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/* ----------------------------------------------------------------------------
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* (c) The GHC Team, 1998-2002
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* -------------------------------------------------------------------------- */
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#ifndef RTS_STORAGE_INFOTABLES_H
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#define RTS_STORAGE_INFOTABLES_H
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/* ----------------------------------------------------------------------------
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Several pointer fields in info tables are expressed as offsets
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relative to the info pointer, so that we can generate
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position-independent code.
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Note [x86-64-relative]
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There is a complication on the x86_64 platform, where pointeres are
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64 bits, but the tools don't support 64-bit relative relocations.
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However, the default memory model (small) ensures that all symbols
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have values in the lower 2Gb of the address space, so offsets all
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fit in 32 bits. Hence we can use 32-bit offset fields.
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When going via-C, the mangler arranges that we only generate
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relative relocations between symbols in the same segment (the text
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segment). The NCG, however, puts things in the right sections and
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uses 32-bit relative offsets instead.
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Somewhere between binutils-2.16.1 and binutils-2.16.91.0.6,
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support for 64-bit PC-relative relocations was added, so maybe this
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hackery can go away sometime.
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------------------------------------------------------------------------- */
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#if x86_64_TARGET_ARCH
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#define OFFSET_FIELD(n) StgHalfInt n; StgHalfWord __pad_##n;
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#define OFFSET_FIELD(n) StgInt n;
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/* -----------------------------------------------------------------------------
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-------------------------------------------------------------------------- */
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#ifndef TABLES_NEXT_TO_CODE
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OFFSET_FIELD(closure_type_off);
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OFFSET_FIELD(closure_desc_off);
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/* -----------------------------------------------------------------------------
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There is no ticky-specific stuff in an info table at this time.
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-------------------------------------------------------------------------- */
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/* -----------------------------------------------------------------------------
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-------------------------------------------------------------------------- */
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#else /* !DEBUG_CLOSURE */
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/* There is no DEBUG-specific stuff in an info table at this time. */
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#endif /* DEBUG_CLOSURE */
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/* -----------------------------------------------------------------------------
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-------------------------------------------------------------------------- */
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/* The type flags provide quick access to certain properties of a closure. */
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#define _HNF (1<<0) /* head normal form? */
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#define _BTM (1<<1) /* bitmap-style layout? */
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#define _NS (1<<2) /* non-sparkable */
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#define _STA (1<<3) /* static? */
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#define _THU (1<<4) /* thunk? */
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#define _MUT (1<<5) /* mutable? */
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#define _UPT (1<<6) /* unpointed? */
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#define _SRT (1<<7) /* has an SRT? */
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#define _IND (1<<8) /* is an indirection? */
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#define isSTATIC(flags) ((flags) &_STA)
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#define isMUTABLE(flags) ((flags) &_MUT)
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#define isBITMAP(flags) ((flags) &_BTM)
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#define isTHUNK(flags) ((flags) &_THU)
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#define isUNPOINTED(flags) ((flags) &_UPT)
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#define hasSRT(flags) ((flags) &_SRT)
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extern StgWord16 closure_flags[];
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#define closureFlags(c) (closure_flags[get_itbl(UNTAG_CLOSURE(c))->type])
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#define closure_HNF(c) ( closureFlags(c) & _HNF)
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#define closure_BITMAP(c) ( closureFlags(c) & _BTM)
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#define closure_NON_SPARK(c) ( (closureFlags(c) & _NS))
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#define closure_SHOULD_SPARK(c) (!(closureFlags(c) & _NS))
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#define closure_STATIC(c) ( closureFlags(c) & _STA)
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#define closure_THUNK(c) ( closureFlags(c) & _THU)
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#define closure_MUTABLE(c) ( closureFlags(c) & _MUT)
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#define closure_UNPOINTED(c) ( closureFlags(c) & _UPT)
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#define closure_SRT(c) ( closureFlags(c) & _SRT)
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#define closure_IND(c) ( closureFlags(c) & _IND)
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/* same as above but for info-ptr rather than closure */
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#define ipFlags(ip) (closure_flags[ip->type])
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#define ip_HNF(ip) ( ipFlags(ip) & _HNF)
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#define ip_BITMAP(ip) ( ipFlags(ip) & _BTM)
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#define ip_SHOULD_SPARK(ip) (!(ipFlags(ip) & _NS))
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#define ip_STATIC(ip) ( ipFlags(ip) & _STA)
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#define ip_THUNK(ip) ( ipFlags(ip) & _THU)
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#define ip_MUTABLE(ip) ( ipFlags(ip) & _MUT)
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#define ip_UNPOINTED(ip) ( ipFlags(ip) & _UPT)
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#define ip_SRT(ip) ( ipFlags(ip) & _SRT)
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#define ip_IND(ip) ( ipFlags(ip) & _IND)
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/* -----------------------------------------------------------------------------
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These are used to describe the pointerhood of a sequence of words
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(usually on the stack) to the garbage collector. The two primary
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uses are for stack frames, and functions (where we need to describe
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the layout of a PAP to the GC).
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In these bitmaps: 0 == ptr, 1 == non-ptr.
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-------------------------------------------------------------------------- */
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* Small bitmaps: for a small bitmap, we store the size and bitmap in
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* the same word, using the following macros. If the bitmap doesn't
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* fit in a single word, we use a pointer to an StgLargeBitmap below.
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#define MK_SMALL_BITMAP(size,bits) (((bits)<<BITMAP_BITS_SHIFT) | (size))
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#define BITMAP_SIZE(bitmap) ((bitmap) & BITMAP_SIZE_MASK)
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#define BITMAP_BITS(bitmap) ((bitmap) >> BITMAP_BITS_SHIFT)
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StgWord bitmap[FLEXIBLE_ARRAY];
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/* -----------------------------------------------------------------------------
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SRTs (Static Reference Tables)
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These tables are used to keep track of the static objects referred
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to by the code for a closure or stack frame, so that we can follow
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static data references from code and thus accurately
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garbage-collect CAFs.
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-------------------------------------------------------------------------- */
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/* An SRT is just an array of closure pointers: */
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typedef StgClosure* StgSRT[];
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* Each info table refers to some subset of the closure pointers in an
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* SRT. It does this using a pair of an StgSRT pointer and a
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* half-word bitmap. If the half-word bitmap isn't large enough, then
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* we fall back to a large SRT, including an unbounded bitmap. If the
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* half-word bitmap is set to all ones (0xffff), then the StgSRT
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* pointer instead points to an StgLargeSRT:
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typedef struct StgLargeSRT_ {
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/* ----------------------------------------------------------------------------
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------------------------------------------------------------------------- */
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* Stuff describing the closure layout. Well, actually, it might
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* contain the selector index for a THUNK_SELECTOR. This union is one
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struct { /* Heap closure payload layout: */
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StgHalfWord ptrs; /* number of pointers */
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StgHalfWord nptrs; /* number of non-pointers */
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StgWord bitmap; /* word-sized bit pattern describing */
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/* a stack frame: see below */
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#ifndef TABLES_NEXT_TO_CODE
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StgLargeBitmap* large_bitmap; /* pointer to large bitmap structure */
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OFFSET_FIELD( large_bitmap_offset ); /* offset from info table to large bitmap structure */
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StgWord selector_offset; /* used in THUNK_SELECTORs */
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* The "standard" part of an info table. Every info table has this bit.
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typedef struct StgInfoTable_ {
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#ifndef TABLES_NEXT_TO_CODE
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StgFunPtr entry; /* pointer to the entry code */
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/* Ticky-specific stuff would go here. */
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/* Debug-specific stuff would go here. */
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StgClosureInfo layout; /* closure layout info (one word) */
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StgHalfWord type; /* closure type */
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StgHalfWord srt_bitmap;
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- the constructor tag
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- a bitmap of SRT entries
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#ifdef TABLES_NEXT_TO_CODE
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StgCode code[FLEXIBLE_ARRAY];
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/* -----------------------------------------------------------------------------
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This is the general form of function info tables. The compiler
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will omit some of the fields in common cases:
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- If fun_type is not ARG_GEN or ARG_GEN_BIG, then the slow_apply
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and bitmap fields may be left out (they are at the end, so omitting
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them doesn't affect the layout).
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- If srt_bitmap (in the std info table part) is zero, then the srt
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field may be omitted. This only applies if the slow_apply and
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bitmap fields have also been omitted.
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-------------------------------------------------------------------------- */
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typedef struct StgFunInfoExtraRev_ {
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OFFSET_FIELD ( slow_apply_offset ); /* apply to args on the stack */
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OFFSET_FIELD ( bitmap_offset ); /* arg ptr/nonptr bitmap */
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OFFSET_FIELD ( srt_offset ); /* pointer to the SRT table */
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StgHalfWord fun_type; /* function type */
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StgHalfWord arity; /* function arity */
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} StgFunInfoExtraRev;
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typedef struct StgFunInfoExtraFwd_ {
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StgHalfWord fun_type; /* function type */
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StgHalfWord arity; /* function arity */
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StgSRT *srt; /* pointer to the SRT table */
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union { /* union for compat. with TABLES_NEXT_TO_CODE version */
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StgWord bitmap; /* arg ptr/nonptr bitmap */
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StgFun *slow_apply; /* apply to args on the stack */
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} StgFunInfoExtraFwd;
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#if defined(TABLES_NEXT_TO_CODE)
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StgFunInfoExtraRev f;
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StgFunInfoExtraFwd f;
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// canned bitmap for each arg type, indexed by constants in FunTypes.h
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extern StgWord stg_arg_bitmaps[];
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/* -----------------------------------------------------------------------------
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-------------------------------------------------------------------------- */
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* When info tables are laid out backwards, we can omit the SRT
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* pointer iff srt_bitmap is zero.
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#if defined(TABLES_NEXT_TO_CODE)
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OFFSET_FIELD( srt_offset ); /* offset to the SRT table */
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StgSRT *srt; /* pointer to the SRT table */
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/* -----------------------------------------------------------------------------
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-------------------------------------------------------------------------- */
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* When info tables are laid out backwards, we can omit the SRT
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* pointer iff srt_bitmap is zero.
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typedef struct StgThunkInfoTable_ {
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#if !defined(TABLES_NEXT_TO_CODE)
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#if defined(TABLES_NEXT_TO_CODE)
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OFFSET_FIELD( srt_offset ); /* offset to the SRT table */
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StgSRT *srt; /* pointer to the SRT table */
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#if defined(TABLES_NEXT_TO_CODE)
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/* -----------------------------------------------------------------------------
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Constructor info tables
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-------------------------------------------------------------------------- */
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typedef struct StgConInfoTable_ {
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#if !defined(TABLES_NEXT_TO_CODE)
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#ifndef TABLES_NEXT_TO_CODE
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OFFSET_FIELD(con_desc) // the name of the data constructor
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// as: Package:Module.Name
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#if defined(TABLES_NEXT_TO_CODE)
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/* -----------------------------------------------------------------------------
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Accessor macros for fields that might be offsets (C version)
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-------------------------------------------------------------------------- */
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* info must be a Stg[Ret|Thunk]InfoTable* (an info table that has a SRT)
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#ifdef TABLES_NEXT_TO_CODE
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#define GET_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->srt_offset))
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#define GET_SRT(info) ((info)->srt)
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* info must be a StgConInfoTable*.
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#ifdef TABLES_NEXT_TO_CODE
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#define GET_CON_DESC(info) ((char *)((StgWord)((info)+1) + (info->con_desc)))
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#define GET_CON_DESC(info) ((info)->con_desc)
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* info must be a StgFunInfoTable*
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#ifdef TABLES_NEXT_TO_CODE
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#define GET_FUN_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->f.srt_offset))
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#define GET_FUN_SRT(info) ((info)->f.srt)
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#ifdef TABLES_NEXT_TO_CODE
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#define GET_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
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+ (info)->layout.large_bitmap_offset))
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#define GET_LARGE_BITMAP(info) ((info)->layout.large_bitmap)
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#ifdef TABLES_NEXT_TO_CODE
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#define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
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+ (info)->f.b.bitmap_offset))
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#define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) ((info)->f.b.bitmap))
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* GET_PROF_TYPE, GET_PROF_DESC
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#ifdef TABLES_NEXT_TO_CODE
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#define GET_PROF_TYPE(info) ((char *)((StgWord)((info)+1) + (info->prof.closure_type_off)))
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#define GET_PROF_TYPE(info) ((info)->prof.closure_type)
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#ifdef TABLES_NEXT_TO_CODE
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#define GET_PROF_DESC(info) ((char *)((StgWord)((info)+1) + (info->prof.closure_desc_off)))
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#define GET_PROF_DESC(info) ((info)->prof.closure_desc)
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#endif /* RTS_STORAGE_INFOTABLES_H */