undefined reference to main

[yetist]

新世界使用 rust 编译 librsvg，在编译其中一个库 proc-macro2 时，在链接阶段报错: undefined reference to main

详细信息如下：

error: linking with `cc` failed: exit status: 1
  |                                            
  = note: "cc" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.0.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build
/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.1.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_s
cript_build.e30a32e1-cgu.10.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.11.rcgu.o" "/archlinux/build/librsvg/src/librsv
g/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.12.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4
b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.13.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.14.rcgu.o" "/archlinux/b
uild/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.15.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1
e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.2.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.3.
rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.4.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-m
acro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.5.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_b
uild.e30a32e1-cgu.6.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.7.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/
release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.build_script_build.e30a32e1-cgu.8.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27d
cd1e6.build_script_build.e30a32e1-cgu.9.rcgu.o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6.23ewl4ikofxq5i5v.rcgu.o" "-Wl,--as-needed" "-L" "/archlinux/build/l
ibrsvg/src/librsvg/target/release/deps" "-L" "/usr/lib64/rustlib/loongarch64-unknown-linux-gnu/lib" "-Wl,--start-group" "-Wl,-Bstatic" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libstd-e45cf875b9375bb0.rlib" "/usr/lib/rustlib/loon
garch64-unknown-linux-gnu/lib/libpanic_unwind-01ed1759f346a29f.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libminiz_oxide-95731f3f5bdd5286.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libadler-fb646b0162bea90e.rl
ib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libobject-efb6496e33c03c13.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libmemchr-6be70ae260cf41b4.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libaddr2line-
de981609553d1179.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libgimli-5ec606accfe21773.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libstd_detect-7a92f7b8f5083e0e.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux
-gnu/lib/librustc_demangle-8b489dc20266b0e9.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libhashbrown-12918ac802989fe3.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/librustc_std_workspace_alloc-f7d9b047dd68e7d7.rli
b" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libunwind-937da1471c4aaa24.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libcfg_if-5e13808e7d636159.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/liblibc-7b79b1
f641133a96.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/liballoc-304a2d21d195bc36.rlib" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/librustc_std_workspace_core-f6725d145d7e6d85.rlib" "/usr/lib/rustlib/loongarch64-unkno
wn-linux-gnu/lib/libcore-b7107a83be44bb5a.rlib" "-Wl,--end-group" "/usr/lib/rustlib/loongarch64-unknown-linux-gnu/lib/libcompiler_builtins-f71783c5179395b9.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-lu
til" "-Wl,--eh-frame-hdr" "-Wl,-znoexecstack" "-L" "/usr/lib64/rustlib/loongarch64-unknown-linux-gnu/lib" "-o" "/archlinux/build/librsvg/src/librsvg/target/release/build/proc-macro2-4b2f7c5e27dcd1e6/build_script_build-4b2f7c5e27dcd1e6" "-W
l,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs"                                                                                                                                                                             
  = note: /usr/bin/ld: /usr/lib/gcc/loongarch64-unknown-linux-gnu/12.0.1/../../../../lib64/Scrt1.o: in function `L0':  
          /archlinux/build/glibc/src/glibc-2.35/csu/../sysdeps/loongarch/start.S:49: undefined reference to `main'     
          /usr/bin/ld: /archlinux/build/glibc/src/glibc-2.35/csu/../sysdeps/loongarch/start.S:49: undefined reference to `main'                                                                                                                
          /usr/bin/ld: /archlinux/build/glibc/src/glibc-2.35/csu/../sysdeps/loongarch/start.S:49: undefined reference to `main'                                                                                                                
          /usr/bin/ld: /archlinux/build/glibc/src/glibc-2.35/csu/../sysdeps/loongarch/start.S:49: undefined reference to `main'                                                                                                                
          /usr/bin/ld: /archlinux/build/glibc/src/glibc-2.35/csu/../sysdeps/loongarch/start.S:49: undefined reference to `main'                                                                                                                
          /usr/bin/ld: /usr/lib/gcc/loongarch64-unknown-linux-gnu/12.0.1/../../../../lib64/Scrt1.o:/archlinux/build/glibc/src/glibc-2.35/csu/../sysdeps/loongarch/start.S:49: more undefined references to `main' follow                       
          collect2: error: ld returned 1 exit status                                                                                                                                                                                           
                                                    
  = help: some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified                                                                                                               
  = note: use the `-l` flag to specify native libraries to link                                                                                                                                                                                
  = note: use the `cargo:rustc-link-lib` directive to specify the native libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorustc-link-libkindname)                                           
                                                                                                                                                                                                                                               
error: could not compile `proc-macro2` due to previous error

这个情况感觉跟 aarch64 上这个注释说的情况很像：

glibc/sysdeps/aarch64/start.S

Lines 86 to 94 in 02cae44

	#if defined PIC && !defined SHARED
	/* When main is not defined in the executable but in a shared library
	then a wrapper is needed in crt1.o of the static-pie enabled libc,
	because crt1.o and rcrt1.o share code and the later must avoid the
	use of GOT relocations before __libc_start_main is called. */
	__wrap_main:
	BTI_C
	b main
	#endif

系统中使用的 gcc 确实也启用了--enable-static-pie：

$ gcc -v
使用内建 specs。
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/loongarch64-unknown-linux-gnu/12.0.1/lto-wrapper
目标：loongarch64-unknown-linux-gnu
配置为：/archlinux/build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,lto,objc,obj-c++ --with-isl --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-static-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-install-libiberty --enable-linker-build-id --enable-lto --disable-multiarch --enable-plugin --enable-shared --enable-threads=posix --enable-libssp --disable-libstdcxx-pch --disable-libunwind-exceptions --enable-link-serialization=1 --enable-tls --disable-werror
线程模型：posix
Supported LTO compression algorithms: zlib zstd
gcc 版本 12.0.1 20220317 (experimental) (GCC) 

请确认这是否是个 bug，谢谢