From 462227dc007d7fa002eca38c010d95d458fa1aef Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 26 Oct 2007 14:17:53 +0000 Subject: [PATCH] Avoid having backend-only code compiled into ecpg. Per Zdenek Kotala --- src/interfaces/ecpg/preproc/Makefile | 7 +- src/interfaces/ecpg/preproc/parser.c | 140 +++++++++++++++++++++ src/interfaces/ecpg/preproc/parser/README | 1 - src/interfaces/ecpg/preproc/parser/parse.h | 3 - 4 files changed, 142 insertions(+), 9 deletions(-) create mode 100644 src/interfaces/ecpg/preproc/parser.c delete mode 100644 src/interfaces/ecpg/preproc/parser/README delete mode 100644 src/interfaces/ecpg/preproc/parser/parse.h diff --git a/src/interfaces/ecpg/preproc/Makefile b/src/interfaces/ecpg/preproc/Makefile index 16f26fafde..e2a41616e5 100644 --- a/src/interfaces/ecpg/preproc/Makefile +++ b/src/interfaces/ecpg/preproc/Makefile @@ -4,7 +4,7 @@ # # Copyright (c) 1998-2007, PostgreSQL Global Development Group # -# $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/Makefile,v 1.128 2007/08/22 08:20:58 meskes Exp $ +# $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/Makefile,v 1.129 2007/10/26 14:17:53 tgl Exp $ # #------------------------------------------------------------------------- @@ -59,9 +59,6 @@ endif c_keywords.o keywords.o preproc.o parser.o: preproc.h -parser.c: $(top_srcdir)/src/backend/parser/parser.c - rm -f $@ && $(LN_S) $< . - distprep: $(srcdir)/preproc.c $(srcdir)/preproc.h $(srcdir)/pgc.c install: all installdirs @@ -74,7 +71,7 @@ uninstall: rm -f '$(DESTDIR)$(bindir)/ecpg$(X)' clean distclean: - rm -f *.o ecpg$(X) parser.c + rm -f *.o ecpg$(X) # garbage from partial builds @rm -f y.tab.c y.tab.h # garbage from development diff --git a/src/interfaces/ecpg/preproc/parser.c b/src/interfaces/ecpg/preproc/parser.c new file mode 100644 index 0000000000..21fd2dd0a5 --- /dev/null +++ b/src/interfaces/ecpg/preproc/parser.c @@ -0,0 +1,140 @@ +/*------------------------------------------------------------------------- + * + * parser.c + * Main entry point/driver for PostgreSQL grammar + * + * Note that the grammar is not allowed to perform any table access + * (since we need to be able to do basic parsing even while inside an + * aborted transaction). Therefore, the data structures returned by + * the grammar are "raw" parsetrees that still need to be analyzed by + * analyze.c and related files. + * + * + * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/parser.c,v 1.1 2007/10/26 14:17:53 tgl Exp $ + * + *------------------------------------------------------------------------- + */ + +#include "postgres_fe.h" + +#include "extern.h" +#include "preproc.h" + + +static bool have_lookahead; /* is lookahead info valid? */ +static int lookahead_token; /* one-token lookahead */ +static YYSTYPE lookahead_yylval; /* yylval for lookahead token */ +static YYLTYPE lookahead_yylloc; /* yylloc for lookahead token */ + + +/* + * Intermediate filter between parser and base lexer (base_yylex in scan.l). + * + * The filter is needed because in some cases the standard SQL grammar + * requires more than one token lookahead. We reduce these cases to one-token + * lookahead by combining tokens here, in order to keep the grammar LALR(1). + * + * Using a filter is simpler than trying to recognize multiword tokens + * directly in scan.l, because we'd have to allow for comments between the + * words. Furthermore it's not clear how to do it without re-introducing + * scanner backtrack, which would cost more performance than this filter + * layer does. + */ +int +filtered_base_yylex(void) +{ + int cur_token; + int next_token; + YYSTYPE cur_yylval; + YYLTYPE cur_yylloc; + + /* Get next token --- we might already have it */ + if (have_lookahead) + { + cur_token = lookahead_token; + base_yylval = lookahead_yylval; + base_yylloc = lookahead_yylloc; + have_lookahead = false; + } + else + cur_token = base_yylex(); + + /* Do we need to look ahead for a possible multiword token? */ + switch (cur_token) + { + case NULLS_P: + /* + * NULLS FIRST and NULLS LAST must be reduced to one token + */ + cur_yylval = base_yylval; + cur_yylloc = base_yylloc; + next_token = base_yylex(); + switch (next_token) + { + case FIRST_P: + cur_token = NULLS_FIRST; + break; + case LAST_P: + cur_token = NULLS_LAST; + break; + default: + /* save the lookahead token for next time */ + lookahead_token = next_token; + lookahead_yylval = base_yylval; + lookahead_yylloc = base_yylloc; + have_lookahead = true; + /* and back up the output info to cur_token */ + base_yylval = cur_yylval; + base_yylloc = cur_yylloc; + break; + } + break; + + case WITH: + /* + * WITH CASCADED, LOCAL, or CHECK must be reduced to one token + * + * XXX an alternative way is to recognize just WITH_TIME and put + * the ugliness into the datetime datatype productions instead of + * WITH CHECK OPTION. However that requires promoting WITH to a + * fully reserved word. If we ever have to do that anyway + * (perhaps for SQL99 recursive queries), come back and simplify + * this code. + */ + cur_yylval = base_yylval; + cur_yylloc = base_yylloc; + next_token = base_yylex(); + switch (next_token) + { + case CASCADED: + cur_token = WITH_CASCADED; + break; + case LOCAL: + cur_token = WITH_LOCAL; + break; + case CHECK: + cur_token = WITH_CHECK; + break; + default: + /* save the lookahead token for next time */ + lookahead_token = next_token; + lookahead_yylval = base_yylval; + lookahead_yylloc = base_yylloc; + have_lookahead = true; + /* and back up the output info to cur_token */ + base_yylval = cur_yylval; + base_yylloc = cur_yylloc; + break; + } + break; + + default: + break; + } + + return cur_token; +} diff --git a/src/interfaces/ecpg/preproc/parser/README b/src/interfaces/ecpg/preproc/parser/README deleted file mode 100644 index e2e45e7379..0000000000 --- a/src/interfaces/ecpg/preproc/parser/README +++ /dev/null @@ -1 +0,0 @@ -The parse.h file has to be in this directory to comply with the backend's source tree. diff --git a/src/interfaces/ecpg/preproc/parser/parse.h b/src/interfaces/ecpg/preproc/parser/parse.h deleted file mode 100644 index 2362ca2f70..0000000000 --- a/src/interfaces/ecpg/preproc/parser/parse.h +++ /dev/null @@ -1,3 +0,0 @@ -#include "extern.h" -#include "preproc.h" -