From 6eecea5dad8537524cbfff18fcea4611b77b08a5 Mon Sep 17 00:00:00 2001
From: Dzmitry Malyshau <kvarkus@gmail.com>
Date: Wed, 24 Jun 2020 22:55:46 -0400
Subject: [PATCH] First bits of IR validation

---
 src/arena.rs          | 12 +++++++++-
 src/proc/mod.rs       |  2 ++
 src/proc/validator.rs | 56 +++++++++++++++++++++++++++++++++++++++++++
 tests/convert.rs      |  3 +++
 4 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 src/proc/validator.rs

diff --git a/src/arena.rs b/src/arena.rs
index d84da77906..d9c760f908 100644
--- a/src/arena.rs
+++ b/src/arena.rs
@@ -1,4 +1,4 @@
-use std::{fmt, hash, marker::PhantomData, num::NonZeroU32};
+use std::{cmp::Ordering, fmt, hash, marker::PhantomData, num::NonZeroU32};
 
 /// An unique index in the arena array that a handle points to.
 ///
@@ -29,6 +29,16 @@ impl<T> PartialEq for Handle<T> {
     }
 }
 impl<T> Eq for Handle<T> {}
+impl<T> PartialOrd for Handle<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        self.index.partial_cmp(&other.index)
+    }
+}
+impl<T> Ord for Handle<T> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.index.cmp(&other.index)
+    }
+}
 impl<T> fmt::Debug for Handle<T> {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         write!(formatter, "Handle({})", self.index)
diff --git a/src/proc/mod.rs b/src/proc/mod.rs
index e4b181a697..18362d183e 100644
--- a/src/proc/mod.rs
+++ b/src/proc/mod.rs
@@ -1,4 +1,6 @@
 mod interface;
 mod typifier;
+mod validator;
 
 pub use typifier::{check_constant_types, ResolveError, Typifier, UnexpectedConstantTypeError};
+pub use validator::{ValidationError, Validator};
diff --git a/src/proc/validator.rs b/src/proc/validator.rs
new file mode 100644
index 0000000000..613357e550
--- /dev/null
+++ b/src/proc/validator.rs
@@ -0,0 +1,56 @@
+use crate::arena::Handle;
+
+pub struct Validator {}
+
+#[derive(Clone, Debug)]
+pub enum ValidationError {
+    /// The type width is not supported.
+    InvalidTypeWidth(crate::ScalarKind, crate::Bytes),
+    /// A type handle can not be resolved.
+    UnresolvedType(Handle<crate::Type>),
+    /// There are instructions after `return`/`break`/`continue`.
+    InvalidControlFlowExitTail,
+}
+
+impl Validator {
+    pub fn new() -> Self {
+        Validator {}
+    }
+
+    pub fn validate(&mut self, module: &crate::Module) -> Result<(), ValidationError> {
+        for (handle, ty) in module.types.iter() {
+            use crate::TypeInner as Ti;
+            match ty.inner {
+                Ti::Scalar { kind, width }
+                | Ti::Vector { kind, width, .. }
+                | Ti::Matrix { kind, width, .. } => {
+                    if width != 32 {
+                        return Err(ValidationError::InvalidTypeWidth(kind, width));
+                    }
+                }
+                Ti::Pointer { base, class: _ } => {
+                    if base >= handle {
+                        return Err(ValidationError::UnresolvedType(base));
+                    }
+                }
+                Ti::Array { base, .. } => {
+                    if base >= handle {
+                        return Err(ValidationError::UnresolvedType(base));
+                    }
+                }
+                Ti::Struct { ref members } => {
+                    //TODO: check that offsets are not intersecting?
+                    for member in members {
+                        if member.ty >= handle {
+                            return Err(ValidationError::UnresolvedType(member.ty));
+                        }
+                    }
+                }
+                Ti::Image { .. } => {}
+                Ti::Sampler { comparison: _ } => {}
+            }
+        }
+
+        Ok(())
+    }
+}
diff --git a/tests/convert.rs b/tests/convert.rs
index 1048b6a618..5a1ed8bd05 100644
--- a/tests/convert.rs
+++ b/tests/convert.rs
@@ -20,6 +20,7 @@ fn load_glsl(name: &str, entry: &str, exec: ExecutionModel) -> naga::Module {
 #[test]
 fn convert_quad() {
     let module = load_wgsl("quad.wgsl");
+    naga::proc::Validator::new().validate(&module).unwrap();
     {
         use naga::back::msl;
         let mut binding_map = msl::BindingMap::default();
@@ -51,6 +52,7 @@ fn convert_quad() {
 #[test]
 fn convert_boids() {
     let module = load_wgsl("boids.wgsl");
+    naga::proc::Validator::new().validate(&module).unwrap();
     {
         use naga::back::msl;
         let mut binding_map = msl::BindingMap::default();
@@ -93,6 +95,7 @@ fn convert_boids() {
 #[ignore]
 fn convert_phong_lighting() {
     let module = load_glsl("glsl_phong_lighting.frag", "main", ExecutionModel::Fragment);
+    naga::proc::Validator::new().validate(&module).unwrap();
 
     let header = naga::Header {
         version: (1, 0, 0),