[src/trunk]: src/usr.bin/make make(1): prevent appending to read-only variables

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

details:   https://anonhg.NetBSD.org/src/rev/8c63c71e0bd7
branches:  trunk
changeset: 1015687:8c63c71e0bd7
user:      rillig <rillig%NetBSD.org@localhost>
date:      Fri Oct 30 16:09:56 2020 +0000

description:
make(1): prevent appending to read-only variables

diffstat:

 usr.bin/make/unit-tests/varname-dot-shell.exp |  18 +++++++++---------
 usr.bin/make/unit-tests/varname-dot-shell.mk  |   8 ++++----
 usr.bin/make/var.c                            |   6 ++++--
 3 files changed, 17 insertions(+), 15 deletions(-)

diffs (89 lines):

diff -r 754ddb0adacf -r 8c63c71e0bd7 usr.bin/make/unit-tests/varname-dot-shell.exp
--- a/usr.bin/make/unit-tests/varname-dot-shell.exp     Fri Oct 30 16:08:44 2020 +0000
+++ b/usr.bin/make/unit-tests/varname-dot-shell.exp     Fri Oct 30 16:09:56 2020 +0000
@@ -12,19 +12,19 @@
 lhs = "(details omitted)", rhs = "(details omitted)", op = !=
 ParseReadLine (19): '.MAKEFLAGS: .SHELL+=appended'
 ParseDoDependency(.MAKEFLAGS: .SHELL+=appended)
-Command:.SHELL = (details omitted) appended
-CondParser_Eval: ${.SHELL} != "${ORIG_SHELL} appended"
-Var_Parse: ${.SHELL} != "${ORIG_SHELL} appended" with VARE_UNDEFERR|VARE_WANTRES
-Var_Parse: ${ORIG_SHELL} appended" with VARE_WANTRES
-lhs = "/bin/sh appended", rhs = "/bin/sh appended", op = !=
+Ignoring append to .SHELL since it is read-only
+CondParser_Eval: ${.SHELL} != ${ORIG_SHELL}
+Var_Parse: ${.SHELL} != ${ORIG_SHELL} with VARE_UNDEFERR|VARE_WANTRES
+Var_Parse: ${ORIG_SHELL} with VARE_UNDEFERR|VARE_WANTRES
+lhs = "(details omitted)", rhs = "(details omitted)", op = !=
 ParseReadLine (27): '.undef .SHELL'
 Global:delete .SHELL
 ParseReadLine (28): '.SHELL=           newly overwritten'
 Global:.SHELL = newly overwritten
-CondParser_Eval: ${.SHELL} != "${ORIG_SHELL} appended"
-Var_Parse: ${.SHELL} != "${ORIG_SHELL} appended" with VARE_UNDEFERR|VARE_WANTRES
-Var_Parse: ${ORIG_SHELL} appended" with VARE_WANTRES
-lhs = "/bin/sh appended", rhs = "/bin/sh appended", op = !=
+CondParser_Eval: ${.SHELL} != ${ORIG_SHELL}
+Var_Parse: ${.SHELL} != ${ORIG_SHELL} with VARE_UNDEFERR|VARE_WANTRES
+Var_Parse: ${ORIG_SHELL} with VARE_UNDEFERR|VARE_WANTRES
+lhs = "(details omitted)", rhs = "(details omitted)", op = !=
 ParseReadLine (33): '.MAKEFLAGS: -d0'
 ParseDoDependency(.MAKEFLAGS: -d0)
 Global:.MAKEFLAGS =  -r -k -d cpv -d
diff -r 754ddb0adacf -r 8c63c71e0bd7 usr.bin/make/unit-tests/varname-dot-shell.mk
--- a/usr.bin/make/unit-tests/varname-dot-shell.mk      Fri Oct 30 16:08:44 2020 +0000
+++ b/usr.bin/make/unit-tests/varname-dot-shell.mk      Fri Oct 30 16:09:56 2020 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: varname-dot-shell.mk,v 1.5 2020/10/30 15:09:13 rillig Exp $
+# $NetBSD: varname-dot-shell.mk,v 1.6 2020/10/30 16:09:56 rillig Exp $
 #
 # Tests for the special .SHELL variable, which contains the shell used for
 # running the commands.
@@ -15,9 +15,9 @@
 .endif
 
 # Trying to append to the variable.
-# Until 2020-10-30 this was possible.
+# Since 2020-10-30 this is prevented.
 .MAKEFLAGS: .SHELL+=appended
-.if ${.SHELL} != "${ORIG_SHELL} appended"
+.if ${.SHELL} != ${ORIG_SHELL}
 .  error
 .endif
 
@@ -26,7 +26,7 @@
 # but in the command-line context.
 .undef .SHELL
 .SHELL=                newly overwritten
-.if ${.SHELL} != "${ORIG_SHELL} appended"
+.if ${.SHELL} != ${ORIG_SHELL}
 .  error
 .endif
 
diff -r 754ddb0adacf -r 8c63c71e0bd7 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Fri Oct 30 16:08:44 2020 +0000
+++ b/usr.bin/make/var.c        Fri Oct 30 16:09:56 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.599 2020/10/30 15:39:17 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.600 2020/10/30 16:09:56 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 1.599 2020/10/30 15:39:17 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.600 2020/10/30 16:09:56 rillig Exp $");
 
 #define VAR_DEBUG1(fmt, arg1) DEBUG1(VAR, fmt, arg1)
 #define VAR_DEBUG2(fmt, arg1, arg2) DEBUG2(VAR, fmt, arg1, arg2)
@@ -945,6 +945,8 @@
 
     if (v == NULL) {
        Var_Set(name, val, ctxt);
+    } else if (v->flags & VAR_READONLY) {
+        VAR_DEBUG1("Ignoring append to %s since it is read-only\n", name);
     } else if (ctxt == VAR_CMDLINE || !(v->flags & VAR_FROM_CMD)) {
        Buf_AddByte(&v->val, ' ');
        Buf_AddStr(&v->val, val);