[sanitizer_common] Only use NT_GNU_BUILD_ID in sanitizer_linux_libcdep.cpp if supported

[ro]

Summary

D114294 broke the Solaris buildbots:

FAILED: projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.i386.dir/sanitizer_linux_libcdep.cpp.o 
/opt/llvm/12/bin/clang++ -DHAVE_RPC_XDR_H=1 -D_DEBUG -D_FILE_OFFSET_BITS=64 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/projects/compiler-rt/lib/sanitizer_common -I/opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/llvm/compiler-rt/lib/sanitizer_common -I/opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/include -I/opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/llvm/llvm/include -I/opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/llvm/llvm/include/llvm/Support/Solaris -I/opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/llvm/compiler-rt/lib/sanitizer_common/.. -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -std=c++14 -Wno-unused-parameter -O3 -DNDEBUG  -m32 -fPIC -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables -fno-stack-protector -fno-sanitize=safe-stack -fvisibility=hidden -fno-lto -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -O3 -gline-tables-only -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions -nostdinc++ -Wno-format -fno-rtti -Wframe-larger-than=570 -Wglobal-constructors -DSANITIZER_SUPPORTS_WEAK_HOOKS=0 -UNDEBUG -std=c++14 -MD -MT projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.i386.dir/sanitizer_linux_libcdep.cpp.o -MF projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.i386.dir/sanitizer_linux_libcdep.cpp.o.d -o projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.i386.dir/sanitizer_linux_libcdep.cpp.o -c /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/llvm/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp
/opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/llvm/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp:613:29: error: use of undeclared identifier 'NT_GNU_BUILD_ID'
        if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == kGnuNamesz) {
                            ^

Like D107556, it forgot that NT_GNU_BUILD_ID is an unportable GNU extension.

Fixed by making the code conditional on the definition of the macro.

Tested on amd64-pc-solaris2.11 and sparcv9-sun-solaris2.11.

[MaskRay]

LGTM

[fmayer]

thanks!

compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp

for (int i = 0; i < (int)info->dlpi_phnum; i++) {
     if (phdr->p_type == PT_LOAD) {
       uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
       uptr cur_end = cur_beg + phdr->p_memsz;
       bool executable = phdr->p_flags & PF_X;
       bool writable = phdr->p_flags & PF_W;
       cur_module.addAddressRange(cur_beg, cur_end, executable,
                                  writable);
     } else if (phdr->p_type == PT_NOTE) {
+#  ifdef NT_GNU_BUILD_ID
       uptr off = 0;
       while (off + sizeof(ElfW(Nhdr)) < phdr->p_memsz) {
         auto *nhdr = reinterpret_cast<const ElfW(Nhdr) *>(info->dlpi_addr +
                                                           phdr->p_vaddr + off);
         constexpr auto kGnuNamesz = 4;  // "GNU" with NUL-byte.
         static_assert(kGnuNamesz % 4 == 0, "kGnuNameSize is aligned to 4.");
         if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == kGnuNamesz) {
           if (off + sizeof(ElfW(Nhdr)) + nhdr->n_namesz + nhdr->n_descsz >
#  ifdef NT_GNU_BUILD_ID
                                 sizeof(*nhdr) + kGnuNamesz;
             cur_module.setUuid(value, nhdr->n_descsz);
             break;
           }
         }
         off += sizeof(*nhdr) + RoundUpTo(nhdr->n_namesz, 4) +
                RoundUpTo(nhdr->n_descsz, 4);
       }
+#  endif
     }
   }
   modules->push_back(cur_module);
   return 0;
 }
 
 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
   DlIteratePhdrData *data = (DlIteratePhdrData *)arg;