[x86] Change the way exceptions are thrown from trampolines: instead of calling mono_...

diff --git a/mono/mini/tramp-x86.c b/mono/mini/tramp-x86.c
index 40faeb689d6ab5710f59d94fcd8a735cd7d5e19b..e416527c2b3ceb59d8979a129a84384581520cfe 100644 (file)
--- a/mono/mini/tramp-x86.c
+++ b/mono/mini/tramp-x86.c
@@ -223,7 +223,7 @@ guchar*
 mono_arch_create_generic_trampoline (MonoTrampolineType tramp_type, MonoTrampInfo **info, gboolean aot)
 {
        char *tramp_name;
-       guint8 *buf, *code, *tramp;
+       guint8 *buf, *code, *tramp, *br_ex_check;
        GSList *unwind_ops = NULL;
        MonoJumpInfo *ji = NULL;
        int i, offset, frame_size, regarray_offset, lmf_offset, caller_ip_offset, arg_offset;
@@ -377,19 +377,60 @@ mono_arch_create_generic_trampoline (MonoTrampolineType tramp_type, MonoTrampInf
         */
        x86_mov_membase_reg (code, X86_EBP, arg_offset, X86_EAX, 4);
 
+       /* Restore LMF */
+       x86_mov_reg_membase (code, X86_EAX, X86_EBP, lmf_offset + G_STRUCT_OFFSET (MonoLMF, lmf_addr), sizeof (mgreg_t));
+       x86_mov_reg_membase (code, X86_ECX, X86_EBP, lmf_offset + G_STRUCT_OFFSET (MonoLMF, previous_lmf), sizeof (mgreg_t));
+       x86_alu_reg_imm (code, X86_SUB, X86_ECX, 1);
+       x86_mov_membase_reg (code, X86_EAX, 0, X86_ECX, sizeof (mgreg_t));
+
        /* Check for interruptions */
        if (aot) {
-               code = mono_arch_emit_load_aotconst (buf, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_interruption_checkpoint_from_trampoline");
+               code = mono_arch_emit_load_aotconst (buf, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_thread_force_interruption_checkpoint_noraise");
                x86_call_reg (code, X86_EAX);
        } else {
-               x86_call_code (code, (guint8*)mono_interruption_checkpoint_from_trampoline);
+               x86_call_code (code, (guint8*)mono_thread_force_interruption_checkpoint_noraise);
        }
 
-       /* Restore LMF */
-       x86_mov_reg_membase (code, X86_EAX, X86_EBP, lmf_offset + G_STRUCT_OFFSET (MonoLMF, lmf_addr), sizeof (mgreg_t));
-       x86_mov_reg_membase (code, X86_ECX, X86_EBP, lmf_offset + G_STRUCT_OFFSET (MonoLMF, previous_lmf), sizeof (mgreg_t));
-       x86_alu_reg_imm (code, X86_SUB, X86_ECX, 1);
-       x86_mov_membase_reg (code, X86_EAX, 0, X86_ECX, sizeof (mgreg_t));
+       x86_test_reg_reg (code, X86_EAX, X86_EAX);
+       br_ex_check = code;
+       x86_branch8 (code, X86_CC_Z, -1, 1);
+
+       /*
+        * Exception case:
+        * We have an exception we want to throw in the caller's frame, so pop
+        * the trampoline frame and throw from the caller.
+        */
+       x86_leave (code);
+       /*
+        * The exception is in eax.
+        * We are calling the throw trampoline used by OP_THROW, so we have to setup the
+        * stack to look the same.
+        * The stack contains the ret addr, and the trampoline argument, the throw trampoline
+        * expects it to contain the ret addr and the exception. It also needs to be aligned
+        * after the exception is pushed.
+        */
+       /* Align stack */
+       x86_push_reg (code, X86_EAX);
+       /* Push the exception */
+       x86_push_reg (code, X86_EAX);
+       //x86_breakpoint (code);
+       /* Push the original return value */
+       x86_push_membase (code, X86_ESP, 3 * 4);
+       /*
+        * EH is initialized after trampolines, so get the address of the variable
+        * which contains throw_exception, and load it from there.
+        */
+       if (aot) {
+               /* Not really a jit icall */
+               code = mono_arch_emit_load_aotconst (buf, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, "throw_exception_addr");
+       } else {
+               x86_mov_reg_imm (code, X86_ECX, (guint8*)mono_get_throw_exception_addr ());
+       }
+       x86_mov_reg_membase (code, X86_ECX, X86_ECX, 0, sizeof(gpointer));
+       x86_jump_reg (code, X86_ECX);
+
+       /* Normal case */
+       mono_x86_patch (br_ex_check, code);
 
        /* Restore registers */
        for (i = X86_EAX; i <= X86_EDI; ++i) {