ubuntu 20.04LST跌跌撞撞安装gcc6.3.0
下载
首先在官网上下载gcc6.3.0，链接如下：
https://ftp.gnu.org/gnu/gcc/gcc-6.3.0/
安装依赖包
按顺序安装gcc必备的几个包：m4、gmp、mpfr、mpc
m4:
./contrib/download_prerequisites
gmp（http://www.gnu.org/software/m4/）:
文件夹打开终端
./configure
make -j12
sudo make install
mpfr（https://mpfr.loria.fr/）：
文件夹打开终端
./configure
make -j12
sudo make install
mpc(https://www.multiprecision.org/mpc/ ):
文件夹打开终端
./configure
make -j12
sudo make install
安装
找到下载的文件，提取，文件夹内打开终端
sudo ./configure --prefix=/usr/local/gcc-6.3 --enable-threads=posix --disable-checking --disable-multilib --enable-languages=c,c++ --with-gmp=$HOME/local/ --with-mpfr=$HOME/local/ --with-cgal=$HOME/local/
make -j12 # j 后面的数字越大编译速度越快
sudo make install
编译过程中出现的问题
问题1：error: dereferencing pointer to incomplete type ‘struct ucontext’
在函数‘x86_64_fallback_frame_state’中: ./md-unwind-support.h:65:47: 错误： dereferencing pointer to incomplete type ‘struct ucontext’
sc = (struct sigcontext *) (void *) &uc_->uc_mcontext;
解决方案：
struct ucontext * uc_ = context->cfa;
修改为
struct ucontext_t * uc_ = context->cfa;
重新make
问题2：sanitizer_platform_limits_posix.cc:158:23: 致命错误：sys/ustat.h：没有那个文件或目录
../../.././libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc:159:
28: fatal error: sys/ustat.h: No such file or directory
#include <sys/ustat.h>
^
compilation terminated.
解决方案：
修改libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc文件：
vim libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
首先注释掉 #include <sys/ustat.h> ：
接着在 251 行修改 unsigned struct_ustat_sz = sizeof(struct ustat); 语句
注释掉251行，换行后粘贴以下内容：
// Use pre-computed size of struct ustat to avoid <sys/ustat.h> which
// has been removed from glibc 2.28.
#if defined(__aarch64__) || defined(__s390x__) || defined (__mips64) \
|| defined(__powerpc64__) || defined(__arch64__) || defined(__sparcv9) \
|| defined(__x86_64__)
#define SIZEOF_STRUCT_USTAT 32
#elif defined(__arm__) || defined(__i386__) || defined(__mips__) \
|| defined(__powerpc__) || defined(__s390__)
#define SIZEOF_STRUCT_USTAT 20
#else
#error Unknown size of struct ustat
#endif
unsigned struct_ustat_sz = SIZEOF_STRUCT_USTAT;
重新make
问题3：
../../.././libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc:270:22: 错误： 聚
合‘sigaltstack handler_stack’类型不完全，无法被定义
struct sigaltstack handler_stack;
^~~~~~~~~~~~~
解决方案：
1.打开libsanitizer/sanitizer_common/sanitizer_linux.h文件，注释第22行的struct sigaltstack;
2.修改31.32行：
uptr internal_sigaltstack(const struct sigaltstack* ss,
struct sigaltstack* oss);
修改为
uptr internal_sigaltstack(const void* ss, void* oss);
3.修改libsanitizer/sanitizer_common/sanitizer_linux.cc文件549、550行
uptr internal_sigaltstack(const struct sigaltstack *ss,
struct sigaltstack *oss) {
修改为
uptr internal_sigaltstack(const void *ss, void *oss) {
4.修改libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc270行
struct sigaltstack handler_stack;
修改为
stack_t handler_stack;
5.修改libsanitizer/tsan/tsan_platform_linux.cc294行
__res_state *statp = (__res_state*)state;
修改为
struct __res_state *statp = (struct __res_state*)state;
重新make
问题4：sanitizer_common/sanitizer_internal_defs.h:254:72: error: size of array ‘assertion_failed__1142’ is negative
解决方案：
修改 /gcc-6.3.0/configure文件
删除文件中 target-libsanitizer \，大概在两千多行
重新make
