Fix handling lower bound in type parameter (#37)

Co-authored-by: Shuhei Kadowaki <[email protected]>

Author: abap34

src/desugaring.jl

@@ -3266,7 +3266,7 @@ function analyze_typevar(ctx, ex)
         (ex[1], nothing, ex[2])
     elseif k == K">:" && numchildren(ex) == 2
         kind(ex[2]) == K"Identifier" || throw(LoweringError(ex[2], "expected type name"))
-        (ex[2], ex[1], nothing)
+        (ex[1], ex[2], nothing)
     else
         throw(LoweringError(ex, "expected type name or type bounds"))
     end

test/functions.jl

@@ -202,6 +202,14 @@ end
     end
     """) === ((1, (), false), (1, (2,), true), (1, (2, 3), true))
 
+    @test JuliaLowering.include_string(test_mod, """
+    begin
+        f_def_typevar_with_lowerbound(x::T) where {T>:Int} =
+            (x, @isdefined(T))
+        (f_def_typevar_with_lowerbound(1), f_def_typevar_with_lowerbound(1.0))
+    end
+    """) == ((1, true), (1.0, false))
+
     @test JuliaLowering.include_string(test_mod, """
     begin
         function f_def_slurp(x=1, ys...)

test/functions_ir.jl

@@ -199,6 +199,34 @@ end
 18  TestMod.f
 19  (return %₁₈)
 
+########################################
+# Static parameter with lower bound
+function f(::S{T}) where T >: X
+    T
+end
+#---------------------
+1   (method TestMod.f)
+2   latestworld
+3   TestMod.X
+4   (= slot₁/T (call core.TypeVar :T %₃ core.Any))
+5   TestMod.f
+6   (call core.Typeof %₅)
+7   TestMod.S
+8   slot₁/T
+9   (call core.apply_type %₇ %₈)
+10  (call core.svec %₆ %₉)
+11  slot₁/T
+12  (call core.svec %₁₁)
+13  SourceLocation::1:10
+14  (call core.svec %₁₀ %₁₂ %₁₃)
+15  --- method core.nothing %₁₄
+    slots: [slot₁/#self#(!read) slot₂/_(!read)]
+    1   static_parameter₁
+    2   (return %₁)
+16  latestworld
+17  TestMod.f
+18  (return %₁₇)
+
 ########################################
 # Static parameter which is used only in the bounds of another static parameter
 # See https://github.com/JuliaLang/julia/issues/49275

test/typedefs_ir.jl

@@ -25,10 +25,10 @@ A where X <: UB
 # where expression with lower bound
 A where X >: LB
 #---------------------
-1   TestMod.X
-2   (call core.TypeVar :LB %₁ core.Any)
-3   (= slot₁/LB %₂)
-4   slot₁/LB
+1   TestMod.LB
+2   (call core.TypeVar :X %₁ core.Any)
+3   (= slot₁/X %₂)
+4   slot₁/X
 5   TestMod.A
 6   (call core.UnionAll %₄ %₅)
 7   (return %₆)