[Bug libgcj/33085] New: liblt_prog_compiler_pic_GCJ='-DDLL_EXPORT' is wrong

["dannysmith at users dot sourceforge dot net" <gcc-bugzilla@gcc.gnu.org>]

Bug reported by Ross Ridge to mingw users list 

When building libgcj for windows targets, libtool puts -DDLL_EXPORT in compiler
flag:

    mingw* | cygwin* | pw32* | os2*)
      # This hack is so that the source file can tell whether it is being
      # built for inclusion in a dll (and should export symbols for example).
      # Although the cygwin gcc ignores -fPIC, still need this for old-style
      # (--disable-auto-import) libraries
      lt_prog_compiler_pic='-DDLL_EXPORT'
      ;;


However that -D is a preprocessor flag (not a proper compiler switch)  gcj
gives -D a different meaning:

from jvspec.c:lang_specific_driver

  if (saw_D && ! main_class_name)
    fatal ("can't specify '-D' without '--main'\n");

As a result, libtool build of shared  libgcj  fails with:

bin/bash ./libtool --tag=GCJ --mode=compile /src/gcc/obj/gcc/gcj
-B/src/gcc/obj/mingw32/libjava/ -B/src/gcc/obj/gcc/ -ffloat-store
-fomit-frame-pointer -Usun -fno-omit-frame-pointer -fclasspath=
-fbootclasspath=../../../gcc/libjava/classpath/lib --encoding=UTF-8
-Wno-deprecated -fbootstrap-classes -g -O2 -c -o java/lang/Object.lo
-fsource-filename=../../../gcc/libjava/java/lang/Object.java
../../../gcc/libjava/classpath/lib/java/lang/Object.class
libtool: compile: /src/gcc/obj/gcc/gcj -B/src/gcc/obj/mingw32/libjava/
-B/src/gcc/obj/gcc/ -ffloat-store -fomit-frame-pointer -Usun
-fno-omit-frame-pointer -fclasspath=
-fbootclasspath=../../../gcc/libjava/classpath/lib --encoding=UTF-8
-Wno-deprecated -fbootstrap-classes -g -O2 -c
-fsource-filename=../../../gcc/libjava/java/lang/Object.java
../../../gcc/libjava/classpath/lib/java/lang/Object.class -DDLL_EXPORT -o
java/lang/.libs/Object.o
gcj.exe: can't specify '-D' without '--main'


-- 
           Summary: liblt_prog_compiler_pic_GCJ='-DDLL_EXPORT'  is wrong
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgcj
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dannysmith at users dot sourceforge dot net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33085