make dependencies of extensions be found in implicit environments (#5…

…3314)

Alternative to #53293

This does kind of the same thing but it does not rely on `EXT_PRIMED` to
identify extensions which I think is a better idea since we don't really
want code lookup to depend on the state of Julia itself imo.

Fixes #53264

-----------------------

Co-authored by: Mark Kittisopikul <`markkitti@fosstodon.org`>

base/loading.jl

@@ -776,15 +776,30 @@ end
 function entry_point_and_project_file(dir::String, name::String)::Union{Tuple{Nothing,Nothing},Tuple{String,Nothing},Tuple{String,String}}
     path = normpath(joinpath(dir, "$name.jl"))
     isfile_casesensitive(path) && return path, nothing
-    dir = joinpath(dir, name)
-    path, project_file = entry_point_and_project_file_inside(dir, name)
+    dir_name = joinpath(dir, name)
+    path, project_file = entry_point_and_project_file_inside(dir_name, name)
     path === nothing || return path, project_file
-    dir = dir * ".jl"
-    path, project_file = entry_point_and_project_file_inside(dir, name)
+    dir_jl = dir_name * ".jl"
+    path, project_file = entry_point_and_project_file_inside(dir_jl, name)
     path === nothing || return path, project_file
     return nothing, nothing
 end
 
+# Find the project file for the extension `ext` in the implicit env `dir``
+function implicit_env_project_file_extension(dir::String, ext::PkgId)
+    for pkg in readdir(dir; join=true)
+        project_file = env_project_file(pkg)
+        project_file isa String || continue
+        proj = project_file_name_uuid(project_file, "")
+        uuid5(proj.uuid, ext.name) == ext.uuid || continue
+        path = project_file_ext_path(project_file, ext.name)
+        if path !== nothing
+            return path, project_file
+        end
+    end
+    return nothing, nothing
+end
+
 # given a path and a name, return the entry point
 function entry_path(path::String, name::String)::Union{Nothing,String}
     isfile_casesensitive(path) && return normpath(path)
@@ -796,11 +811,12 @@ end
 ## explicit project & manifest API ##
 
 # find project file root or deps `name => uuid` mapping
+# `ext` is the name of the extension if `name` is loaded from one
 # return `nothing` if `name` is not found
-function explicit_project_deps_get(project_file::String, name::String)::Union{Nothing,UUID}
+function explicit_project_deps_get(project_file::String, name::String, ext::Union{String,Nothing}=nothing)::Union{Nothing,UUID}
     d = parsed_toml(project_file)
-    root_uuid = dummy_uuid(project_file)
     if get(d, "name", nothing)::Union{String, Nothing} === name
+        root_uuid = dummy_uuid(project_file)
         uuid = get(d, "uuid", nothing)::Union{String, Nothing}
         return uuid === nothing ? root_uuid : UUID(uuid)
     end
@@ -809,6 +825,19 @@ function explicit_project_deps_get(project_file::String, name::String)::Union{No
         uuid = get(deps, name, nothing)::Union{String, Nothing}
         uuid === nothing || return UUID(uuid)
     end
+    if ext !== nothing
+        extensions = get(d, "extensions", nothing)
+        extensions === nothing && return nothing
+        ext_data = get(extensions, ext, nothing)
+        ext_data === nothing && return nothing
+        if (ext_data isa String && name == ext_data) || (ext_data isa Vector{String} && name in ext_data)
+            weakdeps = get(d, "weakdeps", nothing)::Union{Dict{String, Any}, Nothing}
+            weakdeps === nothing && return nothing
+            wuuid = get(weakdeps, name, nothing)::Union{String, Nothing}
+            wuuid === nothing && return nothing
+            return UUID(wuuid)
+        end
+    end
     return nothing
 end
 
@@ -996,11 +1025,28 @@ end
 function implicit_manifest_deps_get(dir::String, where::PkgId, name::String)::Union{Nothing,PkgId}
     @assert where.uuid !== nothing
     project_file = entry_point_and_project_file(dir, where.name)[2]
-    project_file === nothing && return nothing # a project file is mandatory for a package with a uuid
+    if project_file === nothing
+        # `where` could be an extension
+        project_file = implicit_env_project_file_extension(dir, where)[2]
+        project_file === nothing && return nothing
+    end
     proj = project_file_name_uuid(project_file, where.name)
-    proj == where || return nothing # verify that this is the correct project file
+    ext = nothing
+    if proj !== where
+        # `where` could be an extension in `proj`
+        d = parsed_toml(project_file)
+        exts = get(d, "extensions", nothing)::Union{Dict{String, Any}, Nothing}
+        if exts !== nothing && where.name in keys(exts)
+            if where.uuid !== uuid5(proj.uuid, where.name)
+                return nothing
+            end
+            ext = where.name
+        else
+            return nothing
+        end
+    end
     # this is the correct project, so stop searching here
-    pkg_uuid = explicit_project_deps_get(project_file, name)
+    pkg_uuid = explicit_project_deps_get(project_file, name, ext)
     return PkgId(pkg_uuid, name)
 end
 

test/loading.jl

@@ -1131,6 +1131,18 @@ end
         cmd =  `$(Base.julia_cmd()) --startup-file=no -e $sysimg_ext_test_code`
         cmd = addenv(cmd, "JULIA_LOAD_PATH" => join([proj, "@stdlib"], sep))
         run(cmd)
+
+
+        # Extensions in implicit environments
+        old_load_path = copy(LOAD_PATH)
+        try
+            empty!(LOAD_PATH)
+            push!(LOAD_PATH, joinpath(@__DIR__, "project", "Extensions", "ImplicitEnv"))
+            pkgid_B = Base.PkgId(Base.uuid5(Base.identify_package("A").uuid, "BExt"), "BExt")
+            @test Base.identify_package(pkgid_B, "B") isa Base.PkgId
+        finally
+            copy!(LOAD_PATH, old_load_path)
+        end
     finally
         try
             rm(depot_path, force=true, recursive=true)

test/project/Extensions/ImplicitEnv/A/Project.toml

@@ -0,0 +1,9 @@
+name = "A"
+uuid = "299a509a-2181-4868-8714-15151945d902"
+version = "0.1.0"
+
+[weakdeps]
+B = "c2c18cb0-3543-497c-ac2a-523c527589e5"
+
+[extensions]
+BExt = "B"

test/project/Extensions/ImplicitEnv/A/ext/BExt.jl

@@ -0,0 +1,3 @@
+module BExt
+
+end

test/project/Extensions/ImplicitEnv/A/src/A.jl

@@ -0,0 +1,5 @@
+module A
+
+greet() = print("Hello World!")
+
+end # module A

test/project/Extensions/ImplicitEnv/B/Project.toml

@@ -0,0 +1,3 @@
+name = "B"
+uuid = "c2c18cb0-3543-497c-ac2a-523c527589e5"
+version = "0.1.0"

test/project/Extensions/ImplicitEnv/B/src/B.jl

@@ -0,0 +1,5 @@
+module B
+
+greet() = print("Hello World!")
+
+end # module B