From 14f89bf9c397a4268d2b47418de234992b008d6c Mon Sep 17 00:00:00 2001
From: Bernhard Schommer <bschommer@users.noreply.github.com>
Date: Sun, 29 Mar 2020 11:35:58 +0200
Subject: Explicit error messages for ill-formed section attributes (#232)

Introduce an error message for section attributes with non string
arguments,and another for multiple, ambiguous section attributes.
This is more consistent with the handling of other
attributes, like packed, than the old behavior of silently
ignoring them.
---
 common/Sections.ml  | 29 +++++++++++++++++++++--------
 common/Sections.mli |  4 ++--
 2 files changed, 23 insertions(+), 10 deletions(-)

(limited to 'common')

diff --git a/common/Sections.ml b/common/Sections.ml
index 30be9e69..839128a5 100644
--- a/common/Sections.ml
+++ b/common/Sections.ml
@@ -160,9 +160,22 @@ let gcc_section name readonly exec =
     sec_writable = not readonly; sec_executable = exec;
     sec_access = Access_default }
 
+(* Check and extract whether a section was given as attribute *)
+
+let get_attr_section loc attr =
+  match Cutil.find_custom_attributes ["section"; "__section__"] attr with
+  | [] -> None
+  | [[C.AString name]] -> Some name
+  | [[_]] ->
+    Diagnostics.error loc "'section' attribute requires a string";
+    None
+  | _ ->
+    Diagnostics.error loc "ambiguous 'section' attribute";
+    None
+
 (* Determine section for a variable definition *)
 
-let for_variable env id ty init =
+let for_variable env loc id ty init =
   let attr = Cutil.attributes_of_type env ty in
   let readonly = List.mem C.AConst attr && not(List.mem C.AVolatile attr) in
   let si =
@@ -170,11 +183,11 @@ let for_variable env id ty init =
       (* 1- Section explicitly associated with #use_section *)
       Hashtbl.find use_section_table id
     with Not_found ->
-      match Cutil.find_custom_attributes ["section"; "__section__"] attr with
-      | [[C.AString name]] ->
+      match get_attr_section loc attr with
+      | Some name ->
         (* 2- Section given as an attribute, gcc-style *)
         gcc_section name readonly false
-      | _ ->
+      | None ->
         (* 3- Default section appropriate for size and const-ness *)
         let size =
           match Cutil.sizeof env ty with Some sz -> sz | None -> max_int in
@@ -190,17 +203,17 @@ let for_variable env id ty init =
 
 (* Determine sections for a function definition *)
 
-let for_function env id attr =
+let for_function env loc id attr =
   let si_code =
     try
       (* 1- Section explicitly associated with #use_section *)
       Hashtbl.find use_section_table id
     with Not_found ->
-      match Cutil.find_custom_attributes ["section"; "__section__"] attr with
-      | [[C.AString name]] ->
+      match get_attr_section loc attr with
+      | Some name ->
           (* 2- Section given as an attribute, gcc-style *)
           gcc_section name true true
-      | _ ->
+      | None ->
           (* 3- Default section *)
           try
             Hashtbl.find current_section_table "CODE"
diff --git a/common/Sections.mli b/common/Sections.mli
index bc97814d..d9fd9239 100644
--- a/common/Sections.mli
+++ b/common/Sections.mli
@@ -46,7 +46,7 @@ val define_section:
          -> ?writable:bool -> ?executable:bool -> ?access:access_mode -> unit -> unit
 val use_section_for: AST.ident -> string -> bool
 
-val for_variable: Env.t -> AST.ident -> C.typ -> bool ->
+val for_variable: Env.t -> C.location -> AST.ident -> C.typ -> bool ->
                                           section_name * access_mode
-val for_function: Env.t -> AST.ident -> C.attributes -> section_name list
+val for_function: Env.t -> C.location -> AST.ident -> C.attributes -> section_name list
 val for_stringlit: unit -> section_name
-- 
cgit