| Message ID | 20210328122255.29764-1-arne@rfc2549.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [Openvpn-devel] Remove flexible array member autoconf check | expand |
Hi, On 28-03-2021 14:22, Arne Schwabe wrote: > This is configure macro that tries out how to declare a variable array > at the end of struct. This has been standardised in C99, so there is > no more need for non C99 magic. See also this stackoverflow discussion: > > https://stackoverflow.com/questions/14643406/whats-the-need-of-array-with-zero-elements > Signed-off-by: Arne Schwabe <arne@rfc2549.org> > --- > config-msvc.h | 1 - > m4/ax_emptyarray.m4 | 40 ---------------------------------------- > src/openvpn/circ_list.h | 2 +- > src/openvpn/syshead.h | 2 -- > 4 files changed, 1 insertion(+), 44 deletions(-) > delete mode 100644 m4/ax_emptyarray.m4 > > diff --git a/config-msvc.h b/config-msvc.h > index e430ca96f..0260927ce 100644 > --- a/config-msvc.h > +++ b/config-msvc.h > @@ -119,7 +119,6 @@ > #define inline __inline > #endif > > -#define EMPTY_ARRAY_SIZE 0 > #define TARGET_WIN32 1 > #define TARGET_ALIAS "Windows-MSVC" > > diff --git a/m4/ax_emptyarray.m4 b/m4/ax_emptyarray.m4 > deleted file mode 100644 > index c6781c179..000000000 > --- a/m4/ax_emptyarray.m4 > +++ /dev/null > @@ -1,40 +0,0 @@ > -dnl @synopsis AX_EMPTY_ARRAY > -dnl > -dnl Define EMPTY_ARRAY_SIZE to be either "0" > -dnl or "" depending on which syntax the compiler > -dnl prefers for empty arrays in structs. > -dnl > -dnl @version > -dnl @author James Yonan <jim@yonan.net> > -AC_DEFUN([AX_EMPTY_ARRAY], [ > - AS_VAR_PUSHDEF([VAR],[ax_cv_c_empty_array])dnl > - AC_CACHE_CHECK( > - [for C compiler empty array size], > - [VAR], > - [AC_COMPILE_IFELSE( > - [AC_LANG_PROGRAM( > - , > - [[ > -struct { int foo; int bar[0]; } mystruct; > - ]] > - )], > - [VAR=0], > - [AC_COMPILE_IFELSE( > - [AC_LANG_PROGRAM( > - , > - [[ > -struct { int foo; int bar[]; } mystruct; > - ]] > - )], > - [VAR=], > - [AC_MSG_ERROR([C compiler is unable to creaty empty arrays])] > - )] > - )] > - )dnl > - AC_DEFINE_UNQUOTED( > - [EMPTY_ARRAY_SIZE], > - [$VAR], > - [Dimension to use for empty array declaration] > - )dnl > - AS_VAR_POPDEF([VAR])dnl > -]) > diff --git a/src/openvpn/circ_list.h b/src/openvpn/circ_list.h > index 23b42d2ab..ba9115eab 100644 > --- a/src/openvpn/circ_list.h > +++ b/src/openvpn/circ_list.h > @@ -34,7 +34,7 @@ > int x_size; \ > int x_cap; \ > int x_sizeof; \ > - type x_list[EMPTY_ARRAY_SIZE]; \ > + type x_list[]; \ > } > > #define CIRC_LIST_PUSH(obj, item) \ > diff --git a/src/openvpn/syshead.h b/src/openvpn/syshead.h > index 5ee9bf1e8..cf9714593 100644 > --- a/src/openvpn/syshead.h > +++ b/src/openvpn/syshead.h > @@ -392,8 +392,6 @@ typedef int MIB_TCP_STATE; > #ifdef PEDANTIC > #undef HAVE_CPP_VARARG_MACRO_GCC > #undef HAVE_CPP_VARARG_MACRO_ISO > -#undef EMPTY_ARRAY_SIZE > -#define EMPTY_ARRAY_SIZE 1 > #undef inline > #define inline > #endif > Makes sense, and change looks good. This is just unneeded configure delay. Ran a quick configure-make-check to double-check there's not a trivial typo I'm overlooking. I haven't tested compiling with MSVC. Acked-by: Steffan Karger <steffan@karger.me> -Steffan
diff --git a/config-msvc.h b/config-msvc.h index e430ca96f..0260927ce 100644 --- a/config-msvc.h +++ b/config-msvc.h @@ -119,7 +119,6 @@ #define inline __inline #endif -#define EMPTY_ARRAY_SIZE 0 #define TARGET_WIN32 1 #define TARGET_ALIAS "Windows-MSVC" diff --git a/m4/ax_emptyarray.m4 b/m4/ax_emptyarray.m4 deleted file mode 100644 index c6781c179..000000000 --- a/m4/ax_emptyarray.m4 +++ /dev/null @@ -1,40 +0,0 @@ -dnl @synopsis AX_EMPTY_ARRAY -dnl -dnl Define EMPTY_ARRAY_SIZE to be either "0" -dnl or "" depending on which syntax the compiler -dnl prefers for empty arrays in structs. -dnl -dnl @version -dnl @author James Yonan <jim@yonan.net> -AC_DEFUN([AX_EMPTY_ARRAY], [ - AS_VAR_PUSHDEF([VAR],[ax_cv_c_empty_array])dnl - AC_CACHE_CHECK( - [for C compiler empty array size], - [VAR], - [AC_COMPILE_IFELSE( - [AC_LANG_PROGRAM( - , - [[ -struct { int foo; int bar[0]; } mystruct; - ]] - )], - [VAR=0], - [AC_COMPILE_IFELSE( - [AC_LANG_PROGRAM( - , - [[ -struct { int foo; int bar[]; } mystruct; - ]] - )], - [VAR=], - [AC_MSG_ERROR([C compiler is unable to creaty empty arrays])] - )] - )] - )dnl - AC_DEFINE_UNQUOTED( - [EMPTY_ARRAY_SIZE], - [$VAR], - [Dimension to use for empty array declaration] - )dnl - AS_VAR_POPDEF([VAR])dnl -]) diff --git a/src/openvpn/circ_list.h b/src/openvpn/circ_list.h index 23b42d2ab..ba9115eab 100644 --- a/src/openvpn/circ_list.h +++ b/src/openvpn/circ_list.h @@ -34,7 +34,7 @@ int x_size; \ int x_cap; \ int x_sizeof; \ - type x_list[EMPTY_ARRAY_SIZE]; \ + type x_list[]; \ } #define CIRC_LIST_PUSH(obj, item) \ diff --git a/src/openvpn/syshead.h b/src/openvpn/syshead.h index 5ee9bf1e8..cf9714593 100644 --- a/src/openvpn/syshead.h +++ b/src/openvpn/syshead.h @@ -392,8 +392,6 @@ typedef int MIB_TCP_STATE; #ifdef PEDANTIC #undef HAVE_CPP_VARARG_MACRO_GCC #undef HAVE_CPP_VARARG_MACRO_ISO -#undef EMPTY_ARRAY_SIZE -#define EMPTY_ARRAY_SIZE 1 #undef inline #define inline #endif
This is configure macro that tries out how to declare a variable array at the end of struct. This has been standardised in C99, so there is no more need for non C99 magic. See also this stackoverflow discussion: https://stackoverflow.com/questions/14643406/whats-the-need-of-array-with-zero-elements Signed-off-by: Arne Schwabe <arne@rfc2549.org> --- config-msvc.h | 1 - m4/ax_emptyarray.m4 | 40 ---------------------------------------- src/openvpn/circ_list.h | 2 +- src/openvpn/syshead.h | 2 -- 4 files changed, 1 insertion(+), 44 deletions(-) delete mode 100644 m4/ax_emptyarray.m4