How to compile X11R5 (patch level 11) with GCC version 2:

The patches include support for building the shared libraries with GCC 2 on 
the Sparc and 68k machines.  NOTE: Such shared libraries DO NOT WORK
with executables previously linked using Sun CC!  This is because
neither those executables nor the gcc-compiled shared libraries contain
libgcc.a.  The shared libraries do work with executables linked using
GCC (running the Sun linker, of course) because GCC tells the linker to
link in libgcc.a.  Because of these limitations the default behavior is
to NOT build the shared libraries with gcc.  If you want the gcc-compiled
shared libraries turn on "Gcc2BuildLibs" in site.def

If you want to build a shared library that works with executables
linked with Sun CC, you will have to arrange to include libgcc.a in
the shared libraries.  The instructions below do not handle this.

Sun forgot to include a static version of libdl.a with some versions
of SunOS (4.1 mainly).  If you see undefined symbols _dlopen, _dlsym,
or _dlclose when linking with -lX11, compile and link against the file
mit/util/misc/dlsym.c in the MIT X11R5 distribution.

mit/config/Imake.tmpl -- Do not set -fstrength-reduce if we have GCC 2.  If
-fstrength-reduce (or any other -f option) is a major win, then it will
most likely be turned on by -O2 optimization.

mit/config/sunLib.rules -- If HasGcc2 and Gcc2BuildLibs are defined, then 
use gcc -fpic to generate PIC code.  Make sure that gcc does not use gas (the 
GNU assembler) when compiling PIC code; gas does not assemble it correctly.  
If you have gas installed where gcc uses it by default, you might have to add
-B/bin/ to the PositionIndependentCFlags.

mit/config/site.def -- Define HasGcc2 to be YES.

mit/config/sun.cf -- When compiling with GCC 2, use -O2 optimization.

mit/rgb/Imakefile -- No longer need to compile some modules with 
cc on the Sparc since GCC 2 produces proper -fpcc-struct-return code.

mit/server/os/Imakefile -- Likewise.

*** mit/config/Imake.tmpl.ORIG	Tue Dec 31 11:07:56 1991
--- mit/config/Imake.tmpl	Tue Dec 31 12:30:47 1991
***************
*** 499,508 ****
--- 499,512 ----
  #define HasGcc NO
  #endif
  #ifndef CcCmd
+ #if HasGcc2
+ #define CcCmd gcc -fpcc-struct-return
+ #else
  #if HasGcc
  #define CcCmd gcc -fstrength-reduce -fpcc-struct-return 
  #else
  #define CcCmd cc
+ #endif
  #endif
  #endif
  #if HasFortran
*** mit/config/sunLib.rules.ORIG	Tue Dec 31 11:11:24 1991
--- mit/config/sunLib.rules	Tue May  5 12:26:12 1992
***************
*** 23,30 ****
--- 23,34 ----
  #define SharedLibraryLoadFlags -assert pure-text
  #endif
  #ifndef PositionIndependentCFlags
+ #if defined(HasGcc2) && defined (Gcc2BuildLibs)
+ #define PositionIndependentCFlags -fpic
+ #else
  #define PositionIndependentCFlags -pic
  #endif
+ #endif
  
  /*
   * InstallSharedLibrary - generate rules to install the shared library.
*** mit/config/site.def.ORIG	Tue Dec 31 11:13:49 1991
--- mit/config/site.def	Tue Dec 31 12:02:59 1991
***************
*** 25,31 ****
  
  #ifdef BeforeVendorCF
  
! /* #define HasGcc YES */
  
  #endif /* BeforeVendorCF */
  
--- 25,33 ----
  
  #ifdef BeforeVendorCF
  
! #define HasGcc YES 
! #define HasGcc2 YES
! /* #define Gcc2BuildLibs YES */
  
  #endif /* BeforeVendorCF */
  
*** mit/config/sun.cf.ORIG	Tue Dec 31 11:13:57 1991
--- mit/config/sun.cf	Tue May  5 12:29:50 1992
***************
*** 34,42 ****
--- 41,61 ----
  
  #if HasGcc
  
+ #if defined(HasGcc2) 
+ #define OptimizedCDebugFlags -O2 
+ /* Leave Alone XXX */
+ #else 
+ #define OptimizedCDebugFlags -O
  #define SharedLibraryCcCmd cc
  #define ExtraLoadFlags -B/usr/bin/
  #define AllocateLocalDefines /**/
+ #endif
+ 
+ #if !defined(Gcc2BuildLibs)
+ #define SharedLibraryCcCmd cc
+ #define ExtraLoadFlags -B/usr/bin/
+ #define AllocateLocalDefines /**/
+ #endif
  
  .c.o:
  	$(CC) -c $(CFLAGS) $*.c
*** mit/rgb/Imakefile.ORIG	Wed Jan 15 16:43:18 1992
--- mit/rgb/Imakefile	Thu Jan  2 13:34:09 1992
***************
*** 17,23 ****
  #if !(defined(SGIArchitecture) || SystemV4)
         DBMLIB = -ldbm
  #endif
! #if defined(SparcArchitecture) && HasGcc
             CC = cc
      CCOPTIONS = /**/
      EXTRA_LOAD_FLAGS = /**/
--- 17,23 ----
  #if !(defined(SGIArchitecture) || SystemV4)
         DBMLIB = -ldbm
  #endif
! #if defined(SparcArchitecture) && HasGcc && !defined(HasGcc2)
             CC = cc
      CCOPTIONS = /**/
      EXTRA_LOAD_FLAGS = /**/
*** mit/server/os/Imakefile.ORIG	Wed Jan 15 16:46:23 1992
--- mit/server/os/Imakefile	Wed Jan 15 16:46:48 1992
***************
*** 132,138 ****
  SpecialObjectRule(osinit.o,$(ICONFIGFILES),$(ADM_DEFINES))
  SpecialObjectRule(WaitFor.o,$(ICONFIGFILES),$(EXT_DEFINES))
  SpecialObjectRule(fonttype.o,$(ICONFIGFILES),$(FONT_DEFINES))
! #if defined(SparcArchitecture) && HasGcc
  oscolor.o: $(ICONFIGFILES)
  	$(RM) $@
  	cc -c $(DBM_DEFINES) $(CDEBUGFLAGS) $(ALLDEFINES) $*.c
--- 132,138 ----
  SpecialObjectRule(osinit.o,$(ICONFIGFILES),$(ADM_DEFINES))
  SpecialObjectRule(WaitFor.o,$(ICONFIGFILES),$(EXT_DEFINES))
  SpecialObjectRule(fonttype.o,$(ICONFIGFILES),$(FONT_DEFINES))
! #if defined(SparcArchitecture) && HasGcc && !defined(HasGcc2)
  oscolor.o: $(ICONFIGFILES)
  	$(RM) $@
  	cc -c $(DBM_DEFINES) $(CDEBUGFLAGS) $(ALLDEFINES) $*.c
