Changes to m4/src/Attic/eval.c,v [branch-1_4]

[Eric Blake]

CVSROOT:        /sources/m4
Module name:    m4
Branch:         branch-1_4
Changes by:     Eric Blake <ericb>      07/01/09 16:12:43

Index: src/eval.c
===================================================================
RCS file: /sources/m4/m4/src/Attic/eval.c,v
retrieving revision 1.1.1.1.2.8
retrieving revision 1.1.1.1.2.9
diff -u -b -r1.1.1.1.2.8 -r1.1.1.1.2.9
--- src/eval.c  6 Jan 2007 19:56:11 -0000       1.1.1.1.2.8
+++ src/eval.c  9 Jan 2007 16:12:43 -0000       1.1.1.1.2.9
@@ -34,7 +34,7 @@
     PLUS, MINUS,
     EXPONENT,
     TIMES, DIVIDE, MODULO,
-    EQ, NOTEQ, GT, GTEQ, LS, LSEQ,
+    ASSIGN, EQ, NOTEQ, GT, GTEQ, LS, LSEQ,
     LSHIFT, RSHIFT,
     LNOT, LAND, LOR,
     NOT, AND, OR, XOR,
@@ -215,7 +215,7 @@
          eval_text++;
          return EQ;
        }
-      return BADOP;
+      return ASSIGN;
     case '!':
       if (*eval_text == '=')
        {
@@ -517,7 +517,10 @@
   if ((er = cmp_term (et, v1)) != NO_ERROR)
     return er;
 
-  while ((op = eval_lex (&v2)) == EQ || op == NOTEQ)
+  /* In the 1.4.x series, we maintain the traditional behavior that
+     '=' is a synonym for '=='; however, this is contrary to POSIX and
+     we hope to convert '=' to mean assignment in 2.0.  */
+  while ((op = eval_lex (&v2)) == EQ || op == NOTEQ || op == ASSIGN)
     {
       et = eval_lex (&v2);
       if (et == ERROR)
@@ -525,6 +528,13 @@
 
       if ((er = cmp_term (et, &v2)) != NO_ERROR)
        return er;
+
+      if (op == ASSIGN)
+      {
+       M4ERROR ((warning_status, 0, "\
+Warning: recommend ==, not =, for equality operator"));
+       op = EQ;
+      }
       *v1 = (op == EQ) == (*v1 == v2);
     }
   if (op == ERROR)