diff options
| -rw-r--r-- | configure.ac | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/configure.ac b/configure.ac index 8470e3e8..905d717f 100644 --- a/configure.ac +++ b/configure.ac @@ -437,14 +437,6 @@ case $enable_threads in ;; esac -# The Win95 threading lacks thread-safe one-time initialization function. -# It's better to disallow it instead of allowing threaded but thread-unsafe -# build. -if test "x$enable_small$enable_threads" = xyeswin95; then - AC_MSG_ERROR([--enable-threads=win95 and --enable-small cannot be - used at the same time]) -fi - # We use the actual result a little later. @@ -861,6 +853,19 @@ AC_COMPILE_IFELSE([ ]) CFLAGS="$OLD_CFLAGS" +# The Win95 threading lacks a thread-safe one-time initialization function. +# The one-time initialization is needed for crc32_small.c and crc64_small.c +# create the CRC tables. So if small mode is enabled, the threading mode is +# win95, and the compiler does not support attribute constructor, then we +# would end up with a multithreaded build that is thread-unsafe. As a +# result this configuration is not allowed. +if test "x$enable_small$enable_threads$have_func_attribute_constructor"\ + = xyeswin95no; then + AC_MSG_ERROR([--enable-threads=win95 and --enable-small cannot be + used at the same time with a compiler that doesn't support + __attribute__((__constructor__))]) +fi + # __attribute__((__ifunc__())) can be used to choose between different # implementations of the same function at runtime. This is slightly more # efficient than using __attribute__((__constructor__)) and setting |