diff options
Diffstat (limited to 'build-aux/m4')
| -rw-r--r-- | build-aux/m4/bitcoin_runtime_lib.m4 | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/build-aux/m4/bitcoin_runtime_lib.m4 b/build-aux/m4/bitcoin_runtime_lib.m4 new file mode 100644 index 0000000000..1a6922deca --- /dev/null +++ b/build-aux/m4/bitcoin_runtime_lib.m4 @@ -0,0 +1,42 @@ +# On some platforms clang builtin implementations +# require compiler-rt as a runtime library to use. +# +# See: +# - https://bugs.llvm.org/show_bug.cgi?id=28629 + +m4_define([_CHECK_RUNTIME_testbody], [[ + bool f(long long x, long long y, long long* p) + { + return __builtin_mul_overflow(x, y, p); + } + int main() { return 0; } +]]) + +AC_DEFUN([CHECK_RUNTIME_LIB], [ + + AC_LANG_PUSH([C++]) + + AC_MSG_CHECKING([for __builtin_mul_overflow]) + AC_LINK_IFELSE( + [AC_LANG_SOURCE([_CHECK_RUNTIME_testbody])], + [ + AC_MSG_RESULT([yes]) + AC_DEFINE([HAVE_BUILTIN_MUL_OVERFLOW], [1], [Define if you have a working __builtin_mul_overflow]) + ], + [ + ax_check_save_flags="$LDFLAGS" + LDFLAGS="$LDFLAGS --rtlib=compiler-rt -lgcc_s" + AC_LINK_IFELSE( + [AC_LANG_SOURCE([_CHECK_RUNTIME_testbody])], + [ + AC_MSG_RESULT([yes, with additional linker flags]) + RUNTIME_LDFLAGS="--rtlib=compiler-rt -lgcc_s" + AC_DEFINE([HAVE_BUILTIN_MUL_OVERFLOW], [1], [Define if you have a working __builtin_mul_overflow]) + ], + [AC_MSG_RESULT([no])]) + LDFLAGS="$ax_check_save_flags" + ]) + + AC_LANG_POP + AC_SUBST([RUNTIME_LDFLAGS]) +]) |