Bison: enable all the warnings and fix them

First, fix 5547d36: the definition of
YFLAGS was not passed into the Makefile: AC_SUBST does not suffice, we
need PHP_SUBST_OLD.  While at it, allow to pass variable and value at
the same time.

Then pass -Wall to bison, rather than only -Wempty-rules.

Use %precedence where associativity is useless.

Remove useless %precedence.
GH-5138

Author: akimd

Zend/zend_ini_parser.y

@@ -309,7 +309,7 @@ static void zval_ini_dtor(zval *zv)
 %token END_OF_LINE
 %token '=' ':' ',' '.' '"' '\'' '^' '+' '-' '/' '*' '%' '$' '~' '<' '>' '?' '@' '{' '}'
 %left '|' '&' '^'
-%right '~' '!'
+%precedence '~' '!'
 
 %destructor { zval_ini_dtor(&$$); } TC_RAW TC_CONSTANT TC_NUMBER TC_STRING TC_WHITESPACE TC_LABEL TC_OFFSET TC_VARNAME BOOL_TRUE BOOL_FALSE NULL_NULL cfg_var_ref constant_literal constant_string encapsed_list expr option_offset section_string_or_value string_or_value var_string_list var_string_list_section
 

Zend/zend_language_parser.y

@@ -79,7 +79,7 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %precedence T_INSTANCEOF
 %precedence '~' T_INT_CAST T_DOUBLE_CAST T_STRING_CAST T_ARRAY_CAST T_OBJECT_CAST T_BOOL_CAST T_UNSET_CAST '@'
 %right T_POW
-%precedence T_NEW T_CLONE
+%precedence T_CLONE
 
 /* Resolve danging else conflict */
 %precedence T_NOELSE

build/php.m4

@@ -81,22 +81,22 @@ AC_DEFUN([PHP_DEFINE],[
 dnl
 dnl PHP_SUBST(varname)
 dnl
-dnl Adds variable with it's value into Makefile, e.g.:
+dnl Adds variable with its value into Makefile, e.g.:
 dnl CC = gcc
 dnl
 AC_DEFUN([PHP_SUBST],[
   PHP_VAR_SUBST="$PHP_VAR_SUBST $1"
 ])
 
 dnl
-dnl PHP_SUBST_OLD(varname)
+dnl PHP_SUBST_OLD(varname, [VALUE])
 dnl
 dnl Same as PHP_SUBST() but also substitutes all @VARNAME@ instances in every
 dnl file passed to AC_OUTPUT.
 dnl
 AC_DEFUN([PHP_SUBST_OLD],[
-  PHP_SUBST($1)
-  AC_SUBST($1)
+  AC_SUBST($@)
+  PHP_SUBST([$1])
 ])
 
 dnl
@@ -1815,7 +1815,7 @@ AC_DEFUN([PHP_PROG_BISON], [
     done
 
     if test "$php_bison_check" != "invalid"; then
-      AC_SUBST([YFLAGS], [-Wempty-rule])
+      PHP_SUBST_OLD([YFLAGS], [-Wall])
       AC_MSG_RESULT([$php_bison_version (ok)])
     else
       AC_MSG_RESULT([$php_bison_version])