Address sim642 comments: move is_typedef_decl to Lexerhack, consolidate tests, remove noinit file

Agent-Logs-Url: https://github.com/goblint/cil/sessions/e317c474-30b0-43d6-aec0-4a7a9377d477

Co-authored-by: michael-schwarz <13812333+michael-schwarz@users.noreply.github.com>

Author: Copilot

src/frontc/cparser.mly

@@ -78,10 +78,6 @@ let smooth_expression lst =
 
 let currentFunctionName = ref "<outside any function>"
 
-(* Set to true while parsing a typedef declaration's declarator list, so that
-   declarator_no_init calls add_type (not add_identifier) for typedef names. *)
-let is_typedef_decl = ref false
-
 let announceFunctionName ((n, decl, _, _):name) =
   !Lexerhack.add_identifier n;
   (* Start a context that includes the parameter names and the whole body.
@@ -119,7 +115,7 @@ let applyPointer (ptspecs: attribute list list) (dt: decl_type)
   loop ptspecs
 
 let doDeclaration (loc: cabsloc) (specs: spec_elem list) (nl: init_name list) : definition =
-  is_typedef_decl := false;
+  Lexerhack.is_typedef_decl := false;
   (* Lexer registrations (add_type / add_identifier) are done per-declarator in
      declarator_no_init / declarator_init_start as each declarator is parsed
      (C11 6.2.1.7: scope begins just after the completion of the declarator), so
@@ -1050,13 +1046,13 @@ init_declarator:                             /* ISO 6.7 */
       the completion of its declarator).
       - For non-typedef declarations: calls add_identifier so subsequent
         declarators in the same list see the name as a variable (not a type).
-      - For typedef declarations (is_typedef_decl = true): calls add_type so
+      - For typedef declarations (Lexerhack.is_typedef_decl = true): calls add_type so
         subsequent declarators see the name as a type.
       In both cases every declarator is registered at the right time without
       going through doDeclaration. *) */
 declarator_no_init:
     declarator                          { let (n, _, _, _) = $1 in
-                                          if !is_typedef_decl then !Lexerhack.add_type n
+                                          if !Lexerhack.is_typedef_decl then !Lexerhack.add_type n
                                           else !Lexerhack.add_identifier n;
                                           $1 }
 ;
@@ -1071,7 +1067,7 @@ declarator_init_start:
 
 decl_spec_list_common:                  /* ISO 6.7 */
                                         /* ISO 6.7.1 */
-|   TYPEDEF decl_spec_list_opt          { is_typedef_decl := true; SpecTypedef :: $2, $1  }
+|   TYPEDEF decl_spec_list_opt          { Lexerhack.is_typedef_decl := true; SpecTypedef :: $2, $1  }
 |   EXTERN decl_spec_list_opt           { SpecStorage EXTERN :: $2, $1 }
 |   STATIC  decl_spec_list_opt          { SpecStorage STATIC :: $2, $1 }
 |   AUTO   decl_spec_list_opt           { SpecStorage AUTO :: $2, $1 }

src/frontc/lexerhack.ml

@@ -14,7 +14,11 @@ let push_context: (unit -> unit) ref =
   ref (fun _ -> E.s (E.bug "You called an uninitialized push_context")) 
 
 let pop_context: (unit -> unit) ref = 
-  ref (fun _ -> E.s (E.bug "You called an uninitialized pop_context")) 
+  ref (fun _ -> E.s (E.bug "You called an uninitialized pop_context"))
+
+(* Set to true while parsing a typedef declaration's declarator list, so that
+   declarator_no_init calls add_type (not add_identifier) for typedef names. *)
+let is_typedef_decl : bool ref = ref false
 
 
 (* Keep here the current pattern for formatparse *)

test/small1/typedef_varname.c

@@ -21,6 +21,7 @@ typedef struct rax {
 } rax;
 
 typedef int mytype;
+typedef int T;
 
 int main() {
   rax *rax = malloc(sizeof(*rax)); /* variable rax shadows typedef rax in initializer */
@@ -39,5 +40,15 @@ int main() {
     if (b != sizeof(int)) E(4);
   }
 
+  /* Chain initialization: after "T T = 1", T is registered as a variable by the
+     lexer hack, so the subsequent initializer "U = T + 1" sees T as a variable
+     (value 1), not as a type name.  This fails to parse without the fix because
+     "T + 1" would be a syntax error when T is a NAMED_TYPE. */
+  {
+    T T = 1, U = T + 1;
+    if (T != 1) E(5);
+    if (U != 2) E(6);
+  }
+
   SUCCESS;
 }

test/small1/typedef_varname_noinit.c

@@ -472,7 +472,6 @@ sub addToGroup {
 addTest("testrun/void _GNUCC=1");
 addTest("test/voidtypedef ");
 addTest("testrun/typedef_varname ");
-addTest("testrun/typedef_varname_noinit ");
 addTest("testrun/wrongnumargs ");
 addBadComment("testrun/wrongnumargs",
                         "Notbug. Should fail since we don't pad argument lists");