即使我没有提供任何源代码，我也会在 clang 命令上遇到链接器错误。
$ clang
/usr/bin/x86_64-pc-linux-gnu-ld.bfd: /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../lib64/Scrt1.o: in function `_start':
(.text+0x1b): undefined reference to `main'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
$ clang --version
clang version 18.1.8
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/18/bin
Configuration file: /etc/clang/x86_64-pc-linux-gnu-clang.cfg
$ clang -v
clang version 18.1.8
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/18/bin
Configuration file: /etc/clang/x86_64-pc-linux-gnu-clang.cfg
System configuration file directory: /etc/clang
Selected GCC installation: /usr/lib/gcc/x86_64-pc-linux-gnu/13
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
"/usr/bin/x86_64-pc-linux-gnu-ld.bfd" --hash-style=gnu --eh-frame-hdr -m elf_x86_64 -pie -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o a.out /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../lib64/Scrt1.o /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../lib64/crti.o /usr/lib/gcc/x86_64-pc-linux-gnu/13/crtbeginS.o -L/usr/lib/gcc/x86_64-pc-linux-gnu/13 -L/usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../x86_64-pc-linux-gnu/lib -L/lib -L/usr/lib -z relro -z now -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-pc-linux-gnu/13/crtendS.o /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../lib64/crtn.o
/usr/bin/x86_64-pc-linux-gnu-ld.bfd: /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../lib64/Scrt1.o: in function `_start':
(.text+0x1b): undefined reference to `main'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
如果我传递源代码，它就会起作用，但这很奇怪。它应该像 gcc 那样不打印输入错误吗？
$ gcc
gcc: fatal error: no input files
compilation terminated.
我正在使用gentoo，所以也许我的USE标志导致了这个问题？ 或者这是正常行为？
我的 USE 标志以防万一：
$ emerge --info | grep ^USE
USE="X acl amd64 bzip2 cet cjk crypt dbus elogind gdbm grub iconv ipv6 libtirpc multilib ncurses nls openmp pam pcre pipewire pulseaudio readline screencast seccomp ssl test-rust unicode v4l vaapi wayland xattr zlib" ABI_X86="64" ADA_TARGET="gcc_12" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_anon authn_dbm authn_file authz_dbm authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir env expires ext_filter file_cache filter headers include info log_config logio mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="karbon sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="mmx mmxext sse sse2 aes avx avx2 f16c fma3 pclmul popcnt rdrand sse3 sse4_1 sse4_2 ssse3" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 ntrip navcom oceanserver oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 tsip tripmate tnt ublox" GRUB_PLATFORMS="efi-64" GUILE_SINGLE_TARGET="3-0" GUILE_TARGETS="3-0" INPUT_DEVICES="libinput" KERNEL="linux" LCD_DEVICES="bayrad cfontz glk hd44780 lb216 lcdm001 mtxorb text" LUA_SINGLE_TARGET="lua5-1" LUA_TARGETS="lua5-1" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php8-2" POSTGRES_TARGETS="postgres15" PYTHON_SINGLE_TARGET="python3_12" PYTHON_TARGETS="python3_12" RUBY_TARGETS="ruby31 ruby32" VIDEO_CARDS="intel" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipp2p iface geoip fuzzy condition tarpit sysrq proto logmark ipmark dhcpmac delude chaos account"
谢谢。
这是一个已知的 clang 问题。
发生这种情况是因为 Gentoo 的 clang 安装使用配置文件，该文件在幕后添加了链接器标志，如
-Wl,-z,now请参阅：