fix: enable substitute to precompile

Author: AayushSabharwal

src/SymbolicUtils.jl

@@ -178,12 +178,14 @@ PrecompileTools.@setup_workload begin
         ex = x + 2y + sin(x)
         rules1 = Dict(x => y)
         rules2 = Dict(x => 1)
-        substitute(ex, rules1)
+        # Running `fold = Val(true)` invalidates the precompiled statements
+        # for `fold = Val(false)` and itself doesn't precompile anyway.
+        # substitute(ex, rules1)
         substitute(ex, rules1; fold = fold1)
         substitute(ex, rules2; fold = fold1)
-        substitute(ex, rules2)
-        substitute(ex, rules1; fold = fold2)
-        substitute(ex, rules2; fold = fold2)
+        # substitute(ex, rules2)
+        # substitute(ex, rules1; fold = fold2)
+        # substitute(ex, rules2; fold = fold2)
         q[1]
         q'q
     end

src/types.jl

@@ -1621,7 +1621,9 @@ function TermInterface.maketerm(::Type{BasicSymbolic{T}}, f, args, metadata; @no
         end
         return res::BasicSymbolic{T}
     elseif f === getindex
-        res = getindex(unwrap_const.(args)...)
+        # This can't call `getindex` because that goes through `@cache`, which is unstable
+        # and doesn't precompile.
+        res = _getindex(unwrap_const.(args)...)
         if metadata !== nothing && iscall(res)
             @set! res.metadata = metadata
         end

test/precompilation.jl

@@ -16,6 +16,7 @@ expr = x + sin(y) * z
 rules = Dict(x => y)
 fold = Val{false}()
 subs_inf = @snoop_inference substitute(expr, rules; fold)
+args_inf = @snoop_inference arguments(expr)
 
 using SnoopCompile
 
@@ -30,14 +31,10 @@ using SnoopCompile
     ("const_div", const_div_inf),
     ("pow", pow_inf),
     ("const_pow", const_pow_inf),
-    ("substitute", subs_inf)
+    ("substitute", subs_inf),
+    ("arguments", args_inf)
 ]
     @test isempty(staleinstances(inf))
-    # `setindex!` on TaskLocalValue doesn't infer (COMPARE_FULL)
-    if inf === subs_inf
-        @test treesize(inf) == 21
-    else
-        @test isempty(children(inf))
-    end
+    @test isempty(children(inf))
 end