[binutils-gdb] [PATCH[ARM]Check mapping symbol while backward searching for IT block.

[Renlin Li <renlin at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=5bc5ae8810c03b55f46b9e575389c3fa85a62b5c

commit 5bc5ae8810c03b55f46b9e575389c3fa85a62b5c
Author: Renlin Li <renlin.li@arm.com>
Date:   Mon Jan 25 15:06:54 2016 +0000

    [PATCH[ARM]Check mapping symbol while backward searching for IT block.
    
    opcodes/
    
    	* arm-dis.c (mapping_symbol_for_insn): New function.
    	(find_ifthen_state): Call mapping_symbol_for_insn().
    
    gas/
    
    	* testsuite/gas/arm/thumb2_it_search.d: New.
    	* testsuite/gas/arm/thumb2_it_search.s: New.

Diff:
---
 gas/ChangeLog                            |  5 ++
 gas/testsuite/gas/arm/thumb2_it_search.d | 12 +++++
 gas/testsuite/gas/arm/thumb2_it_search.s |  8 ++++
 opcodes/ChangeLog                        |  5 ++
 opcodes/arm-dis.c                        | 81 ++++++++++++++++++++++++++++++--
 5 files changed, 108 insertions(+), 3 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 83f4077..3cb5f14 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2016-01-25  Renlin Li  <renlin.li@arm.com>
+
+	* testsuite/gas/arm/thumb2_it_search.d: New.
+	* testsuite/gas/arm/thumb2_it_search.s: New.
+
 2016-01-21  Nick Clifton  <nickc@redhat.com>
 
 	PR gas/19454
diff --git a/gas/testsuite/gas/arm/thumb2_it_search.d b/gas/testsuite/gas/arm/thumb2_it_search.d
new file mode 100644
index 0000000..6758ef8
--- /dev/null
+++ b/gas/testsuite/gas/arm/thumb2_it_search.d
@@ -0,0 +1,12 @@
+#name: 32-bit Thumb conditional instructions backward search
+#as: -march=armv6kt2
+#skip: *-*-*aout*
+#source: thumb2_it_search.s
+#objdump: -dr --prefix-addresses --show-raw-insn
+
+.*: +file format .*arm.*
+
+Disassembly of section .text:
+0+0 <[^>]+> f3af 8000 	nop.w
+0+4 <[^>]+> bf080000 	.word	0xbf080000
+0+8 <[^>]+> f3af 8000 	nop.w
diff --git a/gas/testsuite/gas/arm/thumb2_it_search.s b/gas/testsuite/gas/arm/thumb2_it_search.s
new file mode 100644
index 0000000..a29cb51
--- /dev/null
+++ b/gas/testsuite/gas/arm/thumb2_it_search.s
@@ -0,0 +1,8 @@
+	.text
+	.thumb
+	.syntax unified
+	.thumb_func
+f:
+	nop.w
+	.long 0xbf080000
+	nop.w
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 8c0648a..130a4a7 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,8 @@
+2016-01-25  Renlin Li  <renlin.li@arm.com>
+
+	* arm-dis.c (mapping_symbol_for_insn): New function.
+	(find_ifthen_state): Call mapping_symbol_for_insn().
+
 2016-01-20  Matthew Wahab  <matthew.wahab@arm.com>
 
 	* aarch64-opc.c (operand_general_constraint_met_p): Check validity
diff --git a/opcodes/arm-dis.c b/opcodes/arm-dis.c
index 56da264..481270e 100644
--- a/opcodes/arm-dis.c
+++ b/opcodes/arm-dis.c
@@ -5947,6 +5947,10 @@ parse_disassembler_options (char *options)
     }
 }
 
+static bfd_boolean
+mapping_symbol_for_insn (bfd_vma pc, struct disassemble_info *info,
+			 enum map_type *map_symbol);
+
 /* Search back through the insn stream to determine if this instruction is
    conditionally executed.  */
 
@@ -6009,9 +6013,15 @@ find_ifthen_state (bfd_vma pc,
 	}
       if ((insn & 0xff00) == 0xbf00 && (insn & 0xf) != 0)
 	{
-	  /* This could be an IT instruction.  */
-	  seen_it = insn;
-	  it_count = count >> 1;
+	  enum map_type type = MAP_ARM;
+	  bfd_boolean found = mapping_symbol_for_insn (addr, info, &type);
+
+	  if (!found || (found && type == MAP_THUMB))
+	    {
+	      /* This could be an IT instruction.  */
+	      seen_it = insn;
+	      it_count = count >> 1;
+	    }
 	}
       if ((insn & 0xf800) >= 0xe800)
 	count++;
@@ -6095,6 +6105,71 @@ get_sym_code_type (struct disassemble_info *info,
   return FALSE;
 }
 
+/* Search the mapping symbol state for instruction at pc.  This is only
+   applicable for elf target.
+
+   There is an assumption Here, info->private_data contains the correct AND
+   up-to-date information about current scan process.  The information will be
+   used to speed this search process.
+
+   Return TRUE if the mapping state can be determined, and map_symbol
+   will be updated accordingly.  Otherwise, return FALSE.  */
+
+static bfd_boolean
+mapping_symbol_for_insn (bfd_vma pc, struct disassemble_info *info,
+			 enum map_type *map_symbol)
+{
+  bfd_vma addr;
+  int n, start = 0;
+  bfd_boolean found = FALSE;
+  enum map_type type = MAP_ARM;
+  struct arm_private_data *private_data;
+
+  if (info->private_data == NULL || info->symtab_size == 0
+      || bfd_asymbol_flavour (*info->symtab) != bfd_target_elf_flavour)
+    return FALSE;
+
+  private_data = info->private_data;
+  if (pc == 0)
+    start = 0;
+  else
+    start = private_data->last_mapping_sym;
+
+  start = (start == -1)? 0 : start;
+  addr = bfd_asymbol_value (info->symtab[start]);
+
+  if (pc >= addr)
+    {
+      if (get_map_sym_type (info, start, &type))
+      found = TRUE;
+    }
+  else
+    {
+      for (n = start - 1; n >= 0; n--)
+	{
+	  if (get_map_sym_type (info, n, &type))
+	    {
+	      found = TRUE;
+	      break;
+	    }
+	}
+    }
+
+  /* No mapping symbols were found.  A leading $d may be
+     omitted for sections which start with data; but for
+     compatibility with legacy and stripped binaries, only
+     assume the leading $d if there is at least one mapping
+     symbol in the file.  */
+  if (!found && private_data->has_mapping_symbols == 1)
+    {
+      type = MAP_DATA;
+      found = TRUE;
+    }
+
+  *map_symbol = type;
+  return found;
+}
+
 /* Given a bfd_mach_arm_XXX value, this function fills in the fields
    of the supplied arm_feature_set structure with bitmasks indicating
    the support base architectures and coprocessor extensions.