Track finished across compound statements

faro-oss · Sep 20, 2021 · 98944bb · 98944bb
1 parent dc8a41d
commit 98944bb
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Showing 2 changed files with 70 additions and 26 deletions.
diff --git a/src/valid/function.rs b/src/valid/function.rs
@@ -135,6 +135,11 @@ bitflags::bitflags! {
     }
 }
 
+struct BlockInfo {
+    stages: ShaderStages,
+    finished: bool,
+}
+
 struct BlockContext<'a> {
     abilities: ControlFlowAbility,
     info: &'a FunctionInfo,
@@ -326,7 +331,7 @@ impl super::Validator {
         &mut self,
         statements: &[crate::Statement],
         context: &BlockContext,
-    ) -> Result<ShaderStages, FunctionError> {
+    ) -> Result<BlockInfo, FunctionError> {
         use crate::{Statement as S, TypeInner as Ti};
         let mut finished = false;
         let mut stages = ShaderStages::all();
@@ -345,7 +350,9 @@ impl super::Validator {
                     }
                 }
                 S::Block(ref block) => {
-                    stages &= self.validate_block(block, context)?;
+                    let info = self.validate_block(block, context)?;
+                    stages &= info.stages;
+                    finished = info.finished;
                 }
                 S::If {
                     condition,
@@ -359,8 +366,8 @@ impl super::Validator {
                         } => {}
                         _ => return Err(FunctionError::InvalidIfType(condition)),
                     }
-                    stages &= self.validate_block(accept, context)?;
-                    stages &= self.validate_block(reject, context)?;
+                    stages &= self.validate_block(accept, context)?.stages;
+                    stages &= self.validate_block(reject, context)?.stages;
                 }
                 S::Switch {
                     selector,
@@ -385,9 +392,9 @@ impl super::Validator {
                     let sub_context =
                         context.with_abilities(pass_through_abilities | ControlFlowAbility::BREAK);
                     for case in cases {
-                        stages &= self.validate_block(&case.body, &sub_context)?;
+                        stages &= self.validate_block(&case.body, &sub_context)?.stages;
                     }
-                    stages &= self.validate_block(default, &sub_context)?;
+                    stages &= self.validate_block(default, &sub_context)?.stages;
                 }
                 S::Loop {
                     ref body,
@@ -397,18 +404,22 @@ impl super::Validator {
                     // because the continuing{} block inherits the scope
                     let base_expression_count = self.valid_expression_list.len();
                     let pass_through_abilities = context.abilities & ControlFlowAbility::RETURN;
-                    stages &= self.validate_block_impl(
-                        body,
-                        &context.with_abilities(
-                            pass_through_abilities
-                                | ControlFlowAbility::BREAK
-                                | ControlFlowAbility::CONTINUE,
-                        ),
-                    )?;
-                    stages &= self.validate_block_impl(
-                        continuing,
-                        &context.with_abilities(ControlFlowAbility::empty()),
-                    )?;
+                    stages &= self
+                        .validate_block_impl(
+                            body,
+                            &context.with_abilities(
+                                pass_through_abilities
+                                    | ControlFlowAbility::BREAK
+                                    | ControlFlowAbility::CONTINUE,
+                            ),
+                        )?
+                        .stages;
+                    stages &= self
+                        .validate_block_impl(
+                            continuing,
+                            &context.with_abilities(ControlFlowAbility::empty()),
+                        )?
+                        .stages;
                     for handle in self.valid_expression_list.drain(base_expression_count..) {
                         self.valid_expression_set.remove(handle.index());
                     }
@@ -593,20 +604,20 @@ impl super::Validator {
                 }
             }
         }
-        Ok(stages)
+        Ok(BlockInfo { stages, finished })
     }
 
     fn validate_block(
         &mut self,
         statements: &[crate::Statement],
         context: &BlockContext,
-    ) -> Result<ShaderStages, FunctionError> {
+    ) -> Result<BlockInfo, FunctionError> {
         let base_expression_count = self.valid_expression_list.len();
-        let stages = self.validate_block_impl(statements, context)?;
+        let info = self.validate_block_impl(statements, context)?;
         for handle in self.valid_expression_list.drain(base_expression_count..) {
             self.valid_expression_set.remove(handle.index());
         }
-        Ok(stages)
+        Ok(info)
     }
 
     fn validate_local_var(
@@ -694,10 +705,12 @@ impl super::Validator {
         }
 
         if self.flags.contains(ValidationFlags::BLOCKS) {
-            let stages = self.validate_block(
-                &fun.body,
-                &BlockContext::new(fun, module, &info, &mod_info.functions),
-            )?;
+            let stages = self
+                .validate_block(
+                    &fun.body,
+                    &BlockContext::new(fun, module, &info, &mod_info.functions),
+                )?
+                .stages;
             info.available_stages &= stages;
         }
         Ok(info)

diff --git a/tests/wgsl-errors.rs b/tests/wgsl-errors.rs
@@ -848,3 +848,34 @@ fn invalid_local_vars() {
         if local_var_name == "not_okay"
     }
 }
+
+#[test]
+fn dead_code() {
+    check_validation_error! {
+        "
+        fn dead_code_after_if(condition: bool) -> i32 {
+            if (condition) {
+                return 1;
+            } else {
+                return 2;
+            }
+            return 3;
+        }
+        ":
+        Ok(_)
+    }
+    check_validation_error! {
+        "
+        fn dead_code_after_block() -> i32 {
+            {
+                return 1;
+            }
+            return 2;
+        }
+        ":
+        Err(naga::valid::ValidationError::Function {
+            error: naga::valid::FunctionError::InstructionsAfterReturn,
+            ..
+        })
+    }
+}