Lazy loading of opaque proofs: fast as -dont-load-proofs without its drawbacks

 The recent experiment with -dont-load-proofs in the stdlib showed that
 this options isn't fully safe: some axioms were generated (Include ?
 functor application ? This is still to be fully understood).

 Instead, I've implemented an idea of Yann: only load opaque proofs when
 we need them. This is almost as fast as -dont-load-proofs (on the stdlib,
 we're now 15% faster than before instead of 20% faster with -dont-load-proofs),
 but fully compatible with Coq standard behavior.

 Technically, the const_body field of Declarations.constant_body now regroup
 const_body + const_opaque + const_inline in a ternary type. It is now either:
  - Undef : an axiom or parameter, with an inline info
  - Def : a transparent definition, with a constr_substituted
  - OpaqueDef : an opaque definition, with a lazy constr_substitued
 Accessing the lazy constr of an OpaqueDef might trigger the read on disk of
 the final section of a .vo, where opaque proofs are located.

 Some functions (body_of_constant, is_opaque, constant_has_body) emulate
 the behavior of the old fields. The rest of Coq (including the checker)
 has been adapted accordingly, either via direct access to the new const_body
 or via these new functions. Many places look nicer now (ok, subjective notion).

 There are now three options: -lazy-load-proofs (default), -force-load-proofs
 (earlier semantics), -dont-load-proofs. Note that -outputstate now implies
 -force-load-proofs (otherwise the marshaling fails on some delayed lazy).

 On the way, I fixed what looked like a bug : a module type
 (T with Definition x := c) was accepted even when x in T was opaque.
 I also tried to clarify Subtyping.check_constant.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@13952 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 3 insertions, 7 deletions

diff --git a/checker/safe_typing.mli b/checker/safe_typing.mli
index 986393b29..cd2c06d20 100644
--- a/checker/safe_typing.mli
+++ b/checker/safe_typing.mli
@@ -33,12 +33,8 @@ sig
   type table 
   type lightened_compiled_library 
 
-  (** [load lpf get_table lcl] builds a compiled library from a
+  (** [load table lcl] builds a compiled library from a
       lightened library [lcl] by remplacing every index by its related
-      opaque terms inside the table obtained by [get_table ()].  
-      If [lpf] is unset then the table is considered empty, which 
-      implies that [get_table] is not evaluated and every index 
-      is replaced by [None] inside the compiled library. *)
-  val load : load_proof:bool -> (unit -> table) 
-    -> lightened_compiled_library -> compiled_library
+      opaque terms inside [table]. *)
+  val load : table -> lightened_compiled_library -> compiled_library
 end