commonlib: Clean up compiler.h

This patch contains several minor cleanups related to compiler.h:

- Replace __always_unused() (which is a Linux-specific concept that
  doesn't make sense without also having __maybe_unused(), and had zero
  uses in the codebase) with __unused() which moves here from helpers.h

- Add __underscores__ to the names of all attributes in the compiler
  attribute shorthand macros. This is necessary to make them work in
  files where the same name was already used for an identifier (e.g.
  cbfstool/cbfs.h's `unused` array of file types).

- Remove libpayload's own copy of compiler.h and make it directly pull
  in the commonlib/bsd copy.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I9644da594bb69133843c6b7f12ce50b2e45fd24b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64737
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>

payloads/libpayload/Makefile.inc

@@ -60,7 +60,8 @@ subdirs-$(CONFIG_LP_LZ4) += liblz4
 subdirs-$(CONFIG_LP_VBOOT_LIB) += vboot
 
 INCLUDES := -Iinclude -Iinclude/$(ARCHDIR-y) -I$(obj)
-INCLUDES += -include include/kconfig.h -include include/compiler.h
+INCLUDES += -include include/kconfig.h
+INCLUDES += -include $(coreboottop)/src/commonlib/bsd/include/commonlib/bsd/compiler.h
 INCLUDES += -I$(coreboottop)/src/commonlib/bsd/include
 INCLUDES += -I$(VBOOT_SOURCE)/firmware/include
 

payloads/libpayload/bin/lpgcc

@@ -168,9 +168,11 @@ if [ $_LIBDIR = $_OBJ ]; then
 	_CFLAGS="$_CFLAGS -I$BASE/../curses"
     fi
 
+    _CFLAGS="$_CFLAGS -include $BASE/../../../src/commonlib/bsd/include/commonlib/bsd/compiler.h"
     _CFLAGS="$_CFLAGS -I$BASE/../../../src/commonlib/bsd/include"
     _CFLAGS="$_CFLAGS -I$BASE/../../../3rdparty/vboot/firmware/include"
 else
+    _CFLAGS="$_CFLAGS -include $BASE/../include/commonlib/bsd/compiler.h"
     _CFLAGS="$_CFLAGS -I$_VBOOTINCDIR"
 fi
 
@@ -179,7 +181,7 @@ fi
 trygccoption -fno-stack-protector
 [ $? -eq 0 ] && _CFLAGS="$_CFLAGS -fno-stack-protector"
 
-_CFLAGS="$_CFLAGS -include $BASE/../include/kconfig.h -include $BASE/../include/compiler.h"
+_CFLAGS="$_CFLAGS -include $BASE/../include/kconfig.h"
 _CFLAGS="$_CFLAGS -I`$DEFAULT_CC $_ARCHEXTRA -print-search-dirs | head -n 1 | cut -d' ' -f2`include"
 
 if [ "$CONFIG_LP_VBOOT_LIB" = y ]; then

payloads/libpayload/include/compiler.h

@@ -1,53 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0-only */
-
-#ifndef _COMMONLIB_BSD_COMPILER_H_
-#define _COMMONLIB_BSD_COMPILER_H_
-
-#ifndef __packed
-#if defined(__WIN32) || defined(__WIN64)
-#define __packed __attribute__((gcc_struct, packed))
-#else
-#define __packed __attribute__((packed))
-#endif
-#endif
-
-#ifndef __aligned
-#define __aligned(x) __attribute__((aligned(x)))
-#endif
-
-#ifndef __always_unused
-#define __always_unused __attribute__((unused))
-#endif
-
-#ifndef __must_check
-#define __must_check __attribute__((warn_unused_result))
-#endif
-
-#ifndef __weak
-#define __weak __attribute__((weak))
-#endif
-
-#ifndef __noreturn
-#define __noreturn __attribute__((noreturn))
-#endif
-
-#ifndef __always_inline
-#define __always_inline inline __attribute__((always_inline))
-#endif
-
-/* This evaluates to the type of the first expression, unless that is constant
-   in which case it evalutates to the type of the second. This is useful when
-   assigning macro parameters to temporary variables, because that would
-   normally circumvent the special loosened type promotion rules for integer
-   literals. By using this macro, the promotion can happen at the time the
-   literal is assigned to the temporary variable. If the literal doesn't fit in
-   the chosen type, -Werror=overflow will catch it, so this should be safe. */
-#define __TYPEOF_UNLESS_CONST(expr, fallback_expr) __typeof__( \
-	__builtin_choose_expr(__builtin_constant_p(expr), fallback_expr, expr))
-
-/* This creates a unique local variable name for use in macros. */
-#define __TMPNAME_3(i) __tmpname_##i
-#define __TMPNAME_2(i) __TMPNAME_3(i)
-#define __TMPNAME __TMPNAME_2(__COUNTER__)
-
-#endif

payloads/libpayload/tests/Makefile.inc

@@ -30,7 +30,8 @@ TEST_CONFIG_ := CONFIG_LP_
 
 
 # Default includes
-TEST_CFLAGS := -include include/kconfig.h -include include/compiler.h
+TEST_CFLAGS := -include include/kconfig.h
+TEST_CFLAGS += -include $(coreboottop)/src/commonlib/bsd/include/commonlib/bsd/compiler.h
 TEST_CFLAGS += -Iinclude -Iinclude/mock
 TEST_CFLAGS += -I$(coreboottop)/src/commonlib/bsd/include
 TEST_CFLAGS += -I$(dir $(TEST_KCONFIG_AUTOHEADER))

src/arch/riscv/opensbi.c

@@ -1,5 +1,9 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+/* OpenSBI wants to make its own definitions for some of our compiler.h macros. */
+#undef __packed
+#undef __noreturn
+
 #include <sbi/fw_dynamic.h>
 #include <arch/boot.h>
 /* DO NOT INCLUDE COREBOOT HEADERS HERE */

src/commonlib/bsd/include/commonlib/bsd/compiler.h

@@ -5,34 +5,34 @@
 
 #ifndef __packed
 #if defined(__WIN32) || defined(__WIN64)
-#define __packed __attribute__((gcc_struct, packed))
+#define __packed __attribute__((__gcc_struct__, __packed__))
 #else
-#define __packed __attribute__((packed))
+#define __packed __attribute__((__packed__))
 #endif
 #endif
 
 #ifndef __aligned
-#define __aligned(x) __attribute__((aligned(x)))
+#define __aligned(x) __attribute__((__aligned__(x)))
 #endif
 
-#ifndef __always_unused
-#define __always_unused __attribute__((unused))
+#ifndef __unused
+#define __unused __attribute__((__unused__))
 #endif
 
 #ifndef __must_check
-#define __must_check __attribute__((warn_unused_result))
+#define __must_check __attribute__((__warn_unused_result__))
 #endif
 
 #ifndef __weak
-#define __weak __attribute__((weak))
+#define __weak __attribute__((__weak__))
 #endif
 
 #ifndef __noreturn
-#define __noreturn __attribute__((noreturn))
+#define __noreturn __attribute__((__noreturn__))
 #endif
 
 #ifndef __always_inline
-#define __always_inline inline __attribute__((always_inline))
+#define __always_inline inline __attribute__((__always_inline__))
 #endif
 
 #ifndef __fallthrough

src/commonlib/include/commonlib/helpers.h

@@ -34,10 +34,6 @@
 	const __typeof__(((type *)0)->member) *__mptr = (ptr);	\
 	(type *)((char *)__mptr - offsetof(type, member)); })
 
-#ifndef __unused
-#define __unused __attribute__((unused))
-#endif
-
 #ifndef alloca
 #define alloca(x) __builtin_alloca(x)
 #endif