From 4e26c69eb6bfb356d1654ca9cba0435413451a42 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Mon, 13 Feb 2006 19:07:04 +0000 Subject: [PATCH] * NEWS: Version 2.1a. * tests/headers.at (AT_TEST_CPP_GUARD_H): Declare yyerror and yylex, since C99 requires this. --- ChangeLog | 8 +++++++- NEWS | 33 +++++++++++++++------------------ tests/headers.at | 2 ++ 3 files changed, 24 insertions(+), 19 deletions(-) diff --git a/ChangeLog b/ChangeLog index a86f6af2..b2a115f3 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2006-02-13 Paul Eggert + + * NEWS: Version 2.1a. + * tests/headers.at (AT_TEST_CPP_GUARD_H): Declare yyerror and yylex, + since C99 requires this. + 2006-02-11 Paul Eggert * m4/c-working.m4: New file. @@ -1376,7 +1382,7 @@ 2005-09-19 Akim Demaille - * NEWS, configure.ac: Version 2.1a. + * NEWS, configure.ac: update version number to 2.1a. 2005-09-16 Paul Eggert diff --git a/NEWS b/NEWS index e982759c..8d321cdf 100644 --- a/NEWS +++ b/NEWS @@ -1,14 +1,14 @@ Bison News ---------- -Changes in version 2.1a: +Changes in version 2.1a, 2006-02-13: * Bison now allows multiple %union declarations, and concatenates their contents together. * New warning: unused values - Typed right-hand side symbols whose value are not used are reported. - For instance: + Typed right-hand side symbols whose values are not used are reported, + if the associated types have destructors. For instance: exp: exp "?" exp ":" exp { $1 ? $1 : $3; } | exp "+" exp @@ -16,14 +16,17 @@ Changes in version 2.1a: will trigger a warning about $$ and $5 in the first rule, and $3 in the second ($1 is copied to $$ by the default rule). This example - most likely contains three errors, and should be rewritten as: + most likely contains three errors, and could be rewritten as: - exp: exp "?" exp ":" exp { $$ = $1 ? $3 : $5; } - | exp "+" exp { $$ = $1 + $3; } + exp: exp "?" exp ":" exp + { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); } + | exp "+" exp + { $$ = $1 ? $1 : $3; if ($1) free ($3); } ; - However, if the original actions were really intended, the warnings - can be suppressed by letting Bison believe the values are used, e.g.: + However, if the original actions were really intended, memory leaks + and all, the warnings can be suppressed by letting Bison believe the + values are used, e.g.: exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); } | exp "+" exp { $$ = $1; (void) $3; } @@ -34,12 +37,6 @@ Changes in version 2.1a: exp: exp { push ($1); } '+' exp { push ($3); sum (); }; - Mid-rule actions that use $$ cause the corresponding value to be - set, therefore the following action must use it. The following rule - triggers a warning about $2. - - exp: '1' { $$ = 1; } '+' exp { $$ = $1 + $4; }; - The warning is intended to help catching lost values and memory leaks. If a value is ignored, its associated memory typically is not reclaimed. @@ -53,14 +50,14 @@ Changes in version 2.1a: instead of warnings. * GLR, YACC parsers. - The %parse-params are available in the %destructor's (and the - experimental %printer's) as per the documentation. + The %parse-params are available in the destructors (and the + experimental printers) as per the documentation. * Bison now warns if it finds a stray `$' or `@' in an action. * %require "VERSION" - To specify that the grammar file depends on features implemented in - Bison version VERSION or higher. + This specifies that the grammar file depends on features implemented + in Bison version VERSION or higher. * lalr1.cc: The token and value types are now class members. The tokens were defined as free form enums and cpp macros. YYSTYPE diff --git a/tests/headers.at b/tests/headers.at index 02d54632..a348d65b 100644 --- a/tests/headers.at +++ b/tests/headers.at @@ -58,6 +58,8 @@ AS_MKDIR_P([$dirname]) AT_DATA_GRAMMAR([$1.y], [%{ #include <$1.h> +void yyerror (const char *); +int yylex (void); %} %% dummy:; -- 2.45.2