The large arrays are now allocated on heap instead of in BSS. This
actually feels like a pretty stupid linker limitation, and the
workaround leads to code that is less readable. But it only impacts
the test program.
The issue was reported with GCC 7.3.0 and compiling for 64-bit arch on
MSYS2's MinGW compiler. GCC 7.3.0 for 64-bit on Linux (my own machine
and Travis) seems perfectly OK with a large BSS segment (around 3 GB
is what the test program uses for test data).
Reported issue:
$ make
cc -Wall -Wextra -Wpedantic -c -o test.o test.c
cc -Wall -Wextra -Wpedantic -c -o sha-256.o sha-256.c
cc test.o sha-256.o -o test
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/crt2.o: in function `__tmainCRTStartup':
C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:251:(.text+0x1cd): relocation truncated to fit: R_X86_64_PC32 against symbol `__imp_Sleep' defined in .idata$5 section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libkernel32.a(dkhchs01360.o)
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:278:(.text+0x255): relocation truncated to fit: R_X86_64_PC32 against symbol `__imp_SetUnhandledExceptionFilter' defined in .idata$5 section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libkernel32.a(dkhchs01346.o)
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:286:(.text+0x283): relocation truncated to fit: R_X86_64_PC32 against symbol `__mingw_winmain_hInstance' defined in COMMON section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/crt2.o
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:312:(.text+0x2f3): relocation truncated to fit: R_X86_64_PC32 against symbol `__mingw_winmain_lpCmdLine' defined in COMMON section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/crt2.o
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:238:(.text+0x475): relocation truncated to fit: R_X86_64_PC32 against symbol `__imp_GetStartupInfoA' defined in .idata$5 section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libkernel32.a(dkhchs00721.o)
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-gccmain.o): in function `__main':
C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/gccmain.c:74:(.text+0xb2): relocation truncated to fit: R_X86_64_PC32 against `.bss'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/gccmain.c:76:(.text+0xc2): relocation truncated to fit: R_X86_64_PC32 against `.bss'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-charmax.o): in function `my_lconv_init':
C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/charmax.c:19:(.text+0x3): relocation truncated to fit: R_X86_64_PC32 against symbol `__imp___lconv_init' defined in .idata$5 section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libmsvcrt.a(dkxcbs00090.o)
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-gs_support.o): in function `__security_init_cookie':
C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/gs_support.c:62:(.text+0x47): relocation truncated to fit: R_X86_64_PC32 against symbol `__imp_GetSystemTimeAsFileTime' defined in .idata$5 section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libkernel32.a(dkhchs00746.o)
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/gs_support.c:70:(.text+0x52): relocation truncated to fit: R_X86_64_PC32 against symbol `__imp_GetCurrentProcessId' defined in .idata$5 section in C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/lib/../lib/libkernel32.a(dkhchs00536.o)
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/repo/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/gs_support.c:71:(.text+0x5b): additional relocation overflows omitted from the output
collect2.exe: error: ld returned 1 exit status
make: *** [<builtin>: test] Error 1```
