From 67e109adbeca35c44f9b3f2e22e41b4db8903114 Mon Sep 17 00:00:00 2001 From: Jilles Tjoelker Date: Sun, 24 Oct 2010 22:03:21 +0000 Subject: [PATCH] sh: Do not allow overriding a special builtin with a function. This is a syntax error. POSIX does not say explicitly whether defining a function with the same name as a special builtin is allowed, but it does say that it is impossible to call such a function. A special builtin can still be overridden with an alias. This commit is part of a set of changes that will ensure that when something looks like a special builtin to the parser, it is one. (Not the other way around, as it remains possible to call a special builtin named by a variable or other substitution.) Exp-run done by: pav (with some other sh(1) changes) --- bin/sh/parser.c | 5 +++++ tools/regression/bin/sh/execution/func3.0 | 7 +++++++ 2 files changed, 12 insertions(+) create mode 100644 tools/regression/bin/sh/execution/func3.0 diff --git a/bin/sh/parser.c b/bin/sh/parser.c index ec1510bf4d5b..4c1b2726f789 100644 --- a/bin/sh/parser.c +++ b/bin/sh/parser.c @@ -57,6 +57,7 @@ __FBSDID("$FreeBSD$"); #include "alias.h" #include "show.h" #include "eval.h" +#include "exec.h" /* to check for special builtins */ #ifndef NO_HISTORY #include "myhistedit.h" #endif @@ -606,6 +607,7 @@ simplecmd(union node **rpp, union node *redir) union node *args, **app; union node **orig_rpp = rpp; union node *n = NULL; + int special; /* If we don't have any redirections already, then we must reset */ /* rpp to be the address of the local redir variable. */ @@ -647,6 +649,9 @@ simplecmd(union node **rpp, union node *redir) strchr(n->narg.text, '/')) synerror("Bad function name"); rmescapes(n->narg.text); + if (find_builtin(n->narg.text, &special) >= 0 && + special) + synerror("Cannot override a special builtin with a function"); n->type = NDEFUN; n->narg.next = command(); funclinno = 0; diff --git a/tools/regression/bin/sh/execution/func3.0 b/tools/regression/bin/sh/execution/func3.0 new file mode 100644 index 000000000000..f7a562a0baad --- /dev/null +++ b/tools/regression/bin/sh/execution/func3.0 @@ -0,0 +1,7 @@ +# $FreeBSD$ + +# This may fail when parsing or when defining the function, or the definition +# may silently do nothing. In no event may the function be executed. + +sh -c 'unset() { echo overriding function executed, bad; }; v=1; unset v; exit "${v-0}"' 2>/dev/null +: