--- /dev/null
+# This shell script emits a C file. -*- C -*-
+# It does some substitutions.
+cat >em_${EMULATION_NAME}.c <<EOF
+/* This file is is generated by a shell script. DO NOT EDIT! */
+
+/* PowerPC/POWER emulation for the linker.
+ Copyright (C) 1994 Free Software Foundation, Inc.
+ Written by Ian Lance Taylor, Cygnus Support
+
+This file is part of GLD, the Gnu Linker.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/* This file is similar to generic.em. However, we need to build
+ linker stubs to handle calls to different modules. A PowerPC call
+ is emitted as a two instruction sequence:
+ bl .{function}
+ cror 31,31,31
+
+ When linking, if the function symbol is defined and in the same
+ module, we leave it alone (actually, if it is more than 26 bits
+ away we should treat it as though it were in a different module).
+ If the function symbol is not defined, we must construct a linker
+ stub. We reroute the call to go to the linker stub instead, and we
+ change the cror instruction to reload the TOC register value. The
+ linker stub looks like this
+ l r12,{function}(r2)
+ st r2,20(r1)
+ l r0,0(r12)
+ l r2,4(r12)
+ mtctr r0
+ bcc
+
+ Since we do not yet support dynamic linking, all function symbols
+ are in the same module. However, we still need to create a stub
+ for an undefined symbol.
+
+ This is actually probably not correct for the PowerPC ABI.
+ However, I do not have that ABI yet. */
+
+#define TARGET_IS_${EMULATION_NAME}
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "bfdlink.h"
+
+/* FIXME! */
+#include "genlink.h"
+
+#include "ld.h"
+#include "config.h"
+#include "ldmain.h"
+#include "ldemul.h"
+#include "ldfile.h"
+#include "ldmisc.h"
+#include "ldexp.h"
+#include "ldlang.h"
+
+static void gld${EMULATION_NAME}_before_parse PARAMS ((void));
+static char *gld${EMULATION_NAME}_get_script PARAMS ((int *isfile));
+static void gld${EMULATION_NAME}_create_output_section_statements
+ PARAMS ((void));
+static void gld${EMULATION_NAME}_before_allocation PARAMS ((void));
+static boolean gld${EMULATION_NAME}_check_symbol
+ PARAMS ((struct bfd_link_hash_entry *, PTR));
+
+static void
+gld${EMULATION_NAME}_before_parse()
+{
+ ldfile_output_architecture = bfd_arch_${ARCH};
+}
+
+/* Section in which we build stubs. */
+
+static asection *stub_sec;
+
+/* Section in which we build TOC entries for stubs. */
+
+static asection *stub_toc_sec;
+
+/* This is called before the input files are opened. We create a new
+ fake input file to hold the stub section. */
+
+static void
+gld${EMULATION_NAME}_create_output_section_statements ()
+{
+ lang_input_statement_type *stub_file;
+
+ stub_file = lang_add_input_file ("linker stubs",
+ lang_input_file_is_fake_enum,
+ (char *) NULL);
+
+ stub_file->the_bfd = bfd_create ("linker stubs", output_bfd);
+ if (stub_file->the_bfd == (bfd *) NULL
+ || ! bfd_set_arch_mach (stub_file->the_bfd,
+ bfd_get_arch (output_bfd),
+ bfd_get_mach (output_bfd)))
+ {
+ einfo ("%X%P: can not create BFD: %E");
+ return;
+ }
+
+ stub_sec = bfd_make_section_old_way (stub_file->the_bfd, ".text");
+ stub_toc_sec = bfd_make_section_old_way (stub_file->the_bfd, ".toc");
+ if (stub_sec == (asection *) NULL
+ || stub_toc_sec == (asection *) NULL
+ || ! bfd_set_section_flags (stub_file->the_bfd, stub_sec,
+ (SEC_HAS_CONTENTS
+ | SEC_ALLOC
+ | SEC_LOAD
+ | SEC_CODE
+ | SEC_RELOC
+ | SEC_IN_MEMORY))
+ || ! bfd_set_section_flags (stub_file->the_bfd, stub_toc_sec,
+ (SEC_HAS_CONTENTS
+ | SEC_ALLOC
+ | SEC_LOAD
+ | SEC_DATA
+ | SEC_RELOC
+ | SEC_IN_MEMORY)))
+ {
+ einfo ("%X%P: can not create stub sections: %E");
+ return;
+ }
+
+ ldlang_add_file (stub_file);
+}
+
+/* This is called after the input sections have been attached to the
+ output sections but before the output section sizes have been set.
+ We can identify the required stubs because they are undefined
+ symbols beginning with ".". For each such symbol, we build a stub
+ in the .text section. */
+
+static void
+gld${EMULATION_NAME}_before_allocation ()
+{
+ bfd_link_hash_traverse (link_info.hash,
+ gld${EMULATION_NAME}_check_symbol,
+ (PTR) NULL);
+}
+
+/* If a particular symbol is undefined and starts with a ".", then we
+ need to make a stub for it. */
+
+/*ARGSUSED*/
+static boolean
+gld${EMULATION_NAME}_check_symbol (h, info)
+ struct bfd_link_hash_entry *h;
+ PTR info;
+{
+ bfd *stub_bfd;
+ bfd_byte *p;
+ arelent *r;
+ struct bfd_link_hash_entry *hnew;
+ asymbol *sym;
+
+ if (h->type != bfd_link_hash_undefined
+ || h->root.string[0] != '.')
+ return true;
+
+ stub_bfd = stub_sec->owner;
+
+ /* Define this symbol to be the current location in stub_sec. */
+ h->type = bfd_link_hash_defined;
+ h->u.def.value = bfd_section_size (stub_bfd, stub_sec);
+ h->u.def.section = stub_sec;
+
+ /* We want to add this:
+ LONG (0x81820000) lwz r12,{TOC index}(r2)
+ LONG (0x90410014) stw r2,20(r1)
+ LONG (0x800c0000) lwz r0,0(r12)
+ LONG (0x804c0004) lwz r2,4(r12)
+ LONG (0x7c0903a6) mtctr r0
+ LONG (0x4e800420) bctr
+ LONG (0) Traceback table
+ LONG (0xc8000)
+ LONG (0)
+ */
+
+ if (! bfd_set_section_size (stub_bfd, stub_sec,
+ h->u.def.value + 9 * 4))
+ {
+ einfo ("%P%X: can not set section size: %E");
+ return false;
+ }
+
+ stub_sec->contents = ((bfd_byte *)
+ xrealloc ((PTR) stub_sec->contents,
+ bfd_section_size (stub_bfd, stub_sec)));
+ p = stub_sec->contents + h->u.def.value;
+ bfd_put_32 (stub_bfd,
+ (bfd_vma) 0x81820000 + bfd_section_size (stub_bfd, stub_toc_sec),
+ p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0x90410014, p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0x800c0000, p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0x804c0004, p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0x7c0903a6, p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0x4e800420, p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0, p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0xc8000, p);
+ p += 4;
+ bfd_put_32 (stub_bfd, (bfd_vma) 0, p);
+
+ /* Add an undefined symbol for the TOC reference. This is the name
+ without the leading ".". */
+ hnew = bfd_link_hash_lookup (link_info.hash, h->root.string + 1, true,
+ false, true);
+ if (hnew == (struct bfd_link_hash_entry *) NULL)
+ einfo ("%P%F: bfd_link_hash_lookup failed: %E");
+ if (hnew->type == bfd_link_hash_new)
+ {
+ hnew->type = bfd_link_hash_undefined;
+ hnew->u.undef.abfd = stub_bfd;
+ bfd_link_add_undef (link_info.hash, hnew);
+ }
+
+ /* Add a relocation entry for the TOC reference in the first
+ instruction. */
+ ++stub_sec->reloc_count;
+ stub_sec->relocation = ((arelent *)
+ xrealloc ((PTR) stub_sec->relocation,
+ (stub_sec->reloc_count
+ * sizeof (arelent))));
+ r = &stub_sec->relocation[stub_sec->reloc_count - 1];
+ r->sym_ptr_ptr = stub_toc_sec->symbol_ptr_ptr;
+ r->address = h->u.def.value;
+ if (stub_bfd->xvec->byteorder_big_p)
+ r->address += 2;
+ r->addend = 0;
+ r->howto = bfd_reloc_type_lookup (stub_bfd, BFD_RELOC_PPC_TOC16);
+ if (r->howto == (reloc_howto_type *) NULL)
+ einfo ("%P%F: no howto for TOC reference: %E");
+
+ /* Add a relocation entry in the TOC section. */
+ ++stub_toc_sec->reloc_count;
+ stub_toc_sec->relocation = ((arelent *)
+ xrealloc ((PTR) stub_toc_sec->relocation,
+ (stub_toc_sec->reloc_count
+ * sizeof (arelent))));
+ r = &stub_toc_sec->relocation[stub_toc_sec->reloc_count - 1];
+
+ sym = bfd_make_empty_symbol (stub_bfd);
+ sym->name = hnew->root.string;
+ sym->value = 0;
+ sym->flags = BSF_NO_FLAGS;
+ sym->section = &bfd_und_section;
+ sym->udata = NULL;
+
+ /* FIXME! */
+ ((struct generic_link_hash_entry *) hnew)->sym = sym;
+
+ r->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
+ *r->sym_ptr_ptr = sym;
+ r->address = bfd_section_size (stub_bfd, stub_toc_sec);
+ r->addend = 0;
+ r->howto = bfd_reloc_type_lookup (stub_bfd, BFD_RELOC_32);
+ if (r->howto == (reloc_howto_type *) NULL)
+ einfo ("%P%F: no howto for TOC entry: %E");
+
+ /* Add more space to the .toc section. */
+ if (! bfd_set_section_size (stub_bfd, stub_toc_sec,
+ bfd_section_size (stub_bfd, stub_toc_sec) + 4))
+ {
+ einfo ("%P%X: can not set section size: %E");
+ return false;
+ }
+
+ stub_toc_sec->contents = ((bfd_byte *)
+ xrealloc ((PTR) stub_toc_sec->contents,
+ bfd_section_size (stub_bfd,
+ stub_toc_sec)));
+ bfd_put_32 (stub_bfd, (bfd_vma) 0,
+ (stub_toc_sec->contents
+ + bfd_section_size (stub_bfd, stub_toc_sec)
+ - 4));
+
+ return true;
+}
+
+static char *
+gld${EMULATION_NAME}_get_script(isfile)
+ int *isfile;
+EOF
+
+if test -n "$COMPILE_IN"
+then
+# Scripts compiled in.
+
+# sed commands to quote an ld script as a C string.
+sc='s/["\\]/\\&/g
+s/$/\\n\\/
+1s/^/"{/
+$s/$/n}"/
+'
+
+cat >>em_${EMULATION_NAME}.c <<EOF
+{
+ *isfile = 0;
+
+ if (link_info.relocateable == true && config.build_constructors == true)
+ return `sed "$sc" ldscripts/${EMULATION_NAME}.xu`;
+ else if (link_info.relocateable == true)
+ return `sed "$sc" ldscripts/${EMULATION_NAME}.xr`;
+ else if (!config.text_read_only)
+ return `sed "$sc" ldscripts/${EMULATION_NAME}.xbn`;
+ else if (!config.magic_demand_paged)
+ return `sed "$sc" ldscripts/${EMULATION_NAME}.xn`;
+ else
+ return `sed "$sc" ldscripts/${EMULATION_NAME}.x`;
+}
+EOF
+
+else
+# Scripts read from the filesystem.
+
+cat >>em_${EMULATION_NAME}.c <<EOF
+{
+ *isfile = 1;
+
+ if (link_info.relocateable == true && config.build_constructors == true)
+ return "ldscripts/${EMULATION_NAME}.xu";
+ else if (link_info.relocateable == true)
+ return "ldscripts/${EMULATION_NAME}.xr";
+ else if (!config.text_read_only)
+ return "ldscripts/${EMULATION_NAME}.xbn";
+ else if (!config.magic_demand_paged)
+ return "ldscripts/${EMULATION_NAME}.xn";
+ else
+ return "ldscripts/${EMULATION_NAME}.x";
+}
+EOF
+
+fi
+
+cat >>em_${EMULATION_NAME}.c <<EOF
+
+struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
+{
+ gld${EMULATION_NAME}_before_parse,
+ syslib_default,
+ hll_default,
+ after_parse_default,
+ after_allocation_default,
+ set_output_arch_default,
+ ldemul_default_target,
+ gld${EMULATION_NAME}_before_allocation,
+ gld${EMULATION_NAME}_get_script,
+ "${EMULATION_NAME}",
+ "${OUTPUT_FORMAT}",
+ 0,
+ gld${EMULATION_NAME}_create_output_section_statements
+};
+EOF
projects / binutils-gdb.git / commitdiff