Merge pull request #8 from CliMA/ck/strictness

Make things more strict

src/macro_utils.jl

@@ -18,22 +18,31 @@ function _fused_pairs(expr::Expr)
         #     error("???")
         #     return ""
         # end
+        if _expr isa QuoteNode
+            error("Dangling symbols are not allowed inside fused blocks")
+        end
         _expr isa LineNumberNode && continue
         if _expr.head == :for
             error("Loops are not allowed inside fused blocks")
-        end
-        if _expr.head == :if
+        elseif _expr.head == :if
             error("If-statements are not allowed inside fused blocks")
-        end
-        if _expr.head == :call
+        elseif _expr.head == :call
             error("Function calls are not allowed inside fused blocks")
+        elseif _expr.head == :(=)
+            error(
+                "Non-broadcast assignments are not allowed inside fused blocks",
+            )
+        elseif _expr.head == :let
+            error("Let-blocks are not allowed inside fused blocks")
+        elseif _expr.head == :quote
+            error("Quotes are not allowed inside fused blocks")
         end
         if _expr.head == :macrocall && _expr.args[1] == Symbol("@__dot__")
             se = code_lowered_single_expression(_expr)
             margs = materialize_args(se)
             push!(exprs_out, :(Pair($(margs[1]), $(margs[2]))))
         else
-            @show _expr
+            @show dump(_expr)
             error("Uncaught edge case")
         end
     end

test/expr_errors_and_edge_cases.jl

@@ -64,6 +64,57 @@ bar() = nothing
     ) MBF.fused_pairs(expr_in)
 end
 
+@testset "Non-broadcast variable assignments" begin
+    # Non-broadcast variable assignments is not allowed, because
+    # this could lead to subtle bugs (order of compute).
+    expr_in = quote
+        @. y1 = x1 + x2 + x3 + x4
+        x1 = x2
+        @. y1 = x1 + x2 + x3 + x4
+    end
+    @test_throws ErrorException(
+        "Non-broadcast assignments are not allowed inside fused blocks",
+    ) MBF.fused_pairs(expr_in)
+end
+
+@testset "No let-blocks" begin
+    # Let-blocks could hide other non-allowed things
+    expr_in = quote
+        @. y1 = x1 + x2 + x3 + x4
+        let z = 1
+        end
+        @. y1 = x1 + x2 + x3 + x4
+    end
+    @test_throws ErrorException(
+        "Let-blocks are not allowed inside fused blocks",
+    ) MBF.fused_pairs(expr_in)
+end
+
+@testset "Dangling symbols" begin
+    # While inaucuous, we prohibit dangling symbols
+    expr_in = quote
+        @. y1 = x1 + x2 + x3 + x4
+        :a
+        @. y1 = x1 + x2 + x3 + x4
+    end
+    @test_throws ErrorException(
+        "Dangling symbols are not allowed inside fused blocks",
+    ) MBF.fused_pairs(expr_in)
+end
+
+@testset "quote" begin
+    # Not sure why this would be needed, so
+    # we don't allow quotes inside fused blocks.
+    expr_in = quote
+        @. y1 = x1 + x2 + x3 + x4
+        quote end
+        @. y1 = x1 + x2 + x3 + x4
+    end
+    @test_throws ErrorException("Quotes are not allowed inside fused blocks") MBF.fused_pairs(
+        expr_in,
+    )
+end
+
 @testset "Comments" begin
     expr_in = quote
         @. y1 = x1 + x2 + x3 + x4