TypeLocBuilder.h source code [clang_source_code/lib/Sema/TypeLocBuilder.h]

1	//===--- TypeLocBuilder.h - Type Source Info collector ----------- C++ --===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This file defines TypeLocBuilder, a class for building TypeLocs
10	// bottom-up.
11	//
12	//===----------------------------------------------------------------------===//
13
14	#ifndef LLVM_CLANG_LIB_SEMA_TYPELOCBUILDER_H
15	#define LLVM_CLANG_LIB_SEMA_TYPELOCBUILDER_H
16
17	#include "clang/AST/ASTContext.h"
18	#include "clang/AST/TypeLoc.h"
19
20	namespace clang {
21
22	class TypeLocBuilder {
23	enum { InlineCapacity = 8 * sizeof(SourceLocation) };
24
25	/// The underlying location-data buffer. Data grows from the end
26	/// of the buffer backwards.
27	char *Buffer;
28
29	/// The capacity of the current buffer.
30	size_t Capacity;
31
32	/// The index of the first occupied byte in the buffer.
33	size_t Index;
34
35	#ifndef NDEBUG
36	/// The last type pushed on this builder.
37	QualType LastTy;
38	#endif
39
40	/// The inline buffer.
41	enum { BufferMaxAlignment = alignof(void *) };
42	llvm::AlignedCharArray<BufferMaxAlignment, InlineCapacity> InlineBuffer;
43	unsigned NumBytesAtAlign4, NumBytesAtAlign8;
44
45	public:
46	TypeLocBuilder()
47	: Buffer(InlineBuffer.buffer), Capacity(InlineCapacity),
48	Index(InlineCapacity), NumBytesAtAlign4(0), NumBytesAtAlign8(0)
49	{
50	}
51
52	~TypeLocBuilder() {
53	if (Buffer != InlineBuffer.buffer)
54	delete[] Buffer;
55	}
56
57	/// Ensures that this buffer has at least as much capacity as described.
58	void reserve(size_t Requested) {
59	if (Requested > Capacity)
60	// For now, match the request exactly.
61	grow(Requested);
62	}
63
64	/// Pushes a copy of the given TypeLoc onto this builder. The builder
65	/// must be empty for this to work.
66	void pushFullCopy(TypeLoc L);
67
68	/// Pushes space for a typespec TypeLoc. Invalidates any TypeLocs
69	/// previously retrieved from this builder.
70	TypeSpecTypeLoc pushTypeSpec(QualType T) {
71	size_t LocalSize = TypeSpecTypeLoc::LocalDataSize;
72	unsigned LocalAlign = TypeSpecTypeLoc::LocalDataAlignment;
73	return pushImpl(T, LocalSize, LocalAlign).castAs<TypeSpecTypeLoc>();
74	}
75
76	/// Resets this builder to the newly-initialized state.
77	void clear() {
78	#ifndef NDEBUG
79	LastTy = QualType();
80	#endif
81	Index = Capacity;
82	NumBytesAtAlign4 = NumBytesAtAlign8 = 0;
83	}
84
85	/// Tell the TypeLocBuilder that the type it is storing has been
86	/// modified in some safe way that doesn't affect type-location information.
87	void TypeWasModifiedSafely(QualType T) {
88	#ifndef NDEBUG
89	LastTy = T;
90	#endif
91	}
92
93	/// Pushes space for a new TypeLoc of the given type. Invalidates
94	/// any TypeLocs previously retrieved from this builder.
95	template <class TyLocType> TyLocType push(QualType T) {
96	TyLocType Loc = TypeLoc(T, nullptr).castAs<TyLocType>();
97	size_t LocalSize = Loc.getLocalDataSize();
98	unsigned LocalAlign = Loc.getLocalDataAlignment();
99	return pushImpl(T, LocalSize, LocalAlign).castAs<TyLocType>();
100	}
101
102	/// Creates a TypeSourceInfo for the given type.
103	TypeSourceInfo *getTypeSourceInfo(ASTContext& Context, QualType T) {
104	#ifndef NDEBUG
105	(0) . __assert_fail ("T == LastTy && \"type doesn't match last type pushed!\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/TypeLocBuilder.h", 105, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(T == LastTy && "type doesn't match last type pushed!");
106	#endif
107
108	size_t FullDataSize = Capacity - Index;
109	TypeSourceInfo *DI = Context.CreateTypeSourceInfo(T, FullDataSize);
110	memcpy(DI->getTypeLoc().getOpaqueData(), &Buffer[Index], FullDataSize);
111	return DI;
112	}
113
114	/// Copies the type-location information to the given AST context and
115	/// returns a \c TypeLoc referring into the AST context.
116	TypeLoc getTypeLocInContext(ASTContext &Context, QualType T) {
117	#ifndef NDEBUG
118	(0) . __assert_fail ("T == LastTy && \"type doesn't match last type pushed!\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/TypeLocBuilder.h", 118, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(T == LastTy && "type doesn't match last type pushed!");
119	#endif
120
121	size_t FullDataSize = Capacity - Index;
122	void *Mem = Context.Allocate(FullDataSize);
123	memcpy(Mem, &Buffer[Index], FullDataSize);
124	return TypeLoc(T, Mem);
125	}
126
127	private:
128
129	TypeLoc pushImpl(QualType T, size_t LocalSize, unsigned LocalAlignment);
130
131	/// Grow to the given capacity.
132	void grow(size_t NewCapacity);
133
134	/// Retrieve a temporary TypeLoc that refers into this \c TypeLocBuilder
135	/// object.
136	///
137	/// The resulting \c TypeLoc should only be used so long as the
138	/// \c TypeLocBuilder is active and has not had more type information
139	/// pushed into it.
140	TypeLoc getTemporaryTypeLoc(QualType T) {
141	#ifndef NDEBUG
142	(0) . __assert_fail ("LastTy == T && \"type doesn't match last type pushed!\"", "/home/seafit/code_projects/clang_source/clang/lib/Sema/TypeLocBuilder.h", 142, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(LastTy == T && "type doesn't match last type pushed!");
143	#endif
144	return TypeLoc(T, &Buffer[Index]);
145	}
146	};
147
148	}
149
150	#endif
151