From a50d37bd3a901f3947271d57742077e5976ab860 Mon Sep 17 00:00:00 2001 From: Richard Dodd Date: Fri, 10 May 2019 13:42:02 +0100 Subject: [PATCH] Handle old versions of visual studio --- libsqlite3-sys/build.rs | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/libsqlite3-sys/build.rs b/libsqlite3-sys/build.rs index d72381f..2321c91 100644 --- a/libsqlite3-sys/build.rs +++ b/libsqlite3-sys/build.rs @@ -70,11 +70,27 @@ mod build_bundled { .flag("-DSQLITE_ENABLE_RTREE") .flag("-DSQLITE_ENABLE_STAT2") .flag("-DSQLITE_ENABLE_STAT4") - .flag("-DSQLITE_HAVE_ISNAN") .flag("-DSQLITE_SOUNDEX") .flag("-DSQLITE_THREADSAFE=1") .flag("-DSQLITE_USE_URI") .flag("-DHAVE_USLEEP=1"); + // Older versions of visual studio don't support c99 (including isnan), which causes a + // build failure when the linker fails to find the `isnan` function. `sqlite` provides its + // own implmentation, using the fact that x != x when x is NaN. + // + // There may be other platforms that don't support `isnan`, they should be tested for here. + if cfg!(target_env = "msvc") { + use self::cc::windows_registry::{find_vs_version, VsVers}; + let vs_has_nan = match find_vs_version() { + Ok(ver) => ver != VsVers::Vs12, + Err(_msg) => false, + }; + if vs_has_nan { + cfg.flag("-DSQLITE_HAVE_ISNAN"); + } + } else { + cfg.flag("-DSQLITE_HAVE_ISNAN"); + } if cfg!(feature = "unlock_notify") { cfg.flag("-DSQLITE_ENABLE_UNLOCK_NOTIFY"); }