libc/utils/HdrGen/Generator.cpp

   1 //===-- Implementation of the main header generation class ----------------===//
   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 #include "Generator.h"
  10
  11 #include "IncludeFileCommand.h"
  12 #include "PublicAPICommand.h"
  13
  14 #include "llvm/ADT/StringRef.h"
  15 #include "llvm/Support/MemoryBuffer.h"
  16 #include "llvm/Support/SourceMgr.h"
  17 #include "llvm/Support/raw_ostream.h"
  18
  19 #include <cstdlib>
  20 #include <memory>
  21
  22 static const char CommandPrefix[] = "%%";
  23 static const size_t CommandPrefixSize = llvm::StringRef(CommandPrefix).size();
  24
  25 static const char CommentPrefix[] = "<!>";
  26
  27 static const char ParamNamePrefix[] = "${";
  28 static const size_t ParamNamePrefixSize =
  29     llvm::StringRef(ParamNamePrefix).size();
  30 static const char ParamNameSuffix[] = "}";
  31 static const size_t ParamNameSuffixSize =
  32     llvm::StringRef(ParamNameSuffix).size();
  33
  34 namespace llvm_libc {
  35
  36 Command *Generator::getCommandHandler(llvm::StringRef CommandName) {
  37   if (CommandName == IncludeFileCommand::Name) {
  38     if (!IncludeFileCmd)
  39       IncludeFileCmd = std::make_unique<IncludeFileCommand>();
  40     return IncludeFileCmd.get();
  41   } else if (CommandName == PublicAPICommand::Name) {
  42     if (!PublicAPICmd)
  43       PublicAPICmd = std::make_unique<PublicAPICommand>(EntrypointNameList);
  44     return PublicAPICmd.get();
  45   } else {
  46     return nullptr;
  47   }
  48 }
  49
  50 void Generator::parseCommandArgs(llvm::StringRef ArgStr, ArgVector &Args) {
  51   if (!ArgStr.contains(',') && ArgStr.trim(' ').trim('\t').size() == 0) {
  52     // If it is just space between the parenthesis
  53     return;
  54   }
  55
  56   ArgStr.split(Args, ",");
  57   for (llvm::StringRef &A : Args) {
  58     A = A.trim(' ');
  59     if (A.startswith(ParamNamePrefix) && A.endswith(ParamNameSuffix)) {
  60       A = A.drop_front(ParamNamePrefixSize).drop_back(ParamNameSuffixSize);
  61       A = ArgMap[std::string(A)];
  62     }
  63   }
  64 }
  65
  66 void Generator::generate(llvm::raw_ostream &OS, llvm::RecordKeeper &Records) {
  67   auto DefFileBuffer = llvm::MemoryBuffer::getFile(HeaderDefFile);
  68   if (!DefFileBuffer) {
  69     llvm::errs() << "Unable to open " << HeaderDefFile << ".\n";
  70     std::exit(1);
  71   }
  72   llvm::SourceMgr SrcMgr;
  73   unsigned DefFileID = SrcMgr.AddNewSourceBuffer(
  74       std::move(DefFileBuffer.get()), llvm::SMLoc::getFromPointer(nullptr));
  75
  76   llvm::StringRef Content = SrcMgr.getMemoryBuffer(DefFileID)->getBuffer();
  77   while (true) {
  78     std::pair<llvm::StringRef, llvm::StringRef> P = Content.split('\n');
  79     Content = P.second;
  80
  81     llvm::StringRef Line = P.first.trim(' ');
  82     if (Line.startswith(CommandPrefix)) {
  83       Line = Line.drop_front(CommandPrefixSize);
  84
  85       P = Line.split("(");
  86       if (P.second.empty() || P.second[P.second.size() - 1] != ')') {
  87         SrcMgr.PrintMessage(llvm::SMLoc::getFromPointer(P.second.data()),
  88                             llvm::SourceMgr::DK_Error,
  89                             "Command argument list should begin with '(' "
  90                             "and end with ')'.");
  91         std::exit(1);
  92       }
  93       llvm::StringRef CommandName = P.first;
  94       Command *Cmd = getCommandHandler(CommandName);
  95       if (Cmd == nullptr) {
  96         SrcMgr.PrintMessage(llvm::SMLoc::getFromPointer(CommandName.data()),
  97                             llvm::SourceMgr::DK_Error,
  98                             "Unknown command '%%" + CommandName + "'.");
  99         std::exit(1);
 100       }
 101
 102       llvm::StringRef ArgStr = P.second.drop_back(1);
 103       ArgVector Args;
 104       parseCommandArgs(ArgStr, Args);
 105
 106       Command::ErrorReporter Reporter(
 107           llvm::SMLoc::getFromPointer(CommandName.data()), SrcMgr);
 108       Cmd->run(OS, Args, StdHeader, Records, Reporter);
 109     } else if (!Line.startswith(CommentPrefix)) {
 110       // There is no comment or command on this line so we just write it as is.
 111       OS << P.first << "\n";
 112     }
 113
 114     if (P.second.empty())
 115       break;
 116   }
 117 }
 118
 119 } // namespace llvm_libc