sh: Allow EV_EXIT through function calls, make {...} <redir more consistent.

If EV_EXIT causes an exit, use the exception mechanism to unwind
redirections and local variables. This way, if the final command is a
redirected command, an EXIT trap now executes without the redirections.

Because of these changes, EV_EXIT can now be inherited by the body of a
function, so do so. This means that a function no longer prevents a fork
before an exec being skipped, such as in
  f() { head -1 /etc/passwd; }; echo $(f)

Wrapping a single builtin in a function may still cause an otherwise
unnecessary fork with command substitution, however.

An exit command or -e failure still invokes the EXIT trap with the
original redirections and local variables in place.

Note: this depends on SHELLPROC being gone. A SHELLPROC depended on
keeping the redirections and local variables and only cleaning up the
state to restore them.

3 files changed, 46 insertions, 0 deletions

diff --git a/tools/regression/bin/sh/execution/fork3.0 b/tools/regression/bin/sh/execution/fork3.0
new file mode 100644
index 0000000..3cb678c
--- /dev/null
+++ b/tools/regression/bin/sh/execution/fork3.0
@@ -0,0 +1,4 @@
+# $FreeBSD$
+
+result=$(${SH} -c 'f() { ps -p $$ -o comm=; }; f')
+test "$result" = "ps"
diff --git a/tools/regression/bin/sh/execution/redir6.0 b/tools/regression/bin/sh/execution/redir6.0
new file mode 100644
index 0000000..4e3ac0c
--- /dev/null
+++ b/tools/regression/bin/sh/execution/redir6.0
@@ -0,0 +1,21 @@
+# $FreeBSD$
+
+failures=0
+
+check() {
+	if [ "$2" != "$3" ]; then
+		echo "Failure at $1" >&2
+		failures=$((failures + 1))
+	fi
+}
+
+check $LINENO "$(trap "echo bye" EXIT; : >/dev/null)" bye
+check $LINENO "$(trap "echo bye" EXIT; { :; } >/dev/null)" bye
+check $LINENO "$(trap "echo bye" EXIT; (:) >/dev/null)" bye
+check $LINENO "$(trap "echo bye" EXIT; (: >/dev/null))" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; : >/dev/null')" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; { :; } >/dev/null')" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; (:) >/dev/null')" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; (: >/dev/null)')" bye
+
+exit $((failures > 0))
diff --git a/tools/regression/bin/sh/execution/redir7.0 b/tools/regression/bin/sh/execution/redir7.0
new file mode 100644
index 0000000..2487bcf
--- /dev/null
+++ b/tools/regression/bin/sh/execution/redir7.0
@@ -0,0 +1,21 @@
+# $FreeBSD$
+
+failures=0
+
+check() {
+	if [ "$2" != "$3" ]; then
+		echo "Failure at $1" >&2
+		failures=$((failures + 1))
+	fi
+}
+
+check $LINENO "$(trap "echo bye" EXIT; f() { :; }; f >/dev/null)" bye
+check $LINENO "$(trap "echo bye" EXIT; f() { :; }; { f; } >/dev/null)" bye
+check $LINENO "$(trap "echo bye" EXIT; f() { :; }; (f) >/dev/null)" bye
+check $LINENO "$(trap "echo bye" EXIT; f() { :; }; (f >/dev/null))" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; f() { :; }; f >/dev/null')" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; f() { :; }; { f; } >/dev/null')" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; f() { :; }; (f) >/dev/null')" bye
+check $LINENO "$(${SH} -c 'trap "echo bye" EXIT; f() { :; }; (f >/dev/null)')" bye
+
+exit $((failures > 0))