svn commit: r264423 - in stable/9: bin/sh tools/regression/bin/sh/expansion
Jilles Tjoelker
jilles at FreeBSD.org
Sun Apr 13 21:49:46 UTC 2014
Author: jilles
Date: Sun Apr 13 21:49:44 2014
New Revision: 264423
URL: http://svnweb.freebsd.org/changeset/base/264423
Log:
MFC r238468: sh: Expand assignment-like words specially for
export/readonly/local.
Examples:
export x=~
now expands the tilde
local y=$1
is now safe, even if $1 contains IFS characters or metacharacters.
For a word to "look like an assignment", it must start with a name followed
by an equals sign, none of which may be quoted.
The special treatment applies when the first word (potentially after
"command") is "export", "readonly" or "local". There may be quoting
characters but no expansions. If "local" is overridden with a function there
is no special treatment ("export" and "readonly" cannot be overridden with a
function).
If things like
local arr=(1 2 3)
are ever allowed in the future, they cannot call a "local" function. This
would either be a run-time error or it would call the builtin.
This matches Austin Group bug #351, planned for the next issue of POSIX.1.
As for the MFC, it is easy to depend on this feature inadvertently, and
adding this fixes a regression from stable/8 that may be apparent in things
like
local x=${y+a @}.
PR: bin/166771
Relnotes: yes
Added:
stable/9/tools/regression/bin/sh/expansion/export2.0
- copied unchanged from r238468, head/tools/regression/bin/sh/expansion/export2.0
stable/9/tools/regression/bin/sh/expansion/export3.0
- copied unchanged from r238468, head/tools/regression/bin/sh/expansion/export3.0
stable/9/tools/regression/bin/sh/expansion/local1.0
- copied unchanged from r238468, head/tools/regression/bin/sh/expansion/local1.0
stable/9/tools/regression/bin/sh/expansion/local2.0
- copied unchanged from r238468, head/tools/regression/bin/sh/expansion/local2.0
stable/9/tools/regression/bin/sh/expansion/readonly1.0
- copied unchanged from r238468, head/tools/regression/bin/sh/expansion/readonly1.0
Modified:
stable/9/bin/sh/eval.c
stable/9/bin/sh/exec.c
stable/9/bin/sh/exec.h
stable/9/bin/sh/sh.1
Directory Properties:
stable/9/bin/sh/ (props changed)
stable/9/tools/regression/bin/sh/ (props changed)
Modified: stable/9/bin/sh/eval.c
==============================================================================
--- stable/9/bin/sh/eval.c Sun Apr 13 21:23:15 2014 (r264422)
+++ stable/9/bin/sh/eval.c Sun Apr 13 21:49:44 2014 (r264423)
@@ -657,6 +657,52 @@ out:
result->fd, result->buf, result->nleft, result->jp));
}
+static int
+mustexpandto(const char *argtext, const char *mask)
+{
+ for (;;) {
+ if (*argtext == CTLQUOTEMARK || *argtext == CTLQUOTEEND) {
+ argtext++;
+ continue;
+ }
+ if (*argtext == CTLESC)
+ argtext++;
+ else if (BASESYNTAX[(int)*argtext] == CCTL)
+ return (0);
+ if (*argtext != *mask)
+ return (0);
+ if (*argtext == '\0')
+ return (1);
+ argtext++;
+ mask++;
+ }
+}
+
+static int
+isdeclarationcmd(struct narg *arg)
+{
+ int have_command = 0;
+
+ if (arg == NULL)
+ return (0);
+ while (mustexpandto(arg->text, "command")) {
+ have_command = 1;
+ arg = &arg->next->narg;
+ if (arg == NULL)
+ return (0);
+ /*
+ * To also allow "command -p" and "command --" as part of
+ * a declaration command, add code here.
+ * We do not do this, as ksh does not do it either and it
+ * is not required by POSIX.
+ */
+ }
+ return (mustexpandto(arg->text, "export") ||
+ mustexpandto(arg->text, "readonly") ||
+ (mustexpandto(arg->text, "local") &&
+ (have_command || !isfunc("local"))));
+}
+
/*
* Check if a builtin can safely be executed in the same process,
* even though it should be in a subshell (command substitution).
@@ -728,11 +774,12 @@ evalcommand(union node *cmd, int flags,
exitstatus = 0;
for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
if (varflag && isassignment(argp->narg.text)) {
- expandarg(argp, &varlist, EXP_VARTILDE);
+ expandarg(argp, varflag == 1 ? &varlist : &arglist,
+ EXP_VARTILDE);
continue;
- }
+ } else if (varflag == 1)
+ varflag = isdeclarationcmd(&argp->narg) ? 2 : 0;
expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
- varflag = 0;
}
*arglist.lastp = NULL;
*varlist.lastp = NULL;
Modified: stable/9/bin/sh/exec.c
==============================================================================
--- stable/9/bin/sh/exec.c Sun Apr 13 21:23:15 2014 (r264422)
+++ stable/9/bin/sh/exec.c Sun Apr 13 21:49:44 2014 (r264423)
@@ -644,6 +644,19 @@ unsetfunc(const char *name)
return (0);
}
+
+/*
+ * Check if a function by a certain name exists.
+ */
+int
+isfunc(const char *name)
+{
+ struct tblentry *cmdp;
+ cmdp = cmdlookup(name, 0);
+ return (cmdp != NULL && cmdp->cmdtype == CMDFUNCTION);
+}
+
+
/*
* Shared code for the following builtin commands:
* type, command -v, command -V
Modified: stable/9/bin/sh/exec.h
==============================================================================
--- stable/9/bin/sh/exec.h Sun Apr 13 21:23:15 2014 (r264422)
+++ stable/9/bin/sh/exec.h Sun Apr 13 21:49:44 2014 (r264423)
@@ -72,5 +72,6 @@ void hashcd(void);
void changepath(const char *);
void defun(const char *, union node *);
int unsetfunc(const char *);
+int isfunc(const char *);
int typecmd_impl(int, char **, int, const char *);
void clearcmdentry(void);
Modified: stable/9/bin/sh/sh.1
==============================================================================
--- stable/9/bin/sh/sh.1 Sun Apr 13 21:23:15 2014 (r264422)
+++ stable/9/bin/sh/sh.1 Sun Apr 13 21:49:44 2014 (r264423)
@@ -1171,6 +1171,20 @@ Assignments are expanded differently fro
tilde expansion is also performed after the equals sign and after any colon
and usernames are also terminated by colons,
and field splitting and pathname expansion are not performed.
+.Pp
+This special expansion applies not only to assignments that form a simple
+command by themselves or precede a command word,
+but also to words passed to the
+.Ic export ,
+.Ic local
+or
+.Ic readonly
+built-in commands that have this form.
+For this, the builtin's name must be literal
+(not the result of an expansion)
+and may optionally be preceded by one or more literal instances of
+.Ic command
+without options.
.Ss Positional Parameters
A positional parameter is a parameter denoted by a number greater than zero.
The shell sets these initially to the values of its command line
Copied: stable/9/tools/regression/bin/sh/expansion/export2.0 (from r238468, head/tools/regression/bin/sh/expansion/export2.0)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/9/tools/regression/bin/sh/expansion/export2.0 Sun Apr 13 21:49:44 2014 (r264423, copy of r238468, head/tools/regression/bin/sh/expansion/export2.0)
@@ -0,0 +1,24 @@
+# $FreeBSD$
+
+w='@ @'
+check() {
+ [ "$v" = "$w" ] || echo "Expected $w got $v"
+}
+
+export v=$w
+check
+
+HOME=/known/value
+check() {
+ [ "$v" = ~ ] || echo "Expected $HOME got $v"
+}
+
+export v=~
+check
+
+check() {
+ [ "$v" = "x:$HOME" ] || echo "Expected x:$HOME got $v"
+}
+
+export v=x:~
+check
Copied: stable/9/tools/regression/bin/sh/expansion/export3.0 (from r238468, head/tools/regression/bin/sh/expansion/export3.0)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/9/tools/regression/bin/sh/expansion/export3.0 Sun Apr 13 21:49:44 2014 (r264423, copy of r238468, head/tools/regression/bin/sh/expansion/export3.0)
@@ -0,0 +1,30 @@
+# $FreeBSD$
+
+w='@ @'
+check() {
+ [ "$v" = "$w" ] || echo "Expected $w got $v"
+}
+
+command export v=$w
+check
+command command export v=$w
+check
+
+HOME=/known/value
+check() {
+ [ "$v" = ~ ] || echo "Expected $HOME got $v"
+}
+
+command export v=~
+check
+command command export v=~
+check
+
+check() {
+ [ "$v" = "x:$HOME" ] || echo "Expected x:$HOME got $v"
+}
+
+command export v=x:~
+check
+command command export v=x:~
+check
Copied: stable/9/tools/regression/bin/sh/expansion/local1.0 (from r238468, head/tools/regression/bin/sh/expansion/local1.0)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/9/tools/regression/bin/sh/expansion/local1.0 Sun Apr 13 21:49:44 2014 (r264423, copy of r238468, head/tools/regression/bin/sh/expansion/local1.0)
@@ -0,0 +1,28 @@
+# $FreeBSD$
+
+run_test() {
+ w='@ @'
+ check() {
+ [ "$v" = "$w" ] || echo "Expected $w got $v"
+ }
+
+ local v=$w
+ check
+
+ HOME=/known/value
+ check() {
+ [ "$v" = ~ ] || echo "Expected $HOME got $v"
+ }
+
+ local v=~
+ check
+
+ check() {
+ [ "$v" = "x:$HOME" ] || echo "Expected x:$HOME got $v"
+ }
+
+ local v=x:~
+ check
+}
+
+run_test
Copied: stable/9/tools/regression/bin/sh/expansion/local2.0 (from r238468, head/tools/regression/bin/sh/expansion/local2.0)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/9/tools/regression/bin/sh/expansion/local2.0 Sun Apr 13 21:49:44 2014 (r264423, copy of r238468, head/tools/regression/bin/sh/expansion/local2.0)
@@ -0,0 +1,34 @@
+# $FreeBSD$
+
+run_test() {
+ w='@ @'
+ check() {
+ [ "$v" = "$w" ] || echo "Expected $w got $v"
+ }
+
+ command local v=$w
+ check
+ command command local v=$w
+ check
+
+ HOME=/known/value
+ check() {
+ [ "$v" = ~ ] || echo "Expected $HOME got $v"
+ }
+
+ command local v=~
+ check
+ command command local v=~
+ check
+
+ check() {
+ [ "$v" = "x:$HOME" ] || echo "Expected x:$HOME got $v"
+ }
+
+ command local v=x:~
+ check
+ command command local v=x:~
+ check
+}
+
+run_test
Copied: stable/9/tools/regression/bin/sh/expansion/readonly1.0 (from r238468, head/tools/regression/bin/sh/expansion/readonly1.0)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/9/tools/regression/bin/sh/expansion/readonly1.0 Sun Apr 13 21:49:44 2014 (r264423, copy of r238468, head/tools/regression/bin/sh/expansion/readonly1.0)
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+w='@ @'
+
+v=0 HOME=/known/value
+readonly v=~:~/:$w
+[ "$v" = "$HOME:$HOME/:$w" ] || echo "Expected $HOME/:$w got $v"
More information about the svn-src-stable-9
mailing list