Drop warning-free support for Flex 2.5.35

petere · petere · commit 6fdd5d956343 · 2025-01-15T15:35:08.000+01:00
This removes all the various workarounds for avoiding compiler warnings with Flex 2.5.35. Several recent patches have added additional warnings that would either need to be fixed along the lines of the existing workarounds, or we decide to no longer care about this, which we do here. Flex 2.5.35 is extremely outdated, and you can't even download it anymore from any of the Flex project sites, so it's nearly impossible to support. After this, using Flex 2.5.35 will still work, but the generated code will produce numerous compiler warnings. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/1a204ccd-7ae6-478c-a431-407b5c48ccc6@eisentraut.org
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
@@ -788,7 +788,6 @@ TAS         = @TAS@
 %.c: %.l
 	$(FLEX) $(if $(FLEX_NO_BACKUP),-b) $(FLEXFLAGS) -o'$@' $<
 	@$(if $(FLEX_NO_BACKUP),if [ `wc -l <lex.backup` -eq 1 ]; then rm lex.backup; else echo "Scanner requires backup; see lex.backup." 1>&2; exit 1; fi)
-	$(if $(FLEX_FIX_WARNING),$(PERL) $(top_srcdir)/src/tools/fix-old-flex-code.pl '$@')
 
 %.c: %.y
 	$(if $(BISON_CHECK_CMD),$(BISON_CHECK_CMD))
diff --git a/src/backend/parser/Makefile b/src/backend/parser/Makefile
@@ -59,7 +59,6 @@ gram.c: BISON_CHECK_CMD = $(PERL) $(srcdir)/check_keywords.pl $< $(top_srcdir)/s
 
 scan.c: FLEXFLAGS = -CF -p -p
 scan.c: FLEX_NO_BACKUP=yes
-scan.c: FLEX_FIX_WARNING=yes
 
 
 # Force these dependencies to be known even without dependency info built:
diff --git a/src/backend/parser/meson.build b/src/backend/parser/meson.build
@@ -30,7 +30,7 @@ parser_sources = files('parser.c')
 backend_scanner = custom_target('scan',
   input: 'scan.l',
   output: 'scan.c',
-  command: [flex_cmd, '--no-backup', '--fix-warnings', '--', '-CF', '-p', '-p'],
+  command: [flex_cmd, '--no-backup', '--', '-CF', '-p', '-p'],
 )
 generated_sources += backend_scanner
 parser_sources += backend_scanner
diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l
@@ -130,15 +130,6 @@ static void addunicode(pg_wchar c, yyscan_t yyscanner);
 static void check_string_escape_warning(unsigned char ychar, core_yyscan_t yyscanner);
 static void check_escape_warning(core_yyscan_t yyscanner);
 
-/*
- * Work around a bug in flex 2.5.35: it emits a couple of functions that
- * it forgets to emit declarations for.  Since we use -Wmissing-prototypes,
- * this would cause warnings.  Providing our own declarations should be
- * harmless even when the bug gets fixed.
- */
-extern int	core_yyget_column(yyscan_t yyscanner);
-extern void core_yyset_column(int column_no, yyscan_t yyscanner);
-
 %}
 
 %option reentrant
diff --git a/src/bin/pgbench/exprscan.l b/src/bin/pgbench/exprscan.l
@@ -44,15 +44,6 @@ static const char *expr_command = NULL;
 /* indicates whether last yylex() call read a newline */
 static bool last_was_newline = false;
 
-/*
- * Work around a bug in flex 2.5.35: it emits a couple of functions that
- * it forgets to emit declarations for.  Since we use -Wmissing-prototypes,
- * this would cause warnings.  Providing our own declarations should be
- * harmless even when the bug gets fixed.
- */
-extern int	expr_yyget_column(yyscan_t yyscanner);
-extern void expr_yyset_column(int column_no, yyscan_t yyscanner);
-
 /* LCOV_EXCL_START */
 
 %}
diff --git a/src/bin/psql/Makefile b/src/bin/psql/Makefile
@@ -60,7 +60,6 @@ sql_help.h: create_help.pl $(wildcard $(REFDOCDIR)/*.sgml)
 
 psqlscanslash.c: FLEXFLAGS = -Cfe -p -p
 psqlscanslash.c: FLEX_NO_BACKUP=yes
-psqlscanslash.c: FLEX_FIX_WARNING=yes
 
 tab-complete.c: gen_tabcomplete.pl tab-complete.in.c
 	$(PERL) $^ --outfile $@
diff --git a/src/bin/psql/meson.build b/src/bin/psql/meson.build
@@ -19,7 +19,7 @@ psql_sources = files(
 psqlscanslash = custom_target('psqlscanslash',
   input: 'psqlscanslash.l',
   output: 'psqlscanslash.c',
-  command: [flex_cmd, '--no-backup', '--fix-warnings', '--', '-Cfe', '-p', '-p'])
+  command: [flex_cmd, '--no-backup', '--', '-Cfe', '-p', '-p'])
 generated_sources += psqlscanslash
 psql_sources += psqlscanslash
 
diff --git a/src/bin/psql/psqlscanslash.l b/src/bin/psql/psqlscanslash.l
@@ -57,15 +57,6 @@ static void evaluate_backtick(PsqlScanState state);
 
 #define ECHO psqlscan_emit(cur_state, yytext, yyleng)
 
-/*
- * Work around a bug in flex 2.5.35: it emits a couple of functions that
- * it forgets to emit declarations for.  Since we use -Wmissing-prototypes,
- * this would cause warnings.  Providing our own declarations should be
- * harmless even when the bug gets fixed.
- */
-extern int	slash_yyget_column(yyscan_t yyscanner);
-extern void slash_yyset_column(int column_no, yyscan_t yyscanner);
-
 /* LCOV_EXCL_START */
 
 %}
diff --git a/src/fe_utils/Makefile b/src/fe_utils/Makefile
@@ -51,7 +51,6 @@ libpgfeutils.a: $(OBJS)
 
 psqlscan.c: FLEXFLAGS = -Cfe -p -p
 psqlscan.c: FLEX_NO_BACKUP=yes
-psqlscan.c: FLEX_FIX_WARNING=yes
 
 # libpgfeutils could be useful to contrib, so install it
 install: all installdirs
diff --git a/src/fe_utils/meson.build b/src/fe_utils/meson.build
@@ -23,7 +23,7 @@ fe_utils_sources = files(
 psqlscan = custom_target('psqlscan',
   input: 'psqlscan.l',
   output: 'psqlscan.c',
-  command: [flex_cmd, '--no-backup', '--fix-warnings', '--', '-Cfe', '-p', '-p'],
+  command: [flex_cmd, '--no-backup', '--', '-Cfe', '-p', '-p'],
 )
 generated_sources += psqlscan
 fe_utils_sources += psqlscan
diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l
@@ -61,15 +61,6 @@ typedef int YYSTYPE;
 
 #define ECHO psqlscan_emit(cur_state, yytext, yyleng)
 
-/*
- * Work around a bug in flex 2.5.35: it emits a couple of functions that
- * it forgets to emit declarations for.  Since we use -Wmissing-prototypes,
- * this would cause warnings.  Providing our own declarations should be
- * harmless even when the bug gets fixed.
- */
-extern int	psql_yyget_column(yyscan_t yyscanner);
-extern void psql_yyset_column(int column_no, yyscan_t yyscanner);
-
 %}
 
 %option reentrant
diff --git a/src/tools/fix-old-flex-code.pl b/src/tools/fix-old-flex-code.pl
diff --git a/src/tools/pgflex b/src/tools/pgflex
@@ -4,7 +4,6 @@
 # Wrapper around flex that:
 # - ensures lex.backup is created in a private directory
 # - can error out if lex.backup is created (--no-backup)
-# - can fix warnings (--fix-warnings)
 # - works around concurrency issues with win_flex.exe:
 #   https://github.com/lexxmark/winflexbison/issues/86
 
@@ -28,8 +27,6 @@ parser.add_argument('-o', dest='output_file', type=abspath, required=True,
 parser.add_argument('-i', dest='input_file', type=abspath, help='input file')
 
 
-parser.add_argument('--fix-warnings', action='store_true',
-                    help='whether to fix warnings in generated file')
 parser.add_argument('--no-backup', action='store_true',
                     help='whether no_backup is enabled or not')
 
@@ -72,14 +69,4 @@ if args.no_backup:
             sys.exit('Scanner requires backup; see lex.backup.')
     os.remove('lex.backup')
 
-# fix warnings
-if args.fix_warnings:
-    fix_warning_script = os.path.join(args.srcdir,
-                                      'src/tools/fix-old-flex-code.pl')
-
-    command = [args.perl, fix_warning_script, args.output_file]
-    sp = subprocess.run(command)
-    if sp.returncode != 0:
-        sys.exit(sp.returncode)
-
 sys.exit(0)

Original file line number	Diff line number	Diff line change
`@@ -30,7 +30,7 @@ parser_sources = files('parser.c')`
`30`	`30`	`backend_scanner = custom_target('scan',`
`31`	`31`	`input: 'scan.l',`
`32`	`32`	`output: 'scan.c',`
`33`		`- command: [flex_cmd, '--no-backup', '--fix-warnings', '--', '-CF', '-p', '-p'],`
	`33`	`+ command: [flex_cmd, '--no-backup', '--', '-CF', '-p', '-p'],`
`34`	`34`	`)`
`35`	`35`	`generated_sources += backend_scanner`
`36`	`36`	`parser_sources += backend_scanner`
Original file line number	Diff line number	Diff line change
`@@ -23,7 +23,7 @@ fe_utils_sources = files(`
`23`	`23`	`psqlscan = custom_target('psqlscan',`
`24`	`24`	`input: 'psqlscan.l',`
`25`	`25`	`output: 'psqlscan.c',`
`26`		`- command: [flex_cmd, '--no-backup', '--fix-warnings', '--', '-Cfe', '-p', '-p'],`
	`26`	`+ command: [flex_cmd, '--no-backup', '--', '-Cfe', '-p', '-p'],`
`27`	`27`	`)`
`28`	`28`	`generated_sources += psqlscan`
`29`	`29`	`fe_utils_sources += psqlscan`