lean4-htt/src/Lean/Setup.lean
Mac Malone 5bb9839887
fix: symbol clashes between packages (#11082)
This PR prevents symbol clashes between (non-`@[export]`) definitions
from different Lean packages.

Previously, if two modules define a function with the same name and were
transitively imported (even privately) by some downstream module,
linking would fail due to a symbol clash. Similarly, if a user defined a
symbol with the same name as one in the `Lean` library, Lean would use
the core symbol even if one did not import `Lean`.

This is solved by changing Lean's name mangling algorithm to include an
optional package identifier. This identifier is provided by Lake via
`--setup` when building a module. This information is weaved through the
elaborator, interpreter, and compiler via a persistent environment
extension that associates modules with their package identifier.

With a package identifier, standard symbols have the form
`lp_<pkg-id>_<mangled-def>`. Without one, the old scheme is used (i.e.,
`l_<mangled-def>`). Module initializers are also prefixed with package
identifier (if any). For example, the initializer for a module `Foo` in
a package `test` is now `initialize_test_Foo` (instead of
`initialize_Foo`). Lake's default for native library names has also been
adjusted accordingly, so that libraries can still, by default, be used
as plugins. Thus, the default library name of the `lean_lib Foo` in
`package test` will now be `libtest_Foo`.

When using Lake to build the Lean core (i.e., `bootstrap = true`), no
package identifier will be used. Thus, definitions in user packages can
never have symbol clashes with core.

Closes #222.
2025-11-19 02:24:44 +00:00

152 lines
5.1 KiB
Text

/-
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura, Mac Malone
-/
module
prelude
public import Lean.Data.Json.Parser
public import Lean.Util.LeanOptions
set_option doc.verso true
public section
/-!
# Module Setup Information
Data types used by Lean module headers and the `--setup` CLI.
-/
namespace Lean
/- Abstract structure of an `import` statement. -/
structure Import where
module : Name
/-- `import all`; whether to import and expose all data saved by the module. -/
importAll : Bool := false
/-- Whether to activate this import when the current module itself is imported. -/
isExported : Bool := true
/-- Whether to import IR for all definitions (transitively) reachable. -/
isMeta : Bool := false
deriving Repr, Inhabited, ToJson, FromJson,
BEq, Hashable -- needed by Lake (in `Lake.Load.Elab.Lean`)
instance : Coe Name Import := ⟨({module := ·})⟩
instance : ToString Import := ⟨fun imp =>
s!"{if imp.isExported then "public " else ""}{if imp.isMeta then "meta " else ""}import \
{if imp.importAll then "all " else ""}{imp.module}"⟩
/-- Abstract structure of a module's header. -/
structure ModuleHeader where
/-- The module's direct imports (i.e., those listed in the header). -/
imports : Array Import
/-- Whether the module is participating in the module system. -/
isModule : Bool
deriving Repr, Inhabited, ToJson, FromJson
/--
Module data files used for an {lit}`import` statement.
This structure is designed for efficient JSON serialization.
-/
structure ImportArtifacts where
ofArray ::
toArray : Array System.FilePath
deriving Repr, Inhabited
instance : ToJson ImportArtifacts := ⟨(toJson ·.toArray)⟩
instance : FromJson ImportArtifacts := ⟨(.ofArray <$> fromJson? ·)⟩
def ImportArtifacts.size (arts : ImportArtifacts) :=
arts.toArray.size
def ImportArtifacts.olean? (arts : ImportArtifacts) :=
arts.toArray[0]?
def ImportArtifacts.ir? (arts : ImportArtifacts) :=
arts.toArray[1]?
def ImportArtifacts.oleanServer? (arts : ImportArtifacts) :=
arts.toArray[2]?
def ImportArtifacts.oleanPrivate? (arts : ImportArtifacts) :=
arts.toArray[3]?
def ImportArtifacts.oleanParts (inServer : Bool) (arts : ImportArtifacts) : Array System.FilePath := Id.run do
let mut fnames := #[]
if let some mFile := arts.olean? then
fnames := fnames.push mFile
if let some sFile := arts.oleanServer? then
-- For uniformity, Lake always provides us with .olean.server, so load it only when we are in
-- server mode or we need it to load further files.
if inServer || arts.oleanPrivate?.isSome then
fnames := fnames.push sFile
if let some pFile := arts.oleanPrivate? then
fnames := fnames.push pFile
return fnames
/-- Files containing data for a single module. -/
structure ModuleArtifacts where
lean? : Option System.FilePath := none
olean? : Option System.FilePath := none
oleanServer? : Option System.FilePath := none
oleanPrivate? : Option System.FilePath := none
ilean? : Option System.FilePath := none
ir? : Option System.FilePath := none
c? : Option System.FilePath := none
bc? : Option System.FilePath := none
deriving Repr, Inhabited, ToJson, FromJson
def ModuleArtifacts.oleanParts (arts : ModuleArtifacts) : Array System.FilePath := Id.run do
let mut fnames := #[]
if let some mFile := arts.olean? then
fnames := fnames.push mFile
if let some sFile := arts.oleanServer? then
fnames := fnames.push sFile
if let some pFile := arts.oleanPrivate? then
fnames := fnames.push pFile
return fnames
/--
The type of module package identifiers.
This is a {name}`String` that is used to disambiguate native symbol prefixes between
different packages (and different versions of the same package).
-/
public abbrev PkgId := String
/-- A module's setup information as described by a JSON file. -/
structure ModuleSetup where
/-- The name of the module. -/
name : Name
/-- The package to which the module belongs (if any). -/
package? : Option PkgId := none
/--
Whether the module, by default, participates in the module system.
Even if {lean}`false`, a module can still choose to participate by using
{lit}`module` in its header.
-/
isModule : Bool := false
/--
The module's direct imports.
If {lean}`none`, uses the imports from the module header.
-/
imports? : Option (Array Import) := none
/-- Pre-resolved artifacts of transitively imported modules. -/
importArts : NameMap ImportArtifacts := {}
/-- Dynamic libraries to load with the module. -/
dynlibs : Array System.FilePath := #[]
/-- Plugins to initialize with the module. -/
plugins : Array System.FilePath := #[]
/-- Additional options for the module. -/
options : LeanOptions := {}
deriving Repr, Inhabited, ToJson, FromJson
/-- Load a {lean}`ModuleSetup` from a JSON file. -/
def ModuleSetup.load (path : System.FilePath) : IO ModuleSetup := do
let contents ← IO.FS.readFile path
match Json.parse contents >>= fromJson? with
| .ok info => pure info
| .error msg => throw <| IO.userError s!"failed to load header from {path}: {msg}"