3dc16d6046
Instead of using version checks per-compiler to define (or not)
each attribute, use __has_attribute to test for them, following
the cleanup started with commit 815f0ddb34
("include/linux/compiler*.h: make compiler-*.h mutually exclusive"),
which is supported on gcc >= 5, clang >= 2.9 and icc >= 17.
In the meantime, to support 4.6 <= gcc < 5, we implement
__has_attribute by hand.
All the attributes that can be unconditionally defined and directly
map to compiler attribute(s) (even if optional) have been moved
to a new file include/linux/compiler_attributes.h
In an effort to make the file as regular as possible, comments
stating the purpose of attributes have been removed. Instead,
links to the compiler docs have been added (i.e. to gcc and,
if available, to clang as well). In addition, they have been sorted.
Finally, if an attribute is optional (i.e. if it is guarded
by __has_attribute), the reason has been stated for future reference.
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # on top of v4.19-rc5, clang 7
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Change-Id: Ibad32cd2889cc2ee578a117c8eb80329231a7080
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
65 lines
2.1 KiB
C
65 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LINUX_COMPILER_TYPES_H
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#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
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#endif
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/* Compiler specific definitions for Clang compiler */
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#define uninitialized_var(x) x = *(&(x))
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/* same as gcc, this was present in clang-2.6 so we can assume it works
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* with any version that can compile the kernel
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*/
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#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
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/* all clang versions usable with the kernel support KASAN ABI version 5 */
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#define KASAN_ABI_VERSION 5
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/* __no_sanitize_address has been already defined compiler-gcc.h */
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#undef __no_sanitize_address
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#if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)
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/* emulate gcc's __SANITIZE_ADDRESS__ flag */
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#define __SANITIZE_ADDRESS__
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#define __no_sanitize_address \
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__attribute__((no_sanitize("address", "hwaddress")))
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#else
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#define __no_sanitize_address
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#endif
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/*
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* Not all versions of clang implement the the type-generic versions
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* of the builtin overflow checkers. Fortunately, clang implements
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* __has_builtin allowing us to avoid awkward version
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* checks. Unfortunately, we don't know which version of gcc clang
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* pretends to be, so the macro may or may not be defined.
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*/
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#if __has_builtin(__builtin_mul_overflow) && \
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__has_builtin(__builtin_add_overflow) && \
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__has_builtin(__builtin_sub_overflow)
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#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
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#endif
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/* The following are for compatibility with GCC, from compiler-gcc.h,
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* and may be redefined here because they should not be shared with other
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* compilers, like ICC.
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*/
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#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
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#ifdef CONFIG_CFI_CLANG
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#define __nocfi __attribute__((__no_sanitize__("cfi")))
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#endif
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#ifdef CONFIG_LTO_CLANG
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#ifdef CONFIG_FTRACE_MCOUNT_RECORD
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#define __norecordmcount \
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__attribute__((__section__(".text..ftrace")))
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#endif
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#endif
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#if __has_feature(shadow_call_stack)
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# define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
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#else
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# define __noscs
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#endif
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