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76426e23 MY |
1 | #!/bin/sh |
2 | # SPDX-License-Identifier: GPL-2.0-only | |
3 | # | |
4 | # Staring v4.18, Kconfig evaluates compiler capabilities, and hides CONFIG | |
5 | # options your compiler does not support. This works well if you configure and | |
6 | # build the kernel on the same host machine. | |
7 | # | |
8 | # It is inconvenient if you prepare the .config that is carried to a different | |
9 | # build environment (typically this happens when you package the kernel for | |
10 | # distros) because using a different compiler potentially produces different | |
11 | # CONFIG options than the real build environment. So, you probably want to make | |
12 | # as many options visible as possible. In other words, you need to create a | |
13 | # super-set of CONFIG options that cover any build environment. If some of the | |
14 | # CONFIG options turned out to be unsupported on the build machine, they are | |
15 | # automatically disabled by the nature of Kconfig. | |
16 | # | |
17 | # However, it is not feasible to get a full-featured compiler for every arch. | |
18 | # Hence these dummy toolchains to make all compiler tests pass. | |
19 | # | |
20 | # Usage: | |
21 | # | |
22 | # From the top directory of the source tree, run | |
23 | # | |
24 | # $ make CROSS_COMPILE=scripts/dummy-tools/ oldconfig | |
25 | # | |
26 | # Most of compiler features are tested by cc-option, which simply checks the | |
27 | # exit code of $(CC). This script does nothing and just exits with 0 in most | |
28 | # cases. So, $(cc-option, ...) is evaluated as 'y'. | |
29 | # | |
30 | # This scripts caters to more checks; handle --version and pre-process __GNUC__ | |
31 | # etc. to pretend to be GCC, and also do right things to satisfy some scripts. | |
32 | ||
33 | # Check if the first parameter appears in the rest. Succeeds if found. | |
34 | # This helper is useful if a particular option was passed to this script. | |
35 | # Typically used like this: | |
36 | # arg_contain <word-you-are-searching-for> "$@" | |
37 | arg_contain () | |
38 | { | |
39 | search="$1" | |
40 | shift | |
41 | ||
42 | while [ $# -gt 0 ] | |
43 | do | |
44 | if [ "$search" = "$1" ]; then | |
45 | return 0 | |
46 | fi | |
47 | shift | |
48 | done | |
49 | ||
50 | return 1 | |
51 | } | |
52 | ||
53 | # To set CONFIG_CC_IS_GCC=y | |
54 | if arg_contain --version "$@"; then | |
55 | echo "gcc (scripts/dummy-tools/gcc)" | |
56 | exit 0 | |
57 | fi | |
58 | ||
59 | if arg_contain -E "$@"; then | |
f9bc754b | 60 | # For scripts/cc-version.sh; This emulates GCC 20.0.0 |
76426e23 | 61 | if arg_contain - "$@"; then |
0df499ea | 62 | sed -n '/^GCC/{s/__GNUC__/20/; s/__GNUC_MINOR__/0/; s/__GNUC_PATCHLEVEL__/0/; p;}; s/__LONG_DOUBLE_128__/1/ p' |
76426e23 MY |
63 | exit 0 |
64 | else | |
65 | echo "no input files" >&2 | |
66 | exit 1 | |
67 | fi | |
68 | fi | |
69 | ||
ba64beb1 MY |
70 | # To set CONFIG_AS_IS_GNU |
71 | if arg_contain -Wa,--version "$@"; then | |
72 | echo "GNU assembler (scripts/dummy-tools) 2.50" | |
73 | exit 0 | |
74 | fi | |
75 | ||
76426e23 MY |
76 | if arg_contain -S "$@"; then |
77 | # For scripts/gcc-x86-*-has-stack-protector.sh | |
78 | if arg_contain -fstack-protector "$@"; then | |
c93db682 MK |
79 | if arg_contain -mstack-protector-guard-reg=fs "$@"; then |
80 | echo "%fs" | |
81 | else | |
82 | echo "%gs" | |
83 | fi | |
76426e23 MY |
84 | exit 0 |
85 | fi | |
2eab791f JS |
86 | |
87 | # For arch/powerpc/tools/gcc-check-mprofile-kernel.sh | |
bfb41e46 | 88 | if arg_contain -m64 "$@" && arg_contain -mprofile-kernel "$@"; then |
2eab791f JS |
89 | if ! test -t 0 && ! grep -q notrace; then |
90 | echo "_mcount" | |
91 | fi | |
92 | exit 0 | |
93 | fi | |
1bfaa37f JSS |
94 | |
95 | # For arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh | |
96 | if arg_contain -m64 "$@" && arg_contain -fpatchable-function-entry=2 "$@"; then | |
97 | echo "func:" | |
98 | echo ".section __patchable_function_entries" | |
99 | echo ".localentry" | |
100 | echo " nop" | |
101 | echo " nop" | |
102 | exit 0 | |
103 | fi | |
76426e23 MY |
104 | fi |
105 | ||
f4c3b83b | 106 | # To set GCC_PLUGINS |
76426e23 | 107 | if arg_contain -print-file-name=plugin "$@"; then |
aac28965 OM |
108 | # Use $0 to find the in-tree dummy directory |
109 | echo "$(dirname "$(readlink -f "$0")")/dummy-plugin-dir" | |
76426e23 MY |
110 | exit 0 |
111 | fi | |
b3d9fc14 JS |
112 | |
113 | # inverted return value | |
114 | if arg_contain -D__SIZEOF_INT128__=0 "$@"; then | |
115 | exit 1 | |
116 | fi |