Merge pull request #93 from AbsInt/separate-compilation

This pull request implements "approach A" to separate compilation in CompCert from the paper

Lightweight verification of separate compilation
by Jeehoon Kang, Yoonseung Kim, Chung-Kil Hur, Derek Dreyer, Viktor Vafeiadis,
POPL 2016, pages 178-190

In a nutshell, semantic preservation is still stated and proved in terms of a whole C program and a whole assembly program. However, the whole C program can be the result of syntactic linking of several C compilation units, each unit being separated compiled by CompCert to produce assembly unit, and these assembly units being linked together to produce the whole assembly program.

This way, the statement of semantic preservation and its proof now take into account the fact that each compilation unit is compiled separately, knowing only a fragment of the whole program (i.e. the current compilation unit) rather than the whole program.

1 files changed, 3 insertions, 12 deletions

diff --git a/backend/Debugvar.v b/backend/Debugvar.v
index dcc4327a..5d31831a 100644
--- a/backend/Debugvar.v
+++ b/backend/Debugvar.v
@@ -13,18 +13,9 @@
 (** Computation of live ranges for local variables that carry
     debugging information. *)
 
-Require Import Coqlib.
-Require Import Axioms.
-Require Import Maps.
-Require Import Iteration.
-Require Import AST.
-Require Import Integers.
-Require Import Floats.
-Require Import Errors.
-Require Import Machregs.
-Require Import Locations.
-Require Import Conventions.
-Require Import Linear.
+Require Import Axioms Coqlib Maps Iteration Errors.
+Require Import Integers Floats AST.
+Require Import Machregs Locations Conventions Linear.
 
 (** A debug info is a [builtin_arg loc] expression that safely evaluates
    in any context. *)