Message-ID: <54BD2C4B.7010102@gmail.com> Date: Tue, 20 Jan 2015 00:09:47 +0800 From: Wei-cheng Wang To: Joel Brobecker CC: Ulrich Weigand , 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 * 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 * 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 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,