{"action":"created","comment":{"url":"https://api.github.com/repos/dotnet/roslyn/pulls/comments/37212714","id":37212714,"diff_hunk":"@@ -16,13 +16,60 @@ public override BoundNode VisitTryStatement(BoundTryStatement node)\n             var origSawAwait = _sawAwait;\n             _sawAwait = false;\n \n-            ImmutableArray<BoundCatchBlock> catchBlocks = (ImmutableArray<BoundCatchBlock>)this.VisitList(node.CatchBlocks);\n+            var optimizing = this._compilation.Options.OptimizationLevel == OptimizationLevel.Release;\n+            ImmutableArray<BoundCatchBlock> catchBlocks =\n+                // When optimizing and we have a morally empty try block, we can discard the catch blocks.\n+                (optimizing && IsMorallyEmpty(tryBlock)) ? 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(BoundNode)tryBlock\n+                : (BoundNode)node.Update(tryBlock, catchBlocks, finallyBlockOpt, node.PreferFaultHandler);\n+        }\n+\n+        /// <summary>\n+        /// Is there no code to execute in the given statement that could have side-effects,\n+        /// such as throwing an exception?\n+        /// </summary>\n+        private static bool IsMorallyEmpty(BoundStatement statement)\n+        {\n+            if (statement == null) return true;\n+            switch (statement.Kind)\n+            {\n+                case BoundKind.NoOpStatement:\n+                    return true;\n+                case BoundKind.Block:\n+                    {\n+                        var block = (BoundBlock)statement;\n+                        for (int i = 0; i < block.Statements.Length; i++)\n+                        {\n+                            if (!IsMorallyEmpty(block.Statements[i])) return false;\n+                        }\n+                        return true;","path":"src/Compilers/CSharp/Portable/Lowering/LocalRewriter/LocalRewriter_TryStatement.cs","position":44,"original_position":44,"commit_id":"1a56996087b03dc7f2e42e321e0bebdd671f399e","original_commit_id":"1a56996087b03dc7f2e42e321e0bebdd671f399e","user":{"login":"cston","id":10732005,"avatar_url":"https://avatars.githubusercontent.com/u/10732005?v=3","gravatar_id":"","url":"https://api.github.com/users/cston","html_url":"https://github.com/cston","followers_url":"https://api.github.com/users/cston/followers","following_url":"https://api.github.com/users/cston/following{/other_user}","gists_url":"https://api.github.com/users/cston/gists{/gist_id}","starred_url":"https://api.github.com/users/cston/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/cston/subscriptions","organizations_url":"https://api.github.com/users/cston/orgs","repos_url":"https://api.github.com/users/cston/repos","events_url":"https://api.github.com/users/cston/events{/privacy}","received_events_url":"https://api.github.com/users/cston/received_events","type":"User","site_admin":false},"body":"Consider using foreach or return block.Statements.All(HasNoSideEffects);","created_at":"2015-08-17T17:27:39Z","updated_at":"2015-08-17T17:27:39Z","html_url":"https://github.com/dotnet/roslyn/pull/4569#discussion_r37212714","pull_request_url":"https://api.github.com/repos/dotnet/roslyn/pulls/4569","_links":{"self":{"href":"https://api.github.com/repos/dotnet/roslyn/pulls/comments/37212714"},"html":{"href":"https://github.com/dotnet/roslyn/pull/4569#discussion_r37212714"},"pull_request":{"href":"https://api.github.com/repos/dotnet/roslyn/pulls/4569"}}},"pull_request":{"url":"https://api.github.com/repos/dotnet/roslyn/pulls/4569","id":42504483,"html_url":"https://github.com/dotnet/roslyn/pull/4569","diff_url":"https://github.com/dotnet/roslyn/pull/4569.diff","patch_url":"https://github.com/dotnet/roslyn/pull/4569.patch","issue_url":"https://api.github.com/repos/dotnet/roslyn/issues/4569","number":4569,"state":"open","locked":false,"title":"Suppress code for empty try-catch with /optimize (Release) mode","user":{"login":"gafter","id":3804346,"avatar_url":"https://avatars.githubusercontent.com/u/3804346?v=3","gravatar_id":"","url":"https://api.github.com/users/gafter","html_url":"https://github.com/gafter","followers_url":"https://api.github.com/users/gafter/followers","following_url":"https://api.github.com/users/gafter/following{/other_user}","gists_url":"https://api.github.com/users/gafter/gists{/gist_id}","starred_url":"https://api.github.com/users/gafter/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/gafter/subscriptions","organizations_url":"https://api.github.com/users/gafter/orgs","repos_url":"https://api.github.com/users/gafter/repos","events_url":"https://api.github.com/users/gafter/events{/privacy}","received_events_url":"https://api.github.com/users/gafter/received_events","type":"User","site_admin":false},"body":"Fixes #2443 \r\n\r\n@AlekseyTs @VSadov @jaredpar @agocke Please review.\r\n@tmat This affects an expression evaluator test. Please 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