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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
commit | 6eb9c5a5657d1fe77b55cc261450f3538d35a94d (patch) | |
tree | 657d8194422a5daccecfd42d654b8a245ef7b4c8 /src/include/parser/scanner.h | |
parent | Initial commit. (diff) | |
download | postgresql-13-upstream.tar.xz postgresql-13-upstream.zip |
Adding upstream version 13.4.upstream/13.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/parser/scanner.h')
-rw-r--r-- | src/include/parser/scanner.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/src/include/parser/scanner.h b/src/include/parser/scanner.h new file mode 100644 index 0000000..a27352a --- /dev/null +++ b/src/include/parser/scanner.h @@ -0,0 +1,150 @@ +/*------------------------------------------------------------------------- + * + * scanner.h + * API for the core scanner (flex machine) + * + * The core scanner is also used by PL/pgSQL, so we provide a public API + * for it. However, the rest of the backend is only expected to use the + * higher-level API provided by parser.h. + * + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/parser/scanner.h + * + *------------------------------------------------------------------------- + */ + +#ifndef SCANNER_H +#define SCANNER_H + +#include "common/keywords.h" + +/* + * The scanner returns extra data about scanned tokens in this union type. + * Note that this is a subset of the fields used in YYSTYPE of the bison + * parsers built atop the scanner. + */ +typedef union core_YYSTYPE +{ + int ival; /* for integer literals */ + char *str; /* for identifiers and non-integer literals */ + const char *keyword; /* canonical spelling of keywords */ +} core_YYSTYPE; + +/* + * We track token locations in terms of byte offsets from the start of the + * source string, not the column number/line number representation that + * bison uses by default. Also, to minimize overhead we track only one + * location (usually the first token location) for each construct, not + * the beginning and ending locations as bison does by default. It's + * therefore sufficient to make YYLTYPE an int. + */ +#define YYLTYPE int + +/* + * Another important component of the scanner's API is the token code numbers. + * However, those are not defined in this file, because bison insists on + * defining them for itself. The token codes used by the core scanner are + * the ASCII characters plus these: + * %token <str> IDENT UIDENT FCONST SCONST USCONST BCONST XCONST Op + * %token <ival> ICONST PARAM + * %token TYPECAST DOT_DOT COLON_EQUALS EQUALS_GREATER + * %token LESS_EQUALS GREATER_EQUALS NOT_EQUALS + * The above token definitions *must* be the first ones declared in any + * bison parser built atop this scanner, so that they will have consistent + * numbers assigned to them (specifically, IDENT = 258 and so on). + */ + +/* + * The YY_EXTRA data that a flex scanner allows us to pass around. + * Private state needed by the core scanner goes here. Note that the actual + * yy_extra struct may be larger and have this as its first component, thus + * allowing the calling parser to keep some fields of its own in YY_EXTRA. + */ +typedef struct core_yy_extra_type +{ + /* + * The string the scanner is physically scanning. We keep this mainly so + * that we can cheaply compute the offset of the current token (yytext). + */ + char *scanbuf; + Size scanbuflen; + + /* + * The keyword list to use, and the associated grammar token codes. + */ + const ScanKeywordList *keywordlist; + const uint16 *keyword_tokens; + + /* + * Scanner settings to use. These are initialized from the corresponding + * GUC variables by scanner_init(). Callers can modify them after + * scanner_init() if they don't want the scanner's behavior to follow the + * prevailing GUC settings. + */ + int backslash_quote; + bool escape_string_warning; + bool standard_conforming_strings; + + /* + * literalbuf is used to accumulate literal values when multiple rules are + * needed to parse a single literal. Call startlit() to reset buffer to + * empty, addlit() to add text. NOTE: the string in literalbuf is NOT + * necessarily null-terminated, but there always IS room to add a trailing + * null at offset literallen. We store a null only when we need it. + */ + char *literalbuf; /* palloc'd expandable buffer */ + int literallen; /* actual current string length */ + int literalalloc; /* current allocated buffer size */ + + /* + * Random assorted scanner state. + */ + int state_before_str_stop; /* start cond. before end quote */ + int xcdepth; /* depth of nesting in slash-star comments */ + char *dolqstart; /* current $foo$ quote start string */ + YYLTYPE save_yylloc; /* one-element stack for PUSH_YYLLOC() */ + + /* first part of UTF16 surrogate pair for Unicode escapes */ + int32 utf16_first_part; + + /* state variables for literal-lexing warnings */ + bool warn_on_first_escape; + bool saw_non_ascii; +} core_yy_extra_type; + +/* + * The type of yyscanner is opaque outside scan.l. + */ +typedef void *core_yyscan_t; + +/* Support for scanner_errposition_callback function */ +typedef struct ScannerCallbackState +{ + core_yyscan_t yyscanner; + int location; + ErrorContextCallback errcallback; +} ScannerCallbackState; + + +/* Constant data exported from parser/scan.l */ +extern PGDLLIMPORT const uint16 ScanKeywordTokens[]; + +/* Entry points in parser/scan.l */ +extern core_yyscan_t scanner_init(const char *str, + core_yy_extra_type *yyext, + const ScanKeywordList *keywordlist, + const uint16 *keyword_tokens); +extern void scanner_finish(core_yyscan_t yyscanner); +extern int core_yylex(core_YYSTYPE *lvalp, YYLTYPE *llocp, + core_yyscan_t yyscanner); +extern int scanner_errposition(int location, core_yyscan_t yyscanner); +extern void setup_scanner_errposition_callback(ScannerCallbackState *scbstate, + core_yyscan_t yyscanner, + int location); +extern void cancel_scanner_errposition_callback(ScannerCallbackState *scbstate); +extern void scanner_yyerror(const char *message, core_yyscan_t yyscanner) pg_attribute_noreturn(); + +#endif /* SCANNER_H */ |