#683 LTO breaks ostream::fil()

[Tavian Barnes]

$ cat foo.cpp
#include <iostream>

int main() {
  std::cout.fill();
  return 0;
}
$ x86_64-w64-mingw32-g++ -O3 -static foo.cpp && wine ./a.exe
$ x86_64-w64-mingw32-g++ -O3 -flto -static foo.cpp && wine ./a.exe
wine: Unhandled page fault on read access to 0x00000000 at address (nil) (thread 0032), starting debugger...
fixme:dbghelp:elf_search_auxv can't find symbol in module
fixme:dbghelp:elf_search_auxv can't find symbol in module
fixme:dbghelp:elf_search_auxv can't find symbol in module
fixme:dbghelp:elf_search_auxv can't find symbol in module
fixme:dbghelp:elf_search_auxv can't find symbol in module
Unhandled exception: page fault on read access to 0x00000000 in 64-bit code (0x0000000000000000).
fixme:dbghelp:elf_search_auxv can't find symbol in module
Register dump:
 rip:0000000000000000 rsp:000000000033fb68 rbp:0000000000d81a70 eflags:00010206 (  R- --  I   - -P- )
 rax:0000000000000020 rbx:00000000004a6ba0 rcx:00000000004a5160 rdx:0000000000000020
 rsi:0000000000000043 rdi:0000000000014f40  r8:0000000000000000  r9:0000000000000006 r10:00000000ffffffff
 r11:0000000000000000 r12:0000000000000001 r13:0000000000000008 r14:0000000000000000 r15:0000000000000000
Stack dump:
0x000000000033fb68:  00000000004a3b48 0000000000000000
0x000000000033fb78:  0000000000000000 0000000000000043
0x000000000033fb88:  0000000000000001 0000000000000001
0x000000000033fb98:  00000000004013f8 0000000000000000
0x000000000033fba8:  0000000000000000 0000000020b235af
0x000000000033fbb8:  01d35424c1be01a4 0000000000000000
0x000000000033fbc8:  0000000000000000 0000000000000000
0x000000000033fbd8:  0000000000000000 0000000000000000
0x000000000033fbe8:  0000000000000000 0000000000000000
0x000000000033fbf8:  0000000000000000 0000000000000000
0x000000000033fc08:  0000000000000000 0000000000000000
0x000000000033fc18:  0000000000000000 0000000000000000
Backtrace:
=>0 0x0000000000000000 (0x0000000000d81a70)
0x0000000000000000: -- no code accessible --
Modules:
Module  Address                                 Debug info      Name (20 modules)
PE                400000-          d72000       Deferred        a
ELF             7b400000-        7b812000       Deferred        kernel32<elf>
  \-PE          7b420000-        7b812000       \               kernel32
ELF             7bc00000-        7bd1b000       Deferred        ntdll<elf>
  \-PE          7bc20000-        7bd1b000       \               ntdll
ELF             7c000000-        7c004000       Deferred        <wine-loader>
ELF         7f348070e000-    7f348093a000       Deferred        libtinfo.so.6
ELF         7f348093a000-    7f3480b72000       Deferred        libncursesw.so.6
ELF         7f3480c72000-    7f3480f53000       Deferred        msvcrt<elf>
  \-PE      7f3480c90000-    7f3480f53000       \               msvcrt
ELF         7f3480f53000-    7f3481165000       Deferred        libnss_files.so.2
ELF         7f3481165000-    7f3481371000       Deferred        libnss_nis.so.2
ELF         7f3481371000-    7f3481589000       Deferred        libnsl.so.1
ELF         7f3481589000-    7f3481791000       Deferred        libnss_compat.so.2
ELF         7f3481ec7000-    7f34820de000       Deferred        libgcc_s.so.1
ELF         7f34820de000-    7f348242a000       Deferred        libm.so.6
ELF         7f348242c000-    7f3482630000       Deferred        libdl.so.2
ELF         7f3482674000-    7f3482a2b000       Deferred        libc.so.6
ELF         7f3482a2b000-    7f3482c49000       Deferred        libpthread.so.0
ELF         7f3482ff0000-    7f3483217000       Deferred        ld-linux-x86-64.so.2
Threads:
process  tid      prio (all id:s are in hex)
0000000e services.exe
        00000022    0
        0000001d    0
        00000013    0
        00000010    0
        0000000f    0
00000011 winedevice.exe
        0000001c    0
        00000017    0
        00000016    0
        00000012    0
0000001a plugplay.exe
        0000001f    0
        0000001e    0
        0000001b    0
00000020 winedevice.exe
        0000002b    0
        00000024    0
        00000023    0
        00000021    0
00000031 (D) Z:\home\tavianator\code\maluuba\NativeNlp\out-windows-x86_64\a.exe
        00000032    0 <==
00000035 explorer.exe
        00000039    0
        00000038    0
        00000037    0
        00000036    0
System information:
    Wine build: wine-2.19
    Platform: x86_64
    Version: Windows XP
    Host system: Linux
    Host version: 4.13.8-1-ARCH

Crashes similarly on native Windows too, so it's not a Wine bug.

[Zufu Liu]

Tried on Win10 with gcc version 7.1.0 (x86_64-posix-seh-rev2, Built by MinGW-W64 project), compile without -static or -static-libstdc++doesn't crash.