blob: 8e4ca4de62f6386420974aa737a77caf5682894a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
module GHC.Linker
(
)
where
import GHC.Prelude ()
-- We need this dummy dependency for the make build system. Otherwise it
-- tries to load GHC.Types which may not be built yet.
-- Note [Linkers and loaders]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~
--
-- Linkers are used to produce linked objects (.so, executables); loaders are
-- used to link in memory (e.g., in GHCi) with the already loaded libraries
-- (ghc-lib, rts, etc.).
--
-- Linking can usually be done with an external linker program ("ld"), but
-- loading is more tricky:
--
-- * Fully dynamic:
-- when GHC is built as a set of dynamic libraries (ghc-lib, rts, etc.)
-- and the modules to load are also compiled for dynamic linking, a
-- solution is to fully rely on external tools:
--
-- 1) link a .so with the external linker
-- 2) load the .so with POSIX's "dlopen"
--
-- * When GHC is built as a static program or when libraries we want to load
-- aren't compiled for dynamic linking, GHC uses its own loader ("runtime
-- linker"). The runtime linker is part of the rts (rts/Linker.c).
--
-- Note that within GHC's codebase we often use the word "linker" to refer to
-- the static object loader in the runtime system.
--
-- Loading can be delegated to an external interpreter ("iserv") when
-- -fexternal-interpreter is used.
|
