constify strings with logging helper funcs

Signed-off-by: Mike Frysinger <vapier@gmail.com>

hocdecl.h

@@ -9,10 +9,10 @@
 */
 
 extern int yylex( void) ;
-extern void execerror( char *, char *) ;
+extern void execerror(const char *, const char *);
 extern void fpecatch( int ) ;
-extern void yyerror( char *) ;
-extern void warning( char *, char *) ;
+extern void yyerror(const char *);
+extern void warning(const char *, const char *);
 
 /*
 **      function in INIT.C
@@ -30,7 +30,7 @@ extern  double Exp(double x);
 extern  double Pow(double x,double y);
 extern  double integer(double x);
 extern  double Sqrt(double x);
-extern  double errcheck( double, char *) ;
+extern  double errcheck(double, const char *);
 extern  double f2c(double d);
 extern  double c2f(double d);
 extern  double in2mm(double d);

math.c

@@ -42,7 +42,7 @@ double Sqrt( double x)
    return errcheck( sqrt(x), "sqrt") ;
 }
 
-double errcheck( double d, char *s)
+double errcheck(double d, const char *s)
 {
     if (errno == EDOM) {
         errno = 0 ;

pcalc.y

@@ -252,7 +252,7 @@ int     main(int argc, char *argv[])
 /*-------------------------------------------------------------------------
 **  EXECERROR
 */
-void    execerror( char *s, char *t)
+void execerror(const char *s, const char *t)
 {
     warning( s, t) ;
     longjmp( begin, 0) ;
@@ -269,17 +269,17 @@ void    fpecatch( int aa)
 /*-------------------------------------------------------------------------
 **  YYERROR
 */
-void    yyerror( char *s)                      /* called by yacc syntax error */
+void yyerror(const char *s)                      /* called by yacc syntax error */
 {
-    warning( s, (char *) 0) ;
+    warning(s, NULL);
     exit(0);
 }
 
 /*-------------------------------------------------------------------------
 **  WARNING
 */
 
-void    warning( char *s, char *t)
+void warning(const char *s, const char *t)
 {
     fprintf( stderr, "%s: %s", progname, s) ;