Merge pull request #409 from Alkarex/patch-1

[mono.git] / mono / mini / unwind.c

diff --git a/mono/mini/unwind.c b/mono/mini/unwind.c
index 9312b25d4773dd1aa9f56129638daa62ec05dcb9..2377e0dd009b5e970a01d2732dc2584f943e4458 100644 (file)
--- a/mono/mini/unwind.c
+++ b/mono/mini/unwind.c
@@ -35,6 +35,7 @@ static CRITICAL_SECTION unwind_mutex;
 
 static MonoUnwindInfo **cached_info;
 static int cached_info_next, cached_info_size;
+static GSList *cached_info_list;
 /* Statistics */
 static int unwind_info_size;
 
@@ -53,7 +54,16 @@ static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
 #define DWARF_DATA_ALIGN (-4)
 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (ARMREG_LR))
 #elif defined (TARGET_X86)
+#ifdef __APPLE__
+/*
+ * LLVM seems to generate unwind info where esp is encoded as 5, and ebp as 4, ie see this line:
+ *   def ESP : RegisterWithSubRegs<"esp", [SP]>, DwarfRegNum<[-2, 5, 4]>;
+ * in lib/Target/X86/X86RegisterInfo.td in the llvm sources.
+ */
+static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 5, 4, 6, 7, 8 };
+#else
 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8 };
+#endif
 /* + 1 is for IP */
 #define NUM_REGS X86_NREG + 1
 #define DWARF_DATA_ALIGN (-4)
@@ -493,8 +503,8 @@ mono_cache_unwind_info (guint8 *unwind_info, guint32 unwind_info_len)
                MonoUnwindInfo **old_table, **new_table;
 
                /*
-                * Have to resize the table, while synchronizing with 
-                * mono_get_cached_unwind_info () using hazard pointers.
+                * Avoid freeing the old table so mono_get_cached_unwind_info ()
+                * doesn't need locks/hazard pointers.
                 */
 
                old_table = cached_info;
@@ -506,9 +516,7 @@ mono_cache_unwind_info (guint8 *unwind_info, guint32 unwind_info_len)
 
                cached_info = new_table;
 
-               mono_memory_barrier ();
-
-               mono_thread_hazardous_free_or_queue (old_table, g_free);
+               cached_info_list = g_slist_prepend (cached_info_list, cached_info);
 
                cached_info_size *= 2;
        }
@@ -530,17 +538,18 @@ mono_get_cached_unwind_info (guint32 index, guint32 *unwind_info_len)
        MonoUnwindInfo **table;
        MonoUnwindInfo *info;
        guint8 *data;
-       MonoThreadHazardPointers *hp = mono_hazard_pointer_get ();
 
-       table = get_hazardous_pointer ((gpointer volatile*)&cached_info, hp, 0);
+       /*
+        * This doesn't need any locks/hazard pointers,
+        * since new tables are copies of the old ones.
+        */
+       table = cached_info;
 
        info = table [index];
 
        *unwind_info_len = info->len;
        data = info->info;
 
-       mono_hazard_pointer_clear (hp, 0);
-
        return data;
 }
 
@@ -613,24 +622,6 @@ decode_cie_op (guint8 *p, guint8 **endp)
        *endp = p;
 }
 
-/* Pointer Encoding in the .eh_frame */
-enum {
-       DW_EH_PE_absptr = 0x00,
-       DW_EH_PE_omit = 0xff,
-
-       DW_EH_PE_udata4 = 0x03,
-       DW_EH_PE_sdata4 = 0x0b,
-       DW_EH_PE_sdata8 = 0x0c,
-
-       DW_EH_PE_pcrel = 0x10,
-       DW_EH_PE_textrel = 0x20,
-       DW_EH_PE_datarel = 0x30,
-       DW_EH_PE_funcrel = 0x40,
-       DW_EH_PE_aligned = 0x50,
-
-       DW_EH_PE_indirect = 0x80
-};
-
 static gint64
 read_encoded_val (guint32 encoding, guint8 *p, guint8 **endp)
 {