[naga] Test CallResult and AtomicResult population.

Add tests to ensure that validation checks that `CallResult` and
`AtomicResult` expressions actually have their values provided by
`Call` and `Atomic` statements, and not `Emit` statements.

Author: jimblandy

naga/tests/root.rs

@@ -1,4 +1,5 @@
 mod example_wgsl;
 mod snapshots;
 mod spirv_capabilities;
+mod validation;
 mod wgsl_errors;

naga/tests/validation.rs

@@ -0,0 +1,230 @@
+use naga::{valid, Expression, Function, Scalar};
+
+#[test]
+fn emit_atomic_result() {
+    use naga::{Module, Type, TypeInner};
+
+    // We want to ensure that the *only* problem with the code is the
+    // use of an `Emit` statement instead of an `Atomic` statement. So
+    // validate two versions of the module varying only in that
+    // aspect.
+    //
+    // Looking at uses of the `atomic` makes it easy to identify the
+    // differences between the two variants.
+    fn variant(
+        atomic: bool,
+    ) -> Result<naga::valid::ModuleInfo, naga::WithSpan<naga::valid::ValidationError>> {
+        let span = naga::Span::default();
+        let mut module = Module::default();
+        let ty_u32 = module.types.insert(
+            Type {
+                name: Some("u32".into()),
+                inner: TypeInner::Scalar(Scalar::U32),
+            },
+            span,
+        );
+        let ty_atomic_u32 = module.types.insert(
+            Type {
+                name: Some("atomic<u32>".into()),
+                inner: TypeInner::Atomic(Scalar::U32),
+            },
+            span,
+        );
+        let var_atomic = module.global_variables.append(
+            naga::GlobalVariable {
+                name: Some("atomic_global".into()),
+                space: naga::AddressSpace::WorkGroup,
+                binding: None,
+                ty: ty_atomic_u32,
+                init: None,
+            },
+            span,
+        );
+
+        let mut fun = Function::default();
+        let ex_global = fun
+            .expressions
+            .append(Expression::GlobalVariable(var_atomic), span);
+        let ex_42 = fun
+            .expressions
+            .append(Expression::Literal(naga::Literal::U32(42)), span);
+        let ex_result = fun.expressions.append(
+            Expression::AtomicResult {
+                ty: ty_u32,
+                comparison: false,
+            },
+            span,
+        );
+
+        if atomic {
+            fun.body.push(
+                naga::Statement::Atomic {
+                    pointer: ex_global,
+                    fun: naga::AtomicFunction::Add,
+                    value: ex_42,
+                    result: ex_result,
+                },
+                span,
+            );
+        } else {
+            fun.body.push(
+                naga::Statement::Emit(naga::Range::new_from_bounds(ex_result, ex_result)),
+                span,
+            );
+        }
+
+        module.functions.append(fun, span);
+
+        valid::Validator::new(
+            valid::ValidationFlags::default(),
+            valid::Capabilities::all(),
+        )
+        .validate(&module)
+    }
+
+    variant(true).expect("module should validate");
+    assert!(variant(false).is_err());
+}
+
+#[test]
+fn emit_call_result() {
+    use naga::{Module, Type, TypeInner};
+
+    // We want to ensure that the *only* problem with the code is the
+    // use of an `Emit` statement instead of a `Call` statement. So
+    // validate two versions of the module varying only in that
+    // aspect.
+    //
+    // Looking at uses of the `call` makes it easy to identify the
+    // differences between the two variants.
+    fn variant(
+        call: bool,
+    ) -> Result<naga::valid::ModuleInfo, naga::WithSpan<naga::valid::ValidationError>> {
+        let span = naga::Span::default();
+        let mut module = Module::default();
+        let ty_u32 = module.types.insert(
+            Type {
+                name: Some("u32".into()),
+                inner: TypeInner::Scalar(Scalar::U32),
+            },
+            span,
+        );
+
+        let mut fun_callee = Function {
+            result: Some(naga::FunctionResult {
+                ty: ty_u32,
+                binding: None,
+            }),
+            ..Function::default()
+        };
+        let ex_42 = fun_callee
+            .expressions
+            .append(Expression::Literal(naga::Literal::U32(42)), span);
+        fun_callee
+            .body
+            .push(naga::Statement::Return { value: Some(ex_42) }, span);
+        let fun_callee = module.functions.append(fun_callee, span);
+
+        let mut fun_caller = Function::default();
+        let ex_result = fun_caller
+            .expressions
+            .append(Expression::CallResult(fun_callee), span);
+
+        if call {
+            fun_caller.body.push(
+                naga::Statement::Call {
+                    function: fun_callee,
+                    arguments: vec![],
+                    result: Some(ex_result),
+                },
+                span,
+            );
+        } else {
+            fun_caller.body.push(
+                naga::Statement::Emit(naga::Range::new_from_bounds(ex_result, ex_result)),
+                span,
+            );
+        }
+
+        module.functions.append(fun_caller, span);
+
+        valid::Validator::new(
+            valid::ValidationFlags::default(),
+            valid::Capabilities::all(),
+        )
+        .validate(&module)
+    }
+
+    variant(true).expect("should validate");
+    assert!(variant(false).is_err());
+}
+
+#[test]
+fn emit_workgroup_uniform_load_result() {
+    use naga::{Module, Type, TypeInner};
+
+    // We want to ensure that the *only* problem with the code is the
+    // use of an `Emit` statement instead of an `Atomic` statement. So
+    // validate two versions of the module varying only in that
+    // aspect.
+    //
+    // Looking at uses of the `wg_load` makes it easy to identify the
+    // differences between the two variants.
+    fn variant(
+        wg_load: bool,
+    ) -> Result<naga::valid::ModuleInfo, naga::WithSpan<naga::valid::ValidationError>> {
+        let span = naga::Span::default();
+        let mut module = Module::default();
+        let ty_u32 = module.types.insert(
+            Type {
+                name: Some("u32".into()),
+                inner: TypeInner::Scalar(Scalar::U32),
+            },
+            span,
+        );
+        let var_workgroup = module.global_variables.append(
+            naga::GlobalVariable {
+                name: Some("workgroup_global".into()),
+                space: naga::AddressSpace::WorkGroup,
+                binding: None,
+                ty: ty_u32,
+                init: None,
+            },
+            span,
+        );
+
+        let mut fun = Function::default();
+        let ex_global = fun
+            .expressions
+            .append(Expression::GlobalVariable(var_workgroup), span);
+        let ex_result = fun
+            .expressions
+            .append(Expression::WorkGroupUniformLoadResult { ty: ty_u32 }, span);
+
+        if wg_load {
+            fun.body.push(
+                naga::Statement::WorkGroupUniformLoad {
+                    pointer: ex_global,
+                    result: ex_result,
+                },
+                span,
+            );
+        } else {
+            fun.body.push(
+                naga::Statement::Emit(naga::Range::new_from_bounds(ex_result, ex_result)),
+                span,
+            );
+        }
+
+        module.functions.append(fun, span);
+
+        valid::Validator::new(
+            valid::ValidationFlags::default(),
+            valid::Capabilities::all(),
+        )
+        .validate(&module)
+    }
+
+    variant(true).expect("module should validate");
+    assert!(variant(false).is_err());
+}