xref: /freebsd/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_asm.h (revision 5ffd83dbcc34f10e07f6d3e968ae6365869615f4)
1 //===-- sanitizer_asm.h -----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Various support for assemebler.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 // Some toolchains do not support .cfi asm directives, so we have to hide
14 // them inside macros.
15 #if defined(__clang__) ||                                                      \
16     (defined(__GNUC__) && defined(__GCC_HAVE_DWARF2_CFI_ASM))
17   // GCC defined __GCC_HAVE_DWARF2_CFI_ASM if it supports CFI.
18   // Clang seems to support CFI by default (or not?).
19   // We need two versions of macros: for inline asm and standalone asm files.
20 # define CFI_INL_ADJUST_CFA_OFFSET(n) ".cfi_adjust_cfa_offset " #n ";"
21 
22 # define CFI_STARTPROC .cfi_startproc
23 # define CFI_ENDPROC .cfi_endproc
24 # define CFI_ADJUST_CFA_OFFSET(n) .cfi_adjust_cfa_offset n
25 # define CFI_DEF_CFA_OFFSET(n) .cfi_def_cfa_offset n
26 # define CFI_REL_OFFSET(reg, n) .cfi_rel_offset reg, n
27 # define CFI_OFFSET(reg, n) .cfi_offset reg, n
28 # define CFI_DEF_CFA_REGISTER(reg) .cfi_def_cfa_register reg
29 # define CFI_DEF_CFA(reg, n) .cfi_def_cfa reg, n
30 # define CFI_RESTORE(reg) .cfi_restore reg
31 
32 #else  // No CFI
33 # define CFI_INL_ADJUST_CFA_OFFSET(n)
34 # define CFI_STARTPROC
35 # define CFI_ENDPROC
36 # define CFI_ADJUST_CFA_OFFSET(n)
37 # define CFI_DEF_CFA_OFFSET(n)
38 # define CFI_REL_OFFSET(reg, n)
39 # define CFI_OFFSET(reg, n)
40 # define CFI_DEF_CFA_REGISTER(reg)
41 # define CFI_DEF_CFA(reg, n)
42 # define CFI_RESTORE(reg)
43 #endif
44 
45 #if !defined(__APPLE__)
46 # define ASM_HIDDEN(symbol) .hidden symbol
47 # define ASM_TYPE_FUNCTION(symbol) .type symbol, %function
48 # define ASM_SIZE(symbol) .size symbol, .-symbol
49 # define ASM_SYMBOL(symbol) symbol
50 # define ASM_SYMBOL_INTERCEPTOR(symbol) symbol
51 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol
52 #else
53 # define ASM_HIDDEN(symbol)
54 # define ASM_TYPE_FUNCTION(symbol)
55 # define ASM_SIZE(symbol)
56 # define ASM_SYMBOL(symbol) _##symbol
57 # define ASM_SYMBOL_INTERCEPTOR(symbol) _wrap_##symbol
58 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol
59 #endif
60 
61 #if defined(__ELF__) && (defined(__GNU__) || defined(__FreeBSD__) || \
62                          defined(__Fuchsia__) || defined(__linux__))
63 // clang-format off
64 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits  // NOLINT
65 // clang-format on
66 #else
67 #define NO_EXEC_STACK_DIRECTIVE
68 #endif
69