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From: Simon Marchi <simon.marchi@ericsson.com>
To: <gdb-patches@sourceware.org>
Cc: Simon Marchi <simon.marchi@ericsson.com>
Subject: [PATCH 2/2] arm-tdep.c: Refactor displaced stepping relocation functions
Date: Thu, 25 Feb 2016 15:47:00 -0000	[thread overview]
Message-ID: <1456415245-24005-3-git-send-email-simon.marchi@ericsson.com> (raw)
In-Reply-To: <1456415245-24005-1-git-send-email-simon.marchi@ericsson.com>

A small refactor so that arm_process_displaced_insn is the only function
specific to GDB.  All functions called from this one will eventually be
moved to common/, so they need to be free of anything GDB-specific.  I
also renamed those functions from "process_displaced" to "relocate",
since they won't be used exclusively for displaced stepping anymore.

The call tree ends up like this:

  - arm_process_displaced_insn
    - arm_relocate_insn_arm
      ...
    - arm_relocate_insn_thumb_32bit
      ...
    - arm_relocate_insn_thumb_16bit
      ...

gdb/ChangeLog:

	* arm-tdep.c (thumb_process_displaced_16bit_insn): Rename to...
	(arm_relocate_insn_thumb_16bit): ... this, and add return error
	code.
	(thumb_process_displaced_32bit_insn): Rename to...
	(arm_relocate_insn_thumb_32bit): ... this, and add return error
	code.
	(thumb_process_displaced_insn): Remove.
	(arm_relocate_insn_arm): New function, extracted mostly from...
	(arm_process_displaced_insn): ... this.  Refactor to adapt to
	other functions changes.
---
 gdb/arm-tdep.c | 122 ++++++++++++++++++++++++++++++---------------------------
 1 file changed, 64 insertions(+), 58 deletions(-)

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index 43b61c2..ef48a90 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -7111,9 +7111,8 @@ thumb_copy_pop_pc_16bit (uint16_t insn1, struct arm_insn_reloc_data *data)
   return 0;
 }
 
-static void
-thumb_process_displaced_16bit_insn (uint16_t insn1,
-				    struct arm_insn_reloc_data *data)
+static int
+arm_relocate_insn_thumb_16bit (uint16_t insn1, struct arm_insn_reloc_data *data)
 {
   unsigned short op_bit_12_15 = bits (insn1, 12, 15);
   unsigned short op_bit_10_11 = bits (insn1, 10, 11);
@@ -7202,9 +7201,7 @@ thumb_process_displaced_16bit_insn (uint16_t insn1,
       err = 1;
     }
 
-  if (err)
-    internal_error (__FILE__, __LINE__,
-		    _("thumb_process_displaced_16bit_insn: Instruction decode error"));
+  return err;
 }
 
 static int
@@ -7279,9 +7276,9 @@ decode_thumb_32bit_ld_mem_hints (uint16_t insn1, uint16_t insn2,
   return 0;
 }
 
-static void
-thumb_process_displaced_32bit_insn (uint16_t insn1, uint16_t insn2,
-				    struct arm_insn_reloc_data *data)
+static int
+arm_relocate_insn_thumb_32bit (uint16_t insn1, uint16_t insn2,
+			       struct arm_insn_reloc_data *data)
 {
   int err = 0;
   unsigned short op = bit (insn2, 15);
@@ -7393,34 +7390,41 @@ thumb_process_displaced_32bit_insn (uint16_t insn1, uint16_t insn2,
       err = 1;
     }
 
-  if (err)
-    internal_error (__FILE__, __LINE__,
-		    _("thumb_process_displaced_32bit_insn: Instruction decode error"));
+  return err;
 
 }
 
-static void
-thumb_process_displaced_insn (CORE_ADDR from, struct arm_insn_reloc_data *data)
+static int
+arm_relocate_insn_arm (uint32_t insn, struct arm_insn_reloc_data *data)
 {
-  enum bfd_endian byte_order_for_code
-    = gdbarch_byte_order_for_code (data->gdbarch);
-  uint16_t insn1
-    = read_memory_unsigned_integer (from, 2, byte_order_for_code);
+  int err = 1;
 
-  if (debug_displaced)
-    fprintf_unfiltered (gdb_stdlog, "displaced: process thumb insn %.4x "
-			"at %.8lx\n", insn1, (unsigned long) from);
-
-  data->dsc->is_thumb = 1;
-  data->dsc->insn_size = thumb_insn_size (insn1);
-  if (thumb_insn_size (insn1) == 4)
+  if ((insn & 0xf0000000) == 0xf0000000)
+    err = arm_decode_unconditional (insn, data);
+  else switch (((insn & 0x10) >> 4) | ((insn & 0xe000000) >> 24))
     {
-      uint16_t insn2
-	= read_memory_unsigned_integer (from + 2, 2, byte_order_for_code);
-      thumb_process_displaced_32bit_insn (insn1, insn2, data);
+    case 0x0: case 0x1: case 0x2: case 0x3:
+      err = arm_decode_dp_misc (insn, data);
+      break;
+
+    case 0x4: case 0x5: case 0x6:
+      err = arm_decode_ld_st_word_ubyte (insn, data);
+      break;
+
+    case 0x7:
+      err = arm_decode_media (insn, data);
+      break;
+
+    case 0x8: case 0x9: case 0xa: case 0xb:
+      err = arm_decode_b_bl_ldmstm (insn, data);
+      break;
+
+    case 0xc: case 0xd: case 0xe: case 0xf:
+      err = arm_decode_svc_copro (insn, data);
+      break;
     }
-  else
-    thumb_process_displaced_16bit_insn (insn1, data);
+
+  return err;
 }
 
 void
@@ -7430,7 +7434,6 @@ arm_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from,
 {
   int err = 0;
   enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
-  uint32_t insn;
   struct arm_insn_reloc_data reloc_data = {
     dsc,
     gdbarch,
@@ -7445,40 +7448,43 @@ arm_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from,
   dsc->cleanup = NULL;
   dsc->wrote_to_pc = 0;
 
-  if (!displaced_in_arm_mode (regs))
-    return thumb_process_displaced_insn (from, &reloc_data);
+  if (displaced_in_arm_mode (regs))
+    {
+      uint32_t insn
+	= read_memory_unsigned_integer (from, 4, byte_order_for_code);
 
-  dsc->is_thumb = 0;
-  dsc->insn_size = 4;
-  insn = read_memory_unsigned_integer (from, 4, byte_order_for_code);
-  if (debug_displaced)
-    fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
-			"at %.8lx\n", (unsigned long) insn,
-			(unsigned long) from);
+      if (debug_displaced)
+        fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
+			    "at %.8lx\n", (unsigned long) insn,
+			    (unsigned long) from);
 
-  if ((insn & 0xf0000000) == 0xf0000000)
-    err = arm_decode_unconditional (insn, &reloc_data);
-  else switch (((insn & 0x10) >> 4) | ((insn & 0xe000000) >> 24))
+      dsc->is_thumb = 0;
+      dsc->insn_size = 4;
+
+      err = arm_relocate_insn_arm (insn, &reloc_data);
+    }
+  else
     {
-    case 0x0: case 0x1: case 0x2: case 0x3:
-      err = arm_decode_dp_misc (insn, &reloc_data);
-      break;
+      uint16_t insn1
+	= read_memory_unsigned_integer (from, 2, byte_order_for_code);
+      unsigned int insn_size = thumb_insn_size (insn1);
 
-    case 0x4: case 0x5: case 0x6:
-      err = arm_decode_ld_st_word_ubyte (insn, &reloc_data);
-      break;
+      if (debug_displaced)
+        fprintf_unfiltered (gdb_stdlog, "displaced: process thumb insn %.4x "
+			    "at %.8lx\n", insn1, (unsigned long) from);
 
-    case 0x7:
-      err = arm_decode_media (insn, &reloc_data);
-      break;
+      dsc->is_thumb = 1;
+      dsc->insn_size = insn_size;
 
-    case 0x8: case 0x9: case 0xa: case 0xb:
-      err = arm_decode_b_bl_ldmstm (insn, &reloc_data);
-      break;
+      if (insn_size == 4)
+        {
+          uint16_t insn2
+	    = read_memory_unsigned_integer (from + 2, 2, byte_order_for_code);
 
-    case 0xc: case 0xd: case 0xe: case 0xf:
-      err = arm_decode_svc_copro (insn, &reloc_data);
-      break;
+	  err = arm_relocate_insn_thumb_32bit (insn1, insn2, &reloc_data);
+        }
+      else
+        err = arm_relocate_insn_thumb_16bit (insn1, &reloc_data);
     }
 
   if (err)
-- 
2.5.1


  reply	other threads:[~2016-02-25 15:47 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-25 15:47 [PATCH 0/2] Decouple ARM instruction decoding/relocating from GDB Simon Marchi
2016-02-25 15:47 ` Simon Marchi [this message]
2016-02-26 16:11   ` [PATCH 2/2] arm-tdep.c: Refactor displaced stepping relocation functions Luis Machado
2016-02-26 16:23     ` Simon Marchi
2016-02-26 16:50       ` Luis Machado
2016-02-25 15:47 ` [PATCH 1/2] arm-tdep.c: Replace arguments to relocation functions by a structure Simon Marchi
2016-02-26 16:12   ` Luis Machado
2016-02-26 16:25     ` Simon Marchi
2016-02-26 16:26       ` Simon Marchi
2016-03-04 12:03 ` [PATCH 0/2] Decouple ARM instruction decoding/relocating from GDB Yao Qi
2016-03-04 18:42   ` Simon Marchi

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