Preliminary support for 'aligned' and 'section' attributes, gcc-style. New-style handling of sections for IA32 and ARM. Work in progress, to be tested.

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1635 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

2 files changed, 44 insertions, 13 deletions

diff --git a/common/Sections.ml b/common/Sections.ml
index 9124f85..f37144a 100644
--- a/common/Sections.ml
+++ b/common/Sections.ml
@@ -14,6 +14,7 @@
 (* *********************************************************************)
 
 open Camlcoq
+open Cparser
 
 module StringMap = Map.Make(String)
 
@@ -165,19 +166,50 @@ let default_use_section id name =
     assert ok
   end
 
-let define_function id =
-  default_use_section id "CODE"
+(* Associate an undeclared section to a global symbol, GCC-style *)
+
+let use_gcc_section id name readonly exec =
+  Hashtbl.add section_table_at_def id !current_section_table;
+  let sn = Section_user(name, not readonly, exec) in
+  let si = { sec_name_init = sn; sec_name_uninit = sn;
+             sec_writable = not readonly; sec_executable = exec;
+             sec_near_access = false } in
+  Hashtbl.add use_section_table id si
+
+(* Record sections for a variable definition *)
+
+let define_variable env id ty =
+  let attr = Cutil.attributes_of_type env ty in
+  let readonly = List.mem C.AConst attr && not(List.mem C.AVolatile attr) in
+  (* Check for a GCC-style "section" attribute *)
+  match Cutil.find_custom_attributes ["section"; "__section__"] attr with
+  | [[C.AString name]] ->
+    (* Use gcc-style section *)
+    use_gcc_section id name readonly false
+  | _ ->
+    (* Use default section appropriate for size and const-ness *)
+    let size = match Cutil.sizeof env ty with Some sz -> sz | None -> max_int in
+    default_use_section id
+      (if readonly
+       then if size <= !Clflags.option_small_const then "SCONST" else "CONST"
+       else if size <= !Clflags.option_small_data then "SDATA" else "DATA")
+
+(* Record sections for a function definition *)
+
+let define_function env id ty_res =
+  let attr = Cutil.attributes_of_type env ty_res in
+  match Cutil.find_custom_attributes ["section"; "__section__"] attr with
+  | [[C.AString name]] ->
+      use_gcc_section id name true true
+  | _ ->
+      default_use_section id "CODE"
+
+(* Record sections for a string literal *)
 
 let define_stringlit id =
   default_use_section id "STRING"
 
-let define_variable id size readonly =
-  default_use_section id
-    (if readonly
-     then if size <= !Clflags.option_small_const then "SCONST" else "CONST"
-     else if size <= !Clflags.option_small_data then "SDATA" else "DATA")
-
-(* Determine section to use for a variable definition *)
+(* Determine section to use for a variable *)
 
 let section_for_variable a initialized =
   try
@@ -186,8 +218,7 @@ let section_for_variable a initialized =
   with Not_found ->
     Section_data initialized
 
-(* Determine (text, literal, jumptable) sections to use 
-   for a function definition *)
+(* Determine (text, literal, jumptable) sections to use for a function *)
 
 let sections_for_function a =
   let s_text =
diff --git a/common/Sections.mli b/common/Sections.mli
index 090d4bb..c6a7c96 100644
--- a/common/Sections.mli
+++ b/common/Sections.mli
@@ -34,8 +34,8 @@ val define_section:
          -> ?writable:bool -> ?executable:bool -> ?near:bool -> unit -> unit
 val use_section_for: AST.ident -> string -> bool
 
-val define_function: AST.ident -> unit
-val define_variable: AST.ident -> int -> bool -> unit
+val define_function: Cparser.Env.t -> AST.ident -> Cparser.C.typ -> unit
+val define_variable: Cparser.Env.t -> AST.ident -> Cparser.C.typ -> unit
 val define_stringlit: AST.ident -> unit
 
 val section_for_variable: AST.ident -> bool -> section_name