openeuler gcc7.3.0 降级 4.8.5-4008云顶国际网站

   在迁移电信某系统，伙伴需要使用openeuler，伙伴工程较旧，使用操作系统自带gcc 7.3.0 编译工程报错，遂决定对gcc降级，以下为gcc降级操作记录

操作系统：openeuler 20.03  gcc 7.3.0

wget

tar xvf gcc-4.8.5.tar.gz

 cd gcc-4.8.5

执行下面脚本下载依赖包

./contrib/download_prerequisites

如上述脚本执行失败手动下载安装包到根目录

wget https://gcc.gnu.org/pub/gcc/infrastructure/gmp-4.3.2.tar.bz2
wget https://gcc.gnu.org/pub/gcc/infrastructure/mpc-0.8.1.tar.gz
wget https://gcc.gnu.org/pub/gcc/infrastructure/mpfr-2.4.2.tar.bz2

mkdir build

cd build/

../configure --enable-checking=release --enable-language=c,c --disable-multilib --prefix=/usr/gcc4.8.5

make  -j64

由于版本差别较大，正常降级是无法编译通过的

1、报错“const char* libc_name_p(const char*, unsigned int)’”

问题截图

解决方法：  其中红色的是旧代码，绿色的是修改后的代码

a、修改 gcc-4.8.5/gcc/cp/make-lang.in

--- a/gcc/cp/make-lang.in
b/gcc/cp/make-lang.in

 # deleting the $(srcdir)/cp/cfns.h file.
 $(srcdir)/cp/cfns.h:
 endif
-       gperf -o -c -e -k '1-6,$$' -j1 -d -n 'libc_name_p' -l ansi-c \
      gperf -o -c -e -k '1-6,$$' -j1 -d -n 'libc_name_p' -l c \
                $(srcdir)/cp/cfns.gperf --output-file $(srcdir)/cp/cfns.h
 
 #\f

如下图：

b、修改gcc-4.8.5/gcc/cp/cfns.gperf
--- a/gcc/cp/cfns.gperf
b/gcc/cp/cfns.gperf

%language=c
�fine class-name libc_name
 %{
 /* 4008云顶国际网站 copyright (c) 2000-2016 free software foundation, inc.
 
@@ -16,14 18,6 @@ for more details.
 you should have received a copy of the gnu general public license
 along with gcc; see the file copying3.  if not see
 .  */
-#ifdef __gnuc__
-__inline
-#endif
-static unsigned int hash (const char *, unsigned int);
-#ifdef __gnuc__
-__inline
-#endif
-const char * libc_name_p (const char *, unsigned int);
 %}
 %%
 # the standard c library functions, for feeding to gperf; the result is used

如下图：

c、修改gcc-4.8.5/gcc/cp/cfns.h

--- a/gcc/cp/cfns.h
b/gcc/cp/cfns.h

-/* ansi-c code produced by gperf version 3.0.3 */
-/* command-line: gperf -o -c -e -k '1-6,$' -j1 -d -n libc_name_p -l ansi-c cfns.gperf  */
/* c code produced by gperf version 3.0.4 */
/* command-line: gperf -o -c -e -k '1-6,$' -j1 -d -n libc_name_p -l c --output-file cfns.h cfns.gperf  */
 
 #if !((' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
       && ('%' == 37) && ('&' == 38) && ('\'' == 39) && ('(' == 40) \
@@ -28,7 28,7 @@
 #error "gperf generated tables don't work with this execution character set. please report a bug to ."
 #endif
 
-#line 1 "cfns.gperf"
#line 3 "cfns.gperf"
 
 /* 4008云顶国际网站 copyright (c) 2000-2016 free software foundation, inc.
 
@@ -47,25 47,18 @@ for more details.
 you should have received a copy of the gnu general public license
 along with gcc; see the file copying3.  if not see
 .  */
-#ifdef __gnuc__
-__inline
-#endif
-static unsigned int hash (const char *, unsigned int);
-#ifdef __gnuc__
-__inline
-#endif
-const char * libc_name_p (const char *, unsigned int);
 /* maximum key range = 391, duplicates = 0 */
 
-#ifdef __gnuc__
-__inline
-#else
-#ifdef __cplusplus
-inline
-#endif
-#endif
-static unsigned int
-hash (register const char *str, register unsigned int len)
class libc_name
{
private:
 static inline unsigned int hash (const char *str, unsigned int len);
public:
 static const char *libc_name_p (const char *str, unsigned int len);
};

inline unsigned int
libc_name::hash (register const char *str, register unsigned int len)
 {
   static const unsigned short asso_values[] =
     {
   return hval asso_values[(unsigned char)str[len - 1]];
 }
 
-#ifdef __gnuc__
-__inline
-#ifdef __gnuc_stdc_inline__
-__attribute__ ((__gnu_inline__))
-#endif
-#endif
 const char *
-libc_name_p (register const char *str, register unsigned int len)
libc_name::libc_name_p (register const char *str, register unsigned int len)
 {
   enum
     {

如下图：

d、修改gcc-4.8.5/gcc/cp/except.c

--- a/gcc/cp/except.c
b/gcc/cp/except.c

      unless the system headers are playing rename tricks, and if
      they are, we don't want to be confused by them.  */
   id = decl_name (fn);
-  return !!libc_name_p (identifier_pointer (id), identifier_length (id));
 return !!libc_name::libc_name_p (identifier_pointer (id),
                                 identifier_length (id));
 

重新编译查看结果

make -j64

1、报错“error: field ‘uc’ has incomplete type”

问题截图

解决方法：

查找文件  md-unwind-support.h，修改 struct ucontext uc; 为 ucontext_t uc;

重新编译 make -j64，编译成功

make install