[freetype2] master 9e345c9: Further fix to visibility flag testing with Solaris Studio compilers.

[Werner LEMBERG]

branch: master
commit 9e345c911714ed62250be13d03d72e25d91fbc77
Author: Alan Coopersmith <address@hidden>
Commit: Werner Lemberg <address@hidden>

    Further fix to visibility flag testing with Solaris Studio compilers.
    
    AC_COMPILE_IFELSE only tries to compile a `*.c' to a `*.o'.  The
    Solaris Studio 12.1 through 12.5 compilers see the
    `-fvisibility=hidden' flag, but ignore it with a warning of:
    
      cc: Warning: Option -fvisibility=hidden passed to ld,
                   if ld is invoked, ignored otherwise
    
    AC_LINK_IFELSE does the compile and then tries to link the result,
    at which point the Solaris linker will issue an error:
    
      ld: fatal: option '-fvisibility=hidden' is incompatible with
          building a dynamic executable
    
    If we don't use AC_LINK_IFELSE to catch the error, then configure
    will fail further tests which attempt to link, such as those testing
    dependencies like `libbz2'.
    
    Also, don't try adding `-fvisibility' if we have already added
    `-xldscope', just use one of them, since Sun Studio 12 and earlier
    compilers only issue a warning, and don't try passing through to the
    linker to generate an error, so AC_LINK_IFELSE doesn't catch them.
    
    Tested on Solaris 11.4 beta with compiler versions:
    
      Sun Studio 8 (Sun C 5.5)
      Sun Studio 10 (Sun C 5.7)
      Sun Studio 11 (Sun C 5.8)
      Sun Studio 12 (Sun C 5.9)
      Sun Studio 12.1 (Sun C 5.10)
      Oracle Solaris Studio 12.2 (Sun C 5.11)
      Oracle Solaris Studio 12.3 (Sun C 5.12)
      Oracle Solaris Studio 12.4 (Sun C 5.13)
      Oracle Developer Studio 12.5 (Sun C 5.14)
      Oracle Developer Studio 12.6 (Sun C 5.15)
      gcc 5.5.0
      gcc 7.3.0
    
    and verified the libfreetype.so.6 generated by each of those
    compilers exported the same set of symbols.
    
    * builds/unix/configure.raw: Implement it.
---
 ChangeLog                 | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 builds/unix/configure.raw | 30 +++++++++++++++++-------------
 2 files changed, 63 insertions(+), 13 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 1c0625e..004c96f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,49 @@
+2018-05-10  Alan Coopersmith  <address@hidden>
+
+       Fix DLL compilation on Solaris.
+
+       AC_COMPILE_IFELSE only tries to compile a `*.c' to a `*.o'.  The
+       Solaris Studio 12.1 through 12.5 compilers see the
+       `-fvisibility=hidden' flag, but ignore it with a warning of:
+
+         cc: Warning: Option -fvisibility=hidden passed to ld,
+                      if ld is invoked, ignored otherwise
+
+       AC_LINK_IFELSE does the compile and then tries to link the result,
+       at which point the Solaris linker will issue an error:
+
+         ld: fatal: option '-fvisibility=hidden' is incompatible with
+             building a dynamic executable
+
+       If we don't use AC_LINK_IFELSE to catch the error, then configure
+       will fail further tests which attempt to link, such as those testing
+       dependencies like `libbz2'.
+
+       Also, don't try adding `-fvisibility' if we have already added
+       `-xldscope', just use one of them, since Sun Studio 12 and earlier
+       compilers only issue a warning, and don't try passing through to the
+       linker to generate an error, so AC_LINK_IFELSE doesn't catch them.
+
+       Tested on Solaris 11.4 beta with compiler versions:
+
+         Sun Studio 8 (Sun C 5.5)
+         Sun Studio 10 (Sun C 5.7)
+         Sun Studio 11 (Sun C 5.8)
+         Sun Studio 12 (Sun C 5.9)
+         Sun Studio 12.1 (Sun C 5.10)
+         Oracle Solaris Studio 12.2 (Sun C 5.11)
+         Oracle Solaris Studio 12.3 (Sun C 5.12)
+         Oracle Solaris Studio 12.4 (Sun C 5.13)
+         Oracle Developer Studio 12.5 (Sun C 5.14)
+         Oracle Developer Studio 12.6 (Sun C 5.15)
+         gcc 5.5.0
+         gcc 7.3.0
+
+       and verified the libfreetype.so.6 generated by each of those
+       compilers exported the same set of symbols.
+
+       * builds/unix/configure.raw: Implement it.
+
 2018-05-08  Werner Lemberg  <address@hidden>
 
        [autofit] Avoid potential SEGV if running out of memory.
diff --git a/builds/unix/configure.raw b/builds/unix/configure.raw
index 8eded34..9c342ad 100644
--- a/builds/unix/configure.raw
+++ b/builds/unix/configure.raw
@@ -311,22 +311,26 @@ AC_SUBST([XX_ANSIFLAGS])
 # It is recommended that shared libraries hide symbols except those with
 # explicit __attribute__((visibility("default"))).
 #
+found_visibility_flag=no
 AC_MSG_CHECKING([for -xldscope=hidden compiler flag])
 orig_CFLAGS="${CFLAGS}"
 CFLAGS="${CFLAGS} -xldscope=hidden"
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[])],
-                  AC_MSG_RESULT(yes),
-                  CFLAGS="${orig_CFLAGS}"
-                  AC_MSG_RESULT(no))
-
-AC_MSG_CHECKING([for -fvisibility=hidden compiler flag])
-orig_CFLAGS="${CFLAGS}"
-CFLAGS="${CFLAGS} -fvisibility=hidden"
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[])],
-                  AC_MSG_RESULT(yes),
-                  CFLAGS="${orig_CFLAGS}"
-                  AC_MSG_RESULT(no))
-
+AC_LINK_IFELSE([AC_LANG_PROGRAM([],[])],
+               [found_visibility_flag=yes
+                AC_MSG_RESULT(yes)],
+               [CFLAGS="${orig_CFLAGS}"
+                AC_MSG_RESULT(no)])
+
+if test "${found_visibility_flag}" = "no"; then
+  AC_MSG_CHECKING([for -fvisibility=hidden compiler flag])
+  orig_CFLAGS="${CFLAGS}"
+  CFLAGS="${CFLAGS} -fvisibility=hidden"
+  AC_LINK_IFELSE([AC_LANG_PROGRAM([],[])],
+                 [found_visibility_flag=yes
+                  AC_MSG_RESULT(yes)],
+                 [CFLAGS="${orig_CFLAGS}"
+                  AC_MSG_RESULT(no)])
+fi
 
 # All library tests below try `pkg-config' first.  If that fails, a function
 # from the library is tested in the traditional autoconf way (zlib, bzip2),