From ddeca1dffbe346eea03b893bf3c5bc46e4439e93 Mon Sep 17 00:00:00 2001 From: Wei-cheng Wang Date: Mon, 19 Jan 2015 23:34:07 +0800 Subject: [PATCH] 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. --- gdb/ChangeLog | 13 +++++++++++++ gdb/ppc-linux-tdep.c | 26 ++++++++++++++++++++++---- gdb/ppc64-tdep.c | 5 ++++- gdb/rs6000-tdep.c | 39 +++++++++++++++++++++++++++++++-------- 4 files changed, 70 insertions(+), 13 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 8a7e1b08a39..bdaa209e914 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2015-01-21 Wei-cheng Wang + + * 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. + 2015-01-20 Joel Brobecker * nat/linux-ptrace.c (linux_ptrace_attach_fail_reason_string) diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c index 13bb479fe3a..a7b11635716 100644 --- a/gdb/ppc-linux-tdep.c +++ b/gdb/ppc-linux-tdep.c @@ -305,7 +305,12 @@ powerpc_linux_in_dynsym_resolve_code (CORE_ADDR pc) 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) @@ -791,11 +796,16 @@ ppc_linux_get_syscall_number (struct gdbarch *gdbarch, 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 */ @@ -821,6 +831,9 @@ 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) { @@ -901,6 +914,9 @@ ppc_linux_syscall_record (struct regcache *regcache) 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) @@ -1417,7 +1433,9 @@ static const struct frame_unwind ppu2spu_unwind = { 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, diff --git a/gdb/ppc64-tdep.c b/gdb/ppc64-tdep.c index 66d7b2362e1..bb23b6a2ee3 100644 --- a/gdb/ppc64-tdep.c +++ b/gdb/ppc64-tdep.c @@ -449,7 +449,10 @@ ppc64_standard_linkage4_target (struct frame_info *frame, /* 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) diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c index 1dd6165331e..ef94bba58b2 100644 --- a/gdb/rs6000-tdep.c +++ b/gdb/rs6000-tdep.c @@ -3349,6 +3349,9 @@ static const struct frame_unwind rs6000_frame_unwind = 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) { @@ -3385,6 +3388,9 @@ rs6000_epilogue_frame_cache (struct frame_info *this_frame, void **this_cache) 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) @@ -3400,6 +3406,9 @@ rs6000_epilogue_frame_this_id (struct frame_info *this_frame, (*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) @@ -3409,6 +3418,9 @@ rs6000_epilogue_frame_prev_register (struct frame_info *this_frame, 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, @@ -3422,6 +3434,9 @@ rs6000_epilogue_frame_sniffer (const struct frame_unwind *self, 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, @@ -3668,7 +3683,9 @@ 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) @@ -3693,11 +3710,12 @@ ppc_record_vsr (struct regcache *regcache, struct gdbarch_tdep *tdep, int vsr) 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); @@ -3961,7 +3979,8 @@ ppc_process_record_op4 (struct gdbarch *gdbarch, struct regcache *regcache, 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, @@ -4004,7 +4023,8 @@ ppc_process_record_op19 (struct gdbarch *gdbarch, struct regcache *regcache, 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, @@ -4482,7 +4502,8 @@ 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, @@ -4574,7 +4595,8 @@ ppc_process_record_op59 (struct gdbarch *gdbarch, struct regcache *regcache, 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, @@ -4856,7 +4878,8 @@ ppc_process_record_op60 (struct gdbarch *gdbarch, struct regcache *regcache, 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, -- 2.30.2