[src/trunk]: src/usr.bin/make make(1): rewrite VarIsDynamic to VarnameIsDynamic

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

details:   https://anonhg.NetBSD.org/src/rev/2338888a3e01
branches:  trunk
changeset: 941848:2338888a3e01
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Oct 31 15:23:52 2020 +0000

description:
make(1): rewrite VarIsDynamic to VarnameIsDynamic

The condition for the context is the same for both short and long names,
therefore move that condition to the only caller.

Clean up the comment and move its parts to the appropriate places.  The
"with the dollar sign escaped" part had been wrong already in 1993, and
it didn't get better over time.

diffstat:

 usr.bin/make/var.c |  43 +++++++++++++++++--------------------------
 1 files changed, 17 insertions(+), 26 deletions(-)

diffs (87 lines):

diff -r 0ddde82181fc -r 2338888a3e01 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sat Oct 31 15:18:09 2020 +0000
+++ b/usr.bin/make/var.c        Sat Oct 31 15:23:52 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.625 2020/10/31 14:55:33 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.626 2020/10/31 15:23:52 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -129,7 +129,7 @@
 #include    "metachar.h"
 
 /*     "@(#)var.c      8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: var.c,v 1.625 2020/10/31 14:55:33 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.626 2020/10/31 15:23:52 rillig Exp $");
 
 #define VAR_DEBUG1(fmt, arg1) DEBUG1(VAR, fmt, arg1)
 #define VAR_DEBUG2(fmt, arg1, arg2) DEBUG2(VAR, fmt, arg1, arg2)
@@ -3326,23 +3326,13 @@
     return var_Error;
 }
 
+/* Only four of the local variables are treated specially as they are the
+ * only four that will be set when dynamic sources are expanded. */
 static Boolean
-VarIsDynamic(GNode *ctxt, const char *varname, size_t namelen)
+VarnameIsDynamic(const char *name, size_t len)
 {
-    if ((namelen == 1 ||
-        (namelen == 2 && (varname[1] == 'F' || varname[1] == 'D'))) &&
-       (ctxt == VAR_CMDLINE || ctxt == VAR_GLOBAL))
-    {
-       /*
-        * If substituting a local variable in a non-local context,
-        * assume it's for dynamic source stuff. We have to handle
-        * this specially and return the longhand for the variable
-        * with the dollar sign escaped so it makes it back to the
-        * caller. Only four of the local variables are treated
-        * specially as they are the only four that will be set
-        * when dynamic sources are expanded.
-        */
-       switch (varname[0]) {
+    if (len == 1 || (len == 2 && (name[1] == 'F' || name[1] == 'D'))) {
+       switch (name[0]) {
        case '@':
        case '%':
        case '*':
@@ -3352,13 +3342,11 @@
        return FALSE;
     }
 
-    if ((namelen == 7 || namelen == 8) && varname[0] == '.' &&
-       ch_isupper(varname[1]) && (ctxt == VAR_CMDLINE || ctxt == VAR_GLOBAL))
-    {
-       return strcmp(varname, ".TARGET") == 0 ||
-              strcmp(varname, ".ARCHIVE") == 0 ||
-              strcmp(varname, ".PREFIX") == 0 ||
-              strcmp(varname, ".MEMBER") == 0;
+    if ((len == 7 || len == 8) && name[0] == '.' && ch_isupper(name[1])) {
+       return strcmp(name, ".TARGET") == 0 ||
+              strcmp(name, ".ARCHIVE") == 0 ||
+              strcmp(name, ".PREFIX") == 0 ||
+              strcmp(name, ".MEMBER") == 0;
     }
 
     return FALSE;
@@ -3587,7 +3575,10 @@
     }
 
     if (v == NULL) {
-       dynamic = VarIsDynamic(ctxt, varname, namelen);
+       /* Defer expansion of dynamic variables if they appear in non-local
+        * context since they are not defined there. */
+       dynamic = VarnameIsDynamic(varname, namelen) &&
+                 (ctxt == VAR_CMDLINE || ctxt == VAR_GLOBAL);
 
        if (!haveModifier) {
            p++;                /* skip endc */
@@ -3714,7 +3705,7 @@
     char eflags_str[VarEvalFlags_ToStringSize];
     VarExprFlags exprFlags = 0;
 
-    VAR_DEBUG3("%s: %s with %s\n", __func__, start,
+    VAR_DEBUG2("Var_Parse: %s with %s\n", start,
               Enum_FlagsToString(eflags_str, sizeof eflags_str, eflags,
                                  VarEvalFlags_ToStringSpecs));