[v3] configure.ac: fix bashisms in configure.ac

  configure scripts need to be runnable with a POSIX-compliant /bin/sh.

On many (but not all!) systems, /bin/sh is provided by Bash, so errors
like this aren't spotted. Notably Debian defaults to /bin/sh provided
by dash which doesn't tolerate such bashisms as '=='.

This retains compatibility with bash.

Fixes configure warnings/errors like:
```
checking if compiler warns about alias for function with incompatible types... yes
/var/tmp/portage/sys-libs/glibc-2.34-r10/work/glibc-2.34/configure: 4209: test: xyes: unexpected operator
```

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Sam James <sam@gentoo.org>
---
 configure                                               | 2 +-
 configure.ac                                            | 2 +-
 sysdeps/powerpc/powerpc64/le/configure                  | 2 +-
 sysdeps/powerpc/powerpc64/le/configure.ac               | 2 +-
 sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure    | 2 +-
 sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure.ac | 2 +-
 6 files changed, 6 insertions(+), 6 deletions(-)
  

On 22/03/2022 14:33, Sam James wrote:
> configure scripts need to be runnable with a POSIX-compliant /bin/sh.
> 
> On many (but not all!) systems, /bin/sh is provided by Bash, so errors
> like this aren't spotted. Notably Debian defaults to /bin/sh provided
> by dash which doesn't tolerate such bashisms as '=='.
> 
> This retains compatibility with bash.
> 
> Fixes configure warnings/errors like:
> ```
> checking if compiler warns about alias for function with incompatible types... yes
> /var/tmp/portage/sys-libs/glibc-2.34-r10/work/glibc-2.34/configure: 4209: test: xyes: unexpected operator
> ```
> 
> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> Signed-off-by: Sam James <sam@gentoo.org>
LGTM ;)

> ---
>  configure                                               | 2 +-
>  configure.ac                                            | 2 +-
>  sysdeps/powerpc/powerpc64/le/configure                  | 2 +-
>  sysdeps/powerpc/powerpc64/le/configure.ac               | 2 +-
>  sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure    | 2 +-
>  sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure.ac | 2 +-
>  6 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/configure b/configure
> index 8e5bee775a..2a3cb49b0b 100755
> --- a/configure
> +++ b/configure
> @@ -4232,7 +4232,7 @@ if test x"$libc_cv_gcc_indirect_function" != xyes; then
>    # GCC 8+ emits a warning for alias with incompatible types and it might
>    # fail to build ifunc resolvers aliases to either weak or internal
>    # symbols.  Disables multiarch build in this case.
> -  if test x"$libc_cv_gcc_incompatible_alias" == xyes; then
> +  if test x"$libc_cv_gcc_incompatible_alias" = xyes; then
>      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: gcc emits a warning for alias between functions of incompatible types" >&5
>  $as_echo "$as_me: WARNING: gcc emits a warning for alias between functions of incompatible types" >&2;}
>      if test x"$multi_arch" = xyes; then
> diff --git a/configure.ac b/configure.ac
> index 87f67d25ec..fa7d3c025b 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -767,7 +767,7 @@ if test x"$libc_cv_gcc_indirect_function" != xyes; then
>    # GCC 8+ emits a warning for alias with incompatible types and it might
>    # fail to build ifunc resolvers aliases to either weak or internal
>    # symbols.  Disables multiarch build in this case.
> -  if test x"$libc_cv_gcc_incompatible_alias" == xyes; then
> +  if test x"$libc_cv_gcc_incompatible_alias" = xyes; then
>      AC_MSG_WARN([gcc emits a warning for alias between functions of incompatible types])
>      if test x"$multi_arch" = xyes; then
>        AC_MSG_ERROR([--enable-multi-arch support requires a gcc with gnu-indirect-function support])
> diff --git a/sysdeps/powerpc/powerpc64/le/configure b/sysdeps/powerpc/powerpc64/le/configure
> index 35950a6ddd..395f9f7309 100644
> --- a/sysdeps/powerpc/powerpc64/le/configure
> +++ b/sysdeps/powerpc/powerpc64/le/configure
> @@ -113,7 +113,7 @@ CFLAGS="$save_CFLAGS"
>  fi
>  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_compiler_powerpc64le_ldbl128_mabi" >&5
>  $as_echo "$libc_cv_compiler_powerpc64le_ldbl128_mabi" >&6; }
> -if test "$libc_cv_compiler_powerpc64le_ldbl128_mabi" == "no"; then :
> +if test "$libc_cv_compiler_powerpc64le_ldbl128_mabi" = "no"; then :
>    critic_missing="$critic_missing The compiler must support -mabi=ieeelongdouble and -mlong-double-128 simultaneously."
>  fi
>  
> diff --git a/sysdeps/powerpc/powerpc64/le/configure.ac b/sysdeps/powerpc/powerpc64/le/configure.ac
> index 9f0423ede2..48d7089b63 100644
> --- a/sysdeps/powerpc/powerpc64/le/configure.ac
> +++ b/sysdeps/powerpc/powerpc64/le/configure.ac
> @@ -63,7 +63,7 @@ long double x;
>  		  [libc_cv_compiler_powerpc64le_ldbl128_mabi=yes],
>  		  [libc_cv_compiler_powerpc64le_ldbl128_mabi=no])
>  CFLAGS="$save_CFLAGS"])
> -AS_IF([test "$libc_cv_compiler_powerpc64le_ldbl128_mabi" == "no"],
> +AS_IF([test "$libc_cv_compiler_powerpc64le_ldbl128_mabi" = "no"],
>        [critic_missing="$critic_missing The compiler must support -mabi=ieeelongdouble and -mlong-double-128 simultaneously."])
>  
>  dnl objcopy (binutils) 2.26 or newer required to support the --update-section
> diff --git a/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure
> index 4ca1d15833..b95a720549 100644
> --- a/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure
> +++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure
> @@ -25,7 +25,7 @@ fi
>  $as_echo "$libc_cv_mcpu_power10" >&6; }
>  config_vars="$config_vars
>  mcpu-power10 = $libc_cv_mcpu_power10"
> -if test "$libc_cv_mcpu_power10" == "yes"; then :
> +if test "$libc_cv_mcpu_power10" = "yes"; then :
>  
>  	$as_echo "#define USE_PPC64_MCPU_POWER10 1" >>confdefs.h
>  
> diff --git a/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure.ac b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure.ac
> index ceb578cc59..257ca6c110 100644
> --- a/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure.ac
> +++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/configure.ac
> @@ -9,6 +9,6 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
>  	       [libc_cv_mcpu_power10=yes],
>  	       [libc_cv_mcpu_power10=no])])
>  LIBC_CONFIG_VAR([mcpu-power10], [$libc_cv_mcpu_power10])
> -AS_IF([[test "$libc_cv_mcpu_power10" == "yes"]],[
> +AS_IF([[test "$libc_cv_mcpu_power10" = "yes"]],[
>  	AC_DEFINE(USE_PPC64_MCPU_POWER10)])
>  CFLAGS="$OLD_CFLAGS"
  

On 22 Mar 2022 17:33, Sam James via Libc-alpha wrote:
> configure scripts need to be runnable with a POSIX-compliant /bin/sh.
> 
> On many (but not all!) systems, /bin/sh is provided by Bash, so errors
> like this aren't spotted. Notably Debian defaults to /bin/sh provided
> by dash which doesn't tolerate such bashisms as '=='.
> 
> This retains compatibility with bash.
> 
> Fixes configure warnings/errors like:
> ```
> checking if compiler warns about alias for function with incompatible types... yes
> /var/tmp/portage/sys-libs/glibc-2.34-r10/work/glibc-2.34/configure: 4209: test: xyes: unexpected operator
> ```

lgtm, pushed!
-mike