參考: https://abseil.io/docs/cpp/quickstart-cmake

abseil-cpp.git/dd4c89b == abseil-cpp.git/20240722.1

1. clone代碼倉庫、編譯

git clone https://github.com/abseil/abseil-cpp.git  /app/abseil-cpp/
#/app/abseil-cpp/.git/config
git checkout 20240722.1git rev-parse HEAD
#dd4c89bd657f1e247ce5111a5c89ffe6ccfd0c92cmake -S  /app/abseil-cpp  -B /app/abseil-cpp/build   -DABSL_BUILD_TESTING=OFF -DABSL_USE_GOOGLETEST_HEAD=ON -DCMAKE_CXX_STANDARD=14
cmake --build /app/abseil-cpp/build  --target all
ls /app/abseil-cpp/absl/strings/str_split.h

2. test.cpp

#include <string>
#include <vector>
#include "absl/strings/str_split.h"#include <stdio.h>
int main(int argc, char** argv){std::vector<std::string> v = absl::StrSplit("a,b,c", ',');
printf("v[0]=%s\n",v[0].c_str());return 0;
}

3. 編譯運行

/app/llvm_release_home/clang+llvm-15.0.0-x86_64-linux-gnu-rhel-8.4/bin/clang++  -v   -L /app/abseil-cpp/build/absl/base/ -L /app/abseil-cpp/build/absl/strings/    -l absl_base  -l absl_raw_logging_internal -l absl_throw_delegate   -l absl_string_view   -l absl_strings_internal -l absl_strings      -I /app/abseil-cpp/   test.cpp  -o test.elf &&  ./test.elf

正常運行，并輸出a

3A. 當少給 .a時 鏈接報錯舉例

/app/llvm_release_home/clang+llvm-15.0.0-x86_64-linux-gnu-rhel-8.4/bin/clang++  -v   -L /app/abseil-cpp/build/absl/base/ -L /app/abseil-cpp/build/absl/strings/ -L /app/abseil-cpp/build/absl/log/   -l absl_base  -l absl_log_internal_format -l absl_string_view   -l absl_strings_internal -l absl_strings      -I /app/abseil-cpp/   test.cpp  -o test.elf &&  ./test.elf

報錯

"/usr/bin/ld" -pie -z relro --hash-style=gnu --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o test.elf /lib/x86_64-linux-gnu/Scrt1.o /lib/x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/12/crtbeginS.o -L/app/abseil-cpp/build/absl/base/ -L/app/abseil-cpp/build/absl/strings/ -L/app/abseil-cpp/build/absl/log/ -L/app/llvm_release_home/clang+llvm-15.0.0-x86_64-linux-gnu-rhel-8.4/bin/../lib/x86_64-unknown-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/12 -L/usr/lib/gcc/x86_64-linux-gnu/12/../../../../x86_64-linux-gnu/lib/../lib64 -L/usr/lib/gcc/x86_64-linux-gnu/12/../../../../lib64 -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-linux-gnu/12/../../../../x86_64-linux-gnu/lib -L/lib -L/usr/lib -labsl_base -labsl_log_internal_format -labsl_string_view -labsl_strings_internal -labsl_strings /tmp/test-9d0c36.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/12/crtendS.o /lib/x86_64-linux-gnu/crtn.o
mold: error: undefined symbol: /app/abseil-cpp/build/absl/strings/libabsl_strings.a(str_split.cc.o): absl::lts_20240722::raw_log_internal::RawLog(absl::lts_20240722::LogSeverity, char const*, int, char const*, ...)
mold: error: undefined symbol: /app/abseil-cpp/build/absl/strings/libabsl_strings.a(str_split.cc.o): absl::lts_20240722::base_internal::ThrowStdOutOfRange(char const*)
clang-15: error: linker command failed with exit code 1 (use -v to see invocation)

3B. 報錯探索并解決: nushell 在*.a中查找給定函數所在.a

nushell == /app5/nu-0.102.0-x86_64-unknown-linux-gnu/nu

3A報錯缺少函數

• absl::lts_20240722::raw_log_internal::RawLog
• absl::lts_20240722::base_internal::ThrowStdOutOfRange

以下用nushell查找這些函數所在.a

/usr/bin/find  /app/abseil-cpp/build/absl/ -name "*.a"  |  lines|each  { |f|  nm --defined-only -C  $f } | str  contains   "absl::lts_20240722::base_internal::ThrowStdOutOfRange" | /usr/bin/grep true
# │  8 │ true  │/usr/bin/find  /app/abseil-cpp/build/absl/ -name "*.a"  |  lines|each  { |f|  $f }  | /usr/bin/grep  " 8 "
#│  8 │ /app/abseil-cpp/build/absl/base/libabsl_throw_delegate.a                           │/usr/bin/find  /app/abseil-cpp/build/absl/ -name "*.a"  |  lines|each  { |f|  nm --defined-only -C  $f } | str  contains   "absl::lts_20240722::raw_log_internal::RawLog" | /usr/bin/grep true
# │  4 │ true  │/usr/bin/find  /app/abseil-cpp/build/absl/ -name "*.a"  |  lines|each  { |f|  $f }  | /usr/bin/grep  " 4 "
# │  4 │ /app/abseil-cpp/build/absl/base/libabsl_raw_logging_internal.a                     │