Fix OCaml bindings crash, PR8847.

See http://caml.inria.fr/mantis/view.php?id=4166
If we call only external functions from a module, then its 'let _' bindings
don't get executed, which means that the exceptions don't get registered for use
in the C code.
This in turn causes llvm_raise to call raise_with_arg() with a NULL pointer and
cause a segmentation fault.

The workaround is to declare all 'external' functions as 'val' in these .mli
files.

Also added a separate testcase (the testcase must call only external functions
for the bug to occur).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122497 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 0 deletions

diff --git a/test/Bindings/Ocaml/ext_exc.ml b/test/Bindings/Ocaml/ext_exc.ml
new file mode 100644
index 0000000000..79543515df
--- /dev/null
+++ b/test/Bindings/Ocaml/ext_exc.ml
@@ -0,0 +1,16 @@
+(* RUN: %ocamlopt -warn-error A llvm.cmxa llvm_bitreader.cmxa llvm_executionengine.cmxa %s -o %t
+ * RUN: %t </dev/null
+ *)
+let context = Llvm.global_context ()
+(* this used to crash, we must not use 'external' in .mli files, but 'val' if we
+ * want the let _ bindings executed, see http://caml.inria.fr/mantis/view.php?id=4166 *)
+let _ =
+    try
+        ignore (Llvm_bitreader.get_module context (Llvm.MemoryBuffer.of_stdin ()))
+    with
+    Llvm_bitreader.Error _ -> ();;
+let _ =
+    try
+        ignore (Llvm.MemoryBuffer.of_file "/path/to/nonexistent/file")
+    with
+    Llvm.IoError _ -> ();;