1 | //===-- BrainF.h - BrainF compiler class ------------------------*- 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 class stores the data for the BrainF compiler so it doesn't have |
10 | // to pass all of it around. The main method is parse. |
11 | // |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef BRAINF_H |
15 | #define BRAINF_H |
16 | |
17 | #include "llvm/IR/IRBuilder.h" |
18 | #include "llvm/IR/LLVMContext.h" |
19 | #include "llvm/IR/Module.h" |
20 | #include <istream> |
21 | |
22 | using namespace llvm; |
23 | |
24 | /// This class provides a parser for the BrainF language. |
25 | /// The class itself is made to store values during |
26 | /// parsing so they don't have to be passed around |
27 | /// as much. |
28 | class BrainF { |
29 | public: |
30 | /// Options for how BrainF should compile |
31 | enum CompileFlags { |
32 | flag_off = 0, |
33 | flag_arraybounds = 1 |
34 | }; |
35 | |
36 | /// This is the main method. It parses BrainF from in1 |
37 | /// and returns the module with a function |
38 | /// void brainf() |
39 | /// containing the resulting code. |
40 | /// On error, it calls abort. |
41 | /// The caller must delete the returned module. |
42 | Module *parse(std::istream *in1, int mem, CompileFlags cf, |
43 | LLVMContext& C); |
44 | |
45 | protected: |
46 | /// The different symbols in the BrainF language |
47 | enum Symbol { |
48 | SYM_NONE, |
49 | SYM_READ, |
50 | SYM_WRITE, |
51 | SYM_MOVE, |
52 | SYM_CHANGE, |
53 | SYM_LOOP, |
54 | SYM_ENDLOOP, |
55 | SYM_EOF |
56 | }; |
57 | |
58 | /// Names of the different parts of the language. |
59 | /// Tape is used for reading and writing the tape. |
60 | /// headreg is used for the position of the head. |
61 | /// label is used for the labels for the BasicBlocks. |
62 | /// testreg is used for testing the loop exit condition. |
63 | static const char *tapereg; |
64 | static const char *headreg; |
65 | static const char *label; |
66 | static const char *testreg; |
67 | |
68 | /// Put the brainf function preamble and other fixed pieces of code |
69 | void (LLVMContext& C); |
70 | |
71 | /// The main loop for parsing. It calls itself recursively |
72 | /// to handle the depth of nesting of "[]". |
73 | void readloop(PHINode *phi, BasicBlock *oldbb, |
74 | BasicBlock *testbb, LLVMContext &Context); |
75 | |
76 | /// Constants during parsing |
77 | int memtotal; |
78 | CompileFlags comflag; |
79 | std::istream *in; |
80 | Module *module; |
81 | Function *brainf_func; |
82 | FunctionCallee getchar_func; |
83 | FunctionCallee putchar_func; |
84 | Value *ptr_arr; |
85 | Value *ptr_arrmax; |
86 | BasicBlock *endbb; |
87 | BasicBlock *aberrorbb; |
88 | |
89 | /// Variables |
90 | IRBuilder<> *builder; |
91 | Value *curhead; |
92 | }; |
93 | |
94 | #endif // BRAINF_H |
95 | |