Convert lexer and parser to be reentrant ("pure lexer" and "pure parser").

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

.gitignore

@@ -3,6 +3,7 @@
 *.output
 
 sql.tab.*
+sql.lex.h
 sql.c
 sql
 

Makefile

@@ -4,7 +4,7 @@
 # Copyright (c) 2009, Taughannock Networks. All rights reserved.
 # See the README file for license conditions and contact info.
 
-CC = cc -g
+CC = gcc -Wall -O -g
 LEX = flex
 YACC = bison
 CFLAGS = -DYYDEBUG=1
@@ -15,7 +15,7 @@ all:	${PROGRAMS}
 
 # chapter 4
 
-OBJS	= sql.tab.o sql.o exec.o
+OBJS	= sql.o sql.tab.o exec.o
 
 sql:	${OBJS} sql-parser.h
 	${CC} -o $@ ${OBJS}
@@ -29,7 +29,7 @@ sql.c:	sql.l
 sql.o:	sql.c sql.tab.h
 
 clean:
-	rm -f sql sql.tab.c sql.tab.h sql.c ${OBJS} \
+	rm -f sql sql.tab.c sql.tab.h sql.lex.h sql.c ${OBJS} \
 	sql.output
 
 .SUFFIXES:	.l .y .c

sql-parser-state.h

@@ -0,0 +1,8 @@
+#ifndef __SQL_PARSER_STATE__
+#define __SQL_PARSER_STATE__
+
+struct psql_state {
+	yyscan_t	scaninfo;
+};
+
+#endif /* __SQL_PARSER_STATE__ */

sql.l

@@ -9,21 +9,28 @@
  * With error reporting and recovery
  */
 
-%option noyywrap nodefault yylineno case-insensitive
+%option noyywrap nodefault yylineno case-insensitive reentrant bison-bridge
+%option bison-locations
+%option header-file="sql.lex.h"
+
 %{
-#include "sql.tab.h"
 #include <stdarg.h>
 #include <string.h>
+#include "sql.tab.h"
+#include "sql-parser-state.h"
+
+void yyerror(YYLTYPE *, struct psql_state *pstate, char *s, ...);
 
-void yyerror(char *s, ...);
 int oldstate;
 
 /* handle locations */
+#if 0
 int yycolumn = 1;
+#endif
 
-#define YY_USER_ACTION yylloc.filename = filename; \
+#define YY_USER_ACTION yylloc->filename = filename; \
-    yylloc.first_line = yylloc.last_line = yylineno; \
+    yylloc->first_line = yylloc->last_line = yylineno; \
-    yylloc.first_column = yycolumn; yylloc.last_column = yycolumn+yyleng-1; \
+    yylloc->first_column = yycolumn; yylloc->last_column = yycolumn+yyleng-1; \
     yycolumn += yyleng;
 
 
@@ -33,6 +40,9 @@ int yycolumn = 1;
 %s BTWMODE
 
 %%
+%{
+	struct psql_state *pstate = yyextra;
+%}
 
   /* keywords */
 
@@ -106,8 +116,8 @@ ELSEIF	{ return ELSEIF; }
 END	{ return END; }
 ENUM { return ENUM; }
 ESCAPED	{ return ESCAPED; }
-EXISTS	{ yylval.subtok = 0; return EXISTS; }
+EXISTS	{ yylval->subtok = 0; return EXISTS; }
-NOT[ \t]+EXISTS	{ yylval.subtok = 1; return EXISTS; }
+NOT[ \t]+EXISTS	{ yylval->subtok = 1; return EXISTS; }
 EXIT	{ return EXIT; }
 EXPLAIN	{ return EXPLAIN; }
 FETCH	{ return FETCH; }
@@ -262,35 +272,35 @@ ZEROFILL	{ return ZEROFILL; }
 
    /* numbers */
 
--?[0-9]+	        { yylval.intval = atoi(yytext); return INTNUM; } 
+-?[0-9]+	        { yylval->intval = atoi(yytext); return INTNUM; } 
 
 -?[0-9]+"."[0-9]* |
 -?"."[0-9]+	|
 -?[0-9]+E[-+]?[0-9]+	|
 -?[0-9]+"."[0-9]*E[-+]?[0-9]+ |
--?"."[0-9]*E[-+]?[0-9]+	{ yylval.floatval = atof(yytext) ;
+-?"."[0-9]*E[-+]?[0-9]+	{ yylval->floatval = atof(yytext) ;
                                   return APPROXNUM; }
     /* booleans */
-TRUE	{ yylval.intval = 1; return BOOL; }
+TRUE	{ yylval->intval = 1; return BOOL; }
-UNKNOWN	{ yylval.intval = -1; return BOOL; }
+UNKNOWN	{ yylval->intval = -1; return BOOL; }
-FALSE	{ yylval.intval = 0; return BOOL; }
+FALSE	{ yylval->intval = 0; return BOOL; }
 
    /* strings */
 
 '(\\.|''|[^'\n])*'	|
-\"(\\.|\"\"|[^"\n])*\"  { yylval.strval = strdup(yytext); return STRING; }
+\"(\\.|\"\"|[^"\n])*\"  { yylval->strval = strdup(yytext); return STRING; }
 
-'(\\.|[^'\n])*$	        { yyerror("Unterminated string %s", yytext); }
+'(\\.|[^'\n])*$	        { yyerror(yylloc, pstate, "Unterminated string %s", yytext); }
-\"(\\.|[^"\n])*$	{ yyerror("Unterminated string %s", yytext); }
+\"(\\.|[^"\n])*$	{ yyerror(yylloc, pstate, "Unterminated string %s", yytext); }
 
    /* hex strings */
 X'[0-9A-F]+' |  
-0X[0-9A-F]+  { yylval.strval = strdup(yytext); return STRING; }
+0X[0-9A-F]+  { yylval->strval = strdup(yytext); return STRING; }
 
    /* bit strings */
 
 0B[01]+      |
-B'[01]+'     { yylval.strval = strdup(yytext); return STRING; }
+B'[01]+'     { yylval->strval = strdup(yytext); return STRING; }
 
 
    /* operators */
@@ -299,17 +309,17 @@ B'[01]+'     { yylval.strval = strdup(yytext); return STRING; }
 "&&"		{ return ANDOP; }
 "||"            { return OR; }
 
-"="	{ yylval.subtok = 4; return COMPARISON; }
+"="	{ yylval->subtok = 4; return COMPARISON; }
-"<=>"	{ yylval.subtok = 12; return COMPARISON; }
+"<=>"	{ yylval->subtok = 12; return COMPARISON; }
-">="	{ yylval.subtok = 6; return COMPARISON; }
+">="	{ yylval->subtok = 6; return COMPARISON; }
-">"	{ yylval.subtok = 2; return COMPARISON; }
+">"	{ yylval->subtok = 2; return COMPARISON; }
-"<="	{ yylval.subtok = 5; return COMPARISON; }
+"<="	{ yylval->subtok = 5; return COMPARISON; }
-"<"	{ yylval.subtok = 1; return COMPARISON; }
+"<"	{ yylval->subtok = 1; return COMPARISON; }
 "!="	|
-"<>"	{ yylval.subtok = 3; return COMPARISON; }
+"<>"	{ yylval->subtok = 3; return COMPARISON; }
 
-"<<"	{ yylval.subtok = 1; return SHIFT; }
+"<<"	{ yylval->subtok = 1; return SHIFT; }
-">>"	{ yylval.subtok = 2; return SHIFT; }
+">>"	{ yylval->subtok = 2; return SHIFT; }
 
         /* functions */
 
@@ -321,28 +331,28 @@ DATE_SUB/"(" { return FDATE_SUB; }
 	/* 
          * peek ahead and return function if name(
          */
-COUNT    { int c = input(); unput(c);
+COUNT    { int c = input(pstate->scaninfo); unput(c);
            if(c == '(') return FCOUNT;
-           yylval.strval = strdup(yytext);
+           yylval->strval = strdup(yytext);
            return NAME; }
 
-[A-Za-z][A-Za-z0-9_]*	{ yylval.strval = strdup(yytext);
+[A-Za-z][A-Za-z0-9_]*	{ yylval->strval = strdup(yytext);
                           return NAME; }
-`[^`/\\.\n]+`           { yylval.strval = strdup(yytext+1);
+`[^`/\\.\n]+`           { yylval->strval = strdup(yytext+1);
-                          yylval.strval[yyleng-2] = 0;
+                          yylval->strval[yyleng-2] = 0;
                           return NAME; }
 
-`[^`\n]*$               { yyerror("unterminated quoted name %s", yytext); }
+`[^`\n]*$               { yyerror(yylloc, pstate, "unterminated quoted name %s", yytext); }
 
 	/* user variables */
 @[0-9a-z_.$]+ |
 @\"[^"\n]+\" |
 @`[^`\n]+` |
-@'[^'\n]+' { yylval.strval = strdup(yytext+1); return USERVAR; }
+@'[^'\n]+' { yylval->strval = strdup(yytext+1); return USERVAR; }
 
-@\"[^"\n]*$ { yyerror("unterminated quoted user variable %s", yytext); }
+@\"[^"\n]*$ { yyerror(yylloc, pstate, "unterminated quoted user variable %s", yytext); }
-@`[^`\n]*$ { yyerror("unterminated quoted user variable %s", yytext); }
+@`[^`\n]*$ { yyerror(yylloc, pstate, "unterminated quoted user variable %s", yytext); }
-@'[^'\n]*$ { yyerror("unterminated quoted user variable %s", yytext); }
+@'[^'\n]*$ { yyerror(yylloc, pstate, "unterminated quoted user variable %s", yytext); }
 
 
 ":="     { return ASSIGN; }
@@ -355,12 +365,12 @@ COUNT    { int c = input(); unput(c);
 <COMMENT>"*/"   { BEGIN oldstate; }
 <COMMENT>.   ;
 <COMMENT>\n     { yycolumn = 1; }
-<COMMENT><<EOF>> { yyerror("unclosed comment"); }
+<COMMENT><<EOF>> { yyerror(yylloc, pstate, "unclosed comment"); }
 
 	        /* everything else */
 [ \t]           /* white space */
 \n              { yycolumn = 1; }
-.               { yyerror("mystery character '%c'", *yytext); }
+.               { yyerror(yylloc, pstate, "mystery character '%c'", *yytext); }
 
 %%
 

sql.y

@@ -4,6 +4,10 @@
  * See the README file for license conditions and contact info.
  * $Header: /home/johnl/flnb/code/sql/RCS/lpmysql.y,v 2.1 2009/11/08 02:53:39 johnl Exp $
  */
+
+%define api.pure
+%parse-param { struct psql_state *pstate }
+
 /*
  * Parser for mysql subset
  */
@@ -56,6 +60,12 @@ typedef struct YYLTYPE {
 	int subtok;
 }
 
+%{
+#include "sql.lex.h"
+#include "sql-parser-state.h"
+#define YYLEX_PARAM pstate->scaninfo
+%}
+	
 	/* names and literal values */
 
 %token <strval> NAME
@@ -330,8 +340,8 @@ typedef struct YYLTYPE {
 %start stmt_list
 
 %{
-void yyerror(char *s, ...);
+void yyerror(YYLTYPE *, struct psql_state *pstate, char *s, ...);
-void lyyerror(YYLTYPE, char *s, ...);
+void lyyerror(YYLTYPE t, char *s, ...);
  %}
   /* free discarded tokens */
 %destructor { printf ("free at %d %s\n",@$.first_line, $$); free($$); } <strval>
@@ -971,14 +981,14 @@ expr: BINARY expr %prec UMINUS { sqlp_expr_op(SEO_STRTOBIN); }
 %%
 
 void
-yyerror(char *s, ...)
+yyerror(YYLTYPE *t, struct psql_state *pstate, char *s, ...)
 {
   va_list ap;
   va_start(ap, s);
 
-  if(yylloc.first_line)
+  if(t->first_line)
-    fprintf(stderr, "%s:%d.%d-%d.%d: error: ", yylloc.filename, yylloc.first_line, yylloc.first_column,
+    fprintf(stderr, "%s:%d.%d-%d.%d: error: ", t->filename, t->first_line, t->first_column,
-	    yylloc.last_line, yylloc.last_column);
+	    t->last_line, t->last_column);
   vfprintf(stderr, s, ap);
   fprintf(stderr, "\n");
 
@@ -997,25 +1007,37 @@ lyyerror(YYLTYPE t, char *s, ...)
   fprintf(stderr, "\n");
 }
 
+int
 main(int ac, char **av)
 {
-  extern FILE *yyin;
+  FILE *in_f;
+  struct psql_state pstate;
 
   if(ac > 1 && !strcmp(av[1], "-d")) {
     yydebug = 1; ac--; av++;
   }
 
+  memset(&pstate, 0, sizeof(pstate));
+  if (yylex_init_extra(&pstate, &pstate.scaninfo))
+  	return 1;
+
   if(ac > 1) {
-    if((yyin = fopen(av[1], "r")) == NULL) {
+    if((in_f = fopen(av[1], "r")) == NULL) {
       perror(av[1]);
       exit(1);
     }
     filename = av[1];
-  } else
+  } else {
     filename = "(stdin)";
+    in_f = stdin;
+  }
 
-  if(!yyparse())
+  yyset_in(in_f, &pstate.scaninfo);
+
+  if(!yyparse(&pstate))
     printf("SQL parse worked\n");
   else
     printf("SQL parse failed\n");
+
+  return 0;
 } /* main */