[PATCH 1/6] disasm: change dump_insns to print a single instruction

[Markus Metzger <markus dot t dot metzger at intel dot com>]

In disasm.c, dump_insns is called to print a sequence of instructions.

Rename it to dump_insn and change it to print only a single instruction
and return its length in bytes.  Move the loop over the desired PC range
and number of instructions printed to its callers.

We will update all but the deprecated callers in subsequent patches.

2015-09-21  Markus Metzger <markus.t.metzger@intel.com>

gdb/
	* disasm.c (dump_insns): Rename to ...
	(dump_insn): ... this.  Change it to print a single instruction and
	return its length.  Change parameters and update users.
	(do_mixed_source_and_assembly_deprecated, do_mixed_source_and_assembly)
	(do_assembly_only): Loop over desired PC range and number of
	instructions.
---
 gdb/disasm.c | 202 +++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 114 insertions(+), 88 deletions(-)

diff --git a/gdb/disasm.c b/gdb/disasm.c
index 2b65c6a..981ab7e 100644
--- a/gdb/disasm.c
+++ b/gdb/disasm.c
@@ -170,101 +170,89 @@ compare_lines (const void *mle1p, const void *mle2p)
   return val;
 }
 
+/* Prints the instruction at PC into UIOUT and returns the length of the
+   printed instruction in bytes.  */
+
 static int
-dump_insns (struct gdbarch *gdbarch, struct ui_out *uiout,
-	    struct disassemble_info * di,
-	    CORE_ADDR low, CORE_ADDR high,
-	    int how_many, int flags, struct ui_file *stb,
-	    CORE_ADDR *end_pc)
+dump_insn (struct gdbarch *gdbarch, struct ui_out *uiout,
+	   struct disassemble_info * di, CORE_ADDR pc, int flags,
+	   struct ui_file *stb)
 {
-  int num_displayed = 0;
-  CORE_ADDR pc;
-
   /* parts of the symbolic representation of the address */
   int unmapped;
   int offset;
   int line;
+  int size;
   struct cleanup *ui_out_chain;
+  char *filename = NULL;
+  char *name = NULL;
+
+  ui_out_chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
+
+  if ((flags & DISASSEMBLY_OMIT_PC) == 0)
+    ui_out_text (uiout, pc_prefix (pc));
+  ui_out_field_core_addr (uiout, "address", gdbarch, pc);
 
-  for (pc = low; pc < high;)
+  if (!build_address_symbolic (gdbarch, pc, 0, &name, &offset, &filename,
+			       &line, &unmapped))
     {
-      char *filename = NULL;
-      char *name = NULL;
+      /* We don't care now about line, filename and unmapped.  But we might in
+	 the future.  */
+      ui_out_text (uiout, " <");
+      if ((flags & DISASSEMBLY_OMIT_FNAME) == 0)
+	ui_out_field_string (uiout, "func-name", name);
+      ui_out_text (uiout, "+");
+      ui_out_field_int (uiout, "offset", offset);
+      ui_out_text (uiout, ">:\t");
+    }
+  else
+    ui_out_text (uiout, ":\t");
 
-      QUIT;
-      if (how_many >= 0)
-	{
-	  if (num_displayed >= how_many)
-	    break;
-	  else
-	    num_displayed++;
-	}
-      ui_out_chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
+  if (filename != NULL)
+    xfree (filename);
+  if (name != NULL)
+    xfree (name);
+
+  ui_file_rewind (stb);
+  if (flags & DISASSEMBLY_RAW_INSN)
+    {
+      CORE_ADDR end_pc;
+      bfd_byte data;
+      int status;
+      const char *spacer = "";
+
+      /* Build the opcodes using a temporary stream so we can
+	 write them out in a single go for the MI.  */
+      struct ui_file *opcode_stream = mem_fileopen ();
+      struct cleanup *cleanups =
+	make_cleanup_ui_file_delete (opcode_stream);
 
-      if ((flags & DISASSEMBLY_OMIT_PC) == 0)
-	ui_out_text (uiout, pc_prefix (pc));
-      ui_out_field_core_addr (uiout, "address", gdbarch, pc);
+      size = gdbarch_print_insn (gdbarch, pc, di);
+      end_pc = pc + size;
 
-      if (!build_address_symbolic (gdbarch, pc, 0, &name, &offset, &filename,
-				   &line, &unmapped))
+      for (;pc < end_pc; ++pc)
 	{
-	  /* We don't care now about line, filename and
-	     unmapped. But we might in the future.  */
-	  ui_out_text (uiout, " <");
-	  if ((flags & DISASSEMBLY_OMIT_FNAME) == 0)
-	    ui_out_field_string (uiout, "func-name", name);
-	  ui_out_text (uiout, "+");
-	  ui_out_field_int (uiout, "offset", offset);
-	  ui_out_text (uiout, ">:\t");
+	  status = (*di->read_memory_func) (pc, &data, 1, di);
+	  if (status != 0)
+	    (*di->memory_error_func) (status, pc, di);
+	  fprintf_filtered (opcode_stream, "%s%02x",
+			    spacer, (unsigned) data);
+	  spacer = " ";
 	}
-      else
-	ui_out_text (uiout, ":\t");
-
-      if (filename != NULL)
-	xfree (filename);
-      if (name != NULL)
-	xfree (name);
-
-      ui_file_rewind (stb);
-      if (flags & DISASSEMBLY_RAW_INSN)
-        {
-          CORE_ADDR old_pc = pc;
-          bfd_byte data;
-          int status;
-          const char *spacer = "";
-
-          /* Build the opcodes using a temporary stream so we can
-             write them out in a single go for the MI.  */
-          struct ui_file *opcode_stream = mem_fileopen ();
-          struct cleanup *cleanups =
-            make_cleanup_ui_file_delete (opcode_stream);
-
-          pc += gdbarch_print_insn (gdbarch, pc, di);
-          for (;old_pc < pc; old_pc++)
-            {
-              status = (*di->read_memory_func) (old_pc, &data, 1, di);
-              if (status != 0)
-                (*di->memory_error_func) (status, old_pc, di);
-              fprintf_filtered (opcode_stream, "%s%02x",
-                                spacer, (unsigned) data);
-              spacer = " ";
-            }
-          ui_out_field_stream (uiout, "opcodes", opcode_stream);
-          ui_out_text (uiout, "\t");
-
-          do_cleanups (cleanups);
-        }
-      else
-        pc += gdbarch_print_insn (gdbarch, pc, di);
-      ui_out_field_stream (uiout, "inst", stb);
-      ui_file_rewind (stb);
-      do_cleanups (ui_out_chain);
-      ui_out_text (uiout, "\n");
+      ui_out_field_stream (uiout, "opcodes", opcode_stream);
+      ui_out_text (uiout, "\t");
+
+      do_cleanups (cleanups);
     }
+  else
+    size = gdbarch_print_insn (gdbarch, pc, di);
+
+  ui_out_field_stream (uiout, "inst", stb);
+  ui_file_rewind (stb);
+  do_cleanups (ui_out_chain);
+  ui_out_text (uiout, "\n");
 
-  if (end_pc != NULL)
-    *end_pc = pc;
-  return num_displayed;
+  return size;
 }
 
 /* The idea here is to present a source-O-centric view of a
@@ -359,6 +347,8 @@ do_mixed_source_and_assembly_deprecated
 
   for (i = 0; i < newlines; i++)
     {
+      CORE_ADDR pc;
+
       /* Print out everything from next_line to the current line.  */
       if (mle[i].line >= next_line)
 	{
@@ -412,9 +402,21 @@ do_mixed_source_and_assembly_deprecated
 	    = make_cleanup_ui_out_list_begin_end (uiout, "line_asm_insn");
 	}
 
-      num_displayed += dump_insns (gdbarch, uiout, di,
-				   mle[i].start_pc, mle[i].end_pc,
-				   how_many, flags, stb, NULL);
+      pc = mle[i].start_pc;
+      while (pc < mle[i].end_pc && (how_many < 0 || num_displayed < how_many))
+	{
+	  int size;
+
+	  size = dump_insn (gdbarch, uiout, di, pc, flags, stb);
+	  if (size <= 0)
+	    break;
+
+	  num_displayed += 1;
+	  pc += size;
+
+	  /* Allow user to bail out with ^C.  */
+	  QUIT;
+	}
 
       /* When we've reached the end of the mle array, or we've seen the last
          assembly range for this source line, close out the list/tuple.  */
@@ -672,9 +674,21 @@ do_mixed_source_and_assembly (struct gdbarch *gdbarch, struct ui_out *uiout,
 	end_pc = min (sal.end, high);
       else
 	end_pc = pc + 1;
-      num_displayed += dump_insns (gdbarch, uiout, di, pc, end_pc,
-				   how_many, flags, stb, &end_pc);
-      pc = end_pc;
+
+      while (pc < end_pc && (how_many < 0 || num_displayed < how_many))
+	{
+	  int size;
+
+	  size = dump_insn (gdbarch, uiout, di, pc, flags, stb);
+	  if (size <= 0)
+	    break;
+
+	  num_displayed += 1;
+	  pc += size;
+
+	  /* Allow user to bail out with ^C.  */
+	  QUIT;
+	}
 
       if (how_many >= 0 && num_displayed >= how_many)
 	break;
@@ -693,13 +707,25 @@ do_assembly_only (struct gdbarch *gdbarch, struct ui_out *uiout,
 		  CORE_ADDR low, CORE_ADDR high,
 		  int how_many, int flags, struct ui_file *stb)
 {
-  int num_displayed = 0;
   struct cleanup *ui_out_chain;
+  int num_displayed = 0;
 
   ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");
 
-  num_displayed = dump_insns (gdbarch, uiout, di, low, high, how_many,
-                              flags, stb, NULL);
+  while (low < high && (how_many < 0 || num_displayed < how_many))
+    {
+      int size;
+
+      size = dump_insn (gdbarch, uiout, di, low, flags, stb);
+      if (size <= 0)
+	break;
+
+      num_displayed += 1;
+      low += size;
+
+      /* Allow user to bail out with ^C.  */
+      QUIT;
+    }
 
   do_cleanups (ui_out_chain);
 }
-- 
1.8.3.1