xref: /llvm-project/llvm/utils/TableGen/OptionRSTEmitter.cpp (revision cdacc9b5c7ec020bad24dbdcbeba96ac1d2713e5)
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");
101