Tweak precompiles for reduced Requires/Revise latency (#37574)

Author: timholy

base/experimental.jl

@@ -220,8 +220,8 @@ Closest candidates are:
     To insulate yourself against changes, consider putting any registrations inside an
     `if isdefined(Base.Experimental, :register_error_hint) ... end` block.
 """
-function register_error_hint(handler, exct::Type)
-    list = get!(()->[], _hint_handlers, exct)
+function register_error_hint(@nospecialize(handler), @nospecialize(exct::Type))
+    list = get!(Vector{Any}, _hint_handlers, exct)
     push!(list, handler)
     return nothing
 end

contrib/generate_precompile.jl

@@ -15,16 +15,18 @@ UP_ARROW = "\e[A"
 DOWN_ARROW = "\e[B"
 
 hardcoded_precompile_statements = """
-@assert precompile(Tuple{typeof(Base.stale_cachefile), String, String})
-@assert precompile(Tuple{typeof(push!), Set{Module}, Module})
-@assert precompile(Tuple{typeof(push!), Set{Method}, Method})
-@assert precompile(Tuple{typeof(push!), Set{Base.PkgId}, Base.PkgId})
-@assert precompile(Tuple{typeof(getindex),  Dict{Base.PkgId,String}, Base.PkgId})
-@assert precompile(Tuple{typeof(setindex!), Dict{String,Base.PkgId}, Base.PkgId, String})
+# used by Revise.jl
+@assert precompile(Tuple{typeof(Base.parse_cache_header), String})
+@assert precompile(Tuple{typeof(pushfirst!), Vector{Any}, Function})
+# used by Requires.jl
 @assert precompile(Tuple{typeof(get!), Type{Vector{Function}}, Dict{Base.PkgId,Vector{Function}}, Base.PkgId})
+@assert precompile(Tuple{typeof(haskey), Dict{Base.PkgId,Vector{Function}}, Base.PkgId})
+@assert precompile(Tuple{typeof(delete!), Dict{Base.PkgId,Vector{Function}}, Base.PkgId})
+@assert precompile(Tuple{typeof(push!), Vector{Function}, Function})
+# miscellaneous
+@assert precompile(Tuple{typeof(Base.require), Base.PkgId})
 @assert precompile(Tuple{typeof(isassigned), Core.SimpleVector, Int})
-@assert precompile(Tuple{typeof(pushfirst!), Vector{Any}, Function})
-@assert precompile(Tuple{typeof(Base.parse_cache_header), String})
+@assert precompile(Tuple{typeof(Base.Experimental.register_error_hint), Any, Type})
 """
 
 precompile_script = """
@@ -43,6 +45,13 @@ f(x) = x03
 f(1,2)
 [][1]
 cd("complet_path\t\t$CTRL_C
+# Used by JuliaInterpreter
+push!(Set{Module}(), Main)
+push!(Set{Method}(), first(methods(collect)))
+# Used by Revise
+(setindex!(Dict{String,Base.PkgId}(), Base.PkgId(Base), "file.jl"))["file.jl"]
+(setindex!(Dict{Base.PkgId,String}(), "file.jl", Base.PkgId(Base)))[Base.PkgId(Base)]
+get(Base.pkgorigins, Base.PkgId(Base), nothing)
 """
 
 julia_exepath() = joinpath(Sys.BINDIR, Base.julia_exename())
@@ -100,6 +109,15 @@ if FileWatching !== nothing
     """
 end
 
+Libdl = get(Base.loaded_modules,
+          Base.PkgId(Base.UUID("8f399da3-3557-5675-b5ff-fb832c97cbdb"), "Libdl"),
+          nothing)
+if Libdl !== nothing
+    hardcoded_precompile_statements *= """
+    precompile(Tuple{typeof(Libc.Libdl.dlopen), String})
+    """
+end
+
 function generate_precompile_statements()
     start_time = time_ns()
     debug_output = devnull # or stdout