commit cd7eb4f968510147e5d9eec3076fbeab3c16c352
author Ben Clayton <bclayton@google.com> Sat Jul 17 18:09:26 2021 +0000
committer Tint LUCI CQ <tint-scoped@luci-project-accounts.iam.gserviceaccount.com> Sat Jul 17 18:09:26 2021 +0000
tree 2d764189f4e5b2d5a3c60ad69ecced76504505b3
parent 725159c17cd5b0c259916533f72ff393186a334a

Resolver: Validation for continuing blocks

Check they do not contain returns, discards
Check they do not directly contain continues, however a nested loop can have its own continue.

Bug: chromium:1229976
Change-Id: Ia3c4ac118ffdaa6cca6025366c19f9897718c930
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/58384
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: David Neto <dneto@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>

src/resolver/resolver.cc

diff --git a/src/resolver/resolver.cc b/src/resolver/resolver.cc
index 8288a3f..ca5ea27 100644
--- a/src/resolver/resolver.cc
+++ b/src/resolver/resolver.cc
@@ -2062,11 +2062,18 @@
   }
   if (stmt->Is<ast::ContinueStatement>()) {
     // Set if we've hit the first continue statement in our parent loop
-    if (auto* loop_block =
-            current_block_->FindFirstParent<sem::LoopBlockStatement>()) {
-      if (loop_block->FirstContinue() == size_t(~0)) {
-        const_cast<sem::LoopBlockStatement*>(loop_block)
-            ->SetFirstContinue(loop_block->Decls().size());
+    if (auto* block =
+            current_block_->FindFirstParent<
+                sem::LoopBlockStatement, sem::LoopContinuingBlockStatement>()) {
+      if (auto* loop_block = block->As<sem::LoopBlockStatement>()) {
+        if (loop_block->FirstContinue() == size_t(~0)) {
+          const_cast<sem::LoopBlockStatement*>(loop_block)
+              ->SetFirstContinue(loop_block->Decls().size());
+        }
+      } else {
+        AddError("continuing blocks must not contain a continue statement",
+                 stmt->source());
+        return false;
       }
     } else {
       AddError("continue statement must be in a loop", stmt->source());
@@ -2076,6 +2083,17 @@
     return true;
   }
   if (stmt->Is<ast::DiscardStatement>()) {
+    if (auto* continuing =
+            sem_statement
+                ->FindFirstParent<sem::LoopContinuingBlockStatement>()) {
+      AddError("continuing blocks must not contain a discard statement",
+               stmt->source());
+      if (continuing != sem_statement->Parent()) {
+        AddNote("see continuing block here",
+                continuing->Declaration()->source());
+      }
+      return false;
+    }
     return true;
   }
   if (stmt->Is<ast::FallthroughStatement>()) {
@@ -4110,6 +4128,17 @@
     return false;
   }
 
+  auto* sem = builder_->Sem().Get(ret);
+  if (auto* continuing =
+          sem->FindFirstParent<sem::LoopContinuingBlockStatement>()) {
+    AddError("continuing blocks must not contain a return statement",
+             ret->source());
+    if (continuing != sem->Parent()) {
+      AddNote("see continuing block here", continuing->Declaration()->source());
+    }
+    return false;
+  }
+
   return true;
 }