Change two-argument IR "const" to K"constdecl"

Differentiate it from AST K"const"

Author: mlechu

src/desugaring.jl

@@ -1187,7 +1187,7 @@ function expand_unionall_def(ctx, srcref, lhs, rhs, is_const=true)
         @ast ctx srcref [
             K"block"
             [K"=" rr [K"where" rhs lhs[2:end]...]]
-            [is_const ? K"const" : K"assign_const_if_global" name rr]
+            [is_const ? K"constdecl" : K"assign_const_if_global" name rr]
             [K"latestworld_if_toplevel"]
             rr
         ]
@@ -1246,7 +1246,7 @@ function expand_assignment(ctx, ex, is_const=false)
             @ast ctx ex [
                 K"block"
                 sink_assignment(ctx, ex, rr, expand_forms_2(ctx, rhs))
-                [K"const" lhs rr]
+                [K"constdecl" lhs rr]
                 [K"latestworld"]
                 [K"removable" rr]
             ]
@@ -1290,7 +1290,7 @@ function expand_assignment(ctx, ex, is_const=false)
         T = lhs[2]
         res = if is_const
             expand_forms_2(ctx, ex, @ast ctx ex [
-                K"const"
+                K"constdecl"
                 lhs[1]
                 convert_for_type_decl(ctx, ex, rhs, T, true)
             ])
@@ -3434,7 +3434,7 @@ function expand_abstract_or_primitive_type(ctx, ex)
                 [K"call" "_equiv_typedef"::K"core" name newtype_var]
             ]
             nothing_(ctx, ex)
-            [K"const" name newtype_var]
+            [K"constdecl" name newtype_var]
         ]
         [K"latestworld"]
         nothing_(ctx, ex)
@@ -3988,7 +3988,7 @@ function expand_struct_def(ctx, ex, docs)
                     newtype_var
                     [K"call" "svec"::K"core" field_types...]
                 ]
-                [K"const"
+                [K"constdecl"
                     global_struct_name
                     newtype_var
                  ]

src/eval.jl

@@ -297,7 +297,7 @@ function to_lowered_expr(mod, ex, ssa_offset=0)
                k == K"splatnew"  ? :splatnew   :
                k == K"="         ? :(=)        :
                k == K"global"    ? :global     :
-               k == K"const"     ? :const      :
+               k == K"constdecl" ? :const      :
                k == K"leave"     ? :leave      :
                k == K"isdefined" ? :isdefined  :
                k == K"latestworld"       ? :latestworld       :

src/kinds.jl

@@ -124,6 +124,9 @@ function _register_kinds()
             # References/declares a global variable within a module
             "globalref"
             "globaldecl"
+            # Two-argument constant declaration and assignment.
+            # Translated to :const in the IR for now (we use K"const" already in parsing).
+            "constdecl"
             # Unconditional goto
             "goto"
             # Conditional goto

src/linear_ir.jl

@@ -325,7 +325,7 @@ function emit_break(ctx, ex)
     emit_jump(ctx, ex, target)
 end
 
-# `op` may also be K"const"
+# `op` may also be K"constdecl"
 function emit_assignment_or_setglobal(ctx, srcref, lhs, rhs, op=K"=")
     # (const (globalref _ _) _) does not use setglobal!
     binfo = lookup_binding(ctx, lhs.var_id)
@@ -648,8 +648,8 @@ function compile(ctx::LinearIRContext, ex, needs_value, in_tail_pos)
             emit(ctx, callex)
             nothing
         end
-    elseif k == K"=" || k == K"const"
-        if k == K"const"
+    elseif k == K"=" || k == K"constdecl"
+        if k == K"constdecl"
             check_no_local_bindings(ctx, ex[1], "unsupported `const` declaration on local variable")
             # other errors (probably this one too) should be handled in previous passes
         end

src/scope_analysis.jl

@@ -571,7 +571,7 @@ function _resolve_scopes(ctx, ex::SyntaxTree)
         if bk == :local && numchildren(ex) != 1
             @ast ctx ex _resolve_scopes(ctx, [K"=" children(ex)...])
         elseif bk != :local # TODO: should this be == :global?
-            @ast ctx ex _resolve_scopes(ctx, [K"const" children(ex)...])
+            @ast ctx ex _resolve_scopes(ctx, [K"constdecl" children(ex)...])
         else
             makeleaf(ctx, ex, K"TOMBSTONE")
         end
@@ -656,7 +656,7 @@ function analyze_variables!(ctx, ex)
     elseif k == K"local" || k == K"global"
         # Presence of BindingId within local/global is ignored.
         return
-    elseif k == K"=" || k == K"const"
+    elseif k == K"="
         lhs = ex[1]
         if kind(lhs) != K"Placeholder"
             update_binding!(ctx, lhs, add_assigned=1)
@@ -684,7 +684,7 @@ function analyze_variables!(ctx, ex)
         if kind(ex[1]) != K"BindingId" || lookup_binding(ctx, ex[1]).kind !== :local
             analyze_variables!(ctx, ex[1])
         end
-    elseif k == K"const"
+    elseif k == K"constdecl"
         id = ex[1]
         if lookup_binding(ctx, id).kind == :local
             throw(LoweringError(ex, "unsupported `const` declaration on local variable"))