Merge pull request #363 from JamesB7/system-security2

[mono.git] / mono / mini / mini-unwind.h

diff --git a/mono/mini/mini-unwind.h b/mono/mini/mini-unwind.h
index 9d2b52e4f9f55f09e479afcca4a60c3774ff98ad..1d5be3190da6ae669686d365b8226e45ef936234 100644 (file)
--- a/mono/mini/mini-unwind.h
+++ b/mono/mini/mini-unwind.h
@@ -16,10 +16,16 @@
  * This is a platform-independent interface for unwinding through stack frames 
  * based on the Dwarf unwinding interface.
  * See http://dwarfstd.org/Dwarf3.pdf, section "Call Frame Information".
- * Currently, this is only used for emitting unwind info in AOT files.
  */
 
-/* CFA = Canonical Frame Address */
+/*
+ * CFA = Canonical Frame Address. By convention, this is the value of the stack pointer
+ * prior to the execution of the call instruction in the caller. I.e. on x86, it is
+ * esp + 4 on entry to a function. The value of the CFA does not change during execution
+ * of a function. There are two kinds of unwind directives:
+ * - those that describe how to compute the CFA at a given pc offset inside a function
+ * - those that describe where a given register is saved relative to the CFA.
+ */
 
 /* Unwind ops */
 
@@ -69,11 +75,11 @@ typedef struct {
  */
 
 /* Set cfa to reg+offset */
-#define mono_emit_unwind_op_def_cfa(cfg,ip,reg,offset) mono_emit_unwind_op (cfg, (ip) - (cfg)->native_code, DW_CFA_def_cfa, (reg), (offset))
+#define mono_emit_unwind_op_def_cfa(cfg,ip,reg,offset) do { mono_emit_unwind_op (cfg, (ip) - (cfg)->native_code, DW_CFA_def_cfa, (reg), (offset)); (cfg)->cfa_reg = (reg); (cfg)->cfa_offset = (offset); } while (0)
 /* Set cfa to reg+existing offset */
-#define mono_emit_unwind_op_def_cfa_reg(cfg,ip,reg) mono_emit_unwind_op (cfg, (ip) - (cfg)->native_code, DW_CFA_def_cfa_register, (reg), (0))
+#define mono_emit_unwind_op_def_cfa_reg(cfg,ip,reg) do { mono_emit_unwind_op (cfg, (ip) - (cfg)->native_code, DW_CFA_def_cfa_register, (reg), (0)); (cfg)->cfa_reg = (reg); } while (0)
 /* Set cfa to existing reg+offset */
-#define mono_emit_unwind_op_def_cfa_offset(cfg,ip,offset) mono_emit_unwind_op (cfg, (ip) - (cfg)->native_code, DW_CFA_def_cfa_offset, (0), (offset))
+#define mono_emit_unwind_op_def_cfa_offset(cfg,ip,offset) do { mono_emit_unwind_op (cfg, (ip) - (cfg)->native_code, DW_CFA_def_cfa_offset, (0), (offset)); (cfg)->cfa_offset = (offset); } while (0)
 /* Reg is the same as it was on enter to the function */
 #define mono_emit_unwind_op_same_value(cfg,ip,reg) mono_emit_unwind_op (cfg, (ip) - (cfg)->native_code, DW_CFA_same_value, (reg), 0)
 /* Reg is saved at cfa+offset */
@@ -86,6 +92,24 @@ typedef struct {
 #define mono_add_unwind_op_same_value(op_list,code,buf,reg) do { (op_list) = g_slist_append ((op_list), mono_create_unwind_op ((code) - (buf), DW_CFA_same_value, (reg), 0)); } while (0)
 #define mono_add_unwind_op_offset(op_list,code,buf,reg,offset) do { (op_list) = g_slist_append ((op_list), mono_create_unwind_op ((code) - (buf), DW_CFA_offset, (reg), (offset))); } while (0)
 
+/* 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
+};
+
 int
 mono_hw_reg_to_dwarf_reg (int reg) MONO_INTERNAL;
 
@@ -103,8 +127,9 @@ mono_unwind_ops_encode (GSList *unwind_ops, guint32 *out_len) MONO_INTERNAL;
 
 void
 mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len, 
-                                  guint8 *start_ip, guint8 *end_ip, guint8 *ip, mgreg_t *regs, 
-                                  int nregs, guint8 **out_cfa) MONO_INTERNAL;
+                                  guint8 *start_ip, guint8 *end_ip, guint8 *ip, mgreg_t *regs, int nregs,
+                                  mgreg_t **save_locations, int save_locations_len,
+                                  guint8 **out_cfa) MONO_INTERNAL;
 
 void mono_unwind_init (void) MONO_INTERNAL;