Random lowering bugfixes

- `init` not provided for possibly-empty `sum()`s in desugaring causing failures
     for empty ctors, empty tuple destruct
- linearize: break_block type error
- missing desugaring when if-condition is a block
- boundserror in `add_ir_debug_info!`
- undef var `ex` in expand_arrow_arglist

Author: mlechu

src/desugaring.jl

@@ -414,7 +414,7 @@ function expand_tuple_destruct(ctx, ex)
     end
 
     if kind(rhs) == K"tuple"
-        num_splat = sum(kind(rh) == K"..." for rh in children(rhs))
+        num_splat = sum(kind(rh) == K"..." for rh in children(rhs); init=0)
         if num_splat == 0 && (numchildren(lhs) - num_slurp) > numchildren(rhs)
             throw(LoweringError(ex, "More variables on left hand side than right hand in tuple assignment"))
         end
@@ -1402,7 +1402,7 @@ function expand_condition(ctx, ex)
     if isblock
         # Special handling so that the rules for `&&` and `||` can be applied
         # to the last statement of a block
-        @ast ctx ex [K"block" ex[1:end-1]... test]
+        @ast ctx ex [K"block" map(e->expand_forms_2(ctx,e), ex[1:end-1])... test]
     else
         test
     end
@@ -3094,13 +3094,13 @@ function expand_arrow_arglist(ctx, arglist, arrowname)
         if k == K"block"
             @chk numchildren(arglist) == 2
             arglist = @ast ctx arglist [K"tuple"
-                ex[1]
-                [K"parameters" ex[2]]
+                arglist[1]
+                [K"parameters" arglist[2]]
             ]
         elseif k != K"tuple"
             # `x::Int -> body`
             arglist = @ast ctx arglist [K"tuple"
-                ex[1]
+                arglist[1]
             ]
         end
         @ast ctx arglist [K"call"
@@ -3665,7 +3665,7 @@ function _rewrite_ctor_new_calls(ctx, ex, struct_name, global_struct_name, ctor_
     full_struct_type = if kind(ex[1]) == K"curly"
         # new{A,B}(...)
         new_type_params = ex[1][2:end]
-        n_type_splat = sum(kind(t) == K"..." for t in new_type_params)
+        n_type_splat = sum(kind(t) == K"..." for t in new_type_params; init=0)
         n_type_nonsplat = length(new_type_params) - n_type_splat
         if n_type_splat == 0 && n_type_nonsplat < length(struct_typevars)
             throw(LoweringError(ex[1], "too few type parameters specified in `new{...}`"))
@@ -3685,7 +3685,7 @@ function _rewrite_ctor_new_calls(ctx, ex, struct_name, global_struct_name, ctor_
         end
     end
     new_args = ex[2:end]
-    n_splat = sum(kind(t) == K"..." for t in new_args)
+    n_splat = sum(kind(t) == K"..." for t in new_args; init=0)
     n_nonsplat = length(new_args) - n_splat
     n_fields = length(field_types)
     function throw_n_fields_error(desc)

src/eval.jl

@@ -84,7 +84,7 @@ function add_ir_debug_info!(current_codelocs_stack, stmt)
                                   current_codelocs_stack[j][1] != locstk[j][1])
             while length(current_codelocs_stack) >= j
                 info = pop!(current_codelocs_stack)
-                push!(last(current_codelocs_stack)[2], info)
+                !isempty(current_codelocs_stack) && push!(last(current_codelocs_stack)[2], info)
             end
         end
         if j > length(locstk)

src/linear_ir.jl

@@ -703,7 +703,7 @@ function compile(ctx::LinearIRContext, ex, needs_value, in_tail_pos)
         if isnothing(outer_target)
             delete!(ctx.break_targets, name)
         else
-            ctx.break_targets = outer_target
+            ctx.break_targets[name] = outer_target
         end
         emit(ctx, end_label)
         if needs_value

test/destructuring.jl

@@ -36,6 +36,17 @@ let
 end
 """) == ([1, 2, 3], 4)
 
+@test_throws JuliaLowering.LoweringError JuliaLowering.include_string(test_mod, """
+let
+    (x,) = ()
+end
+""") == ([1, 2, 3], 4)
+@test_throws JuliaLowering.LoweringError JuliaLowering.include_string(test_mod, """
+let
+    (x,y,ys...) = (1,)
+end
+""")
+
 # Case where indexed_iterate is just iteration
 @test JuliaLowering.include_string(test_mod, """
 let

test/loops.jl

@@ -95,6 +95,18 @@ let
     a
 end
 """) == [1, 2]
+@test JuliaLowering.include_string(test_mod, """
+let
+    a = []
+    for i in 1:2
+       for j in 3:4
+           push!(a, (i, j))
+           j == 6 && break
+       end
+    end
+    a
+end
+""") == [(1, 3), (1, 4), (2, 3), (2, 4)]
 
 # continue
 @test JuliaLowering.include_string(test_mod, """