From 782d47dfbdfde099cccd06a944e843368cccda76 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Fri, 6 Dec 2013 19:48:00 +0000 Subject: Fix "info frame" in the outermost frame. Doing "info frame" in the outermost frame, when that was indicated by the next frame saying the unwound PC is undefined/not saved, results in error and incomplete output: (gdb) bt #0 thread_function0 (arg=0x0) at threads.c:63 #1 0x00000034cf407d14 in start_thread (arg=0x7ffff7fcb700) at pthread_create.c:309 #2 0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115 (gdb) frame 2 #2 0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115 115 call *%rax (gdb) info frame Stack level 2, frame at 0x0: rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip Register 16 was not saved (gdb) Not saved register values are treated as optimized out values internally throughout. stack.c:frame_info is handing unvailable values, but not optimized out ones. The patch deletes the frame_unwind_caller_pc_if_available wrapper function and instead lets errors propagate to frame_info (it's only user). As frame_unwind_pc now needs to be able to handle and cache two different error scenarios, the prev_pc.p variable is replaced with an enumeration. (FWIW, I looked into making gdbarch_unwind_pc or a variant return struct value's instead, but it results in lots of boxing and unboxing for no real gain -- e.g., the mips and arm implementations need to do computation on the unboxed PC value. Might as well throw an error on first attempt to get at invalid contents.) After the patch, we get: (gdb) info frame Stack level 2, frame at 0x0: rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip = Outermost frame: outermost caller of frame at 0x7ffff7fcafc0 source language asm. Arglist at 0x7ffff7fcafb8, args: Locals at 0x7ffff7fcafb8, Previous frame's sp is 0x7ffff7fcafc8 (gdb) A new test is added. It's based off dw2-reg-undefined.exp, and tweaked to mark the return address (rip) of "stop_frame" as undefined. Tested on x86_64 Fedora 17. gdb/ 2013-12-06 Pedro Alves * frame.c (enum cached_copy_status): New enum. (struct frame_info) : Change type to enum cached_copy_status. (fprint_frame): Handle not saved and unavailable prev_pc values. (frame_unwind_pc_if_available): Delete and merge contents into ... (frame_unwind_pc): ... here. Handle OPTIMIZED_OUT_ERROR. Adjust to use enum cached_copy_status. (frame_unwind_caller_pc_if_available): Delete. (create_new_frame): Adjust. * frame.h (frame_unwind_caller_pc_if_available): Delete declaration. * stack.c (frame_info): Use frame_unwind_caller_pc instead of frame_unwind_caller_pc_if_available, and handle NOT_AVAILABLE_ERROR and OPTIMIZED_OUT_ERROR errors. * valprint.c (val_print_optimized_out): Use val_print_not_saved. (val_print_not_saved): New function. * valprint.h (val_print_not_saved): Declare. gdb/testsuite/ 2013-12-06 Pedro Alves * gdb.dwarf2/dw2-undefined-ret-addr.S: New file. * gdb.dwarf2/dw2-undefined-ret-addr.c: New file. * gdb.dwarf2/dw2-undefined-ret-addr.exp: New file. --- gdb/frame.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'gdb/frame.h') diff --git a/gdb/frame.h b/gdb/frame.h index a5e1629..f8d5bc1 100644 --- a/gdb/frame.h +++ b/gdb/frame.h @@ -548,14 +548,6 @@ extern void put_frame_register_bytes (struct frame_info *frame, int regnum, extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame); -/* Same as frame_unwind_caller_pc, but returns a boolean indication of - whether the caller PC is determinable (when the PC is unavailable, - it will not be), instead of possibly throwing an error trying to - read unavailable memory or registers. */ - -extern int frame_unwind_caller_pc_if_available (struct frame_info *this_frame, - CORE_ADDR *pc); - /* Discard the specified frame. Restoring the registers to the state of the caller. */ extern void frame_pop (struct frame_info *frame); -- cgit v1.1