[PATCH 01/16] disas: add precise instructions flag

[markus.t.metzger@intel.com]

From: Markus Metzger <markus.t.metzger@intel.com>

When disassembling an address range with interleaved sources, the addresses that
are being disassembled may not exactly match the specified range.

Addresses may be:
  - added after the specified range
  - omitted at the beginning of the specified range

Add a new disassembly flag that fixes the above two cases.

2012-05-23 Markus Metzger <markus.t.metzger@intel.com>

  gdb/
  * disasm.h: Add new flag DISASSEMBLY_PRECISE_INSN
  * disasm.c (do_mixed_source_and_assembly): Adjust mle boundaries


---
 gdb/disasm.c |   28 ++++++++++++++++++++++++----
 gdb/disasm.h |    7 ++++---
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/gdb/disasm.c b/gdb/disasm.c
index e3d3349..4902d95 100644
--- a/gdb/disasm.c
+++ b/gdb/disasm.c
@@ -217,13 +217,22 @@ do_mixed_source_and_assembly (struct gdbarch *gdbarch, struct ui_out *uiout,
 
   /* First, skip all the preceding functions.  */
 
-  for (i = 0; i < nlines - 1 && le[i].pc < low; i++);
+  /* If we want precise instructions, we only skip the line entries for which
+     the pc range between this and the next entry precedes the requested
+     instruction range.  */
+  if (flags & DISASSEMBLY_PRECISE_INSN)
+    for (i = 0; i < nlines - 2 && le[i + 1].pc <= low; i++);
+  else
+    for (i = 0; i < nlines - 1 && le[i].pc < low; i++);
 
   /* Now, copy all entries before the end of this function.  */
 
   for (; i < nlines - 1 && le[i].pc < high; i++)
     {
-      if (le[i].line == le[i + 1].line && le[i].pc == le[i + 1].pc)
+      CORE_ADDR start = le[i].pc;
+      CORE_ADDR end = le[i + 1].pc;
+
+      if (le[i].line == le[i + 1].line && start == end)
 	continue;		/* Ignore duplicates.  */
 
       /* Skip any end-of-function markers.  */
@@ -233,8 +242,19 @@ do_mixed_source_and_assembly (struct gdbarch *gdbarch, struct ui_out *uiout,
       mle[newlines].line = le[i].line;
       if (le[i].line > le[i + 1].line)
 	out_of_order = 1;
-      mle[newlines].start_pc = le[i].pc;
-      mle[newlines].end_pc = le[i + 1].pc;
+
+      /* If we want precise instructions, adjust the line ranges to only contain
+         instructions in the requested range.  */
+      if (flags & DISASSEMBLY_PRECISE_INSN)
+        {
+          if (high < end)
+            end = high;
+          if (start < low)
+            start = low;
+        }
+
+      mle[newlines].start_pc = start;
+      mle[newlines].end_pc = end;
       newlines++;
     }
 
diff --git a/gdb/disasm.h b/gdb/disasm.h
index 646ee8e..5b459f4 100644
--- a/gdb/disasm.h
+++ b/gdb/disasm.h
@@ -19,9 +19,10 @@
 #ifndef DISASM_H
 #define DISASM_H
 
-#define DISASSEMBLY_SOURCE	(0x1 << 0)
-#define DISASSEMBLY_RAW_INSN	(0x1 << 1)
-#define DISASSEMBLY_OMIT_FNAME	(0x1 << 2)
+#define DISASSEMBLY_SOURCE		(0x1 << 0)
+#define DISASSEMBLY_RAW_INSN		(0x1 << 1)
+#define DISASSEMBLY_OMIT_FNAME		(0x1 << 2)
+#define DISASSEMBLY_PRECISE_INSN	(0x1 << 3)
 
 struct ui_out;
 struct ui_file;
-- 
1.7.1