postgresql/contrib/seg/segscan.l
Andres Freund bbfd7edae5 Add macros wrapping all usage of gcc's __attribute__.
Until now __attribute__() was defined to be empty for all compilers but
gcc. That's problematic because it prevents using it in other compilers;
which is necessary e.g. for atomics portability.  It's also just
generally dubious to do so in a header as widely included as c.h.

Instead add pg_attribute_format_arg, pg_attribute_printf,
pg_attribute_noreturn macros which are implemented in the compilers that
understand them. Also add pg_attribute_noreturn and pg_attribute_packed,
but don't provide fallbacks, since they can affect functionality.

This means that external code that, possibly unwittingly, relied on
__attribute__ defined to be empty on !gcc compilers may now run into
warnings or errors on those compilers. But there shouldn't be many
occurances of that and it's hard to work around...

Discussion: 54B58BA3.8040302@ohmu.fi
Author: Oskari Saarenmaa, with some minor changes by me.
2015-03-11 14:30:01 +01:00

120 lines
2.6 KiB
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%{
/*
* A scanner for EMP-style numeric ranges
*/
#include "postgres.h"
/* No reason to constrain amount of data slurped */
#define YY_READ_BUF_SIZE 16777216
/* Avoid exit() on fatal scanner errors (a bit ugly -- see yy_fatal_error) */
#undef fprintf
#define fprintf(file, fmt, msg) fprintf_to_ereport(fmt, msg)
static void
fprintf_to_ereport(const char *fmt, const char *msg)
{
ereport(ERROR, (errmsg_internal("%s", msg)));
}
/* Handles to the buffer that the lexer uses internally */
static YY_BUFFER_STATE scanbufhandle;
static char *scanbuf;
static int scanbuflen;
/* flex 2.5.4 doesn't bother with a decl for this */
int seg_yylex(void);
void seg_scanner_init(const char *str);
void seg_scanner_finish(void);
%}
%option 8bit
%option never-interactive
%option nodefault
%option noinput
%option nounput
%option noyywrap
%option warn
%option prefix="seg_yy"
range (\.\.)(\.)?
plumin (\'\+\-\')|(\(\+\-)\)
integer [+-]?[0-9]+
real [+-]?[0-9]+\.[0-9]+
float ({integer}|{real})([eE]{integer})?
%%
{range} yylval.text = yytext; return RANGE;
{plumin} yylval.text = yytext; return PLUMIN;
{float} yylval.text = yytext; return SEGFLOAT;
\< yylval.text = "<"; return EXTENSION;
\> yylval.text = ">"; return EXTENSION;
\~ yylval.text = "~"; return EXTENSION;
[ \t\n\r\f]+ /* discard spaces */
. return yytext[0]; /* alert parser of the garbage */
%%
void pg_attribute_noreturn
yyerror(SEG *result, const char *message)
{
if (*yytext == YY_END_OF_BUFFER_CHAR)
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("bad seg representation"),
/* translator: %s is typically "syntax error" */
errdetail("%s at end of input", message)));
}
else
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("bad seg representation"),
/* translator: first %s is typically "syntax error" */
errdetail("%s at or near \"%s\"", message, yytext)));
}
}
/*
* Called before any actual parsing is done
*/
void
seg_scanner_init(const char *str)
{
Size slen = strlen(str);
/*
* Might be left over after ereport()
*/
if (YY_CURRENT_BUFFER)
yy_delete_buffer(YY_CURRENT_BUFFER);
/*
* Make a scan buffer with special termination needed by flex.
*/
scanbuflen = slen;
scanbuf = palloc(slen + 2);
memcpy(scanbuf, str, slen);
scanbuf[slen] = scanbuf[slen + 1] = YY_END_OF_BUFFER_CHAR;
scanbufhandle = yy_scan_buffer(scanbuf, slen + 2);
BEGIN(INITIAL);
}
/*
* Called after parsing is done to clean up after seg_scanner_init()
*/
void
seg_scanner_finish(void)
{
yy_delete_buffer(scanbufhandle);
pfree(scanbuf);
}