1 //===- OptParserEmitter.cpp - Table Driven Command Line 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 "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 /// OptParserEmitter - This tablegen backend takes an input .td file
18 /// describing a list of options and emits a RST man page.
19 static void EmitOptRST(RecordKeeper &Records, raw_ostream &OS) {
20   llvm::StringMap<std::vector<Record *>> OptionsByGroup;
21   std::vector<Record *> OptionsWithoutGroup;
22 
23   // Get the options.
24   std::vector<Record *> Opts = Records.getAllDerivedDefinitions("Option");
25   array_pod_sort(Opts.begin(), Opts.end(), CompareOptionRecords);
26 
27   // Get the option groups.
28   const std::vector<Record *> &Groups =
29       Records.getAllDerivedDefinitions("OptionGroup");
30   for (unsigned i = 0, e = Groups.size(); i != e; ++i) {
31     const Record &R = *Groups[i];
32     OptionsByGroup.try_emplace(R.getValueAsString("Name"));
33   }
34 
35   // Map options to their group.
36   for (unsigned i = 0, e = Opts.size(); i != e; ++i) {
37     const Record &R = *Opts[i];
38     if (const DefInit *DI = dyn_cast<DefInit>(R.getValueInit("Group"))) {
39       OptionsByGroup[DI->getDef()->getValueAsString("Name")].push_back(Opts[i]);
40     } else {
41       OptionsByGroup["options"].push_back(Opts[i]);
42     }
43   }
44 
45   // Print options under their group.
46   for (const auto &KV : OptionsByGroup) {
47     std::string GroupName = KV.getKey().upper();
48     OS << GroupName << '\n';
49     OS << std::string(GroupName.size(), '-') << '\n';
50     OS << '\n';
51 
52     for (Record *R : KV.getValue()) {
53       OS << ".. option:: ";
54 
55       // Print the prefix.
56       std::vector<StringRef> Prefixes = R->getValueAsListOfStrings("Prefixes");
57       if (!Prefixes.empty())
58         OS << Prefixes[0];
59 
60       // Print the option name.
61       OS << R->getValueAsString("Name");
62 
63       StringRef MetaVarName;
64       // Print the meta-variable.
65       if (!isa<UnsetInit>(R->getValueInit("MetaVarName"))) {
66         MetaVarName = R->getValueAsString("MetaVarName");
67       } else if (!isa<UnsetInit>(R->getValueInit("Values")))
68         MetaVarName = "<value>";
69 
70       if (!MetaVarName.empty()) {
71         OS << '=';
72         OS.write_escaped(MetaVarName);
73       }
74 
75       OS << "\n\n";
76 
77       std::string HelpText;
78       // The option help text.
79       if (!isa<UnsetInit>(R->getValueInit("HelpText"))) {
80         HelpText = R->getValueAsString("HelpText").trim().str();
81         if (!HelpText.empty() && HelpText.back() != '.')
82           HelpText.push_back('.');
83       }
84 
85       if (!isa<UnsetInit>(R->getValueInit("Values"))) {
86         SmallVector<StringRef> Values;
87         SplitString(R->getValueAsString("Values"), Values, ",");
88         HelpText += (" " + MetaVarName + " must be '").str();
89 
90         if (Values.size() > 1) {
91           HelpText += join(Values.begin(), Values.end() - 1, "', '");
92           HelpText += "' or '";
93         }
94         HelpText += (Values.back() + "'.").str();
95       }
96 
97       if (!HelpText.empty()) {
98         OS << ' ';
99         OS.write_escaped(HelpText);
100         OS << "\n\n";
101       }
102     }
103   }
104 }
105 
106 static TableGen::Emitter::Opt X("gen-opt-rst", EmitOptRST,
107                                 "Generate option RST");
108