add special treatment for known setjmp/longjmp function names

diff --git a/builtins.c b/builtins.c
index 453fa92..d15a982 100644 (file)
--- a/builtins.c
+++ b/builtins.c
@@ -209,3 +209,59 @@ void create_microsoft_intrinsics(void)
        f(ir_bk_outport,  "__outdword",           make_function_2_type(type_void, type_unsigned_short, type_unsigned_long, DM_NONE));
        f(ir_bk_trap,     "__ud2",                make_function_type(type_void, 0, NULL, DM_NORETURN));
 }
+
+static type_t *add_type_modifier(type_t *orig_type, decl_modifiers_t modifiers)
+{
+       type_t *type = skip_typeref(orig_type);
+
+       assert(type->kind == TYPE_FUNCTION);
+       if ((type->function.modifiers & modifiers) == modifiers)
+               return orig_type;
+
+       type_t *new_type = duplicate_type(type);
+       new_type->function.modifiers |= modifiers;
+       return identify_new_type(new_type);
+}
+
+void adapt_special_functions(function_t *function)
+{
+       symbol_t *symbol = function->base.base.symbol;
+       if (symbol == NULL)
+               return;
+       const char *name = symbol->string;
+
+       /* the following list of names is taken from gcc (calls.c) */
+
+       /* Disregard prefix _, __, __x or __builtin_.  */
+       if (name[0] == '_') {
+               if (!strncmp(name + 3, "uiltin_", 7))
+                       name += 10;
+               else if (name[1] == '_' && name[2] == 'x')
+                       name += 3;
+               else if (name[1] == '_')
+                       name += 2;
+               else
+                       name += 1;
+       }
+
+       if (name[0] == 's') {
+               if ((name[1] == 'e' && (!strcmp(name, "setjmp")
+                                    || !strcmp(name, "setjmp_syscall")))
+                   || (name[1] == 'i' && !strcmp(name, "sigsetjmp"))
+                   || (name[1] == 'a' && !strcmp(name, "savectx"))) {
+                       function->base.type
+                               = add_type_modifier(function->base.type, DM_RETURNS_TWICE);
+               } else if (name[1] == 'i' && !strcmp(name, "siglongjmp")) {
+                       function->base.type
+                               = add_type_modifier(function->base.type, DM_NORETURN);
+               }
+       } else if ((name[0] == 'q' && !strcmp(name, "qsetjmp"))
+                  || (name[0] == 'v' && !strcmp(name, "vfork"))
+                  || (name[0] == 'g' && !strcmp(name, "getcontext"))) {
+               function->base.type
+                       = add_type_modifier(function->base.type, DM_RETURNS_TWICE);
+       } else if (name[0] == 'l' && !strcmp(name, "longjmp")) {
+               function->base.type
+                       = add_type_modifier(function->base.type, DM_NORETURN);
+       }
+}

diff --git a/builtins.h b/builtins.h
index 6bc4139..b903d96 100644 (file)
--- a/builtins.h
+++ b/builtins.h
@@ -47,4 +47,13 @@ void create_gnu_builtins(void);
  */
 void create_microsoft_intrinsics(void);
 
+/**
+ * Some functions like setjmp,longjmp are known from libc and need special
+ * attributes like noreturn or returns_twice.
+ * (Adding __attribute__(())s in the libc headers would be enough but apparently
+ *  this is not done in most cases since people rely on a list of hardcoded
+ *  names in gcc, so we have to duplicate this here)
+ */
+void adapt_special_functions(function_t *function);
+
 #endif

diff --git a/parser.c b/parser.c
index 6cf1a1a..6001f4c 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -3888,6 +3888,10 @@ static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
                handle_entity_attributes(attributes, entity);
        }
 
+       if (entity->kind == ENTITY_FUNCTION && !freestanding) {
+               adapt_special_functions(&entity->function);
+       }
+
        return entity;
 }