Message-ID: <54BD2C4B.7010102@gmail.com>
Date: Tue, 20 Jan 2015 00:09:47 +0800
From: Wei-cheng Wang <cole945 at gmail dot com>
To: Joel Brobecker <brobecker at adacore dot com>
CC: Ulrich Weigand <uweigand at de dot ibm dot com>, gdb-patches at sourceware dot org
Subject: Re: [PATCH 2/3 v4] Process record support for PowerPC
On 2015/1/19 下午 03:48, Joel Brobecker wrote:
>> Using %s+paddress instead of %lx+long in this patch.
> The change looks fine to me, but there is no ChangeLog.
Hi Joel,
ChangeLog is in my last mail. Re-post below for your review.
2015-01-18 Wei-cheng Wang <cole945@gmail.com>
* rs6000-tdep.c (ppc_process_record_op4, ppc_process_record_op19,
ppc_process_record_op31, ppc_process_record_op59,
ppc_process_record_op60, ppc_process_record_op63,
ppc_process_record): Fix -Wformat warning.
* rs6000-tdep.c (rs6000_epilogue_frame_cache, ppc_process_record_op60):
Remove unused variables.
> Also, I ended glancing at some of the patches you recently pushed,
> and noticed that you added a lot of new functions for which there
> is no introductory comment describing the function's behavior and
> arguments. It is now mandatory that all new functions, no matter
> how trivial, have such introductory comment. Would you mind going
> back over your patches, and send a patch that adds the missing
> comments, please?
I've added the missing comments. See below.
Thanks,
Wei-cheng
2015-01-18 Wei-cheng Wang <cole945@gmail.com>
* ppc-linux-tdep.c (ppc_skip_trampoline_code,
ppc_canonicalize_syscall, ppc_linux_syscall_record,
ppc_linux_record_signal, ppc_init_linux_record_tdep): Add comments.
* ppc64-tdep.c (ppc64_skip_trampoline_code): Likewise.
* rs6000-tdep.c (rs6000_epilogue_frame_cache,
rs6000_epilogue_frame_this_id, rs6000_epilogue_frame_prev_register,
rs6000_epilogue_frame_sniffer, ppc_record_vsr, ppc_process_record_op4,
ppc_process_record_op19, ppc_process_record_op31,
ppc_process_record_op59, ppc_process_record_op60,
ppc_process_record_op63): Likewise.
commit ddeca1dffbe346eea03b893bf3c5bc46e4439e93
Author: Wei-cheng Wang <cole945@gmail.com>
Date: Mon Jan 19 23:34:07 2015 +0800
Add missing comments in rs6000-tdep.c, ppc64-tdep.c and ppc-linux-tdep.c.
gdb/ChangeLog:
* ppc-linux-tdep.c (ppc_skip_trampoline_code,
ppc_canonicalize_syscall, ppc_linux_syscall_record,
ppc_linux_record_signal, ppc_init_linux_record_tdep): Add comments.
* ppc64-tdep.c (ppc64_skip_trampoline_code): Likewise.
* rs6000-tdep.c (rs6000_epilogue_frame_cache,
rs6000_epilogue_frame_this_id, rs6000_epilogue_frame_prev_register,
rs6000_epilogue_frame_sniffer, ppc_record_vsr, ppc_process_record_op4,
ppc_process_record_op19, ppc_process_record_op31,
ppc_process_record_op59, ppc_process_record_op60,
ppc_process_record_op63): Likewise.
Index: gdb-7.6.1/gdb/ppc64-tdep.c
===================================================================
--- gdb-7.6.1.orig/gdb/ppc64-tdep.c
+++ gdb-7.6.1/gdb/ppc64-tdep.c
@@ -449,7 +449,10 @@ ppc64_standard_linkage4_target (struct f
/* Given that we've begun executing a call trampoline at PC, return
- the entry point of the function the trampoline will go to. */
+ the entry point of the function the trampoline will go to.
+
+ When the execution direction is EXEC_REVERSE, scan backward to
+ check whether we are in the middle of a PLT stub. */
CORE_ADDR
ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
Index: gdb-7.6.1/gdb/ppc-linux-tdep.c
===================================================================
--- gdb-7.6.1.orig/gdb/ppc-linux-tdep.c
+++ gdb-7.6.1/gdb/ppc-linux-tdep.c
@@ -353,7 +353,12 @@ powerpc_linux_in_dynsym_resolve_code (CO
return 0;
}
-/* Follow PLT stub to actual routine. */
+/* Follow PLT stub to actual routine.
+
+ When the execution direction is EXEC_REVERSE, scan backward to
+ check whether we are in the middle of a PLT stub. Currently,
+ we only look-behind at most 4 instructions (the max length of PLT
+ stub sequence. */
static CORE_ADDR
ppc_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
@@ -839,11 +844,16 @@ ppc_linux_get_syscall_number (struct gdb
static struct linux_record_tdep ppc_linux_record_tdep;
static struct linux_record_tdep ppc64_linux_record_tdep;
+/* ppc_canonicalize_syscall maps from the native PowerPC Linux set of
+ syscall ids into a canonical set of syscall ids used by process
+ record. (See arch/powerpc/include/uapi/asm/unistd.h in kernel tree.)
+ Return -1 if this system call is not supported by process record.
+ Otherwise, return the syscall number for preocess reocrd of given
+ SYSCALL. */
+
static enum gdb_syscall
ppc_canonicalize_syscall (int syscall)
{
- /* See arch/powerpc/include/uapi/asm/unistd.h */
-
if (syscall <= 165)
return syscall;
else if (syscall >= 167 && syscall <= 190) /* Skip query_module 166 */
@@ -869,6 +879,9 @@ ppc_canonicalize_syscall (int syscall)
return -1;
}
+/* Record registers which might be clobbered during system call.
+ Return 0 if successful. */
+
static int
ppc_linux_syscall_record (struct regcache *regcache)
{
@@ -949,6 +962,9 @@ ppc_linux_syscall_record (struct regcach
return 0;
}
+/* Record registers which might be clobbered during signal handling.
+ Return 0 if successful. */
+
static int
ppc_linux_record_signal (struct gdbarch *gdbarch, struct regcache *regcache,
enum gdb_signal signal)
@@ -1470,7 +1486,9 @@ static const struct frame_unwind ppu2spu
ppu2spu_prev_arch,
};
-/* Initialize linux_record_tdep if not initialized yet. */
+/* Initialize linux_record_tdep if not initialized yet.
+ WORDSIZE is 4 or 8 for 32- or 64-bit PowerPC Linux respectively.
+ Sizes of data structures are initialized accordingly. */
static void
ppc_init_linux_record_tdep (struct linux_record_tdep *record_tdep,
Index: gdb-7.6.1/gdb/rs6000-tdep.c
===================================================================
--- gdb-7.6.1.orig/gdb/rs6000-tdep.c
+++ gdb-7.6.1/gdb/rs6000-tdep.c
@@ -3398,6 +3398,9 @@ static const struct frame_unwind rs6000_
default_frame_sniffer
};
+/* Allocate and initialize a frame cache for an epilogue frame.
+ SP is restored and prev-PC is stored in LR. */
+
static struct rs6000_frame_cache *
rs6000_epilogue_frame_cache (struct frame_info *this_frame, void **this_cache)
{
@@ -3434,6 +3437,9 @@ rs6000_epilogue_frame_cache (struct fram
return cache;
}
+/* Implementation of frame_unwind.this_id, as defined in frame_unwind.h.
+ Return the frame ID of an epilogue frame. */
+
static void
rs6000_epilogue_frame_this_id (struct frame_info *this_frame,
void **this_cache, struct frame_id *this_id)
@@ -3449,6 +3455,9 @@ rs6000_epilogue_frame_this_id (struct fr
(*this_id) = frame_id_build (info->base, pc);
}
+/* Implementation of frame_unwind.prev_register, as defined in frame_unwind.h.
+ Return the register value of REGNUM in previous frame. */
+
static struct value *
rs6000_epilogue_frame_prev_register (struct frame_info *this_frame,
void **this_cache, int regnum)
@@ -3458,6 +3467,9 @@ rs6000_epilogue_frame_prev_register (str
return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum);
}
+/* Implementation of frame_unwind.sniffer, as defined in frame_unwind.h.
+ Check whether this an epilogue frame. */
+
static int
rs6000_epilogue_frame_sniffer (const struct frame_unwind *self,
struct frame_info *this_frame,
@@ -3471,6 +3483,9 @@ rs6000_epilogue_frame_sniffer (const str
return 0;
}
+/* Frame unwinder for epilogue frame. This is required for reverse step-over
+ a function without debug information. */
+
static const struct frame_unwind rs6000_epilogue_frame_unwind =
{
NORMAL_FRAME,
@@ -3717,7 +3732,9 @@ bfd_uses_spe_extensions (bfd *abfd)
#define PPC_XT(insn) ((PPC_TX (insn) << 5) | PPC_T (insn))
#define PPC_XER_NB(xer) (xer & 0x7f)
-/* Record Vector-Scalar Registers. */
+/* Record Vector-Scalar Registers.
+ For VSR less than 32, it's represented by an FPR and an VSR-upper register.
+ Otherwise, it's just a VR register. Record them accordingly. */
static int
ppc_record_vsr (struct regcache *regcache, struct gdbarch_tdep *tdep, int vsr)
@@ -3742,11 +3759,12 @@ ppc_record_vsr (struct regcache *regcach
return 0;
}
-/* Parse instructions of primary opcode-4. */
+/* Parse and record instructions primary opcode-4 at ADDR.
+ Return 0 if successful. */
static int
ppc_process_record_op4 (struct gdbarch *gdbarch, struct regcache *regcache,
- CORE_ADDR addr, uint32_t insn)
+ CORE_ADDR addr, uint32_t insn)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
int ext = PPC_FIELD (insn, 21, 11);
@@ -4010,7 +4028,8 @@ ppc_process_record_op4 (struct gdbarch *
return -1;
}
-/* Parse instructions of primary opcode-19. */
+/* Parse and record instructions of primary opcode-19 at ADDR.
+ Return 0 if successful. */
static int
ppc_process_record_op19 (struct gdbarch *gdbarch, struct regcache *regcache,
@@ -4053,7 +4072,8 @@ ppc_process_record_op19 (struct gdbarch
return -1;
}
-/* Parse instructions of primary opcode-31. */
+/* Parse and record instructions of primary opcode-31 at ADDR.
+ Return 0 if successful. */
static int
ppc_process_record_op31 (struct gdbarch *gdbarch, struct regcache *regcache,
@@ -4531,7 +4551,8 @@ UNKNOWN_OP:
return -1;
}
-/* Parse instructions of primary opcode-59. */
+/* Parse and record instructions of primary opcode-59 at ADDR.
+ Return 0 if successful. */
static int
ppc_process_record_op59 (struct gdbarch *gdbarch, struct regcache *regcache,
@@ -4623,7 +4644,8 @@ ppc_process_record_op59 (struct gdbarch
return -1;
}
-/* Parse instructions of primary opcode-60. */
+/* Parse and record instructions of primary opcode-60 at ADDR.
+ Return 0 if successful. */
static int
ppc_process_record_op60 (struct gdbarch *gdbarch, struct regcache *regcache,
@@ -4905,7 +4927,8 @@ ppc_process_record_op60 (struct gdbarch
return -1;
}
-/* Parse instructions of primary opcode-63. */
+/* Parse and record instructions of primary opcode-63 at ADDR.
+ Return 0 if successful. */
static int
ppc_process_record_op63 (struct gdbarch *gdbarch, struct regcache *regcache,