Improve type stability in Artifacts code (JuliaLang#52759)

This was in an attempt to fix
JuliaLang#52711 which ultimately proved
unsuccessful. This might however still be useful in other scenarios.

```
using JET
 report_opt(Tuple{typeof(Artifacts._artifact_str), Module, String, Base.SubString{String}, String, Base.Dict{String, Any}, Base.SHA1, Base.BinaryPlatforms.Platform, Any}; target_modules=[Artifacts])
```

is quite a bit cleaner with this.

base/parse.jl

@@ -251,8 +251,9 @@ function tryparse(::Type{T}, s::AbstractString; base::Union{Nothing,Integer} = n
 end
 
 function parse(::Type{T}, s::AbstractString; base::Union{Nothing,Integer} = nothing) where {T<:Integer}
- convert(T, tryparse_internal(T, s, firstindex(s), lastindex(s),
- base===nothing ? 0 : check_valid_base(base), true))
+ v = tryparse_internal(T, s, firstindex(s), lastindex(s), base===nothing ? 0 : check_valid_base(base), true)
+ v === nothing && error("should not happoen")
+ convert(T, v)
 end
 tryparse(::Type{Union{}}, slurp...; kwargs...) = error("cannot parse a value as Union{}")
 

stdlib/Artifacts/src/Artifacts.jl

@@ -67,8 +67,8 @@ function parse_mapping(mapping::String, name::String, override_file::String)
  end
  return mapping
 end
-function parse_mapping(mapping::Dict, name::String, override_file::String)
- return Dict(k => parse_mapping(v, name, override_file) for (k, v) in mapping)
+function parse_mapping(mapping::Dict{String, Any}, name::String, override_file::String)
+ return Dict{String, Any}(k => parse_mapping(v, name, override_file) for (k, v) in mapping)
 end
 # Fallthrough for invalid Overrides.toml files
 parse_mapping(mapping, name::String, override_file::String) = nothing
@@ -96,7 +96,7 @@ overriding to another artifact by its content-hash.
 const ARTIFACT_OVERRIDES = Ref{Union{Dict{Symbol,Any},Nothing}}(nothing)
 function load_overrides(;force::Bool = false)::Dict{Symbol, Any}
  if ARTIFACT_OVERRIDES[] !== nothing && !force
- return ARTIFACT_OVERRIDES[]
+ return ARTIFACT_OVERRIDES[]::Dict{Symbol,Any}
  end
 
  # We organize our artifact location overrides into two camps:
@@ -106,13 +106,8 @@ function load_overrides(;force::Bool = false)::Dict{Symbol, Any}
  # Overrides per UUID/bound name are intercepted upon Artifacts.toml load, and new
  # entries within the "hash" overrides are generated on-the-fly. Thus, all redirects
  # mechanistically happen through the "hash" overrides.
- overrides = Dict{Symbol,Any}(
- # Overrides by UUID
- :UUID => Dict{Base.UUID,Dict{String,Union{String,SHA1}}}(),
-
- # Overrides by hash
- :hash => Dict{SHA1,Union{String,SHA1}}(),
- )
+ overrides_uuid = Dict{Base.UUID,Dict{String,Union{String,SHA1}}}()
+ overrides_hash = Dict{SHA1,Union{String,SHA1}}()
 
  for override_file in reverse(artifacts_dirs("Overrides.toml"))
  !isfile(override_file) && continue
@@ -131,20 +126,19 @@ function load_overrides(;force::Bool = false)::Dict{Symbol, Any}
  # Next, determine if this is a hash override or a UUID/name override
  if isa(mapping, String) || isa(mapping, SHA1)
  # if this mapping is a direct mapping (e.g. a String), store it as a hash override
- local hash_str
  hash = tryparse(Base.SHA1, k)
  if hash === nothing
  @error("Invalid override in '$(override_file)': Invalid SHA1 hash '$(k)'")
  continue
  end
 
  # If this mapping is the empty string, un-override it
- if mapping == ""
- delete!(overrides[:hash], hash)
+ if mapping isa String && isempty(mapping)
+ delete!(overrides_hash, hash)
  else
- overrides[:hash][hash] = mapping
+ overrides_hash[hash] = mapping
  end
- elseif isa(mapping, Dict)
+ elseif isa(mapping, Dict{String, Any})
  # Convert `k` into a uuid
  uuid = tryparse(Base.UUID, k)
  if uuid === nothing
@@ -153,19 +147,18 @@ function load_overrides(;force::Bool = false)::Dict{Symbol, Any}
  end
 
  # If this mapping is itself a dict, store it as a set of UUID/artifact name overrides
- ovruuid = overrides[:UUID]::Dict{Base.UUID,Dict{String,Union{String,SHA1}}}
- if !haskey(ovruuid, uuid)
- ovruuid[uuid] = Dict{String,Union{String,SHA1}}()
+ if !haskey(overrides_uuid, uuid)
+ overrides_uuid[uuid] = Dict{String,Union{String,SHA1}}()
  end
 
  # For each name in the mapping, update appropriately
  for (name, override_value) in mapping
  # If the mapping for this name is the empty string, un-override it
- if override_value == ""
- delete!(ovruuid[uuid], name)
+ if override_value isa String && isempty(override_value)
+ delete!(overrides_uuid[uuid], name)
  else
  # Otherwise, store it!
- ovruuid[uuid][name] = override_value
+ overrides_uuid[uuid][name] = override_value::Union{Base.SHA1, String}
  end
  end
  else
@@ -174,6 +167,14 @@ function load_overrides(;force::Bool = false)::Dict{Symbol, Any}
  end
  end
 
+ overrides = Dict{Symbol,Any}(
+ # Overrides by UUID
+ :UUID => overrides_uuid,
+
+ # Overrides by hash
+ :hash => overrides_hash
+ )
+
  ARTIFACT_OVERRIDES[] = overrides
  return overrides
 end
@@ -190,11 +191,13 @@ Query the loaded `<DEPOT>/artifacts/Overrides.toml` settings for artifacts that
 redirected to a particular path or another content-hash.
 """
 function query_override(hash::SHA1; overrides::Dict{Symbol,Any} = load_overrides())
- return map_override_path(get(overrides[:hash], hash, nothing))
+ overrides_hash = overrides[:hash]::Dict{SHA1,Union{String,SHA1}}
+ return map_override_path(get(overrides_hash, hash, nothing))
 end
 function query_override(pkg::Base.UUID, artifact_name::String; overrides::Dict{Symbol,Any} = load_overrides())
- if haskey(overrides[:UUID], pkg)
- return map_override_path(get(overrides[:UUID][pkg], artifact_name, nothing))
+ overrides_uuid = overrides[:UUID]::Dict{Base.UUID,Dict{String,Union{String,SHA1}}}
+ if haskey(overrides_uuid, pkg)
+ return map_override_path(get(overrides_uuid[pkg], artifact_name, nothing))
  end
  return nothing
 end
@@ -284,7 +287,7 @@ function unpack_platform(entry::Dict{String,Any}, name::String,
  delete!(tags, "os")
  delete!(tags, "arch")
  delete!(tags, "git-tree-sha1")
- return Platform(entry["arch"], entry["os"], tags)
+ return Platform(entry["arch"]::String, entry["os"]::String, tags)
 end
 
 function pack_platform!(meta::Dict, p::AbstractPlatform)
@@ -326,8 +329,11 @@ function process_overrides(artifact_dict::Dict, pkg_uuid::Base.UUID)
  # Insert just-in-time hash overrides by looking up the names of anything we need to
  # override for this UUID, and inserting new overrides for those hashes.
  overrides = load_overrides()
- if haskey(overrides[:UUID], pkg_uuid)
- pkg_overrides = overrides[:UUID][pkg_uuid]::Dict{String, <:Any}
+ overrides_uuid = overrides[:UUID]::Dict{Base.UUID,Dict{String,Union{String,SHA1}}}
+ overrides_hash = overrides[:hash]::Dict{SHA1,Union{String,SHA1}}
+
+ if haskey(overrides_uuid, pkg_uuid)
+ pkg_overrides = overrides_uuid[pkg_uuid]::Dict{String, <:Any}
 
  for name in keys(artifact_dict)
  # Skip names that we're not overriding
@@ -336,14 +342,16 @@ function process_overrides(artifact_dict::Dict, pkg_uuid::Base.UUID)
  end
 
  # If we've got a platform-specific friend, override all hashes:
- if isa(artifact_dict[name], Array)
- for entry in artifact_dict[name]
- hash = SHA1(entry["git-tree-sha1"])
- overrides[:hash][hash] = overrides[:UUID][pkg_uuid][name]
+ artifact_dict_name = artifact_dict[name]
+ if isa(artifact_dict_name, Array)
+ for entry in artifact_dict_name
+ entry = entry::Dict{String,Any}
+ hash = SHA1(entry["git-tree-sha1"]::String)
+ overrides_hash[hash] = overrides_uuid[pkg_uuid][name]
  end
- elseif isa(artifact_dict[name], Dict)
- hash = SHA1(artifact_dict[name]["git-tree-sha1"])
- overrides[:hash][hash] = overrides[:UUID][pkg_uuid][name]
+ elseif isa(artifact_dict_name, Dict{String, Any})
+ hash = SHA1(artifact_dict_name["git-tree-sha1"]::String)
+ overrides_hash[hash] = overrides_uuid[pkg_uuid][name]
  end
  end
  end
@@ -388,7 +396,7 @@ function artifact_meta(name::String, artifact_dict::Dict, artifacts_toml::String
  if isa(meta, Vector)
  dl_dict = Dict{AbstractPlatform,Dict{String,Any}}()
  for x in meta
- x::Dict{String}
+ x = x::Dict{String, Any}
  dl_dict[unpack_platform(x, name, artifacts_toml)] = x
  end
  meta = select_platform(dl_dict, platform)
@@ -399,9 +407,12 @@ function artifact_meta(name::String, artifact_dict::Dict, artifacts_toml::String
  end
 
  # This is such a no-no, we are going to call it out right here, right now.
- if meta !== nothing && !haskey(meta, "git-tree-sha1")
- @error("Invalid artifacts file at $(artifacts_toml): artifact '$name' contains no `git-tree-sha1`!")
- return nothing
+ if meta !== nothing
+ meta = meta::Dict{String, Any}
+ if !haskey(meta, "git-tree-sha1")
+ @error("Invalid artifacts file at $(artifacts_toml): artifact '$name' contains no `git-tree-sha1`!")
+ return nothing
+ end
  end
 
  # Return the full meta-dict.