1 //===- TableGenBackends.h - Declarations for LLVM TableGen Backends -------===//
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 contains the declarations for all of the LLVM TableGen
11 // backends. A "TableGen backend" is just a function. See below for a
12 // precise description.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_UTILS_TABLEGEN_TABLEGENBACKENDS_H
17 #define LLVM_UTILS_TABLEGEN_TABLEGENBACKENDS_H
18 
19 // A TableGen backend is a function that looks like
20 //
21 //    EmitFoo(RecordKeeper &RK, raw_ostream &OS /*, anything else you need */ )
22 //
23 // What you do inside of that function is up to you, but it will usually
24 // involve generating C++ code to the provided raw_ostream.
25 //
26 // The RecordKeeper is just a top-level container for an in-memory
27 // representation of the data encoded in the TableGen file. What a TableGen
28 // backend does is walk around that in-memory representation and generate
29 // stuff based on the information it contains.
30 //
31 // The in-memory representation is a node-graph (think of it like JSON but
32 // with a richer ontology of types), where the nodes are subclasses of
33 // Record. The methods `getClass`, `getDef` are the basic interface to
34 // access the node-graph.  RecordKeeper also provides a handy method
35 // `getAllDerivedDefinitions`. Consult "include/llvm/TableGen/Record.h" for
36 // the exact interfaces provided by Record's and RecordKeeper.
37 //
38 // A common pattern for TableGen backends is for the EmitFoo function to
39 // instantiate a class which holds some context for the generation process,
40 // and then have most of the work happen in that class's methods. This
41 // pattern partly has historical roots in the previous TableGen backend API
42 // that involved a class and an invocation like `FooEmitter(RK).run(OS)`.
43 //
44 // Remember to wrap private things in an anonymous namespace. For most
45 // backends, this means that the EmitFoo function is the only thing not in
46 // the anonymous namespace.
47 
48 
49 // FIXME: Reorganize TableGen so that build dependencies can be more
50 // accurately expressed. Currently, touching any of the emitters (or
51 // anything that they transitively depend on) causes everything dependent
52 // on TableGen to be rebuilt (this includes all the targets!). Perhaps have
53 // a standalone TableGen binary and have the backends be loadable modules
54 // of some sort; then the dependency could be expressed as being on the
55 // module, and all the modules would have a common dependency on the
56 // TableGen binary with as few dependencies as possible on the rest of
57 // LLVM.
58 
59 
60 namespace llvm {
61 
62 class raw_ostream;
63 class RecordKeeper;
64 
65 void EmitIntrinsics(RecordKeeper &RK, raw_ostream &OS, bool TargetOnly = false);
66 void EmitAsmMatcher(RecordKeeper &RK, raw_ostream &OS);
67 void EmitAsmWriter(RecordKeeper &RK, raw_ostream &OS);
68 void EmitCallingConv(RecordKeeper &RK, raw_ostream &OS);
69 void EmitCodeEmitter(RecordKeeper &RK, raw_ostream &OS);
70 void EmitDAGISel(RecordKeeper &RK, raw_ostream &OS);
71 void EmitDFAPacketizer(RecordKeeper &RK, raw_ostream &OS);
72 void EmitDisassembler(RecordKeeper &RK, raw_ostream &OS);
73 void EmitFastISel(RecordKeeper &RK, raw_ostream &OS);
74 void EmitInstrInfo(RecordKeeper &RK, raw_ostream &OS);
75 void EmitPseudoLowering(RecordKeeper &RK, raw_ostream &OS);
76 void EmitRegisterInfo(RecordKeeper &RK, raw_ostream &OS);
77 void EmitSubtarget(RecordKeeper &RK, raw_ostream &OS);
78 void EmitMapTable(RecordKeeper &RK, raw_ostream &OS);
79 void EmitOptParser(RecordKeeper &RK, raw_ostream &OS);
80 void EmitCTags(RecordKeeper &RK, raw_ostream &OS);
81 
82 } // End llvm namespace
83 
84 #endif
85