Add more debug assertions

sailfish/src/runtime/buffer.rs

@@ -103,6 +103,7 @@ impl Buffer {
         if unlikely!(self.len + size > self.capacity) {
             self.reserve_internal(size);
         }
+        debug_assert!(self.len + size <= self.capacity);
     }
 
     #[inline]
@@ -115,6 +116,7 @@ impl Buffer {
     /// This consumes the `Buffer`, so we do not need to copy its contents.
     #[inline]
     pub fn into_string(self) -> String {
+        debug_assert!(self.len <= self.capacity);
         let buf = ManuallyDrop::new(self);
         unsafe { String::from_raw_parts(buf.data, buf.len, buf.capacity) }
     }
@@ -128,6 +130,7 @@ impl Buffer {
             std::ptr::copy_nonoverlapping(data.as_ptr(), p, size);
             self.len += size;
         }
+        debug_assert!(self.len <= self.capacity);
     }
 
     #[inline]
@@ -141,9 +144,12 @@ impl Buffer {
     fn reserve_internal(&mut self, size: usize) {
         unsafe {
             let new_capacity = std::cmp::max(self.capacity * 2, self.len + size);
+            debug_assert!(new_capacity > self.capacity);
             self.data = safe_realloc(self.data, self.capacity, new_capacity);
             self.capacity = new_capacity;
         }
+        debug_assert!(!self.data.is_null());
+        debug_assert!(self.len <= self.capacity);
     }
 }
 

sailfish/src/runtime/render.rs

@@ -160,6 +160,7 @@ macro_rules! render_int {
                         let l = itoap::write_to_ptr(ptr, *self);
                         b.set_len(b.len() + l);
                     }
+                    debug_assert!(b.len() <= b.capacity());
                     Ok(())
                 }
 
@@ -184,6 +185,7 @@ impl Render for f32 {
                 let ptr = b.as_mut_ptr().add(b.len());
                 let l = ryu::raw::format32(*self, ptr);
                 b.set_len(b.len() + l);
+                debug_assert!(b.len() <= b.capacity());
             }
         } else if self.is_nan() {
             b.push_str("NaN");
@@ -212,6 +214,7 @@ impl Render for f64 {
                 let ptr = b.as_mut_ptr().add(b.len());
                 let l = ryu::raw::format64(*self, ptr);
                 b.set_len(b.len() + l);
+                debug_assert!(b.len() <= b.capacity());
             }
         } else if self.is_nan() {
             b.push_str("NaN");