[patch v4 01/13] disas: add precise instructions flag

markus.t.metzger
2012-11-27T10:49:33Z

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.

2012-11-27 Markus Metzger <markus.t.metzger@intel.com>

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

---
gdb/disasm.c | 26 ++++++++++++++++++++++----
gdb/disasm.h | 9 +++++----
2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/gdb/disasm.c b/gdb/disasm.c
index 25d87d7..2120add 100644
--- a/gdb/disasm.c
+++ b/gdb/disasm.c
@@ -221,13 +221,22 @@ 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. */
@@ -237,8 +246,17 @@ 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)
+ {
+ end = min (end, high);
+ start = max (start, low);
+ }
+
+ mle[newlines].start_pc = start;
+ mle[newlines].end_pc = end;
newlines++;
}

diff --git a/gdb/disasm.h b/gdb/disasm.h
index a254642..a033b72 100644
--- a/gdb/disasm.h
+++ b/gdb/disasm.h
@@ -19,10 +19,11 @@
#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_FILENAME (0x1 << 3)
+#define DISASSEMBLY_SOURCE (0x1 << 0)
+#define DISASSEMBLY_RAW_INSN (0x1 << 1)
+#define DISASSEMBLY_OMIT_FNAME (0x1 << 2)
+#define DISASSEMBLY_FILENAME (0x1 << 3)
+#define DISASSEMBLY_PRECISE_INSN (0x1 << 4)

struct ui_out;
struct ui_file;
--
1.7.1