|
return psprintf(_("Expected string, but found \"%s\"."),
|
|
extract_token(lex));
|
|
case JSON_INVALID_TOKEN:
|
|
return psprintf(_("Token \"%s\" is invalid."),
|
|
extract_token(lex));
|
|
case JSON_UNICODE_CODE_POINT_ZERO:
|
|
return _("\\u0000 cannot be converted to text.");
|
|
case JSON_UNICODE_ESCAPE_FORMAT:
|
|
return _("\"\\u\" must be followed by four hexadecimal digits.");
|
|
case JSON_UNICODE_HIGH_ESCAPE:
|
|
/* note: this case is only reachable in frontend not backend */
|
|
return _("Unicode escape values cannot be used for code point values above 007F when the encoding is not UTF8.");
|
|
case JSON_UNICODE_HIGH_SURROGATE:
|
|
return _("Unicode high surrogate must not follow a high surrogate.");
|
|
case JSON_UNICODE_LOW_SURROGATE:
|
|
return _("Unicode low surrogate must follow a high surrogate.");
|
|
}
|
|
|
|
/*
|
|
* We don't use a default: case, so that the compiler will warn about
|
|
* unhandled enum values. But this needs to be here anyway to cover the
|
|
* possibility of an incorrect input.
|
|
*/
|
|
json_log_and_abort("unexpected json parse error type: %d", (int) error);
|
|
return NULL; /* silence stupider compilers */
|
|
}
|
|
|
|
/*
|
|
* Extract the current token from a lexing context, for error reporting.
|
|
*/
|
|
static char *
|
|
extract_token(JsonLexContext *lex)
|
|
{
|
|
int toklen = lex->token_terminator - lex->token_start;
|
|
char *token = palloc(toklen + 1);
|
|
|
|
memcpy(token, lex->token_start, toklen);
|
|
token[toklen] = '\0';
|
|
return token;
|
|
}
|