compiler: handle non-locally-exiting top-level forms.

* stdlib/compiler.tl (compile-file-conditionally): When evaluation
of a compiled top-level form is not suppressed, there is a risk
that it can terminate non-locally, via throwing an exception or
performing a block return. The compilation of the file is then
aborted. We can do better: using an unwind-protect, we can catch
all non-local control transfers out of the form and just ignore
them. The motivation for this is that it lets us compile files
which call (return-from load ...), without requiring that it be
written as (compile-only (return-from load ...)). Other things will
work, like compiling a (load "foo") where foo doesn't exist or
aborts due to errors.

1 files changed, 4 insertions, 1 deletions

diff --git a/stdlib/compiler.tl b/stdlib/compiler.tl
index a837571e..ce28e012 100644
--- a/stdlib/compiler.tl
+++ b/stdlib/compiler.tl
@@ -2590,7 +2590,10 @@
                                      (fence (isecp symvec %package-manip%)))
                                 (when *eval*
                                   (let ((pa *package-alist*))
-                                    (sys:vm-execute-toplevel vm-desc)
+                                    (block* err-ret
+                                      (unwind-protect
+                                        (sys:vm-execute-toplevel vm-desc)
+                                        (return* err-ret)))
                                     (when (neq pa *package-alist*)
                                       (set fence t))))
                                 (when (and *emit* (consp form))