FFI: Add unwind definitions for lj_vm_ffi_call.

Adds exception interoperability for C/C++ functions called via FFI
from the interpreter.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/buildvm_asm.c b/src/buildvm_asm.c
index 6a860c9f..01330456 100644
--- a/src/buildvm_asm.c
+++ b/src/buildvm_asm.c
@@ -202,6 +202,17 @@ void emit_asm(BuildCtx *ctx)
   for (i = rel = 0; i < ctx->nsym; i++) {
     int32_t ofs = ctx->sym[i].ofs;
     int32_t next = ctx->sym[i+1].ofs;
+#if LJ_TARGET_ARM && defined(__GNUC__) && !defined(LUAJIT_NO_UNWIND) && \
+    LJ_HASFFI
+    if (!strcmp(ctx->sym[i].name, "lj_vm_ffi_call"))
+      fprintf(ctx->fp,
+              ".globl lj_err_unwind_arm\n"
+              ".personality lj_err_unwind_arm\n"
+              ".fnend\n"
+              ".fnstart\n"
+              ".save {r4, r5, r11, lr}\n"
+              ".setfp r11, sp\n");
+#endif
     emit_asm_label(ctx, ctx->sym[i].name, next - ofs, 1);
     while (rel < ctx->nreloc && ctx->reloc[rel].ofs <= next) {
       BuildReloc *r = &ctx->reloc[rel];
@@ -229,8 +240,10 @@ void emit_asm(BuildCtx *ctx)
 
 #if LJ_TARGET_ARM && defined(__GNUC__) && !defined(LUAJIT_NO_UNWIND)
   fprintf(ctx->fp,
+#if !LJ_HASFFI
           ".globl lj_err_unwind_arm\n"
           ".personality lj_err_unwind_arm\n"
+#endif
           ".fnend\n");
 #endif