llvm/utils/TableGen/OptionRSTEmitter.cpp

   1 //===- OptionRSTEmitter.cpp - Table Driven Command Line Option Parsing ----===//
   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 "Common/OptEmitter.h"
  10 #include "llvm/ADT/STLExtras.h"
  11 #include "llvm/ADT/StringMap.h"
  12 #include "llvm/TableGen/Record.h"
  13 #include "llvm/TableGen/TableGenBackend.h"
  14
  15 using namespace llvm;
  16
  17 /// This tablegen backend takes an input .td file describing a list of options
  18 /// and emits a RST man page.
  19 static void emitOptionRst(const RecordKeeper &Records, raw_ostream &OS) {
  20   llvm::StringMap<std::vector<const Record *>> OptionsByGroup;
  21
  22   // Get the options.
  23   std::vector<const Record *> Opts = Records.getAllDerivedDefinitions("Option");
  24   llvm::sort(Opts, IsOptionRecordsLess);
  25
  26   // Get the option groups.
  27   for (const Record *R : Records.getAllDerivedDefinitions("OptionGroup"))
  28     OptionsByGroup.try_emplace(R->getValueAsString("Name"));
  29
  30   // Map options to their group.
  31   for (const Record *R : Opts) {
  32     if (const DefInit *DI = dyn_cast<DefInit>(R->getValueInit("Group")))
  33       OptionsByGroup[DI->getDef()->getValueAsString("Name")].push_back(R);
  34     else
  35       OptionsByGroup["options"].push_back(R);
  36   }
  37
  38   // Print options under their group.
  39   for (const auto &KV : OptionsByGroup) {
  40     std::string GroupName = KV.getKey().upper();
  41     OS << GroupName << '\n';
  42     OS << std::string(GroupName.size(), '-') << '\n';
  43     OS << '\n';
  44
  45     for (const Record *R : KV.getValue()) {
  46       OS << ".. option:: ";
  47
  48       // Print the prefix.
  49       std::vector<StringRef> Prefixes = R->getValueAsListOfStrings("Prefixes");
  50       if (!Prefixes.empty())
  51         OS << Prefixes[0];
  52
  53       // Print the option name.
  54       OS << R->getValueAsString("Name");
  55
  56       StringRef MetaVarName;
  57       // Print the meta-variable.
  58       if (!isa<UnsetInit>(R->getValueInit("MetaVarName"))) {
  59         MetaVarName = R->getValueAsString("MetaVarName");
  60       } else if (!isa<UnsetInit>(R->getValueInit("Values")))
  61         MetaVarName = "<value>";
  62
  63       if (!MetaVarName.empty()) {
  64         OS << '=';
  65         OS.write_escaped(MetaVarName);
  66       }
  67
  68       OS << "\n\n";
  69
  70       std::string HelpText;
  71       // The option help text.
  72       if (!isa<UnsetInit>(R->getValueInit("HelpText"))) {
  73         HelpText = R->getValueAsString("HelpText").trim().str();
  74         if (!HelpText.empty() && HelpText.back() != '.')
  75           HelpText.push_back('.');
  76       }
  77
  78       if (!isa<UnsetInit>(R->getValueInit("Values"))) {
  79         SmallVector<StringRef> Values;
  80         SplitString(R->getValueAsString("Values"), Values, ",");
  81         HelpText += (" " + MetaVarName + " must be '").str();
  82
  83         if (Values.size() > 1) {
  84           HelpText += join(Values.begin(), Values.end() - 1, "', '");
  85           HelpText += "' or '";
  86         }
  87         HelpText += (Values.back() + "'.").str();
  88       }
  89
  90       if (!HelpText.empty()) {
  91         OS << ' ';
  92         OS.write_escaped(HelpText);
  93         OS << "\n\n";
  94       }
  95     }
  96   }
  97 }
  98
  99 static TableGen::Emitter::Opt X("gen-opt-rst", emitOptionRst,
 100                                 "Generate option RST");