[src/trunk]: src/usr.bin/make make(1): extract ParseVarnameShort from Var_Parse

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

details:   https://anonhg.NetBSD.org/src/rev/7a87090dfe8e
branches:  trunk
changeset: 956488:7a87090dfe8e
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Oct 31 14:12:01 2020 +0000

description:
make(1): extract ParseVarnameShort from Var_Parse

With its more than 200 lines, the latter has too much code to be read
easily.

diffstat:

 usr.bin/make/var.c |  84 +++++++++++++++++++++++++++++++++--------------------
 1 files changed, 52 insertions(+), 32 deletions(-)

diffs (112 lines):

diff -r 51abc3930a07 -r 7a87090dfe8e usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sat Oct 31 13:58:22 2020 +0000
+++ b/usr.bin/make/var.c        Sat Oct 31 14:12:01 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.621 2020/10/31 12:59:28 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.622 2020/10/31 14:12:01 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 1.621 2020/10/31 12:59:28 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.622 2020/10/31 14:12:01 rillig Exp $");
 
 #define VAR_DEBUG1(fmt, arg1) DEBUG1(VAR, fmt, arg1)
 #define VAR_DEBUG2(fmt, arg1, arg2) DEBUG2(VAR, fmt, arg1, arg2)
@@ -3462,6 +3462,51 @@
     return FALSE;
 }
 
+/* Parse a single-character variable name such as $V or $@.
+ * Return whether to continue parsing. */
+static Boolean
+ParseVarnameShort(char const startc, const char **const pp, GNode *const ctxt,
+                 VarEvalFlags const eflags,
+                 const char **const out_FALSE_val,
+                 VarParseResult *const out_FALSE_res,
+                 Var **out_TRUE_var)
+{
+    char name[2];
+    Var *v;
+
+    /*
+     * If it's not bounded by braces of some sort, life is much simpler.
+     * We just need to check for the first character and return the
+     * value if it exists.
+     */
+
+    if (!ValidShortVarname(startc, *pp)) {
+       (*pp)++;
+       *out_FALSE_val = var_Error;
+       *out_FALSE_res = VPR_PARSE_MSG;
+       return FALSE;
+    }
+
+    name[0] = startc;
+    name[1] = '\0';
+    v = VarFind(name, ctxt, TRUE);
+    if (v == NULL) {
+       *pp += 2;
+
+       *out_FALSE_val = UndefinedShortVarValue(startc, ctxt, eflags);
+       if (DEBUG(LINT) && *out_FALSE_val == var_Error) {
+           Parse_Error(PARSE_FATAL, "Variable \"%s\" is undefined", name);
+           *out_FALSE_res = VPR_UNDEF_MSG;
+           return FALSE;
+       }
+       *out_FALSE_res = eflags & VARE_UNDEFERR ? VPR_UNDEF_SILENT : VPR_OK;
+       return FALSE;
+    }
+
+    *out_TRUE_var = v;
+    return TRUE;
+}
+
 /*-
  *-----------------------------------------------------------------------
  * Var_Parse --
@@ -3544,36 +3589,11 @@
 
     startc = start[1];
     if (startc != '(' && startc != '{') {
-       char name[2];
-
-       /*
-        * If it's not bounded by braces of some sort, life is much simpler.
-        * We just need to check for the first character and return the
-        * value if it exists.
-        */
-
-       if (!ValidShortVarname(startc, start)) {
-           (*pp)++;
-           *out_val = var_Error;
-           return VPR_PARSE_MSG;
-       }
-
-       name[0] = startc;
-       name[1] = '\0';
-       v = VarFind(name, ctxt, TRUE);
-       if (v == NULL) {
-           *pp += 2;
-
-           *out_val = UndefinedShortVarValue(startc, ctxt, eflags);
-           if (DEBUG(LINT) && *out_val == var_Error) {
-               Parse_Error(PARSE_FATAL, "Variable \"%s\" is undefined", name);
-               return VPR_UNDEF_MSG;
-           }
-           return eflags & VARE_UNDEFERR ? VPR_UNDEF_SILENT : VPR_OK;
-       } else {
-           haveModifier = FALSE;
-           p = start + 1;
-       }
+        VarParseResult res;
+       if (!ParseVarnameShort(startc, pp, ctxt, eflags, out_val, &res, &v))
+           return res;
+       haveModifier = FALSE;
+       p = start + 1;
     } else {
        size_t namelen;
        char *varname;