Fixes PR85 for arm.

[cacao.git] / src / vm / jit / patcher-common.c

diff --git a/src/vm/jit/patcher-common.c b/src/vm/jit/patcher-common.c
index 4da024f77a0e808c1d9d175360d7b732b104cda3..b6de72591687d5fbd9394e7c544e03b2d9f57c63 100644 (file)
--- a/src/vm/jit/patcher-common.c
+++ b/src/vm/jit/patcher-common.c
@@ -2,6 +2,7 @@
 
    Copyright (C) 2007, 2008
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
+   Copyright (C) 2008 Theobroma Systems Ltd.
 
    This file is part of CACAO.
 
@@ -247,6 +248,49 @@ void patcher_resolve(jitdata* jd)
 }
 
 
+/**
+ * Check if the patcher is already patched.  This is done by comparing
+ * the machine instruction.
+ *
+ * @param pr Patcher structure.
+ *
+ * @return true if patched, false otherwise.
+ */
+bool patcher_is_patched(patchref_t* pr)
+{
+       // Validate the instruction at the patching position is the same
+       // instruction as the patcher structure contains.
+       uint32_t mcode = *((uint32_t*) pr->mpc);
+
+       if (mcode != pr->mcode) {
+               // The code differs.
+               return false;
+       }
+
+       return true;
+}
+
+
+/**
+ *
+ */
+bool patcher_is_patched_at(void* pc)
+{
+       codeinfo* code = code_find_codeinfo_for_pc(pc);
+
+       // Get the patcher for the given PC.
+       patchref_t* pr = patcher_list_find(code, pc);
+
+       if (pr == NULL) {
+               // The given PC is not a patcher position.
+               return false;
+       }
+
+       // Validate the instruction.
+       return patcher_is_patched(pr);
+}
+
+
 /* patcher_handler *************************************************************
 
    Handles the request to patch JIT code at the given patching