Merge pull request #58 from goblint/c11-noreturn

Support for C11 `_Noreturn`

Author: michael-schwarz

src/frontc/cabs.ml

@@ -105,6 +105,7 @@ and spec_elem =
   | SpecAttr of attribute       (* __attribute__ *)
   | SpecStorage of storage
   | SpecInline
+  | SpecNoreturn
   | SpecType of typeSpecifier
   | SpecPattern of string       (* specifier pattern variable *)
 

src/frontc/cabs2cil.ml

@@ -2333,6 +2333,7 @@ let rec doSpecList (suggestedAnonName: string) (* This string will be part of
     match se with
       A.SpecTypedef -> acc
     | A.SpecInline -> isinline := true; acc
+    | A.SpecNoreturn -> attrs := ("noreturn", []) :: !attrs; acc
     | A.SpecStorage st ->
         if !storage <> NoStorage then
           E.s (error "Multiple storage specifiers");

src/frontc/cabsvisit.ml

@@ -217,7 +217,7 @@ and childrenTypeSpecifier vis ts =
 
 and childrenSpecElem (vis: cabsVisitor) (se: spec_elem) : spec_elem =
   match se with
-    SpecTypedef | SpecInline | SpecStorage _ | SpecPattern _ -> se
+    SpecTypedef | SpecInline | SpecStorage _ | SpecPattern _ | SpecNoreturn -> se
   | SpecCV _ -> se    (* cop out *)
   | SpecAttr a -> begin
       let al' = visitCabsAttribute vis a in

src/frontc/clexer.mll

@@ -163,6 +163,7 @@ let init_lexicon _ =
       ("inline", fun loc -> INLINE loc);
       ("__inline", fun loc -> INLINE loc);
       ("_inline", fun loc -> IDENT ("_inline", loc));
+      ("_Noreturn", fun loc -> NORETURN loc);
       ("__attribute__", fun loc -> ATTRIBUTE loc);
       ("__attribute", fun loc -> ATTRIBUTE loc);
 (*

src/frontc/cparser.mly

@@ -252,7 +252,7 @@ let transformOffsetOf (speclist, dtype) member =
 %token EOF
 %token<Cabs.cabsloc> CHAR INT BOOL DOUBLE FLOAT VOID INT64 INT32
 %token<Cabs.cabsloc> INT128 FLOAT128 COMPLEX /* C99 */
-%token<Cabs.cabsloc> GENERIC /* C11 */
+%token<Cabs.cabsloc> GENERIC NORETURN /* C11 */
 %token<Cabs.cabsloc> ENUM STRUCT TYPEDEF UNION
 %token<Cabs.cabsloc> SIGNED UNSIGNED LONG SHORT
 %token<Cabs.cabsloc> VOLATILE EXTERN STATIC CONST RESTRICT AUTO REGISTER
@@ -474,7 +474,7 @@ primary_expression:                     /*(* 6.5.1. *)*/
 ;
 
 /* (specifier, expression) list */
-generic_assoc_list: 
+generic_assoc_list:
 | generic_association {[$1]}
 | generic_assoc_list COMMA generic_association {$3 :: $1}
 
@@ -951,6 +951,7 @@ decl_spec_list:                         /* ISO 6.7 */
 |   type_spec decl_spec_list_opt_no_named { SpecType (fst $1) :: $2, snd $1 }
                                         /* ISO 6.7.4 */
 |   INLINE decl_spec_list_opt           { SpecInline :: $2, $1 }
+|   NORETURN decl_spec_list_opt         { SpecNoreturn  :: $2, $1 }
 |   cvspec decl_spec_list_opt           { (fst $1) :: $2, snd $1 }
 |   attribute_nocv decl_spec_list_opt   { SpecAttr (fst $1) :: $2, snd $1 }
 /* specifier pattern variable (must be last in spec list) */
@@ -1360,7 +1361,9 @@ pragma:
 /* (* We want to allow certain strange things that occur in pragmas, so we
     * cannot use directly the language of expressions *) */
 primary_attr:
-    IDENT				{ VARIABLE (fst $1) }
+    IDENT				                        { VARIABLE (fst $1) }
+    /* (* This is just so code such as __attribute(_NoReturn) is not rejected, which may arise when combining GCC noreturn attribute and including C11 stdnoreturn.h *) */
+|   NORETURN                            { VARIABLE ("__noreturn__") }
     /*(* The NAMED_TYPE here creates conflicts with IDENT *)*/
 |   NAMED_TYPE				{ VARIABLE (fst $1) }
 |   LPAREN attr RPAREN                  { $2 }

src/frontc/cprint.ml

@@ -135,6 +135,7 @@ let rec print_specifiers (specs: spec_elem list) =
   let print_spec_elem = function
       SpecTypedef -> print "typedef"
     | SpecInline -> printu "inline"
+    | SpecNoreturn -> printu "_Noreturn"
     | SpecStorage sto ->
         printu (match sto with
           NO_STORAGE -> (comstring "/*no storage*/")
@@ -532,11 +533,11 @@ and print_expression_level (lvl: int) (exp : expression) =
       print ")"
   | GENERIC (exp, lst) ->
       let rec print_generic_list l =
-        match l with 
+        match l with
         [] -> ()
         | (t, e) :: tl ->
           print ", ";
-          print_onlytype t; 
+          print_onlytype t;
           print ": ";
           print_expression_level 0 e;
           print_generic_list tl

test/small1/c11-noreturn.c

@@ -0,0 +1,24 @@
+#include "testharness.h"
+#include <stdnoreturn.h>
+
+_Noreturn int fun() {
+    SUCCESS;
+}
+
+noreturn int blub() {
+    SUCCESS;
+}
+
+int blabla() __attribute__((noreturn));
+
+int blabla() {
+    SUCCESS;
+}
+
+int main() {
+    fun();
+    blub();
+    blabla();
+
+    SUCCESS;
+}

test/small1/gcc-c11-generic-1.c

@@ -1,7 +1,7 @@
 // https://github.com/gcc-mirror/gcc/blob/16e2427f50c208dfe07d07f18009969502c25dc8/gcc/testsuite/gcc.dg/c11-generic-1.c
 #include "testharness.h"
 
-// _Noreturn extern void abort (void);
+_Noreturn extern void abort (void);
 
 int e = 0;
 
@@ -50,9 +50,8 @@ main (void)
   check (n);
 
   /* _Noreturn is not part of the function type.  */
-  // TODO: add back when C11 _Noreturn supported
-  /* check (_Generic (&abort, void (*) (void): 0, default: n++));
-  check (n); */
+  check (_Generic (&abort, void (*) (void): 0, default: n++));
+  check (n);
 
   /* Integer promotions do not occur.  */
   short s;

test/testcil.pl

@@ -695,6 +695,7 @@ sub addToGroup {
 
 addTest("testrunc11/c11-generic");
 addTest("testrunc11/c11-caserange");
+addTest("testrunc11/c11-noreturn");
 addTest("testrunc11/gcc-c11-generic-1");
 # TODO: these messages are not even checked?
 addTestFail("testc11/gcc-c11-generic-2-1", "Multiple defaults in generic");