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1 //===---- llvm/Support/TypeBuilder.h - Builder for LLVM types ---*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the TypeBuilder class, which is used as a convenient way to
11 // create LLVM types with a consistent and simplified interface.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_SUPPORT_TYPEBUILDER_H
16 #define LLVM_SUPPORT_TYPEBUILDER_H
17 
18 #include "llvm/DerivedTypes.h"
19 #include "llvm/LLVMContext.h"
20 #include <limits.h>
21 
22 namespace llvm {
23 
24 /// TypeBuilder - This provides a uniform API for looking up types
25 /// known at compile time.  To support cross-compilation, we define a
26 /// series of tag types in the llvm::types namespace, like i<N>,
27 /// ieee_float, ppc_fp128, etc.  TypeBuilder<T, false> allows T to be
28 /// any of these, a native C type (whose size may depend on the host
29 /// compiler), or a pointer, function, or struct type built out of
30 /// these.  TypeBuilder<T, true> removes native C types from this set
31 /// to guarantee that its result is suitable for cross-compilation.
32 /// We define the primitive types, pointer types, and functions up to
33 /// 5 arguments here, but to use this class with your own types,
34 /// you'll need to specialize it.  For example, say you want to call a
35 /// function defined externally as:
36 ///
37 ///   struct MyType {
38 ///     int32 a;
39 ///     int32 *b;
40 ///     void *array[1];  // Intended as a flexible array.
41 ///   };
42 ///   int8 AFunction(struct MyType *value);
43 ///
44 /// You'll want to use
45 ///   Function::Create(TypeBuilder<types::i<8>(MyType*), true>::get(), ...)
46 /// to declare the function, but when you first try this, your compiler will
47 /// complain that TypeBuilder<MyType, true>::get() doesn't exist. To fix this,
48 /// write:
49 ///
50 ///   namespace llvm {
51 ///   template<bool xcompile> class TypeBuilder<MyType, xcompile> {
52 ///   public:
53 ///     static StructType *get(LLVMContext &Context) {
54 ///       // If you cache this result, be sure to cache it separately
55 ///       // for each LLVMContext.
56 ///       return StructType::get(
57 ///         TypeBuilder<types::i<32>, xcompile>::get(Context),
58 ///         TypeBuilder<types::i<32>*, xcompile>::get(Context),
59 ///         TypeBuilder<types::i<8>*[], xcompile>::get(Context),
60 ///         NULL);
61 ///     }
62 ///
63 ///     // You may find this a convenient place to put some constants
64 ///     // to help with getelementptr.  They don't have any effect on
65 ///     // the operation of TypeBuilder.
66 ///     enum Fields {
67 ///       FIELD_A,
68 ///       FIELD_B,
69 ///       FIELD_ARRAY
70 ///     };
71 ///   }
72 ///   }  // namespace llvm
73 ///
74 /// TypeBuilder cannot handle recursive types or types you only know at runtime.
75 /// If you try to give it a recursive type, it will deadlock, infinitely
76 /// recurse, or do something similarly undesirable.
77 template<typename T, bool cross_compilable> class TypeBuilder {};
78 
79 // Types for use with cross-compilable TypeBuilders.  These correspond
80 // exactly with an LLVM-native type.
81 namespace types {
82 /// i<N> corresponds to the LLVM IntegerType with N bits.
83 template<uint32_t num_bits> class i {};
84 
85 // The following classes represent the LLVM floating types.
86 class ieee_float {};
87 class ieee_double {};
88 class x86_fp80 {};
89 class fp128 {};
90 class ppc_fp128 {};
91 // X86 MMX.
92 class x86_mmx {};
93 }  // namespace types
94 
95 // LLVM doesn't have const or volatile types.
96 template<typename T, bool cross> class TypeBuilder<const T, cross>
97   : public TypeBuilder<T, cross> {};
98 template<typename T, bool cross> class TypeBuilder<volatile T, cross>
99   : public TypeBuilder<T, cross> {};
100 template<typename T, bool cross> class TypeBuilder<const volatile T, cross>
101   : public TypeBuilder<T, cross> {};
102 
103 // Pointers
104 template<typename T, bool cross> class TypeBuilder<T*, cross> {
105 public:
get(LLVMContext & Context)106   static PointerType *get(LLVMContext &Context) {
107     return PointerType::getUnqual(TypeBuilder<T,cross>::get(Context));
108   }
109 };
110 
111 /// There is no support for references
112 template<typename T, bool cross> class TypeBuilder<T&, cross> {};
113 
114 // Arrays
115 template<typename T, size_t N, bool cross> class TypeBuilder<T[N], cross> {
116 public:
get(LLVMContext & Context)117   static ArrayType *get(LLVMContext &Context) {
118     return ArrayType::get(TypeBuilder<T, cross>::get(Context), N);
119   }
120 };
121 /// LLVM uses an array of length 0 to represent an unknown-length array.
122 template<typename T, bool cross> class TypeBuilder<T[], cross> {
123 public:
get(LLVMContext & Context)124   static ArrayType *get(LLVMContext &Context) {
125     return ArrayType::get(TypeBuilder<T, cross>::get(Context), 0);
126   }
127 };
128 
129 // Define the C integral types only for TypeBuilder<T, false>.
130 //
131 // C integral types do not have a defined size. It would be nice to use the
132 // stdint.h-defined typedefs that do have defined sizes, but we'd run into the
133 // following problem:
134 //
135 // On an ILP32 machine, stdint.h might define:
136 //
137 //   typedef int int32_t;
138 //   typedef long long int64_t;
139 //   typedef long size_t;
140 //
141 // If we defined TypeBuilder<int32_t> and TypeBuilder<int64_t>, then any use of
142 // TypeBuilder<size_t> would fail.  We couldn't define TypeBuilder<size_t> in
143 // addition to the defined-size types because we'd get duplicate definitions on
144 // platforms where stdint.h instead defines:
145 //
146 //   typedef int int32_t;
147 //   typedef long long int64_t;
148 //   typedef int size_t;
149 //
150 // So we define all the primitive C types and nothing else.
151 #define DEFINE_INTEGRAL_TYPEBUILDER(T) \
152 template<> class TypeBuilder<T, false> { \
153 public: \
154   static IntegerType *get(LLVMContext &Context) { \
155     return IntegerType::get(Context, sizeof(T) * CHAR_BIT); \
156   } \
157 }; \
158 template<> class TypeBuilder<T, true> { \
159   /* We provide a definition here so users don't accidentally */ \
160   /* define these types to work. */ \
161 }
162 DEFINE_INTEGRAL_TYPEBUILDER(char);
163 DEFINE_INTEGRAL_TYPEBUILDER(signed char);
164 DEFINE_INTEGRAL_TYPEBUILDER(unsigned char);
165 DEFINE_INTEGRAL_TYPEBUILDER(short);
166 DEFINE_INTEGRAL_TYPEBUILDER(unsigned short);
167 DEFINE_INTEGRAL_TYPEBUILDER(int);
168 DEFINE_INTEGRAL_TYPEBUILDER(unsigned int);
169 DEFINE_INTEGRAL_TYPEBUILDER(long);
170 DEFINE_INTEGRAL_TYPEBUILDER(unsigned long);
171 #ifdef _MSC_VER
172 DEFINE_INTEGRAL_TYPEBUILDER(__int64);
173 DEFINE_INTEGRAL_TYPEBUILDER(unsigned __int64);
174 #else /* _MSC_VER */
175 DEFINE_INTEGRAL_TYPEBUILDER(long long);
176 DEFINE_INTEGRAL_TYPEBUILDER(unsigned long long);
177 #endif /* _MSC_VER */
178 #undef DEFINE_INTEGRAL_TYPEBUILDER
179 
180 template<uint32_t num_bits, bool cross>
181 class TypeBuilder<types::i<num_bits>, cross> {
182 public:
get(LLVMContext & C)183   static IntegerType *get(LLVMContext &C) {
184     return IntegerType::get(C, num_bits);
185   }
186 };
187 
188 template<> class TypeBuilder<float, false> {
189 public:
get(LLVMContext & C)190   static Type *get(LLVMContext& C) {
191     return Type::getFloatTy(C);
192   }
193 };
194 template<> class TypeBuilder<float, true> {};
195 
196 template<> class TypeBuilder<double, false> {
197 public:
get(LLVMContext & C)198   static Type *get(LLVMContext& C) {
199     return Type::getDoubleTy(C);
200   }
201 };
202 template<> class TypeBuilder<double, true> {};
203 
204 template<bool cross> class TypeBuilder<types::ieee_float, cross> {
205 public:
get(LLVMContext & C)206   static Type *get(LLVMContext& C) { return Type::getFloatTy(C); }
207 };
208 template<bool cross> class TypeBuilder<types::ieee_double, cross> {
209 public:
get(LLVMContext & C)210   static Type *get(LLVMContext& C) { return Type::getDoubleTy(C); }
211 };
212 template<bool cross> class TypeBuilder<types::x86_fp80, cross> {
213 public:
get(LLVMContext & C)214   static Type *get(LLVMContext& C) { return Type::getX86_FP80Ty(C); }
215 };
216 template<bool cross> class TypeBuilder<types::fp128, cross> {
217 public:
get(LLVMContext & C)218   static Type *get(LLVMContext& C) { return Type::getFP128Ty(C); }
219 };
220 template<bool cross> class TypeBuilder<types::ppc_fp128, cross> {
221 public:
get(LLVMContext & C)222   static Type *get(LLVMContext& C) { return Type::getPPC_FP128Ty(C); }
223 };
224 template<bool cross> class TypeBuilder<types::x86_mmx, cross> {
225 public:
get(LLVMContext & C)226   static Type *get(LLVMContext& C) { return Type::getX86_MMXTy(C); }
227 };
228 
229 template<bool cross> class TypeBuilder<void, cross> {
230 public:
get(LLVMContext & C)231   static Type *get(LLVMContext &C) {
232     return Type::getVoidTy(C);
233   }
234 };
235 
236 /// void* is disallowed in LLVM types, but it occurs often enough in C code that
237 /// we special case it.
238 template<> class TypeBuilder<void*, false>
239   : public TypeBuilder<types::i<8>*, false> {};
240 template<> class TypeBuilder<const void*, false>
241   : public TypeBuilder<types::i<8>*, false> {};
242 template<> class TypeBuilder<volatile void*, false>
243   : public TypeBuilder<types::i<8>*, false> {};
244 template<> class TypeBuilder<const volatile void*, false>
245   : public TypeBuilder<types::i<8>*, false> {};
246 
247 template<typename R, bool cross> class TypeBuilder<R(), cross> {
248 public:
get(LLVMContext & Context)249   static FunctionType *get(LLVMContext &Context) {
250     return FunctionType::get(TypeBuilder<R, cross>::get(Context), false);
251   }
252 };
253 template<typename R, typename A1, bool cross> class TypeBuilder<R(A1), cross> {
254 public:
get(LLVMContext & Context)255   static FunctionType *get(LLVMContext &Context) {
256     Type *params[] = {
257       TypeBuilder<A1, cross>::get(Context),
258     };
259     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
260                              params, false);
261   }
262 };
263 template<typename R, typename A1, typename A2, bool cross>
264 class TypeBuilder<R(A1, A2), cross> {
265 public:
get(LLVMContext & Context)266   static FunctionType *get(LLVMContext &Context) {
267     Type *params[] = {
268       TypeBuilder<A1, cross>::get(Context),
269       TypeBuilder<A2, cross>::get(Context),
270     };
271     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
272                              params, false);
273   }
274 };
275 template<typename R, typename A1, typename A2, typename A3, bool cross>
276 class TypeBuilder<R(A1, A2, A3), cross> {
277 public:
get(LLVMContext & Context)278   static FunctionType *get(LLVMContext &Context) {
279     Type *params[] = {
280       TypeBuilder<A1, cross>::get(Context),
281       TypeBuilder<A2, cross>::get(Context),
282       TypeBuilder<A3, cross>::get(Context),
283     };
284     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
285                              params, false);
286   }
287 };
288 
289 template<typename R, typename A1, typename A2, typename A3, typename A4,
290          bool cross>
291 class TypeBuilder<R(A1, A2, A3, A4), cross> {
292 public:
get(LLVMContext & Context)293   static FunctionType *get(LLVMContext &Context) {
294     Type *params[] = {
295       TypeBuilder<A1, cross>::get(Context),
296       TypeBuilder<A2, cross>::get(Context),
297       TypeBuilder<A3, cross>::get(Context),
298       TypeBuilder<A4, cross>::get(Context),
299     };
300     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
301                              params, false);
302   }
303 };
304 
305 template<typename R, typename A1, typename A2, typename A3, typename A4,
306          typename A5, bool cross>
307 class TypeBuilder<R(A1, A2, A3, A4, A5), cross> {
308 public:
get(LLVMContext & Context)309   static FunctionType *get(LLVMContext &Context) {
310     Type *params[] = {
311       TypeBuilder<A1, cross>::get(Context),
312       TypeBuilder<A2, cross>::get(Context),
313       TypeBuilder<A3, cross>::get(Context),
314       TypeBuilder<A4, cross>::get(Context),
315       TypeBuilder<A5, cross>::get(Context),
316     };
317     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
318                              params, false);
319   }
320 };
321 
322 template<typename R, bool cross> class TypeBuilder<R(...), cross> {
323 public:
get(LLVMContext & Context)324   static FunctionType *get(LLVMContext &Context) {
325     return FunctionType::get(TypeBuilder<R, cross>::get(Context), true);
326   }
327 };
328 template<typename R, typename A1, bool cross>
329 class TypeBuilder<R(A1, ...), cross> {
330 public:
get(LLVMContext & Context)331   static FunctionType *get(LLVMContext &Context) {
332     Type *params[] = {
333       TypeBuilder<A1, cross>::get(Context),
334     };
335     return FunctionType::get(TypeBuilder<R, cross>::get(Context), params, true);
336   }
337 };
338 template<typename R, typename A1, typename A2, bool cross>
339 class TypeBuilder<R(A1, A2, ...), cross> {
340 public:
get(LLVMContext & Context)341   static FunctionType *get(LLVMContext &Context) {
342     Type *params[] = {
343       TypeBuilder<A1, cross>::get(Context),
344       TypeBuilder<A2, cross>::get(Context),
345     };
346     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
347                                    params, true);
348   }
349 };
350 template<typename R, typename A1, typename A2, typename A3, bool cross>
351 class TypeBuilder<R(A1, A2, A3, ...), cross> {
352 public:
get(LLVMContext & Context)353   static FunctionType *get(LLVMContext &Context) {
354     Type *params[] = {
355       TypeBuilder<A1, cross>::get(Context),
356       TypeBuilder<A2, cross>::get(Context),
357       TypeBuilder<A3, cross>::get(Context),
358     };
359     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
360                                    params, true);
361   }
362 };
363 
364 template<typename R, typename A1, typename A2, typename A3, typename A4,
365          bool cross>
366 class TypeBuilder<R(A1, A2, A3, A4, ...), cross> {
367 public:
get(LLVMContext & Context)368   static FunctionType *get(LLVMContext &Context) {
369     Type *params[] = {
370       TypeBuilder<A1, cross>::get(Context),
371       TypeBuilder<A2, cross>::get(Context),
372       TypeBuilder<A3, cross>::get(Context),
373       TypeBuilder<A4, cross>::get(Context),
374     };
375     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
376                              params, true);
377   }
378 };
379 
380 template<typename R, typename A1, typename A2, typename A3, typename A4,
381          typename A5, bool cross>
382 class TypeBuilder<R(A1, A2, A3, A4, A5, ...), cross> {
383 public:
get(LLVMContext & Context)384   static FunctionType *get(LLVMContext &Context) {
385     Type *params[] = {
386       TypeBuilder<A1, cross>::get(Context),
387       TypeBuilder<A2, cross>::get(Context),
388       TypeBuilder<A3, cross>::get(Context),
389       TypeBuilder<A4, cross>::get(Context),
390       TypeBuilder<A5, cross>::get(Context),
391     };
392     return FunctionType::get(TypeBuilder<R, cross>::get(Context),
393                                    params, true);
394   }
395 };
396 
397 }  // namespace llvm
398 
399 #endif
400