[src/trunk]: src/usr.bin/make make(1): document and reorder ApplyModifiersState

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

details:   https://anonhg.NetBSD.org/src/rev/4ae1836efb7c
branches:  trunk
changeset: 936501:4ae1836efb7c
user:      rillig <rillig%NetBSD.org@localhost>
date:      Mon Jul 27 23:56:15 2020 +0000

description:
make(1): document and reorder ApplyModifiersState

diffstat:

 usr.bin/make/var.c |  24 +++++++++++++++---------
 1 files changed, 15 insertions(+), 9 deletions(-)

diffs (72 lines):

diff -r 65efd56737d8 -r 4ae1836efb7c usr.bin/make/var.c
--- a/usr.bin/make/var.c        Mon Jul 27 23:37:37 2020 +0000
+++ b/usr.bin/make/var.c        Mon Jul 27 23:56:15 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.349 2020/07/27 23:37:37 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.350 2020/07/27 23:56:15 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.349 2020/07/27 23:37:37 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.350 2020/07/27 23:56:15 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 1.349 2020/07/27 23:37:37 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.350 2020/07/27 23:56:15 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -2036,16 +2036,24 @@
     return bmake_strdup(buf);
 }
 
+/* The ApplyModifier functions all work in the same way.
+ * They parse the modifier (often until the next colon) and store the
+ * updated position for the parser into st->next.
+ * They take the st->val and generate st->newVal from it.
+ * On success, they set st->termc to *st->next, redundantly.
+ * On failure, many of them update st->missing_delim.
+ */
 typedef struct {
-    /* const parameters */
     int startc;                        /* '\0' or '{' or '(' */
     int endc;
     Var *v;
     GNode *ctxt;
     VarEvalFlags eflags;
 
-    /* read-write */
-    char *val;
+    char *val;                 /* The value of the expression before the
+                                * modifier is applied */
+    char *newVal;              /* The new value after applying the modifier
+                                * to the expression */
     const char *next;          /* The position where parsing continues
                                 * after the current modifier. */
     char termc;                        /* Character which terminated scan */
@@ -2058,8 +2066,6 @@
                                 * usual behaviour of treating it as
                                 * several space-separated words). */
 
-    /* result */
-    char *newVal;              /* New value to return */
 } ApplyModifiersState;
 
 /* we now have some modifiers with long names */
@@ -3070,7 +3076,7 @@
 {
     ApplyModifiersState st = {
        startc, endc, v, ctxt, eflags,
-       val, tstr, '\0', '\0', ' ', FALSE, NULL
+       val, NULL, NULL, '\0', '\0', ' ', FALSE
     };
 
     const char *p = tstr;