lib/TableGen/Main.cpp

   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 "llvm/TableGen/Main.h"
  19 #include "TGParser.h"
  20 #include "llvm/ADT/StringExtras.h"
  21 #include "llvm/Support/CommandLine.h"
  22 #include "llvm/Support/FileSystem.h"
  23 #include "llvm/Support/MemoryBuffer.h"
  24 #include "llvm/Support/ToolOutputFile.h"
  25 #include "llvm/TableGen/Error.h"
  26 #include "llvm/TableGen/Record.h"
  27 #include <algorithm>
  28 #include <cstdio>
  29 #include <system_error>
  30 using namespace llvm;
  31
  32 static cl::opt<std::string>
  33 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"),
  34                cl::init("-"));
  35
  36 static cl::opt<std::string>
  37 DependFilename("d",
  38                cl::desc("Dependency filename"),
  39                cl::value_desc("filename"),
  40                cl::init(""));
  41
  42 static cl::opt<std::string>
  43 InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));
  44
  45 static cl::list<std::string>
  46 IncludeDirs("I", cl::desc("Directory of include files"),
  47             cl::value_desc("directory"), cl::Prefix);
  48
  49 static int reportError(const char *ProgName, Twine Msg) {
  50   errs() << ProgName << ": " << Msg;
  51   errs().flush();
  52   return 1;
  53 }
  54
  55 /// Create a dependency file for `-d` option.
  56 ///
  57 /// This functionality is really only for the benefit of the build system.
  58 /// It is similar to GCC's `-M*` family of options.
  59 static int createDependencyFile(const TGParser &Parser, const char *argv0) {
  60   if (OutputFilename == "-")
  61     return reportError(argv0, "the option -d must be used together with -o\n");
  62
  63   std::error_code EC;
  64   ToolOutputFile DepOut(DependFilename, EC, sys::fs::F_Text);
  65   if (EC)
  66     return reportError(argv0, "error opening " + DependFilename + ":" +
  67                                   EC.message() + "\n");
  68   DepOut.os() << OutputFilename << ":";
  69   for (const auto &Dep : Parser.getDependencies()) {
  70     DepOut.os() << ' ' << Dep.first;
  71   }
  72   DepOut.os() << "\n";
  73   DepOut.keep();
  74   return 0;
  75 }
  76
  77 int llvm::TableGenMain(char *argv0, TableGenMainFn *MainFn) {
  78   RecordKeeper Records;
  79
  80   // Parse the input file.
  81   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
  82       MemoryBuffer::getFileOrSTDIN(InputFilename);
  83   if (std::error_code EC = FileOrErr.getError())
  84     return reportError(argv0, "Could not open input file '" + InputFilename +
  85                                   "': " + EC.message() + "\n");
  86
  87   // Tell SrcMgr about this buffer, which is what TGParser will pick up.
  88   SrcMgr.AddNewSourceBuffer(std::move(*FileOrErr), SMLoc());
  89
  90   // Record the location of the include directory so that the lexer can find
  91   // it later.
  92   SrcMgr.setIncludeDirs(IncludeDirs);
  93
  94   TGParser Parser(SrcMgr, Records);
  95
  96   if (Parser.ParseFile())
  97     return 1;
  98
  99   std::error_code EC;
 100   ToolOutputFile Out(OutputFilename, EC, sys::fs::F_Text);
 101   if (EC)
 102     return reportError(argv0, "error opening " + OutputFilename + ":" +
 103                                   EC.message() + "\n");
 104   if (!DependFilename.empty()) {
 105     if (int Ret = createDependencyFile(Parser, argv0))
 106       return Ret;
 107   }
 108
 109   if (MainFn(Out.os(), Records))
 110     return 1;
 111
 112   if (ErrorsPrinted > 0)
 113     return reportError(argv0, Twine(ErrorsPrinted) + " errors.\n");
 114
 115   // Declare success.
 116   Out.keep();
 117   return 0;
 118 }