From 86b08b49b3b1b9fc27a3c64d8421a6f30c12d942 Mon Sep 17 00:00:00 2001 From: Akim Demaille Date: Tue, 15 May 2012 11:22:34 +0200 Subject: [PATCH] build: do not prototype flex-generated functions. Some versions of Flex, possibly modified by the distribution package maintainers, have incompatible signatures. Since newer versions of Flex prototype their functions, avoid the conflicts in that case. Reported by Stefano Lattarini. . * src/flex-scanner.h (FLEX_VERSION_GT): New. Use it to issue prototypes for flex-generated functions only for versions up to 2.5.31, in accordance with the comment. See commit dc9701e848f27ae64b6ddcf809580998667d60f2. Use it to define yylex_destroy when needed. --- NEWS | 8 +++++++- src/flex-scanner.h | 21 +++++++++++++++------ 2 files changed, 22 insertions(+), 7 deletions(-) diff --git a/NEWS b/NEWS index b56746e6..f554b9ff 100644 --- a/NEWS +++ b/NEWS @@ -59,7 +59,13 @@ Bison News format. Incorrect index entries were fixed. Some other errors were fixed. -** Changes to the build system: +** Building bison: + +*** Conflicting prototypes with recent/modified Flex. + + Fixed build problems with the current, unreleased, version of Flex, + and some modified versions of 2.5.35, which have modified function + prototypes. *** Warnings during the build procedure have been eliminated. diff --git a/src/flex-scanner.h b/src/flex-scanner.h index 23a266ac..f27938dc 100644 --- a/src/flex-scanner.h +++ b/src/flex-scanner.h @@ -21,7 +21,20 @@ # error "FLEX_PREFIX not defined" #endif +/* Whether this version of Flex is (strictly) greater than + Major.Minor.Subminor. */ +#define FLEX_VERSION_GT(Major, Minor, Subminor) \ + (defined YY_FLEX_MAJOR_VERSION \ + && (Major < YY_FLEX_MAJOR_VERSION \ + || (Major == YY_FLEX_MAJOR_VERSION \ + && (defined YY_FLEX_MINOR_VERSION \ + && (Minor < YY_FLEX_MINOR_VERSION \ + || (Minor == YY_FLEX_MINOR_VERSION \ + && defined YY_FLEX_SUBMINOR_VERSION \ + && Subminor < YY_FLEX_SUBMINOR_VERSION)))))) + /* Pacify "gcc -Wmissing-prototypes" when flex 2.5.31 is used. */ +# if ! FLEX_VERSION_GT (2, 5, 31) int FLEX_PREFIX (get_lineno) (void); FILE *FLEX_PREFIX (get_in) (void); FILE *FLEX_PREFIX (get_out) (void); @@ -33,6 +46,7 @@ void FLEX_PREFIX (set_out) (FILE *); int FLEX_PREFIX (get_debug) (void); void FLEX_PREFIX (set_debug) (int); int FLEX_PREFIX (lex_destroy) (void); +#endif #define last_string FLEX_PREFIX (last_string) @@ -51,12 +65,7 @@ int FLEX_PREFIX (lex_destroy) (void); versions according to the Flex manual) leak memory if yylex_destroy is not invoked. However, yylex_destroy is not defined before Flex 2.5.9, so give an implementation here that at least appears to work with Flex 2.5.4. */ -#if !defined YY_FLEX_MAJOR_VERSION || YY_FLEX_MAJOR_VERSION < 2 \ - || (YY_FLEX_MAJOR_VERSION == 2 \ - && (!defined YY_FLEX_MINOR_VERSION || YY_FLEX_MINOR_VERSION < 5 \ - || (YY_FLEX_MINOR_VERSION == 5 \ - && (!defined YY_FLEX_SUBMINOR_VERSION \ - || YY_FLEX_SUBMINOR_VERSION < 9)))) +#if ! FLEX_VERSION_GT (2, 5, 9) # define yylex_destroy() yy_delete_buffer (YY_CURRENT_BUFFER) #endif -- 2.45.2