[src/trunk]: src/usr.bin/make make(1): clean up and update module comment in ...

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

details:   https://anonhg.NetBSD.org/src/rev/a6b525c4709c
branches:  trunk
changeset: 977625:a6b525c4709c
user:      rillig <rillig%NetBSD.org@localhost>
date:      Fri Oct 30 06:44:57 2020 +0000

description:
make(1): clean up and update module comment in var.c

diffstat:

 usr.bin/make/var.c |  56 ++++++++++++++++++++++++++++++-----------------------
 1 files changed, 32 insertions(+), 24 deletions(-)

diffs (89 lines):

diff -r 8e53c87d8a8b -r a6b525c4709c usr.bin/make/var.c
--- a/usr.bin/make/var.c        Fri Oct 30 06:44:37 2020 +0000
+++ b/usr.bin/make/var.c        Fri Oct 30 06:44:57 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.591 2020/10/27 07:16:27 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.592 2020/10/30 06:44:57 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -68,40 +68,48 @@
  * SUCH DAMAGE.
  */
 
-/*-
- * var.c --
- *     Variable-handling functions
+/*
+ * Handling of variables and the expressions formed from them.
+ *
+ * Variables are set using lines of the form VAR=value.  Both the variable
+ * name and the value can contain references to other variables, by using
+ * expressions like ${VAR}, ${VAR:Modifiers}, ${${VARNAME}} or ${VAR:${MODS}}.
  *
  * Interface:
- *     Var_Set         Set the value of a variable in the given
- *                     context. The variable is created if it doesn't
- *                     yet exist.
+ *     Var_Init        Initialize this module.
+ *
+ *     Var_End         Clean up the module.
  *
- *     Var_Append      Append more characters to an existing variable
- *                     in the given context. The variable needn't
- *                     exist already -- it will be created if it doesn't.
- *                     A space is placed between the old value and the
- *                     new one.
+ *     Var_Set         Set the value of the variable, creating it if
+ *                     necessary.
+ *
+ *     Var_Append      Append more characters to the variable, creating it if
+ *                     necessary. A space is placed between the old value and
+ *                     the new one.
  *
  *     Var_Exists      See if a variable exists.
  *
- *     Var_Value       Return the unexpanded value of a variable in a
- *                     context or NULL if the variable is undefined.
+ *     Var_Value       Return the unexpanded value of a variable, or NULL if
+ *                     the variable is undefined.
  *
- *     Var_Subst       Substitute either a single variable or all
- *                     variables in a string, using the given context.
+ *     Var_Subst       Substitute all variable expressions in a string.
+ *
+ *     Var_Parse       Parse a variable expression such as ${VAR:Mpattern}.
  *
- *     Var_Parse       Parse a variable expansion from a string and
- *                     return the result and the number of characters
- *                     consumed.
+ *     Var_Delete      Delete a variable.
+ *
+ *     Var_ExportVars  Export some or even all variables to the environment
+ *                     of this process and its child processes.
  *
- *     Var_Delete      Delete a variable in a context.
+ *     Var_Export      Export the variable to the environment of this process
+ *                     and its child processes.
  *
- *     Var_Init        Initialize this module.
+ *     Var_UnExport    Don't export the variable anymore.
  *
  * Debugging:
- *     Var_Dump        Print out all variables defined in the given
- *                     context.
+ *     Var_Stats       Print out hashing statistics if in -dh mode.
+ *
+ *     Var_Dump        Print out all variables defined in the given context.
  *
  * XXX: There's a lot of duplication in these functions.
  */
@@ -121,7 +129,7 @@
 #include    "metachar.h"
 
 /*     "@(#)var.c      8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: var.c,v 1.591 2020/10/27 07:16:27 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.592 2020/10/30 06:44:57 rillig Exp $");
 
 #define VAR_DEBUG1(fmt, arg1) DEBUG1(VAR, fmt, arg1)
 #define VAR_DEBUG2(fmt, arg1, arg2) DEBUG2(VAR, fmt, arg1, arg2)