X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/91116f94e1683dc902a7e10eadd6186fe7d7255c..342d5d1d830b7cd5c88d61ba52836f6c59299f9a:/lib/sod.h

diff --git a/lib/sod.h b/lib/sod.h
index faffb20..3ad4250 100644
--- a/lib/sod.h
+++ b/lib/sod.h
@@ -104,7 +104,7 @@ SOD__VARARGS_MACROS_PREAMBLE
 #  define SOD__ALIGNOF(type) __alignof__(type)
 #else
 #  define SOD__ALIGNOF(type)						\
-offsetof(struct { char sod__x; type sod__y; }, sod__y)
+	offsetof(struct { char sod__x; type sod__y; }, sod__y)
 #endif
 
 /* --- @SOD__IGNORE@ --- *
@@ -116,6 +116,35 @@ offsetof(struct { char sod__x; type sod__y; }, sod__y)
 
 #define SOD__IGNORE(var) ((void)(var))
 
+/* --- @SOD__NORETURN@ --- *
+ *
+ * Use:		Marks functions which are not expected to return.
+ */
+
+#if SOD__GCC_P(2, 5)
+#  define SOD__NORETURN __attribute__((__noreturn__))
+#endif
+
+#ifndef SOD__NORETURN
+#  define SOD__NORETURN
+#endif
+
+/* --- @SOD__PARANOIA@ --- *
+ *
+ * Arguments:	@cond@ = a condition to check
+ *		@conseq@ = a thing to evaluate to if the check passes
+ *		@alt@ = a thing to do if the check fails
+ *
+ * Use:		Check to make sure something is good at runtime, unless
+ *		disabled.
+ */
+
+#if SOD_RECKLESS
+#  define SOD__PARANOIA(cond, conseq, alt) (conseq)
+#else
+#  define SOD__PARANOIA(cond, conseq, alt) ((cond) ? (conseq) : (alt))
+#endif
+
 /* --- @SOD__CAR@ --- *
  *
  * Arguments:	@...@ = a nonempty list of arguments
@@ -291,7 +320,7 @@ struct sod_chain {
 
 /* --- @SOD_DECL@ --- *
  *
- * Arguments:	@cls@ = a class type name
+ * Arguments:	@cls_@ = a class type name
  *		@var@ = a variable name
  *		@keys@ = a @KWARGS(...)@ keyword argument sequence
  *
@@ -299,17 +328,36 @@ struct sod_chain {
  *		@cls@ with automatic lifetime.
  */
 
-#define SOD_DECL(cls, var, keys)					\
-  struct cls##__ilayout var##__layout;					\
-  cls *var = (cls *)sod_init(cls##__class, &var##__layout, keys)
+#define SOD_DECL(cls_, var, keys)					\
+  struct cls_##__ilayout var##__layout;					\
+  cls_ *var =								\
+    SOD__PARANOIA(sizeof(var##__layout) == cls_##__class->cls.initsz,	\
+		  (cls_ *)sod_init(cls_##__class, &var##__layout, keys), \
+		  (sod__chksz_fail(cls_##__class, sizeof(var##__layout)), \
+		   (cls_ *)0))
 
 /*----- Functions provided ------------------------------------------------*/
 
+/* --- @sod__chksz_fail@ --- *
+ *
+ * Arguments:	@const SodClass *cls@ = class we were trying to instantiate
+ *		@size_t sz@ = size allocated
+ *
+ * Returns:	Doesn't.
+ *
+ * Use:		Reports instantiation failure caused by a mismatch between
+ *		the size allocated (@sz@) and the size required for an
+ *		instance of class @cls@.
+ */
+
+extern SOD__NORETURN
+  void sod__chksz_fail(const SodClass */*cls*/, size_t /*sz*/);
+
 /* --- @sod_subclassp@ --- *
  *
  * Arguments:	@const SodClass *sub, *super@ = pointers to two classes
  *
- * Returns:	Nonzero if @c@ is a subclass of @d@.
+ * Returns:	Nonzero if @sub@ is a subclass of @super@.
  */
 
 extern int sod_subclassp(const SodClass */*sub*/, const SodClass */*super*/);