[src/trunk]: src/usr.bin/make make(1): split local variable into two

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/277ae44108a4
branches:  trunk
changeset: 1012285:277ae44108a4
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Jul 26 19:11:06 2020 +0000

description:
make(1): split local variable into two

Reusing a const char * parameter to store a char * and later free that
string was not a good idea. It made the pretty long code of Var_Parse
more difficult to understand.

diffstat:

 usr.bin/make/var.c |  49 +++++++++++++++++++++++++------------------------
 1 files changed, 25 insertions(+), 24 deletions(-)

diffs (141 lines):

diff -r 0199e1122a09 -r 277ae44108a4 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sun Jul 26 18:53:50 2020 +0000
+++ b/usr.bin/make/var.c        Sun Jul 26 19:11:06 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.324 2020/07/26 18:47:02 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.325 2020/07/26 19:11:06 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.324 2020/07/26 18:47:02 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.325 2020/07/26 19:11:06 rillig Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)var.c      8.3 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: var.c,v 1.324 2020/07/26 18:47:02 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.325 2020/07/26 19:11:06 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -3452,7 +3452,7 @@
            return (flags & VARE_UNDEFERR) ? var_Error : varNoError;
        } else {
            haveModifier = FALSE;
-           tstr = &str[1];
+           tstr = str + 1;
            endc = str[1];
        }
     } else {
@@ -3501,10 +3501,11 @@
            Buf_Destroy(&buf, TRUE);
            return var_Error;
        }
-       str = Buf_GetAll(&buf, &vlen);
+
+       char *varname = Buf_GetAll(&buf, &vlen);
 
        /*
-        * At this point, str points into newly allocated memory from
+        * At this point, varname points into newly allocated memory from
         * buf, containing only the name of the variable.
         *
         * start and tstr point into the const string that was pointed
@@ -3514,23 +3515,23 @@
         * will be '\0', ':', PRCLOSE, or BRCLOSE.
         */
 
-       v = VarFind(str, ctxt, FIND_ENV | FIND_GLOBAL | FIND_CMD);
+       v = VarFind(varname, ctxt, FIND_ENV | FIND_GLOBAL | FIND_CMD);
        /*
         * Check also for bogus D and F forms of local variables since we're
         * in a local context and the name is the right length.
         */
-       if ((v == NULL) && (ctxt != VAR_CMD) && (ctxt != VAR_GLOBAL) &&
-               (vlen == 2) && (str[1] == 'F' || str[1] == 'D') &&
-               strchr("@%?*!<>", str[0]) != NULL) {
+       if (v == NULL && ctxt != VAR_CMD && ctxt != VAR_GLOBAL &&
+               vlen == 2 && (varname[1] == 'F' || varname[1] == 'D') &&
+               strchr("@%?*!<>", varname[0]) != NULL) {
            /*
             * Well, it's local -- go look for it.
             */
-           name[0] = *str;
+           name[0] = varname[0];
            name[1] = '\0';
            v = VarFind(name, ctxt, 0);
 
            if (v != NULL) {
-               if (str[1] == 'D') {
+               if (varname[1] == 'D') {
                    extramodifiers = "H:";
                } else { /* F */
                    extramodifiers = "T:";
@@ -3539,9 +3540,9 @@
        }
 
        if (v == NULL) {
-           if (((vlen == 1) ||
-                (((vlen == 2) && (str[1] == 'F' || str[1] == 'D')))) &&
-               ((ctxt == VAR_CMD) || (ctxt == VAR_GLOBAL)))
+           if ((vlen == 1 ||
+                ((vlen == 2 && (varname[1] == 'F' || varname[1] == 'D')))) &&
+               (ctxt == VAR_CMD || ctxt == VAR_GLOBAL))
            {
                /*
                 * If substituting a local variable in a non-local context,
@@ -3552,7 +3553,7 @@
                 * specially as they are the only four that will be set
                 * when dynamic sources are expanded.
                 */
-               switch (*str) {
+               switch (varname[0]) {
                case '@':
                case '%':
                case '*':
@@ -3560,15 +3561,15 @@
                    dynamic = TRUE;
                    break;
                }
-           } else if (vlen > 2 && *str == '.' &&
-                      isupper((unsigned char) str[1]) &&
+           } else if (vlen > 2 && varname[0] == '.' &&
+                      isupper((unsigned char) varname[1]) &&
                       (ctxt == VAR_CMD || ctxt == VAR_GLOBAL))
            {
                int len = vlen - 1;
-               if ((strncmp(str, ".TARGET", len) == 0) ||
-                   (strncmp(str, ".ARCHIVE", len) == 0) ||
-                   (strncmp(str, ".PREFIX", len) == 0) ||
-                   (strncmp(str, ".MEMBER", len) == 0))
+               if ((strncmp(varname, ".TARGET", len) == 0) ||
+                   (strncmp(varname, ".ARCHIVE", len) == 0) ||
+                   (strncmp(varname, ".PREFIX", len) == 0) ||
+                   (strncmp(varname, ".MEMBER", len) == 0))
                {
                    dynamic = TRUE;
                }
@@ -3595,7 +3596,7 @@
                 * so kludge up a Var structure for the modifications
                 */
                v = bmake_malloc(sizeof(Var));
-               v->name = UNCONST(str);
+               v->name = varname;
                Buf_Init(&v->val, 1);
                v->flags = VAR_JUNK;
                Buf_Destroy(&buf, FALSE);
@@ -3668,7 +3669,7 @@
        /*
         * Perform any free'ing needed and set *freePtr to NULL so the caller
         * doesn't try to free a static pointer.
-        * If VAR_KEEP is also set then we want to keep str as is.
+        * If VAR_KEEP is also set then we want to keep str(?) as is.
         */
        if (!(v->flags & VAR_KEEP)) {
            if (*freePtr) {