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Re: make cleaning the environment for children
On Sun, 15 Nov 2009 08:51:26 +0000, David Laight writes:
>Adding ".unexport" and ".unexportall" might be safest.
Agreed. Here's an updated patch which adds
.unexport
.unexport-env
Hopefully make.1 explains clearly. Here's the rendered version:
.unexport variable ...
The opposite of `.export'. The specified variable will be
removed from .MAKE.EXPORTED. If no variable list is provided,
all globals are unexported, and .MAKE.EXPORTED deleted.
.unexport-env variable ...
Clear the environment inherited from the parent, and re-export
variable. If no variable is provided, all previously exported
globals are re-exported. This operation will cause a memory leak
of the original environment, so should be used sparingly. Test-
ing for .MAKE.LEVEL being 0, would make sense. Also note that
any variables which originated in the parent environment should
be explicitly preserved if desired. For example:
.if ${.MAKE.LEVEL} == 0
PATH := ${PATH}
.unexport-env PATH
.endif
Would result in an environment containing only `PATH', which is
the minimal useful environment. Actually `.MAKE.LEVEL' will also
be pushed into the new environment.
--sjg
Index: make.1
===================================================================
RCS file: /cvsroot/src/usr.bin/make/make.1,v
retrieving revision 1.163
diff -u -p -r1.163 make.1
--- make.1 2 Oct 2009 07:43:15 -0000 1.163
+++ make.1 16 Nov 2009 04:00:25 -0000
@@ -29,7 +29,7 @@
.\"
.\" from: @(#)make.1 8.4 (Berkeley) 3/19/94
.\"
-.Dd October 1, 2009
+.Dd November 15, 2009
.Dt MAKE 1
.Os
.Sh NAME
@@ -1282,17 +1282,54 @@ Conditional expressions are also precede
character of a line.
The possible conditionals are as follows:
.Bl -tag -width Ds
-.It Ic .export Ar variable
+.It Ic .export Ar variable ...
Export the specified global variable.
-If no variable is provided, all globals are exported
+If no variable list is provided, all globals are exported
except for internal variables (those that start with
.Ql \&. ) .
This is not affected by the
.Fl X
flag, so should be used with caution.
+.Pp
Appending a variable name to
.Va .MAKE.EXPORTED
is equivalent to exporting a variable.
+.It Ic .unexport Ar variable ...
+The opposite of
+.Ql .export .
+The specified
+.Va variable
+will be removed from
+.Va .MAKE.EXPORTED .
+If no variable list is provided, all globals are unexported,
+and
+.Va .MAKE.EXPORTED
+deleted.
+.It Ic .unexport-env Ar variable ...
+Clear the environment inherited from the parent,
+and re-export
+.Va variable .
+If no variable is provided, all previously exported globals are re-exported.
+This operation will cause a memory leak of the original environment,
+so should be used sparingly. Testing for
+.Va .MAKE.LEVEL
+being 0, would make sense.
+Also note that any variables which originated in the parent environment
+should be explicitly preserved if desired.
+For example:
+.Bd -literal -offset indent
+.Li .if ${.MAKE.LEVEL} == 0
+PATH := ${PATH}
+.Li .unexport-env PATH
+.Li .endif
+.Pp
+.Ed
+Would result in an environment containing only
+.Ql Ev PATH ,
+which is the minimal useful environment.
+Actually
+.Ql Ev .MAKE.LEVEL
+will also be pushed into the new environment.
.It Ic .undef Ar variable
Un-define the specified global variable.
Only global variables may be un-defined.
Index: nonints.h
===================================================================
RCS file: /cvsroot/src/usr.bin/make/nonints.h,v
retrieving revision 1.56
diff -u -p -r1.56 nonints.h
--- nonints.h 28 Jan 2009 21:38:13 -0000 1.56
+++ nonints.h 16 Nov 2009 04:00:25 -0000
@@ -193,3 +193,4 @@ void Var_End(void);
void Var_Dump(GNode *);
void Var_ExportVars(void);
void Var_Export(char *, int);
+void Var_UnExport(char *);
Index: parse.c
===================================================================
RCS file: /cvsroot/src/usr.bin/make/parse.c,v
retrieving revision 1.158
diff -u -p -r1.158 parse.c
--- parse.c 7 Oct 2009 16:40:30 -0000 1.158
+++ parse.c 16 Nov 2009 04:00:26 -0000
@@ -2506,6 +2506,9 @@ Parse_File(const char *name, int fd)
continue;
Var_Export(cp, 1);
continue;
+ } else if (strncmp(cp, "unexport", 8) == 0) {
+ Var_UnExport(cp);
+ continue;
}
}
Index: var.c
===================================================================
RCS file: /cvsroot/src/usr.bin/make/var.c,v
retrieving revision 1.154
diff -u -p -r1.154 var.c
--- var.c 8 Sep 2009 17:29:20 -0000 1.154
+++ var.c 16 Nov 2009 04:00:26 -0000
@@ -527,6 +527,9 @@ Var_Delete(const char *name, GNode *ctxt
if ((v->flags & VAR_EXPORTED)) {
unsetenv(v->name);
}
+ if (strcmp(MAKE_EXPORTED, v->name) == 0) {
+ var_exportedVars = VAR_EXPORTED_NONE;
+ }
if (v->name != ln->name)
free(v->name);
Hash_DeleteEntry(&ctxt->context, ln);
@@ -572,9 +575,15 @@ Var_Export1(const char *name, int parent
if (v == NULL) {
return 0;
}
- if (!parent &&
- (v->flags & (VAR_EXPORTED|VAR_REEXPORT)) == VAR_EXPORTED) {
- return 0; /* nothing to do */
+ if (!parent) {
+ switch ((v->flags & (VAR_EXPORTED|VAR_REEXPORT))) {
+ case 0:
+ if (VAR_EXPORTED_ALL != var_exportedVars)
+ return 0; /* unexported */
+ break;
+ case VAR_EXPORTED:
+ return 0; /* nothing to do */
+ }
}
val = Buf_GetAll(&v->val, NULL);
if (strchr(val, '$')) {
@@ -711,6 +720,115 @@ Var_Export(char *str, int isExport)
free(av);
}
+
+/*
+ * This is called when .unexport[-env] is seen.
+ */
+void
+Var_UnExport(char *str)
+{
+ char tmp[BUFSIZ];
+ char *vlist;
+ char *cp;
+ Boolean reexport;
+ int n;
+
+ if (!str || !str[0]) {
+ return; /* assert? */
+ }
+
+ vlist = NULL;
+ reexport = 0;
+
+ str += 8;
+ if (strncmp(str, "-env", 4) == 0) {
+ extern char **environ;
+ static char **savenv;
+ char **newenv;
+
+ cp = getenv(MAKE_LEVEL); /* we should preserve this */
+ if (environ == savenv) {
+ /* we have been here before! */
+ newenv = bmake_realloc(environ, 2 * sizeof(char *));
+ } else {
+ if (savenv) {
+ free(savenv);
+ savenv = NULL;
+ }
+ newenv = bmake_malloc(2 * sizeof(char *));
+ }
+ if (!newenv)
+ return;
+ environ = savenv = newenv;
+ newenv[0] = NULL;
+ newenv[1] = NULL;
+ setenv(MAKE_LEVEL, cp, 1);
+ reexport = 1;
+ str += 4;
+ }
+ for (; *str != '\n' && isspace((unsigned char) *str); str++)
+ continue;
+ if (str[0] && str[0] != '\n') {
+ vlist = str;
+ }
+
+ if (!vlist) {
+ /* Using .MAKE.EXPORTED */
+ n = snprintf(tmp, sizeof(tmp), "${" MAKE_EXPORTED ":O:u}");
+ if (n < (int)sizeof(tmp)) {
+ vlist = Var_Subst(NULL, tmp, VAR_GLOBAL, 0);
+ }
+ }
+ if (vlist) {
+ Var *v;
+ char **av;
+ char *as;
+ int ac;
+ int i;
+
+ av = brk_string(vlist, &ac, FALSE, &as);
+ for (i = 0; i < ac; i++) {
+ v = VarFind(av[i], VAR_GLOBAL, 0);
+ if (!v)
+ continue;
+ if ((v->flags & (VAR_EXPORTED|VAR_REEXPORT)) == VAR_EXPORTED) {
+ if (reexport) {
+ /*
+ * If it had VAR_REEXPORT set, we could skip it.
+ */
+ v->flags &= ~(VAR_EXPORTED|VAR_REEXPORT);
+ Var_Export1(v->name, VAR_EXPORT_PARENT);
+ } else {
+ unsetenv(v->name);
+ }
+ }
+ if (!reexport) {
+ v->flags &= ~(VAR_EXPORTED|VAR_REEXPORT);
+ if (vlist == str) {
+ /*
+ * remove v->name from .MAKE.EXPORTED
+ */
+ n = snprintf(tmp, sizeof(tmp),
+ "${" MAKE_EXPORTED ":N%s}", v->name);
+ if (n < (int)sizeof(tmp)) {
+ cp = Var_Subst(NULL, tmp, VAR_GLOBAL, 0);
+ Var_Set(MAKE_EXPORTED, cp, VAR_GLOBAL, 0);
+ free(cp);
+ }
+ }
+ }
+ }
+ free(as);
+ free(av);
+ if (vlist != str) {
+ if (!reexport) {
+ Var_Delete(MAKE_EXPORTED, VAR_GLOBAL);
+ }
+ free(vlist);
+ }
+ }
+}
+
/*-
*-----------------------------------------------------------------------
* Var_Set --
Index: unit-tests/Makefile
===================================================================
RCS file: /cvsroot/src/usr.bin/make/unit-tests/Makefile,v
retrieving revision 1.24
diff -u -p -r1.24 Makefile
--- unit-tests/Makefile 7 Oct 2009 16:40:30 -0000 1.24
+++ unit-tests/Makefile 16 Nov 2009 04:00:26 -0000
@@ -34,6 +34,8 @@ SUBFILES= \
posix \
qequals \
ternary \
+ unexport \
+ unexport2 \
varcmd
all: ${SUBFILES}
Index: unit-tests/test.exp
===================================================================
RCS file: /cvsroot/src/usr.bin/make/unit-tests/test.exp,v
retrieving revision 1.29
diff -u -p -r1.29 test.exp
--- unit-tests/test.exp 7 Oct 2009 16:40:30 -0000 1.29
+++ unit-tests/test.exp 16 Nov 2009 04:00:26 -0000
@@ -302,6 +302,11 @@ The answer is empty
The answer is known
The answer is 42
The answer is 42
+UT_DOLLAR=This is $UT_FU
+UT_FOO=foobar is fubar
+UT_FU=fubar
+UT_TEST=unexport
+UT_TEST=unexport2
default FU=<v>fu</v> FOO=<v>foo</v> VAR=<v></v>
two FU=<v>bar</v> FOO=<v>goo</v> VAR=<v></v>
three FU=<v>bar</v> FOO=<v>goo</v> VAR=<v></v>
Index: unit-tests/unexport
===================================================================
RCS file: unit-tests/unexport
diff -N unit-tests/unexport
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ unit-tests/unexport 16 Nov 2009 04:00:26 -0000
@@ -0,0 +1,15 @@
+# $Id$
+
+# pick up a bunch of exported vars
+.include "export"
+
+# an example of setting up a minimal environment.
+PATH = /bin:/usr/bin:/sbin:/usr/sbin
+
+.unexport UT_ZOO
+
+UT_TEST = unexport
+
+# trim the environment
+# this will re-export everything in .MAKE.EXPORTED
+.unexport-env
Index: unit-tests/unexport2
===================================================================
RCS file: unit-tests/unexport2
diff -N unit-tests/unexport2
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ unit-tests/unexport2 16 Nov 2009 04:00:26 -0000
@@ -0,0 +1,15 @@
+# $Id$
+
+# pick up a bunch of exported vars
+.include "export"
+
+# an example of setting up a minimal environment.
+PATH = /bin:/usr/bin:/sbin:/usr/sbin
+
+# now clobber the environment to just PATH and UT_TEST
+UT_TEST = unexport2
+
+.unexport
+.export PATH UT_TEST
+# trim the environment
+.unexport-env PATH UT_TEST
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