1 //===- Main.cpp - Top-Level TableGen implementation -----------------------===//
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 // TableGen is a tool which can be used to build up a description of something,
11 // then invoke one or more "tablegen backends" to emit information about the
12 // description in some predefined format.  In practice, this is used by the LLVM
13 // code generators to automate generation of a code generator through a
14 // high-level description of the target.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #include "TGParser.h"
19 #include "llvm/ADT/OwningPtr.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Support/MemoryBuffer.h"
22 #include "llvm/Support/ToolOutputFile.h"
23 #include "llvm/Support/system_error.h"
24 #include "llvm/TableGen/Error.h"
25 #include "llvm/TableGen/Main.h"
26 #include "llvm/TableGen/Record.h"
27 #include <algorithm>
28 #include <cstdio>
29 using namespace llvm;
30 
31 namespace {
32   cl::opt<std::string>
33   OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"),
34                  cl::init("-"));
35 
36   cl::opt<std::string>
37   DependFilename("d",
38                  cl::desc("Dependency filename"),
39                  cl::value_desc("filename"),
40                  cl::init(""));
41 
42   cl::opt<std::string>
43   InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));
44 
45   cl::list<std::string>
46   IncludeDirs("I", cl::desc("Directory of include files"),
47               cl::value_desc("directory"), cl::Prefix);
48 }
49 
50 /// \brief Create a dependency file for `-d` option.
51 ///
52 /// This functionality is really only for the benefit of the build system.
53 /// It is similar to GCC's `-M*` family of options.
54 static int createDependencyFile(const TGParser &Parser, const char *argv0) {
55   if (OutputFilename == "-") {
56     errs() << argv0 << ": the option -d must be used together with -o\n";
57     return 1;
58   }
59   std::string Error;
60   tool_output_file DepOut(DependFilename.c_str(), Error);
61   if (!Error.empty()) {
62     errs() << argv0 << ": error opening " << DependFilename
63       << ":" << Error << "\n";
64     return 1;
65   }
66   DepOut.os() << OutputFilename << ":";
67   const std::vector<std::string> &Dependencies = Parser.getDependencies();
68   for (std::vector<std::string>::const_iterator I = Dependencies.begin(),
69                                                 E = Dependencies.end();
70        I != E; ++I) {
71     DepOut.os() << " " << (*I);
72   }
73   DepOut.os() << "\n";
74   DepOut.keep();
75   return 0;
76 }
77 
78 namespace llvm {
79 
80 int TableGenMain(char *argv0, TableGenMainFn *MainFn) {
81   RecordKeeper Records;
82 
83   try {
84     // Parse the input file.
85     OwningPtr<MemoryBuffer> File;
86     if (error_code ec =
87           MemoryBuffer::getFileOrSTDIN(InputFilename.c_str(), File)) {
88       errs() << "Could not open input file '" << InputFilename << "': "
89              << ec.message() <<"\n";
90       return 1;
91     }
92     MemoryBuffer *F = File.take();
93 
94     // Tell SrcMgr about this buffer, which is what TGParser will pick up.
95     SrcMgr.AddNewSourceBuffer(F, SMLoc());
96 
97     // Record the location of the include directory so that the lexer can find
98     // it later.
99     SrcMgr.setIncludeDirs(IncludeDirs);
100 
101     TGParser Parser(SrcMgr, Records);
102 
103     if (Parser.ParseFile())
104       return 1;
105 
106     std::string Error;
107     tool_output_file Out(OutputFilename.c_str(), Error);
108     if (!Error.empty()) {
109       errs() << argv0 << ": error opening " << OutputFilename
110         << ":" << Error << "\n";
111       return 1;
112     }
113     if (!DependFilename.empty())
114       if (int Ret = createDependencyFile(Parser, argv0))
115         return Ret;
116 
117     if (MainFn(Out.os(), Records))
118       return 1;
119 
120     // Declare success.
121     Out.keep();
122     return 0;
123 
124   } catch (const TGError &Error) {
125     PrintError(Error);
126   } catch (const std::string &Error) {
127     PrintError(Error);
128   } catch (const char *Error) {
129     PrintError(Error);
130   } catch (...) {
131     errs() << argv0 << ": Unknown unexpected exception occurred.\n";
132   }
133 
134   return 1;
135 }
136 
137 }
138