Add a macro to disable direct threading in the match engine

When defined, ONIG_DISABLE_DIRECT_THREADING disallows using computed
gotos in the match engine. Defining this macro enables onig to build
with the wasm32-unknown-unknown target on clang-8.

clang trunk enables support for computed gotos:
<https://bugs.llvm.org/show_bug.cgi?id=42498>

This commit enables building on released clang.

diff --git a/src/regint.h b/src/regint.h
index 5f5e6da3947f50535840b958130dee838650c7ec..1e6dc0cfb797f439516c3837720f752b0b64e45a 100644 (file)
--- a/src/regint.h
+++ b/src/regint.h
@@ -54,9 +54,11 @@
 #define PLATFORM_UNALIGNED_WORD_ACCESS
 #endif
 
+#ifndef ONIG_DISABLE_DIRECT_THREADING
 #ifdef __GNUC__
 #define USE_GOTO_LABELS_AS_VALUES
 #endif
+#endif
 
 /* config */
 /* spec. config */