blob: 1d1e5b3a91fd89f821b8fca3e884ab4dd59e5a43 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
# - Try to find how to link to the standard math library, if anything at all is needed to do.
# On most platforms this is automatic, but for example it's not automatic on QNX.
#
# Once done this will define
#
# STANDARD_MATH_LIBRARY_FOUND - we found how to successfully link to the standard math library
# STANDARD_MATH_LIBRARY - the name of the standard library that one has to link to.
# -- this will be left empty if it's automatic (most platforms).
# -- this will be set to "m" on platforms where one must explicitly
# pass the "-lm" linker flag.
#
# Copyright (c) 2010 Benoit Jacob <jacob.benoit.1@gmail.com>
# 2020 Susi Lehtola <susi.lehtola@gmail.com>
# Redistribution and use is allowed according to the terms of the 2-clause BSD license.
include(CheckCXXSourceCompiles)
# a little test program for c++ math functions.
# notice the std:: is required on some platforms such as QNX
# notice the (void) is required if -Wall (-Wunused-value) is added to CMAKE_CXX_FLAG
# We read in the arguments from standard input to avoid the compiler optimizing away the calls
set(find_standard_math_library_test_program
"
#include<cmath>
int main(int argc, char **){
return int(std::sin(double(argc)) + std::log(double(argc)));
}")
# first try compiling/linking the test program without any linker flags
set(CMAKE_REQUIRED_FLAGS "")
set(CMAKE_REQUIRED_LIBRARIES "")
CHECK_CXX_SOURCE_COMPILES(
"${find_standard_math_library_test_program}"
standard_math_library_linked_to_automatically
)
if(standard_math_library_linked_to_automatically)
# the test program linked successfully without any linker flag.
set(STANDARD_MATH_LIBRARY "")
set(STANDARD_MATH_LIBRARY_FOUND TRUE)
else()
# the test program did not link successfully without any linker flag.
# This is a very uncommon case that so far we only saw on QNX. The next try is the
# standard name 'm' for the standard math library.
set(CMAKE_REQUIRED_LIBRARIES "m")
CHECK_CXX_SOURCE_COMPILES(
"${find_standard_math_library_test_program}"
standard_math_library_linked_to_as_m)
if(standard_math_library_linked_to_as_m)
# the test program linked successfully when linking to the 'm' library
set(STANDARD_MATH_LIBRARY "m")
set(STANDARD_MATH_LIBRARY_FOUND TRUE)
else()
# the test program still doesn't link successfully
set(STANDARD_MATH_LIBRARY_FOUND FALSE)
endif()
endif()
|
