config.gcc (m68k-*-uclinux*): Add flat.h to $tm_file.

gcc/
	* config.gcc (m68k-*-uclinux*): Add flat.h to $tm_file.
	* config/flat.h: New file.
	* crtstuff.c (USE_PT_GNU_EH_FRAME): Don't define if
	OBJECT_FORMAT_FLAT.
	* config/m68k/m68k.h (ASM_PREFERRED_EH_DATA_FORMAT): Do not use
	indirect references for -msep-data or -mid-shared-library.
	Do not use PC-relative code addresses either.
	* config/m68k/m68k.c (override_options): Restrict -fPIC error
	to -mpcrel.
	* config/m68k/uclinux.h (STARTFILE_SPEC): Define.  Use Scrt1.o
	for shared libraries and crt1.o for executables.  Use crti.o and
	crtbegin.o.
	(ENDFILE_SPEC): Use crtend.o and crtn.o.
	(LIB_SPEC): Suppress -Rlibc.gdb if -static-libc is given.
	Do not add -elf2flt or -shared-lib-id options here.
	(LINK_SPEC): Define.  Pass -elf2flt if no -elf2flt option is given.
	Pass -shared-lib-id if -mid-shared-library, taking the library
	identifier from -mshared-library-id if given, otherwise
	defaulting to 0.
	(EH_FRAME_IN_DATA_SECTION): Do not undefine.
	(INIT_SECTION_ASM_OP, FINI_SECTION_ASM_OP): Likewise.
	(TARGET_OS_CPP_BUILTINS): Define __GXX_MERGED_TYPEINFO_NAMES=0
	and __GXX_TYPEINFO_EQUALITY_INLINE=0 if -mid-shared-library.
	(DRIVER_SELF_SPECS): Map unadorned PIC options to -msep-data.
	* config/m68k/t-uclinux (EXTRA_MULTILIB_PARTS): Add crtbegin.o
	and crtend.o.
	* config/m68k/lb1sf68.asm (PICCALL): Use an lea and pc-relative
	jump sequence for ISA A and ISA A+.
	(PICJUMP): Likewise.

From-SVN: r120912

gcc/ChangeLog

 2007-01-18  Richard Sandiford  <richard@codesourcery.com>
 
+	* config.gcc (m68k-*-uclinux*): Add flat.h to $tm_file.
+	* config/flat.h: New file.
+	* crtstuff.c (USE_PT_GNU_EH_FRAME): Don't define if
+	OBJECT_FORMAT_FLAT.
+	* config/m68k/m68k.h (ASM_PREFERRED_EH_DATA_FORMAT): Do not use
+	indirect references for -msep-data or -mid-shared-library.
+	Do not use PC-relative code addresses either.
+	* config/m68k/m68k.c (override_options): Restrict -fPIC error
+	to -mpcrel.
+	* config/m68k/uclinux.h (STARTFILE_SPEC): Define.  Use Scrt1.o
+	for shared libraries and crt1.o for executables.  Use crti.o and
+	crtbegin.o.
+	(ENDFILE_SPEC): Use crtend.o and crtn.o.
+	(LIB_SPEC): Suppress -Rlibc.gdb if -static-libc is given.
+	Do not add -elf2flt or -shared-lib-id options here.
+	(LINK_SPEC): Define.  Pass -elf2flt if no -elf2flt option is given.
+	Pass -shared-lib-id if -mid-shared-library, taking the library
+	identifier from -mshared-library-id if given, otherwise
+	defaulting to 0.
+	(EH_FRAME_IN_DATA_SECTION): Do not undefine.
+	(INIT_SECTION_ASM_OP, FINI_SECTION_ASM_OP): Likewise.
+	(TARGET_OS_CPP_BUILTINS): Define __GXX_MERGED_TYPEINFO_NAMES=0
+	and __GXX_TYPEINFO_EQUALITY_INLINE=0 if -mid-shared-library.
+	(DRIVER_SELF_SPECS): Map unadorned PIC options to -msep-data.
+	* config/m68k/t-uclinux (EXTRA_MULTILIB_PARTS): Add crtbegin.o
+	and crtend.o.
+	* config/m68k/lb1sf68.asm (PICCALL): Use an lea and pc-relative
+	jump sequence for ISA A and ISA A+.
+	(PICJUMP): Likewise.
+
+2007-01-18  Richard Sandiford  <richard@codesourcery.com>
+
 	* config.gcc (m68k-*-uclinux*): Base the port on the common
 	and m68k GNU/Linux files rather than on the generic ELF ones.
 	* config/m68k/uclinux.h (TARGET_VERSION): Override.

gcc/config.gcc

@@ -1523,7 +1523,7 @@ m68k-*-uclinux*)		# Motorola m68k/ColdFire running uClinux
 				# with uClibc, using the new GNU/Linux-style
 				# ABI.
 	default_m68k_cpu=68020
-	tm_file="m68k/m68k.h dbxelf.h elfos.h svr4.h linux.h m68k/linux.h m68k/uclinux.h"
+	tm_file="m68k/m68k.h dbxelf.h elfos.h svr4.h linux.h flat.h m68k/linux.h m68k/uclinux.h"
  	tm_defines="${tm_defines} MOTOROLA USE_GAS UCLIBC_DEFAULT=1"
 	extra_options="${extra_options} linux.opt"
 	tmake_file=m68k/t-uclinux

gcc/config/flat.h

+/* Defines to be used for targets that support flat executables.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to
+the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+/* This macro applies on top of OBJECT_FORMAT_ELF and indicates that
+   we want to support both flat and ELF output.  */
+#define OBJECT_FORMAT_FLAT

gcc/config/m68k/lb1sf68.asm

@@ -120,11 +120,21 @@ Boston, MA 02110-1301, USA.  */
 	/* Common for -mid-shared-libary and -msep-data */
 
 	.macro PICCALL addr
+#if defined (__mcoldfire__) && !defined (__mcfisab__)
+	lea	\addr-.-8,a0
+	jsr	pc@(a0)
+#else
 	bsr	\addr
+#endif
 	.endm
 
 	.macro PICJUMP addr
+#if defined (__mcoldfire__) && !defined (__mcfisab__)
+	lea	\addr-.-8,a0
+	jmp	pc@(a0)
+#else
 	bra	\addr
+#endif
 	.endm
 
 # if defined(__ID_SHARED_LIBRARY__)

gcc/config/m68k/m68k.c

@@ -519,10 +519,10 @@ override_options (void)
   if (TARGET_SEP_DATA || TARGET_ID_SHARED_LIBRARY)
     flag_pic = 2;
 
-  /* -fPIC uses 32-bit pc-relative displacements, which don't exist
-     until the 68020.  */
-  if (!TARGET_68020 && !TARGET_COLDFIRE && (flag_pic == 2))
-    error ("-fPIC is not currently supported on the 68000 or 68010");
+  /* -mpcrel -fPIC uses 32-bit pc-relative displacements.  Raise an
+     error if the target does not support them.  */
+  if (TARGET_PCREL && !TARGET_68020 && flag_pic == 2)
+    error ("-mpcrel -fPIC is not currently supported on selected cpu");
 
   /* ??? A historic way of turning on pic, or is this intended to
      be an embedded thing that doesn't have the same name binding

gcc/config/m68k/m68k.h

@@ -1090,9 +1090,34 @@ do { if (cc_prev_status.flags & CC_IN_68881)			\
 
 /* Select a format to encode pointers in exception handling data.  CODE
    is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
-   true if the symbol may be affected by dynamic relocations.  */
+   true if the symbol may be affected by dynamic relocations.
+
+   TARGET_ID_SHARED_LIBRARY and TARGET_SEP_DATA are designed to support
+   a read-only text segment without imposing a fixed gap between the
+   text and data segments.  As a result, the text segment cannot refer
+   to anything in the data segment, even in PC-relative form.  Because
+   .eh_frame refers to both code and data, it follows that .eh_frame
+   must be in the data segment itself, and that the offset between
+   .eh_frame and code will not be a link-time constant.
+
+   In theory, we could create a read-only .eh_frame by using DW_EH_PE_pcrel
+   | DW_EH_PE_indirect for all code references.  However, gcc currently
+   handles indirect references using a per-TU constant pool.  This means
+   that if a function and its eh_frame are removed by the linker, the
+   eh_frame's indirect references to the removed function will not be
+   removed, leading to an unresolved symbol error.
+
+   It isn't clear that any -msep-data or -mid-shared-library target
+   would benefit from a read-only .eh_frame anyway.  In particular,
+   no known target that supports these options has a feature like
+   PT_GNU_RELRO.  Without any such feature to motivate them, indirect
+   references would be unnecessary bloat, so we simply use an absolute
+   pointer for code and global references.  We still use pc-relative
+   references to data, as this avoids a relocation.  */
 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL)			   \
   (flag_pic								   \
+   && !((TARGET_ID_SHARED_LIBRARY || TARGET_SEP_DATA)			   \
+	&& ((GLOBAL) || (CODE)))					   \
    ? ((GLOBAL) ? DW_EH_PE_indirect : 0) | DW_EH_PE_pcrel | DW_EH_PE_sdata4 \
    : DW_EH_PE_absptr)
 

gcc/config/m68k/t-uclinux

+# crti and crtn are provided by uClibc.
+EXTRA_MULTILIB_PARTS=crtbegin.o crtend.o
+
 LIB1ASMSRC = m68k/lb1sf68.asm
 LIB1ASMFUNCS = _mulsi3 _udivsi3 _divsi3 _umodsi3 _modsi3 \
    _double _float _floatex \
@@ -19,6 +22,3 @@ MULTILIB_EXCEPTIONS = m68000/msep-data* m68000/mid-shared-library* msep-data* mi
 
 LIBGCC = stmp-multilib
 INSTALL_LIBGCC = install-multilib
-
-# We don't use crtbegin.o and crtend.o
-EXTRA_MULTILIB_PARTS=

gcc/config/m68k/uclinux.h

@@ -24,29 +24,27 @@ Boston, MA 02110-1301, USA.  */
 #undef TARGET_VERSION
 #define TARGET_VERSION fprintf (stderr, " (68k uClinux)");
 
-/* Undo the definition of STARTFILE_SPEC from m68kelf.h so we'll
-   pick the default from gcc.c (just link crt0.o from multilib dir).  */
-#undef	STARTFILE_SPEC
+#undef STARTFILE_SPEC
+#define STARTFILE_SPEC \
+"%{mshared-library-id=0|!mshared-library-id=*: crt1.o%s ;: Scrt1.o%s} \
+ crti.o%s crtbegin.o%s"
+
+#undef ENDFILE_SPEC
+#define ENDFILE_SPEC "crtend.o%s crtn.o%s"
 
 /* Override the default LIB_SPEC from gcc.c.  We don't currently support
    profiling, or libg.a.  */
 #undef LIB_SPEC
-#define LIB_SPEC "\
-%{mid-shared-library:-R libc.gdb%s -elf2flt -shared-lib-id 0} -lc \
-"
-
-/* we don't want a .eh_frame section.  */
-#define EH_FRAME_IN_DATA_SECTION
-
-/* ??? Quick hack to get constructors working.  Make this look more like a
-   COFF target, so the existing dejagnu/libgloss support works.  A better
-   solution would be to make the necessary dejagnu and libgloss changes so
-   that we can use normal the ELF constructor mechanism.  */
-#undef INIT_SECTION_ASM_OP
-#undef FINI_SECTION_ASM_OP
-#undef ENDFILE_SPEC
-#define ENDFILE_SPEC ""
- 
+#define LIB_SPEC \
+"%{mid-shared-library:%{!static-libc:-R libc.gdb%s}} -lc"
+
+/* Default to using -elf2flt with no options.  */
+#undef LINK_SPEC
+#define LINK_SPEC \
+"%{!elf2flt*:-elf2flt} \
+ %{mid-shared-library: \
+   %{mshared-library-id=*:-shared-lib-id %*;:-shared-lib-id 0}}"
+
 #undef TARGET_OS_CPP_BUILTINS
 #define TARGET_OS_CPP_BUILTINS()				\
   do								\
@@ -54,7 +52,16 @@ Boston, MA 02110-1301, USA.  */
       LINUX_TARGET_OS_CPP_BUILTINS ();				\
       builtin_define ("__uClinux__");				\
       if (TARGET_ID_SHARED_LIBRARY)				\
-	builtin_define ("__ID_SHARED_LIBRARY__");		\
+	{							\
+	  builtin_define ("__ID_SHARED_LIBRARY__");		\
+	  /* Shared libraries and executables do not share	\
+	     typeinfo names.  */				\
+	  builtin_define ("__GXX_MERGED_TYPEINFO_NAMES=0");	\
+	  builtin_define ("__GXX_TYPEINFO_EQUALITY_INLINE=0");	\
+	}							\
     }								\
   while (0)
 
+/* -msep-data is the default PIC mode on this target.  */
+#define DRIVER_SELF_SPECS \
+  "%{fpie|fPIE|fpic|fPIC:%{!msep-data:%{!mid-shared-library: -msep-data}}}"

gcc/crtstuff.c

@@ -86,7 +86,9 @@ call_ ## FUNC (void)					\
 }
 #endif
 
-#if defined(OBJECT_FORMAT_ELF) && defined(HAVE_LD_EH_FRAME_HDR) \
+#if defined(OBJECT_FORMAT_ELF) \
+    && !defined(OBJECT_FORMAT_FLAT) \
+    && defined(HAVE_LD_EH_FRAME_HDR) \
     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
     && defined(__GLIBC__) && __GLIBC__ >= 2
 #include <link.h>