From 94993901cdb75fad7b68080eaa0e9b546810a107 Mon Sep 17 00:00:00 2001
From: Terence <terence@taraz>
Date: Tue, 1 Jun 2021 20:41:38 -0400
Subject: wip

---
 src/utils.rs | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

(limited to 'src/utils.rs')

diff --git a/src/utils.rs b/src/utils.rs
index c1eb31d..4ea2339 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -4,6 +4,7 @@ use na::{Matrix3, Point2, Point3, Scalar, SimdRealField, Vector2, Vector3};
 use num::Zero;
 use simba::simd::SimdValue;
 use std::ops::IndexMut;
+use std::os::raw::c_int;
 
 use parry::utils::SdpMatrix3;
 use {
@@ -670,6 +671,48 @@ impl Drop for FlushToZeroDenormalsAreZeroFlags {
     }
 }
 
+// This is an RAII structure that disables floating point exceptions while
+// it is alive, so that operations which generate NaNs and infinite values
+// intentionally will not trip an exception when debugging problematic
+// code that is generating NaNs and infinite values erroneously.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) struct DisableFloatingPointExceptionsFlags {
+    original_flags: c_int,
+}
+
+#[cfg(feature = "avoid-fe-exceptions")]
+extern "C" {
+    fn feenableexcept(flags: c_int);
+    fn fecleareexcept(flags: c_int);
+    fn fetestexcept(flags: c_int) -> c_int;
+    static FE_ALL_EXCEPT: c_int;
+}
+
+impl DisableFloatingPointExceptionsFlags {
+    #[cfg(not(feature = "avoid-fe-exceptions"))]
+    pub fn disable_floating_point_exceptions() -> Self {
+        Self { original_flags: 0 }
+    }
+
+    #[cfg(feature = "avoid-fe-exceptions")]
+    pub fn disable_floating_point_exceptions() -> Self {
+        unsafe {
+            let original_flags = fetestexcept(FE_ALL_EXCEPT);
+            fecleareexcept(FE_ALL_EXCEPT);
+            Self { original_flags }
+        }
+    }
+}
+
+#[cfg(feature = "avoid-fe-exceptions")]
+impl Drop for DisableFloatingPointExceptionsFlags {
+    fn drop(&mut self) {
+        unsafe {
+            feenableexcept(self.original_flags);
+        }
+    }
+}
+
 pub(crate) fn select_other<T: PartialEq>(pair: (T, T), elt: T) -> T {
     if pair.0 == elt {
         pair.1
-- 
cgit 


From 16fd97595d54adbe715d2059a115ae904531f553 Mon Sep 17 00:00:00 2001
From: Terence <terence@taraz>
Date: Tue, 1 Jun 2021 21:27:51 -0400
Subject: wee

---
 src/utils.rs | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

(limited to 'src/utils.rs')

diff --git a/src/utils.rs b/src/utils.rs
index 4ea2339..4602142 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -677,28 +677,32 @@ impl Drop for FlushToZeroDenormalsAreZeroFlags {
 // code that is generating NaNs and infinite values erroneously.
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) struct DisableFloatingPointExceptionsFlags {
-    original_flags: c_int,
+    #[cfg(feature = "avoid-fe-exceptions")]
+    // We can't get a precise size for this, because it's of type
+    // `fenv_t`, which is a definition that doesn't exist in rust
+    // (not even in the libc crate, as of the time of writing.)
+    // But since the state is intended to be stored on the stack,
+    // 256 bytes should be more than enough.
+    original_flags: [u8; 256],
 }
 
 #[cfg(feature = "avoid-fe-exceptions")]
 extern "C" {
-    fn feenableexcept(flags: c_int);
-    fn fecleareexcept(flags: c_int);
-    fn fetestexcept(flags: c_int) -> c_int;
-    static FE_ALL_EXCEPT: c_int;
+    fn feholdexcept(env: *mut std::ffi::c_void);
+    fn fesetenv(env: *const std::ffi::c_void);
 }
 
 impl DisableFloatingPointExceptionsFlags {
     #[cfg(not(feature = "avoid-fe-exceptions"))]
     pub fn disable_floating_point_exceptions() -> Self {
-        Self { original_flags: 0 }
+        Self { }
     }
 
     #[cfg(feature = "avoid-fe-exceptions")]
     pub fn disable_floating_point_exceptions() -> Self {
         unsafe {
-            let original_flags = fetestexcept(FE_ALL_EXCEPT);
-            fecleareexcept(FE_ALL_EXCEPT);
+            let mut original_flags = [0; 256];
+            feholdexcept(original_flags.as_mut_ptr() as *mut _);
             Self { original_flags }
         }
     }
@@ -708,7 +712,7 @@ impl DisableFloatingPointExceptionsFlags {
 impl Drop for DisableFloatingPointExceptionsFlags {
     fn drop(&mut self) {
         unsafe {
-            feenableexcept(self.original_flags);
+            fesetenv(self.original_flags.as_ptr() as *const _);
         }
     }
 }
-- 
cgit 


From 6356dca1d5a753768bbb479aa9491805223e1c60 Mon Sep 17 00:00:00 2001
From: Terence <terence@taraz>
Date: Tue, 1 Jun 2021 21:35:29 -0400
Subject: remove c_int

---
 src/utils.rs | 1 -
 1 file changed, 1 deletion(-)

(limited to 'src/utils.rs')

diff --git a/src/utils.rs b/src/utils.rs
index 4602142..84ed250 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -4,7 +4,6 @@ use na::{Matrix3, Point2, Point3, Scalar, SimdRealField, Vector2, Vector3};
 use num::Zero;
 use simba::simd::SimdValue;
 use std::ops::IndexMut;
-use std::os::raw::c_int;
 
 use parry::utils::SdpMatrix3;
 use {
-- 
cgit