Some precompiles to reduce JLL latency

base/Base.jl

@@ -426,7 +426,7 @@ end_base_include = time_ns()
 const _sysimage_modules = PkgId[]
 in_sysimage(pkgid::PkgId) = pkgid in _sysimage_modules
 
-# Precompiles for Revise
+# Precompiles for Revise and other packages
 # TODO: move these to contrib/generate_precompile.jl
 # The problem is they don't work there
 for match = _methods(+, (Int, Int), -1, get_world_counter())
@@ -460,6 +460,16 @@ for match = _methods(+, (Int, Int), -1, get_world_counter())
 
     # Code loading uses this
     sortperm(mtime.(readdir(".")), rev=true)
+    # JLLWrappers uses these
+    Dict{UUID,Set{String}}()[UUID("692b3bcd-3c85-4b1f-b108-f13ce0eb3210")] = Set{String}()
+    get!(Set{String}, Dict{UUID,Set{String}}(), UUID("692b3bcd-3c85-4b1f-b108-f13ce0eb3210"))
+    eachindex(IndexLinear(), Expr[])
+    push!(Expr[], Expr(:return, false))
+    vcat(String[], String[])
+    k, v = (:hello => nothing)
+    precompile(indexed_iterate, (Pair{Symbol, Union{Nothing, String}}, Int))
+    precompile(indexed_iterate, (Pair{Symbol, Union{Nothing, String}}, Int, Int))
+    precompile(Base.record_compiletime_preference, (Base.UUID, String))
 
     break   # only actually need to do this once
 end

base/binaryplatforms.jl

@@ -708,9 +708,9 @@ function Base.parse(::Type{Platform}, triplet::AbstractString; validate_strict::
         function split_tags(tagstr)
             tag_fields = split(tagstr, "-"; keepempty=false)
             if isempty(tag_fields)
-                return Pair{String,String}[]
+                return Pair{Symbol,String}[]
             end
-            return map(v -> Symbol(v[1]) => v[2], split.(tag_fields, "+"))
+            return map(v -> Symbol(v[1]) => String(v[2]), split.(tag_fields, "+"))
         end
         tags = split_tags(m["tags"])
 
@@ -1067,4 +1067,33 @@ function select_platform(download_info::Dict, platform::AbstractPlatform = HostP
     return download_info[p]
 end
 
+# precompiles to reduce latency (see https://github.com/JuliaLang/julia/pull/43990#issuecomment-1025692379)
+Dict{Platform,String}()[HostPlatform()] = ""
+Platform("x86_64", "linux"; validate_strict=true, libc="glibc")
+for nt in (
+    (cxxstring_abi="",),
+    (libc="glibc", cxxstring_abi=""),
+    (libc="glibc", cxxstring_abi="", call_abi=""),
+    (                       libc=nothing, call_abi=nothing, libgfortran_version=nothing, cxxstring_abi=nothing, libstdcxx_version=nothing, os_version=nothing),
+    (                       libc="glibc", call_abi=nothing, libgfortran_version=nothing, cxxstring_abi=nothing, libstdcxx_version=nothing, os_version=nothing),
+    (                       libc="glibc", call_abi="",      libgfortran_version=nothing, cxxstring_abi=nothing, libstdcxx_version=nothing, os_version=nothing),
+    (                       libc=nothing, call_abi=nothing, libgfortran_version=nothing, cxxstring_abi="cxx11", libstdcxx_version=nothing, os_version=nothing),
+    (                       libc="glibc", call_abi=nothing, libgfortran_version=nothing, cxxstring_abi="cxx11", libstdcxx_version=nothing, os_version=nothing),
+    (                       libc="glibc", call_abi="",      libgfortran_version=nothing, cxxstring_abi="cxx11", libstdcxx_version=nothing, os_version=nothing),
+    (validate_strict=false, libc=nothing, call_abi=nothing, libgfortran_version=nothing, cxxstring_abi=nothing, libstdcxx_version=nothing, os_version=nothing),
+    (validate_strict=false, libc="glibc", call_abi=nothing, libgfortran_version=nothing, cxxstring_abi=nothing, libstdcxx_version=nothing, os_version=nothing),
+    (validate_strict=false, libc="glibc", call_abi="",      libgfortran_version=nothing, cxxstring_abi=nothing, libstdcxx_version=nothing, os_version=nothing),
+    (validate_strict=false, libc=nothing, call_abi=nothing, libgfortran_version=nothing, cxxstring_abi="cxx11", libstdcxx_version=nothing, os_version=nothing),
+    (validate_strict=false, libc="glibc", call_abi=nothing, libgfortran_version=nothing, cxxstring_abi="cxx11", libstdcxx_version=nothing, os_version=nothing),
+    (validate_strict=false, libc="glibc", call_abi="",      libgfortran_version=nothing, cxxstring_abi="cxx11", libstdcxx_version=nothing, os_version=nothing),
+)
+    pairs(nt)
+    iterate(pairs(nt))
+    iterate(pairs(nt), haskey(nt, :libgfortran_version) ? (nt.libgfortran_version === nothing)+1 : 1)
+    merge(nt, NamedTuple())
+    merge(nt, Pair{Symbol,String}[])
+    Base.structdiff(nt, (validate_strict=false, compare_strategies=Dict{String,Function}()))
+    Platform("x86_64", "linux"; nt...)
+end
+
 end # module

base/loading.jl

@@ -2051,12 +2051,12 @@ end
 
 Compile the given function `f` for the argument tuple (of types) `args`, but do not execute it.
 """
-function precompile(@nospecialize(f), args::Tuple)
+function precompile(@nospecialize(f), @nospecialize(args::Tuple))
     precompile(Tuple{Core.Typeof(f), args...})
 end
 
 const ENABLE_PRECOMPILE_WARNINGS = Ref(false)
-function precompile(argt::Type)
+function precompile(@nospecialize(argt::Type))
     ret = ccall(:jl_compile_hint, Int32, (Any,), argt) != 0
     if !ret && ENABLE_PRECOMPILE_WARNINGS[]
         @warn "Inactive precompile statement" maxlog=100 form=argt _module=nothing _file=nothing _line=0

stdlib/Artifacts/src/Artifacts.jl

@@ -718,4 +718,8 @@ split_artifact_slash(name::AbstractString) =
 artifact_slash_lookup(name::AbstractString, artifact_dict::Dict, artifacts_toml::AbstractString) =
     artifact_slash_lookup(String(name)::String, artifact_dict, String(artifacts_toml)::String)
 
+# Precompilation to reduce latency
+precompile(load_artifacts_toml, (String,))
+precompile(Core.kwfunc(load_artifacts_toml), (NamedTuple{(:pkg_uuid,), Tuple{Base.UUID}}, typeof(load_artifacts_toml), String))
+
 end # module Artifacts