From: Carl Love Date: Tue, 15 Nov 2022 16:57:32 +0000 (-0600) Subject: Bug fix in commit for printing the function return value for non-trivial values X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d2bbd19d8e16370ebb853e2bf436e5b282177830;p=binutils-gdb.git Bug fix in commit for printing the function return value for non-trivial values The recent commit: commit a0eda3df5b750ae32576a9be092b361281a41787 Author: Carl Love Date: Mon Nov 14 16:22:37 2022 -0500 PowerPC, fix support for printing the function return value for non-trivial values. Is generating a segmentation fault on x86_64-linux. segfault: ... PASS: gdb.asm/asm-source.exp: info source asmsrc1.s ERROR: GDB process no longer exists UNRESOLVED: gdb.asm/asm-source.exp: finish from foo3 ... Reproduced on command line: ... $ gdb -q -batch -x outputs/gdb.asm/asm-source/gdb.in.1 ... The problem seems to be that: ... Thread 1 "gdb" received signal SIGSEGV, Segmentation fault. 0x000000000043de7a in symbol::type (this=0x0) at .../gdb_versions/devel/src/gdb/symtab.h:1287 1287 return m_type; ... because: ... (gdb) up #1 0x0000000000852d94 in finish_command (arg=0x0, from_tty=0) at .../gdb_versions/devel/src/gdb/infcmd.c:1887 1887 = check_typedef (sm->function->type ()->target_type ()); (gdb) p sm->function $1 = (symbol *) 0x0 The code is not checking if sm->function is NULL. If sm->function is NULL the check for the return buffer should be skipped. --- diff --git a/gdb/infcmd.c b/gdb/infcmd.c index b71dc10370b..a72df2d6a01 100644 --- a/gdb/infcmd.c +++ b/gdb/infcmd.c @@ -1877,26 +1877,28 @@ finish_command (const char *arg, int from_tty) /* Find the function we will return from. */ frame_info_ptr callee_frame = get_selected_frame (NULL); sm->function = find_pc_function (get_frame_pc (callee_frame)); + sm->return_buf = 0; /* Initialize buffer address is not available. */ /* Determine the return convention. If it is RETURN_VALUE_STRUCT_CONVENTION, attempt to determine the address of the return buffer. */ - enum return_value_convention return_value; - struct gdbarch *gdbarch = get_frame_arch (callee_frame); + if (sm->function != NULL) + { + enum return_value_convention return_value; + struct gdbarch *gdbarch = get_frame_arch (callee_frame); - struct type * val_type - = check_typedef (sm->function->type ()->target_type ()); + struct type * val_type + = check_typedef (sm->function->type ()->target_type ()); - return_value = gdbarch_return_value (gdbarch, - read_var_value (sm->function, NULL, - callee_frame), - val_type, NULL, NULL, NULL); + return_value = gdbarch_return_value (gdbarch, + read_var_value (sm->function, NULL, + callee_frame), + val_type, NULL, NULL, NULL); - if (return_value == RETURN_VALUE_STRUCT_CONVENTION - && val_type->code () != TYPE_CODE_VOID) - sm->return_buf = gdbarch_get_return_buf_addr (gdbarch, val_type, - callee_frame); - else - sm->return_buf = 0; + if (return_value == RETURN_VALUE_STRUCT_CONVENTION + && val_type->code () != TYPE_CODE_VOID) + sm->return_buf = gdbarch_get_return_buf_addr (gdbarch, val_type, + callee_frame); + } /* Print info on the selected frame, including level number but not source. */