#197 Project failed to build on environment with clang

[Xiao Hanyu]

Hello,

This is a following issue after https://sourceforge.net/p/xetex/bugs/195/.

I found that if a system contains both gcc and clang, then the build will fail (build log attached).

The rationale here is, most of the libs would use gcc to compile, while libs/icu prefer to use clang over gcc.

To override this and force to use gcc for compiling libs/icu, there're several ways:
1. call build.sh with CC=gcc CXX=g++ ./build.sh
2. modify build.sh:
```
diff --git a/build.sh b/build.sh
index 4e556321..f21c859a 100755
--- a/build.sh
+++ b/build.sh
@@ -189,7 +189,7 @@ fi

 if [ "$ONLY_MAKE" = "FALSE" ]
 then

• TL_MAKE=$MAKE ../source/configure $CONFHOST $CONFBUILD $WARNINGFLAGS $CONF_OPTIONS || exit 1

• CC=gcc CXX=g++ TL_MAKE=$MAKE ../source/configure $CONFHOST $CONFBUILD $WARNINGFLAGS $CONF_OPTIONS || exit 1
  fi

  $MAKE || exit 1
  `` 3. modify libs/icu by changing libs/icu's [configure.ac](https://github.com/TeX-Live/xetex/blob/master/source/libs/icu/icu-55.1/source/configure.ac#L133-L136) and [configure](https://github.com/TeX-Live/xetex/blob/master/source/libs/icu/icu-55.1/source/configure) to remove clang as a candidate compiler inAC_PROG_CC` macro.

Which way do you prefer? I can provide a patch if necessary.

Thanks!

[Xiao Hanyu]

Shitty format, revised:

To override this and force to use gcc for compiling libs/icu, there're several ways:

• call build.sh with CC=gcc CXX=g++ ./build.sh
• modify build.sh:

diff --git a/build.sh b/build.sh
index 4e556321..f21c859a 100755
--- a/build.sh
+++ b/build.sh
@@ -189,7 +189,7 @@ fi

if [ "$ONLY_MAKE" = "FALSE" ]
then
-    TL_MAKE=$MAKE ../source/configure $CONFHOST $CONFBUILD $WARNINGFLAGS $CONF_OPTIONS || exit 1
+    CC=gcc CXX=g++ TL_MAKE=$MAKE ../source/configure $CONFHOST $CONFBUILD $WARNINGFLAGS $CONF_OPTIONS || exit 1
fi

$MAKE || exit 1

• modify libs/icu by changing libs/icu's configure.ac and configure to remove clang as a candidate compiler inAC_PROG_CC` macro.

[Xiao Hanyu]

I kind of prefer approach 2 here, by modifying build.sh and force the project to use gcc/g++.