LLVM 18.0.0git
Main.cpp
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1//===- Main.cpp - Top-Level TableGen implementation -----------------------===//
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// TableGen is a tool which can be used to build up a description of something,
10// then invoke one or more "tablegen backends" to emit information about the
11// description in some predefined format. In practice, this is used by the LLVM
12// code generators to automate generation of a code generator through a
13// high-level description of the target.
14//
15//===----------------------------------------------------------------------===//
16
17#include "llvm/TableGen/Main.h"
18#include "TGLexer.h"
19#include "TGParser.h"
20#include "llvm/ADT/StringRef.h"
21#include "llvm/ADT/Twine.h"
26#include "llvm/Support/SMLoc.h"
30#include "llvm/TableGen/Error.h"
33#include <memory>
34#include <string>
35#include <system_error>
36#include <utility>
37#include <vector>
38using namespace llvm;
39
41OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"),
42 cl::init("-"));
43
46 cl::desc("Dependency filename"),
47 cl::value_desc("filename"),
48 cl::init(""));
49
52
54IncludeDirs("I", cl::desc("Directory of include files"),
55 cl::value_desc("directory"), cl::Prefix);
56
58MacroNames("D", cl::desc("Name of the macro to be defined"),
59 cl::value_desc("macro name"), cl::Prefix);
60
61static cl::opt<bool>
62WriteIfChanged("write-if-changed", cl::desc("Only write output if it changed"));
63
64static cl::opt<bool>
65TimePhases("time-phases", cl::desc("Time phases of parser and backend"));
66
68 "no-warn-on-unused-template-args",
69 cl::desc("Disable unused template argument warnings."));
70
71static int reportError(const char *ProgName, Twine Msg) {
72 errs() << ProgName << ": " << Msg;
73 errs().flush();
74 return 1;
75}
76
77/// Create a dependency file for `-d` option.
78///
79/// This functionality is really only for the benefit of the build system.
80/// It is similar to GCC's `-M*` family of options.
81static int createDependencyFile(const TGParser &Parser, const char *argv0) {
82 if (OutputFilename == "-")
83 return reportError(argv0, "the option -d must be used together with -o\n");
84
85 std::error_code EC;
87 if (EC)
88 return reportError(argv0, "error opening " + DependFilename + ":" +
89 EC.message() + "\n");
90 DepOut.os() << OutputFilename << ":";
91 for (const auto &Dep : Parser.getDependencies()) {
92 DepOut.os() << ' ' << Dep;
93 }
94 DepOut.os() << "\n";
95 DepOut.keep();
96 return 0;
97}
98
99int llvm::TableGenMain(const char *argv0,
100 std::function<TableGenMainFn> MainFn) {
101 RecordKeeper Records;
102
103 if (TimePhases)
104 Records.startPhaseTiming();
105
106 // Parse the input file.
107
108 Records.startTimer("Parse, build records");
111 if (std::error_code EC = FileOrErr.getError())
112 return reportError(argv0, "Could not open input file '" + InputFilename +
113 "': " + EC.message() + "\n");
114
116
117 // Tell SrcMgr about this buffer, which is what TGParser will pick up.
118 SrcMgr.AddNewSourceBuffer(std::move(*FileOrErr), SMLoc());
119
120 // Record the location of the include directory so that the lexer can find
121 // it later.
123
125
126 if (Parser.ParseFile())
127 return 1;
128 Records.stopTimer();
129
130 // Write output to memory.
131 Records.startBackendTimer("Backend overall");
132 std::string OutString;
133 raw_string_ostream Out(OutString);
134 unsigned status = 0;
136 if (ActionFn)
137 ActionFn(Records, Out);
138 else if (MainFn)
139 status = MainFn(Out, Records);
140 else
141 return 1;
142 Records.stopBackendTimer();
143 if (status)
144 return 1;
145
146 // Always write the depfile, even if the main output hasn't changed.
147 // If it's missing, Ninja considers the output dirty. If this was below
148 // the early exit below and someone deleted the .inc.d file but not the .inc
149 // file, tablegen would never write the depfile.
150 if (!DependFilename.empty()) {
151 if (int Ret = createDependencyFile(Parser, argv0))
152 return Ret;
153 }
154
155 Records.startTimer("Write output");
156 bool WriteFile = true;
157 if (WriteIfChanged) {
158 // Only updates the real output file if there are any differences.
159 // This prevents recompilation of all the files depending on it if there
160 // aren't any.
161 if (auto ExistingOrErr =
162 MemoryBuffer::getFile(OutputFilename, /*IsText=*/true))
163 if (std::move(ExistingOrErr.get())->getBuffer() == Out.str())
164 WriteFile = false;
165 }
166 if (WriteFile) {
167 std::error_code EC;
169 if (EC)
170 return reportError(argv0, "error opening " + OutputFilename + ": " +
171 EC.message() + "\n");
172 OutFile.os() << Out.str();
173 if (ErrorsPrinted == 0)
174 OutFile.keep();
175 }
176
177 Records.stopTimer();
178 Records.stopPhaseTiming();
179
180 if (ErrorsPrinted > 0)
181 return reportError(argv0, Twine(ErrorsPrinted) + " errors.\n");
182 return 0;
183}
Provides ErrorOr<T> smart pointer.
static cl::opt< bool > NoWarnOnUnusedTemplateArgs("no-warn-on-unused-template-args", cl::desc("Disable unused template argument warnings."))
static cl::list< std::string > IncludeDirs("I", cl::desc("Directory of include files"), cl::value_desc("directory"), cl::Prefix)
static int createDependencyFile(const TGParser &Parser, const char *argv0)
Create a dependency file for -d option.
Definition: Main.cpp:81
static cl::opt< bool > WriteIfChanged("write-if-changed", cl::desc("Only write output if it changed"))
static cl::opt< std::string > DependFilename("d", cl::desc("Dependency filename"), cl::value_desc("filename"), cl::init(""))
static cl::opt< std::string > OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"), cl::init("-"))
static cl::opt< bool > TimePhases("time-phases", cl::desc("Time phases of parser and backend"))
static cl::opt< std::string > InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"))
static cl::list< std::string > MacroNames("D", cl::desc("Name of the macro to be defined"), cl::value_desc("macro name"), cl::Prefix)
static int reportError(const char *ProgName, Twine Msg)
Definition: Main.cpp:71
Represents either an error or a value T.
Definition: ErrorOr.h:56
std::error_code getError() const
Definition: ErrorOr.h:152
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFileOrSTDIN(const Twine &Filename, bool IsText=false, bool RequiresNullTerminator=true, std::optional< Align > Alignment=std::nullopt)
Open the specified file as a MemoryBuffer, or open stdin if the Filename is "-".
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFile(const Twine &Filename, bool IsText=false, bool RequiresNullTerminator=true, bool IsVolatile=false, std::optional< Align > Alignment=std::nullopt)
Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful,...
void stopPhaseTiming()
Stop phase timing and print the report.
Definition: Record.h:2034
void stopBackendTimer()
Stop timing the overall backend.
Definition: Record.cpp:3170
void saveInputFilename(std::string Filename)
Definition: Record.h:1988
void startPhaseTiming()
Start phase timing; called if the –time-phases option is specified.
Definition: Record.h:2016
void stopTimer()
Stop timing a phase.
Definition: Record.cpp:3156
void startTimer(StringRef Name)
Start timing a phase. Automatically stops any previous phase timer.
Definition: Record.cpp:3141
void startBackendTimer(StringRef Name)
Start timing the overall backend.
Definition: Record.cpp:3163
Represents a location in source code.
Definition: SMLoc.h:23
void setIncludeDirs(const std::vector< std::string > &Dirs)
Definition: SourceMgr.h:106
unsigned AddNewSourceBuffer(std::unique_ptr< MemoryBuffer > F, SMLoc IncludeLoc)
Add a new source buffer to this source manager.
Definition: SourceMgr.h:144
const TGLexer::DependenciesSetTy & getDependencies() const
Definition: TGParser.h:193
bool ParseFile()
ParseFile - Main entrypoint for parsing a tblgen file.
Definition: TGParser.cpp:4276
This class contains a raw_fd_ostream and adds a few extra features commonly needed for compiler-like ...
void keep()
Indicate that the tool's job wrt this output file has been successful and the file should not be dele...
raw_fd_ostream & os()
Return the contained raw_fd_ostream.
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:642
std::string & str()
Returns the string's reference.
Definition: raw_ostream.h:660
ManagedStatic< cl::opt< FnT >, OptCreatorT > Action
void(*)(RecordKeeper &Records, raw_ostream &OS) FnT
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:445
@ OF_Text
The file should be opened in text mode on platforms like z/OS that make this distinction.
Definition: FileSystem.h:759
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
unsigned ErrorsPrinted
Definition: Error.cpp:25
SourceMgr SrcMgr
Definition: Error.cpp:24
int TableGenMain(const char *argv0, std::function< TableGenMainFn > MainFn=nullptr)
Definition: Main.cpp:99
raw_fd_ostream & errs()
This returns a reference to a raw_ostream for standard error.