[project @ 1996-01-08 20:28:12 by partain]

[ghc-hetmet.git] / ghc / includes / StgMachDeps.h

diff --git a/ghc/includes/StgMachDeps.h b/ghc/includes/StgMachDeps.h
new file mode 100644 (file)
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+++ b/ghc/includes/StgMachDeps.h
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+#ifndef STGMACHDEPS_H
+#define STGMACHDEPS_H
+
+#define COMMENT__(a)
+
+COMMENT__(The COMMON_ITBLS macro determines whether we use commoned-up
+  info tables and rep tables instead of the old info table system.)
+
+#define COMMON_ITBLS 1
+
+
+COMMENT__(This code has to go through a Haskell compiler too)
+
+COMMENT__(We assume 8 bit bytes.)
+#define BITS_PER_BYTE 8
+#define BITS_IN(x) (BITS_PER_BYTE * sizeof(x))
+
+#ifdef __STDC__
+#define PROTO(x)       x
+#define NON_PROTO(x)   /* nothing */
+#define STG_VOLATILE   volatile
+#define STG_NO_ARGS    void
+#define CAT2(a,b) a##b
+#define CAT3(a,b,c) a##b##c
+#define CAT4(a,b,c,d) a##b##c##d
+#define CAT5(a,b,c,d,e) a##b##c##d##e
+#define CAT6(a,b,c,d,e,f) a##b##c##d##e##f
+
+#else
+#define PROTO(x)       ()
+#define NON_PROTO(x)   x
+#define STG_VOLATILE   /* no volatile */
+#define STG_NO_ARGS    /* no such thing either */
+#define CAT2(a,b) a/**/b
+#define CAT3(a,b,c) a/**/b/**/c
+#define CAT4(a,b,c,d) a/**/b/**/c/**/d
+#define CAT5(a,b,c,d,e) a/**/b/**/c/**/d/**/e
+#define CAT6(a,b,c,d,e,f) a/**/b/**/c/**/d/**/e/**/f
+#endif /* ! __STDC__ */
+
+#ifdef __GNUC__
+#define STG_NORETURN   __attribute__((noreturn))
+#define STG_INLINE __inline__
+#else
+#define STG_NORETURN   /* no such thing */
+#define STG_INLINE /* no inline functions */
+#endif
+
+#if 0
+------------------------------------------------------------------------
+  Steve Maguires "Writing Solid Code" suggests that (in the debugging
+  version) we should work hard to make bugs show themselves at the
+  earliest possible moment.  
+
+  In particular, it suggests that the memory management system should
+  trash memory when it is allocated and when it is deallocated so that
+  references to uninitialised memory or to released memory will show up
+  as the bugs they are.
+
+  By "trashing", I mean writing easily recognisable "nonsense" bit
+  patterns over the block of memory.  It is worth taking some care to
+  choose values which:
+
+  1) Are meaningless pointers (ideally causing memory exceptions)
+
+     (eg not word-aligned)
+
+  2) Are "weird-looking" integers (whether treated as 8, 16, 32 or 64
+     bits) (A large (definately non-zero) value).
+
+  3) Make strange-looking strings when concatenated.
+
+  4) Are meaningless machine code (ideally causing exceptions)
+
+  We should also choose different values for initialisation and
+  deallocation to make it easier to identify the source of the bug.
+
+  ADR
+------------------------------------------------------------------------
+#endif /* 0 */
+
+
+#if alpha_TARGET_ARCH
+#define DEALLOCATED_TRASH   0xdeadbeefdeadbeef
+#else
+#define DEALLOCATED_TRASH   0xdeadbeef
+#endif
+
+#endif /* ! STGMACHDEPS_H */