objtool: Rework header include paths

Currently objtool headers are being included either by their base name
or included via ../ from a parent directory. In case of a base name usage:

 #include "warn.h"
 #include "arch_elf.h"

it does not make it apparent from which directory the file comes from.
To make it slightly better, and actually to avoid name clashes some arch
specific files have "arch_" suffix. And files from an arch folder have
to revert to including via ../ e.g:
 #include "../../elf.h"

With additional architectures support and the code base growth there is
a need for clearer headers naming scheme for multiple reasons:
1. to make it instantly obvious where these files come from (objtool
   itself / objtool arch|generic folders / some other external files),
2. to avoid name clashes of objtool arch specific headers, potential
   obtool arch generic headers and the system header files (there is
   /usr/include/elf.h already),
3. to avoid ../ includes and improve code readability.
4. to give a warm fuzzy feeling to developers who are mostly kernel
   developers and are accustomed to linux kernel headers arranging
   scheme.

Doesn't this make it instantly obvious where are these files come from?

 #include <objtool/warn.h>
 #include <arch/elf.h>

And doesn't it look nicer to avoid ugly ../ includes? Which also
guarantees this is elf.h from the objtool and not /usr/include/elf.h.

 #include <objtool/elf.h>

This patch defines and implements new objtool headers arranging
scheme. Which is:
- all generic headers go to include/objtool (similar to include/linux)
- all arch headers go to arch/$(SRCARCH)/include/arch (to get arch
  prefix). This is similar to linux arch specific "asm/*" headers but we
  are not abusing "asm" name and calling it what it is. This also helps
  to prevent name clashes (arch is not used in system headers or kernel
  exports).

To bring objtool to this state the following things are done:
1. current top level tools/objtool/ headers are moved into
   include/objtool/ subdirectory,
2. arch specific headers, currently only arch/x86/include/ are moved into
   arch/x86/include/arch/ and were stripped of "arch_" suffix,
3. new -I$(srctree)/tools/objtool/include include path to make
   includes like <objtool/warn.h> possible,
4. rewriting file includes,
5. make git not to ignore include/objtool/ subdirectory.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>

1 files changed, 0 insertions, 41 deletions

diff --git a/tools/objtool/special.h b/tools/objtool/special.h
deleted file mode 100644
index abddf38ef334..000000000000
--- a/tools/objtool/special.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
- */
-
-#ifndef _SPECIAL_H
-#define _SPECIAL_H
-
-#include <stdbool.h>
-#include "check.h"
-#include "elf.h"
-
-#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
-
-struct special_alt {
-	struct list_head list;
-
-	bool group;
-	bool skip_orig;
-	bool skip_alt;
-	bool jump_or_nop;
-
-	struct section *orig_sec;
-	unsigned long orig_off;
-
-	struct section *new_sec;
-	unsigned long new_off;
-
-	unsigned int orig_len, new_len; /* group only */
-};
-
-int special_get_alts(struct elf *elf, struct list_head *alts);
-
-void arch_handle_alternative(unsigned short feature, struct special_alt *alt);
-
-bool arch_support_alt_relocation(struct special_alt *special_alt,
-				 struct instruction *insn,
-				 struct reloc *reloc);
-struct reloc *arch_find_switch_table(struct objtool_file *file,
-				    struct instruction *insn);
-#endif /* _SPECIAL_H */