1 /* ----------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2002
7 * -------------------------------------------------------------------------- */
9 #ifndef RTS_STORAGE_INFOTABLES_H
10 #define RTS_STORAGE_INFOTABLES_H
12 /* ----------------------------------------------------------------------------
15 Several pointer fields in info tables are expressed as offsets
16 relative to the info pointer, so that we can generate
17 position-independent code.
19 Note [x86-64-relative]
20 There is a complication on the x86_64 platform, where pointeres are
21 64 bits, but the tools don't support 64-bit relative relocations.
22 However, the default memory model (small) ensures that all symbols
23 have values in the lower 2Gb of the address space, so offsets all
24 fit in 32 bits. Hence we can use 32-bit offset fields.
26 When going via-C, the mangler arranges that we only generate
27 relative relocations between symbols in the same segment (the text
28 segment). The NCG, however, puts things in the right sections and
29 uses 32-bit relative offsets instead.
31 Somewhere between binutils-2.16.1 and binutils-2.16.91.0.6,
32 support for 64-bit PC-relative relocations was added, so maybe this
33 hackery can go away sometime.
34 ------------------------------------------------------------------------- */
36 #if x86_64_TARGET_ARCH
37 #define OFFSET_FIELD(n) StgHalfInt n; StgHalfWord __pad_##n;
39 #define OFFSET_FIELD(n) StgInt n;
42 /* -----------------------------------------------------------------------------
44 -------------------------------------------------------------------------- */
47 #ifndef TABLES_NEXT_TO_CODE
51 OFFSET_FIELD(closure_type_off);
52 OFFSET_FIELD(closure_desc_off);
56 /* -----------------------------------------------------------------------------
59 There is no ticky-specific stuff in an info table at this time.
60 -------------------------------------------------------------------------- */
62 /* -----------------------------------------------------------------------------
64 -------------------------------------------------------------------------- */
72 #else /* !DEBUG_CLOSURE */
74 /* There is no DEBUG-specific stuff in an info table at this time. */
76 #endif /* DEBUG_CLOSURE */
78 /* -----------------------------------------------------------------------------
80 -------------------------------------------------------------------------- */
82 /* The type flags provide quick access to certain properties of a closure. */
84 #define _HNF (1<<0) /* head normal form? */
85 #define _BTM (1<<1) /* bitmap-style layout? */
86 #define _NS (1<<2) /* non-sparkable */
87 #define _STA (1<<3) /* static? */
88 #define _THU (1<<4) /* thunk? */
89 #define _MUT (1<<5) /* mutable? */
90 #define _UPT (1<<6) /* unpointed? */
91 #define _SRT (1<<7) /* has an SRT? */
92 #define _IND (1<<8) /* is an indirection? */
94 #define isSTATIC(flags) ((flags) &_STA)
95 #define isMUTABLE(flags) ((flags) &_MUT)
96 #define isBITMAP(flags) ((flags) &_BTM)
97 #define isTHUNK(flags) ((flags) &_THU)
98 #define isUNPOINTED(flags) ((flags) &_UPT)
99 #define hasSRT(flags) ((flags) &_SRT)
101 extern StgWord16 closure_flags[];
103 #define closureFlags(c) (closure_flags[get_itbl(UNTAG_CLOSURE(c))->type])
105 #define closure_HNF(c) ( closureFlags(c) & _HNF)
106 #define closure_BITMAP(c) ( closureFlags(c) & _BTM)
107 #define closure_NON_SPARK(c) ( (closureFlags(c) & _NS))
108 #define closure_SHOULD_SPARK(c) (!(closureFlags(c) & _NS))
109 #define closure_STATIC(c) ( closureFlags(c) & _STA)
110 #define closure_THUNK(c) ( closureFlags(c) & _THU)
111 #define closure_MUTABLE(c) ( closureFlags(c) & _MUT)
112 #define closure_UNPOINTED(c) ( closureFlags(c) & _UPT)
113 #define closure_SRT(c) ( closureFlags(c) & _SRT)
114 #define closure_IND(c) ( closureFlags(c) & _IND)
116 /* same as above but for info-ptr rather than closure */
117 #define ipFlags(ip) (closure_flags[ip->type])
119 #define ip_HNF(ip) ( ipFlags(ip) & _HNF)
120 #define ip_BITMAP(ip) ( ipFlags(ip) & _BTM)
121 #define ip_SHOULD_SPARK(ip) (!(ipFlags(ip) & _NS))
122 #define ip_STATIC(ip) ( ipFlags(ip) & _STA)
123 #define ip_THUNK(ip) ( ipFlags(ip) & _THU)
124 #define ip_MUTABLE(ip) ( ipFlags(ip) & _MUT)
125 #define ip_UNPOINTED(ip) ( ipFlags(ip) & _UPT)
126 #define ip_SRT(ip) ( ipFlags(ip) & _SRT)
127 #define ip_IND(ip) ( ipFlags(ip) & _IND)
129 /* -----------------------------------------------------------------------------
132 These are used to describe the pointerhood of a sequence of words
133 (usually on the stack) to the garbage collector. The two primary
134 uses are for stack frames, and functions (where we need to describe
135 the layout of a PAP to the GC).
137 In these bitmaps: 0 == ptr, 1 == non-ptr.
138 -------------------------------------------------------------------------- */
141 * Small bitmaps: for a small bitmap, we store the size and bitmap in
142 * the same word, using the following macros. If the bitmap doesn't
143 * fit in a single word, we use a pointer to an StgLargeBitmap below.
145 #define MK_SMALL_BITMAP(size,bits) (((bits)<<BITMAP_BITS_SHIFT) | (size))
147 #define BITMAP_SIZE(bitmap) ((bitmap) & BITMAP_SIZE_MASK)
148 #define BITMAP_BITS(bitmap) ((bitmap) >> BITMAP_BITS_SHIFT)
155 StgWord bitmap[FLEXIBLE_ARRAY];
158 /* -----------------------------------------------------------------------------
159 SRTs (Static Reference Tables)
161 These tables are used to keep track of the static objects referred
162 to by the code for a closure or stack frame, so that we can follow
163 static data references from code and thus accurately
164 garbage-collect CAFs.
165 -------------------------------------------------------------------------- */
167 /* An SRT is just an array of closure pointers: */
168 typedef StgClosure* StgSRT[];
171 * Each info table refers to some subset of the closure pointers in an
172 * SRT. It does this using a pair of an StgSRT pointer and a
173 * half-word bitmap. If the half-word bitmap isn't large enough, then
174 * we fall back to a large SRT, including an unbounded bitmap. If the
175 * half-word bitmap is set to all ones (0xffff), then the StgSRT
176 * pointer instead points to an StgLargeSRT:
178 typedef struct StgLargeSRT_ {
183 /* ----------------------------------------------------------------------------
185 ------------------------------------------------------------------------- */
188 * Stuff describing the closure layout. Well, actually, it might
189 * contain the selector index for a THUNK_SELECTOR. This union is one
193 struct { /* Heap closure payload layout: */
194 StgHalfWord ptrs; /* number of pointers */
195 StgHalfWord nptrs; /* number of non-pointers */
198 StgWord bitmap; /* word-sized bit pattern describing */
199 /* a stack frame: see below */
201 #ifndef TABLES_NEXT_TO_CODE
202 StgLargeBitmap* large_bitmap; /* pointer to large bitmap structure */
204 OFFSET_FIELD( large_bitmap_offset ); /* offset from info table to large bitmap structure */
207 StgWord selector_offset; /* used in THUNK_SELECTORs */
213 * The "standard" part of an info table. Every info table has this bit.
215 typedef struct StgInfoTable_ {
217 #ifndef TABLES_NEXT_TO_CODE
218 StgFunPtr entry; /* pointer to the entry code */
225 /* Ticky-specific stuff would go here. */
228 /* Debug-specific stuff would go here. */
231 StgClosureInfo layout; /* closure layout info (one word) */
233 StgHalfWord type; /* closure type */
234 StgHalfWord srt_bitmap;
236 - the constructor tag
238 - a bitmap of SRT entries
241 #ifdef TABLES_NEXT_TO_CODE
242 StgCode code[FLEXIBLE_ARRAY];
247 /* -----------------------------------------------------------------------------
250 This is the general form of function info tables. The compiler
251 will omit some of the fields in common cases:
253 - If fun_type is not ARG_GEN or ARG_GEN_BIG, then the slow_apply
254 and bitmap fields may be left out (they are at the end, so omitting
255 them doesn't affect the layout).
257 - If srt_bitmap (in the std info table part) is zero, then the srt
258 field may be omitted. This only applies if the slow_apply and
259 bitmap fields have also been omitted.
260 -------------------------------------------------------------------------- */
262 typedef struct StgFunInfoExtraRev_ {
263 OFFSET_FIELD ( slow_apply_offset ); /* apply to args on the stack */
266 OFFSET_FIELD ( bitmap_offset ); /* arg ptr/nonptr bitmap */
268 OFFSET_FIELD ( srt_offset ); /* pointer to the SRT table */
269 StgHalfWord fun_type; /* function type */
270 StgHalfWord arity; /* function arity */
271 } StgFunInfoExtraRev;
273 typedef struct StgFunInfoExtraFwd_ {
274 StgHalfWord fun_type; /* function type */
275 StgHalfWord arity; /* function arity */
276 StgSRT *srt; /* pointer to the SRT table */
277 union { /* union for compat. with TABLES_NEXT_TO_CODE version */
278 StgWord bitmap; /* arg ptr/nonptr bitmap */
280 StgFun *slow_apply; /* apply to args on the stack */
281 } StgFunInfoExtraFwd;
284 #if defined(TABLES_NEXT_TO_CODE)
285 StgFunInfoExtraRev f;
289 StgFunInfoExtraFwd f;
293 // canned bitmap for each arg type, indexed by constants in FunTypes.h
294 extern StgWord stg_arg_bitmaps[];
296 /* -----------------------------------------------------------------------------
298 -------------------------------------------------------------------------- */
301 * When info tables are laid out backwards, we can omit the SRT
302 * pointer iff srt_bitmap is zero.
306 #if defined(TABLES_NEXT_TO_CODE)
307 OFFSET_FIELD( srt_offset ); /* offset to the SRT table */
311 StgSRT *srt; /* pointer to the SRT table */
315 /* -----------------------------------------------------------------------------
317 -------------------------------------------------------------------------- */
320 * When info tables are laid out backwards, we can omit the SRT
321 * pointer iff srt_bitmap is zero.
324 typedef struct StgThunkInfoTable_ {
325 #if !defined(TABLES_NEXT_TO_CODE)
328 #if defined(TABLES_NEXT_TO_CODE)
329 OFFSET_FIELD( srt_offset ); /* offset to the SRT table */
331 StgSRT *srt; /* pointer to the SRT table */
333 #if defined(TABLES_NEXT_TO_CODE)
338 /* -----------------------------------------------------------------------------
339 Constructor info tables
340 -------------------------------------------------------------------------- */
342 typedef struct StgConInfoTable_ {
343 #if !defined(TABLES_NEXT_TO_CODE)
347 #ifndef TABLES_NEXT_TO_CODE
350 OFFSET_FIELD(con_desc) // the name of the data constructor
351 // as: Package:Module.Name
354 #if defined(TABLES_NEXT_TO_CODE)
360 /* -----------------------------------------------------------------------------
361 Accessor macros for fields that might be offsets (C version)
362 -------------------------------------------------------------------------- */
366 * info must be a Stg[Ret|Thunk]InfoTable* (an info table that has a SRT)
368 #ifdef TABLES_NEXT_TO_CODE
369 #define GET_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->srt_offset))
371 #define GET_SRT(info) ((info)->srt)
376 * info must be a StgConInfoTable*.
378 #ifdef TABLES_NEXT_TO_CODE
379 #define GET_CON_DESC(info) ((char *)((StgWord)((info)+1) + (info->con_desc)))
381 #define GET_CON_DESC(info) ((info)->con_desc)
386 * info must be a StgFunInfoTable*
388 #ifdef TABLES_NEXT_TO_CODE
389 #define GET_FUN_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->f.srt_offset))
391 #define GET_FUN_SRT(info) ((info)->f.srt)
394 #ifdef TABLES_NEXT_TO_CODE
395 #define GET_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
396 + (info)->layout.large_bitmap_offset))
398 #define GET_LARGE_BITMAP(info) ((info)->layout.large_bitmap)
401 #ifdef TABLES_NEXT_TO_CODE
402 #define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
403 + (info)->f.b.bitmap_offset))
405 #define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) ((info)->f.b.bitmap))
409 * GET_PROF_TYPE, GET_PROF_DESC
411 #ifdef TABLES_NEXT_TO_CODE
412 #define GET_PROF_TYPE(info) ((char *)((StgWord)((info)+1) + (info->prof.closure_type_off)))
414 #define GET_PROF_TYPE(info) ((info)->prof.closure_type)
416 #ifdef TABLES_NEXT_TO_CODE
417 #define GET_PROF_DESC(info) ((char *)((StgWord)((info)+1) + (info->prof.closure_desc_off)))
419 #define GET_PROF_DESC(info) ((info)->prof.closure_desc)
422 #endif /* RTS_STORAGE_INFOTABLES_H */