Merge pull request #149 from tautschnig/c-frontend

C front end fixes: attributes, packing

Author: kroening

regression/ansi-c/Struct_Padding6/main.c

@@ -0,0 +1,32 @@
+#define STATIC_ASSERT(condition) \
+  int some_array##__LINE__[(condition) ? 1 : -1]
+
+#pragma pack(4)
+
+typedef unsigned short domid_t;
+typedef unsigned evtchn_port_t;
+struct evtchn_status {
+    domid_t dom;
+    evtchn_port_t port;
+    unsigned status;
+    unsigned vcpu;
+    union {
+        struct {
+            domid_t dom;
+        } unbound;
+        struct {
+            domid_t dom;
+            evtchn_port_t port;
+        } interdomain;
+        unsigned pirq;
+        unsigned virq;
+    } u;
+    char a;
+};
+
+int main()
+{
+  STATIC_ASSERT(__builtin_offsetof(struct evtchn_status,u.interdomain.port)==20);
+  STATIC_ASSERT(sizeof(struct evtchn_status)==28);
+  return 0;
+};

regression/ansi-c/Struct_Padding6/test.desc

@@ -0,0 +1,8 @@
+CORE
+main.c
+
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring
+^CONVERSION ERROR$

regression/ansi-c/gcc_attributes9/main.c

@@ -8,6 +8,9 @@ const char* __attribute__((section("s"))) bar1();
 const char* __attribute__((section("s"),weak)) bar2();
 const char* __attribute__((section("s"))) __attribute__((weak)) bar();
 
+volatile int __attribute__((__section__(".init.data1"))) txt_heap_base1;
+volatile int __attribute__((__section__(".init.data3"))) txt_heap_base, __attribute__((__section__(".init.data4"))) txt_heap_size;
+
 #endif
 
 int main()

src/ansi-c/c_storage_spec.h

@@ -82,10 +82,7 @@ class c_storage_spect
     a.is_register     |=b.is_register;
     a.is_inline       |=b.is_inline;
     a.is_thread_local |=b.is_thread_local;
-    a.is_weak         |=b.is_weak;
-    if(!b.alias.empty()) a.alias=b.alias;
-    if(!b.asm_label.empty()) a.asm_label=b.asm_label;
-    if(!b.section.empty()) a.section=b.section;
+    // attributes belong to the declarator, don't replace them
 
     return a;
   }

src/ansi-c/padding.cpp

@@ -188,8 +188,9 @@ void add_padding(struct_typet &type, const namespacet &ns)
     }  
   }
 
-  // Is the struct packed?
-  if(type.get_bool(ID_C_packed))
+  // Is the struct packed, without any alignment specification?
+  if(type.get_bool(ID_C_packed) &&
+     type.find(ID_C_alignment).is_nil())
     return; // done
 
   mp_integer offset=0;
@@ -291,6 +292,9 @@ void add_padding(struct_typet &type, const namespacet &ns)
         max_alignment=tmp_i;
     }
   }
+  // Is the struct packed, without any alignment specification?
+  else if(type.get_bool(ID_C_packed))
+    return; // done
 
   // There may be a need for 'end of struct' padding.
   // We use 'max_alignment'.

src/ansi-c/parser.y

@@ -971,18 +971,19 @@ declaring_list:
           // add the initializer
           to_ansi_c_declaration(stack($$)).add_initializer(stack($5));
         }
-        | declaring_list ',' declarator
+        | declaring_list ',' gcc_type_attribute_opt declarator
           post_declarator_attributes_opt
           {
             // type attribute goes into declarator
-            $3=merge($4, $3);
-            PARSER.add_declarator(stack($1), stack($3));
+            $5=merge($5, $3);
+            $4=merge($5, $4);
+            PARSER.add_declarator(stack($1), stack($4));
           }
           initializer_opt
         {
           // add in the initializer
           $$=$1;
-          to_ansi_c_declaration(stack($$)).add_initializer(stack($6));
+          to_ansi_c_declaration(stack($$)).add_initializer(stack($7));
         }
         ;