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[commit] Improve Xtensa Call0 ABI prologue analysis
- From: Maxim Grigoriev <maxim at tensilica dot com>
- To: "gdb-patches at sourceware dot org" <gdb-patches at sourceware dot org>
- Date: Wed, 21 Oct 2009 11:50:36 -0700
- Subject: [commit] Improve Xtensa Call0 ABI prologue analysis
Improve handling Xtensa CALL0 ABI by making prologue analysis more reliable.
2009-10-21 Maxim Grigoriev <maxim2405@gmail.com>
* xtensa-tdep.c (XTENSA_ISA_BADPC): New.
(xtensa_scan_prologue): Replace read_memory with target_read_memory.
(call0_analyze_prologue): Use XTENSA_ISA_BADPC instead of "0".
(call0_frame_cache): Check error conditions on call0_analyze_prologue.
Index: gdb/xtensa-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/xtensa-tdep.c,v
retrieving revision 1.40
diff -u -r1.40 xtensa-tdep.c
--- gdb/xtensa-tdep.c 19 Sep 2009 03:56:31 -0000 1.40
+++ gdb/xtensa-tdep.c 21 Oct 2009 18:30:07 -0000
@@ -1046,7 +1046,8 @@
/* Returns the best guess about which register is a frame pointer
for the function containing CURRENT_PC. */
-#define XTENSA_ISA_BSZ 32 /* Instruction buffer size. */
+#define XTENSA_ISA_BSZ 32 /* Instruction buffer size. */
+#define XTENSA_ISA_BADPC ((CORE_ADDR)0) /* Bad PC value. */
static unsigned int
xtensa_scan_prologue (struct gdbarch *gdbarch, CORE_ADDR current_pc)
@@ -1083,7 +1084,8 @@
ba = ia;
bt = (ba + XTENSA_ISA_BSZ) < current_pc
? ba + XTENSA_ISA_BSZ : current_pc;
- read_memory (ba, ibuf, bt - ba);
+ if (target_read_memory (ba, ibuf, bt - ba) != 0)
+ RETURN_FP;
}
xtensa_insnbuf_from_chars (isa, ins, &ibuf[ia-ba], 0);
@@ -2171,6 +2173,8 @@
ba = ia;
bt = (ba + XTENSA_ISA_BSZ) < body_pc ? ba + XTENSA_ISA_BSZ : body_pc;
read_memory (ba, ibuf, bt - ba);
+ /* If there is a memory reading error read_memory () will report it
+ and then throw an exception, stopping command execution. */
}
/* Decode format information. */
@@ -2290,7 +2294,7 @@
(unsigned)ia, fail ? "failed" : "succeeded");
xtensa_insnbuf_free(isa, slot);
xtensa_insnbuf_free(isa, ins);
- return fail ? 0 : ia;
+ return fail ? XTENSA_ISA_BADPC : ia;
}
/* Initialize frame cache for the current frame in CALL0 ABI. */
@@ -2315,6 +2319,10 @@
C0_NREGS,
&cache->c0.c0_rt[0],
&cache->call0);
+
+ if (body_pc == XTENSA_ISA_BADPC)
+ error (_("Xtensa-specific internal error: CALL0 prologue \
+analysis failed in this frame. GDB command execution stopped."));
}
sp = get_frame_register_unsigned