LLVM  16.0.0git
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 "TGParser.h"
23 #include "llvm/TableGen/Error.h"
24 #include "llvm/TableGen/Record.h"
25 #include <algorithm>
26 #include <system_error>
27 using namespace llvm;
28 
30 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"),
31  cl::init("-"));
32 
34 DependFilename("d",
35  cl::desc("Dependency filename"),
36  cl::value_desc("filename"),
37  cl::init(""));
38 
40 InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));
41 
43 IncludeDirs("I", cl::desc("Directory of include files"),
44  cl::value_desc("directory"), cl::Prefix);
45 
47 MacroNames("D", cl::desc("Name of the macro to be defined"),
48  cl::value_desc("macro name"), cl::Prefix);
49 
50 static cl::opt<bool>
51 WriteIfChanged("write-if-changed", cl::desc("Only write output if it changed"));
52 
53 static cl::opt<bool>
54 TimePhases("time-phases", cl::desc("Time phases of parser and backend"));
55 
57  "no-warn-on-unused-template-args",
58  cl::desc("Disable unused template argument warnings."));
59 
60 static int reportError(const char *ProgName, Twine Msg) {
61  errs() << ProgName << ": " << Msg;
62  errs().flush();
63  return 1;
64 }
65 
66 /// Create a dependency file for `-d` option.
67 ///
68 /// This functionality is really only for the benefit of the build system.
69 /// It is similar to GCC's `-M*` family of options.
70 static int createDependencyFile(const TGParser &Parser, const char *argv0) {
71  if (OutputFilename == "-")
72  return reportError(argv0, "the option -d must be used together with -o\n");
73 
74  std::error_code EC;
76  if (EC)
77  return reportError(argv0, "error opening " + DependFilename + ":" +
78  EC.message() + "\n");
79  DepOut.os() << OutputFilename << ":";
80  for (const auto &Dep : Parser.getDependencies()) {
81  DepOut.os() << ' ' << Dep;
82  }
83  DepOut.os() << "\n";
84  DepOut.keep();
85  return 0;
86 }
87 
88 int llvm::TableGenMain(const char *argv0, TableGenMainFn *MainFn) {
89  RecordKeeper Records;
90 
91  if (TimePhases)
92  Records.startPhaseTiming();
93 
94  // Parse the input file.
95 
96  Records.startTimer("Parse, build records");
99  if (std::error_code EC = FileOrErr.getError())
100  return reportError(argv0, "Could not open input file '" + InputFilename +
101  "': " + EC.message() + "\n");
102 
104 
105  // Tell SrcMgr about this buffer, which is what TGParser will pick up.
106  SrcMgr.AddNewSourceBuffer(std::move(*FileOrErr), SMLoc());
107 
108  // Record the location of the include directory so that the lexer can find
109  // it later.
111 
113 
114  if (Parser.ParseFile())
115  return 1;
116  Records.stopTimer();
117 
118  // Write output to memory.
119  Records.startBackendTimer("Backend overall");
120  std::string OutString;
121  raw_string_ostream Out(OutString);
122  unsigned status = MainFn(Out, Records);
123  Records.stopBackendTimer();
124  if (status)
125  return 1;
126 
127  // Always write the depfile, even if the main output hasn't changed.
128  // If it's missing, Ninja considers the output dirty. If this was below
129  // the early exit below and someone deleted the .inc.d file but not the .inc
130  // file, tablegen would never write the depfile.
131  if (!DependFilename.empty()) {
132  if (int Ret = createDependencyFile(Parser, argv0))
133  return Ret;
134  }
135 
136  Records.startTimer("Write output");
137  bool WriteFile = true;
138  if (WriteIfChanged) {
139  // Only updates the real output file if there are any differences.
140  // This prevents recompilation of all the files depending on it if there
141  // aren't any.
142  if (auto ExistingOrErr =
143  MemoryBuffer::getFile(OutputFilename, /*IsText=*/true))
144  if (std::move(ExistingOrErr.get())->getBuffer() == Out.str())
145  WriteFile = false;
146  }
147  if (WriteFile) {
148  std::error_code EC;
150  if (EC)
151  return reportError(argv0, "error opening " + OutputFilename + ": " +
152  EC.message() + "\n");
153  OutFile.os() << Out.str();
154  if (ErrorsPrinted == 0)
155  OutFile.keep();
156  }
157 
158  Records.stopTimer();
159  Records.stopPhaseTiming();
160 
161  if (ErrorsPrinted > 0)
162  return reportError(argv0, Twine(ErrorsPrinted) + " errors.\n");
163  return 0;
164 }
MemoryBuffer.h
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::RecordKeeper
Definition: Record.h:1867
WriteIfChanged
static cl::opt< bool > WriteIfChanged("write-if-changed", cl::desc("Only write output if it changed"))
FileSystem.h
llvm::ToolOutputFile
This class contains a raw_fd_ostream and adds a few extra features commonly needed for compiler-like ...
Definition: ToolOutputFile.h:26
llvm::cl::Prefix
@ Prefix
Definition: CommandLine.h:160
llvm::TableGenMainFn
bool(raw_ostream &OS, RecordKeeper &Records) TableGenMainFn
Perform the action using Records, and write output to OS.
Definition: Main.h:23
llvm::raw_string_ostream
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:628
llvm::ToolOutputFile::keep
void keep()
Indicate that the tool's job wrt this output file has been successful and the file should not be dele...
Definition: ToolOutputFile.h:67
reportError
static int reportError(const char *ProgName, Twine Msg)
Definition: Main.cpp:60
llvm::errs
raw_fd_ostream & errs()
This returns a reference to a raw_ostream for standard error.
Definition: raw_ostream.cpp:891
llvm::MipsISD::Ret
@ Ret
Definition: MipsISelLowering.h:119
llvm::RecordKeeper::startBackendTimer
void startBackendTimer(StringRef Name)
Start timing the overall backend.
Definition: Record.cpp:2859
CommandLine.h
InputFilename
static cl::opt< std::string > InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"))
llvm::RecordKeeper::startTimer
void startTimer(StringRef Name)
Start timing a phase. Automatically stops any previous phase timer.
Definition: Record.cpp:2837
llvm::MemoryBuffer::getFile
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFile(const Twine &Filename, bool IsText=false, bool RequiresNullTerminator=true, bool IsVolatile=false)
Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful,...
Definition: MemoryBuffer.cpp:239
llvm::SMLoc
Represents a location in source code.
Definition: SMLoc.h:23
llvm::SrcMgr
SourceMgr SrcMgr
Definition: Error.cpp:24
createDependencyFile
static int createDependencyFile(const TGParser &Parser, const char *argv0)
Create a dependency file for -d option.
Definition: Main.cpp:70
llvm::ErrorOr::getError
std::error_code getError() const
Definition: ErrorOr.h:153
llvm::RecordKeeper::stopBackendTimer
void stopBackendTimer()
Stop timing the overall backend.
Definition: Record.cpp:2866
llvm::cl::Positional
@ Positional
Definition: CommandLine.h:159
llvm::raw_ostream::flush
void flush()
Definition: raw_ostream.h:185
llvm::ErrorsPrinted
unsigned ErrorsPrinted
Definition: Error.cpp:25
llvm::RecordKeeper::startPhaseTiming
void startPhaseTiming()
Start phase timing; called if the –time-phases option is specified.
Definition: Record.h:1938
Error.h
llvm::cl::opt
Definition: CommandLine.h:1399
llvm::TGParser
Definition: TGParser.h:130
llvm::sys::fs::OF_Text
@ OF_Text
The file should be opened in text mode on platforms like z/OS that make this distinction.
Definition: FileSystem.h:761
move
compiles ldr LCPI1_0 ldr ldr mov lsr tst moveq r1 ldr LCPI1_1 and r0 bx lr It would be better to do something like to fold the shift into the conditional move
Definition: README.txt:546
llvm::MemoryBuffer::getFileOrSTDIN
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFileOrSTDIN(const Twine &Filename, bool IsText=false, bool RequiresNullTerminator=true)
Open the specified file as a MemoryBuffer, or open stdin if the Filename is "-".
Definition: MemoryBuffer.cpp:146
llvm::cl::init
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:439
ToolOutputFile.h
MacroNames
static cl::list< std::string > MacroNames("D", cl::desc("Name of the macro to be defined"), cl::value_desc("macro name"), cl::Prefix)
llvm::RecordKeeper::stopPhaseTiming
void stopPhaseTiming()
Stop phase timing and print the report.
Definition: Record.h:1956
IncludeDirs
static cl::list< std::string > IncludeDirs("I", cl::desc("Directory of include files"), cl::value_desc("directory"), cl::Prefix)
llvm::TableGenMain
int TableGenMain(const char *argv0, TableGenMainFn *MainFn)
Definition: Main.cpp:88
TimePhases
static cl::opt< bool > TimePhases("time-phases", cl::desc("Time phases of parser and backend"))
llvm::SourceMgr::setIncludeDirs
void setIncludeDirs(const std::vector< std::string > &Dirs)
Definition: SourceMgr.h:106
llvm::RecordKeeper::stopTimer
void stopTimer()
Stop timing a phase.
Definition: Record.cpp:2852
llvm::AMDGPU::SendMsg::Msg
const CustomOperand< const MCSubtargetInfo & > Msg[]
Definition: AMDGPUAsmUtils.cpp:39
llvm::Twine
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
llvm::ToolOutputFile::os
raw_fd_ostream & os()
Return the contained raw_fd_ostream.
Definition: ToolOutputFile.h:60
llvm::TGParser::getDependencies
const TGLexer::DependenciesSetTy & getDependencies() const
Definition: TGParser.h:185
llvm::SourceMgr::AddNewSourceBuffer
unsigned AddNewSourceBuffer(std::unique_ptr< MemoryBuffer > F, SMLoc IncludeLoc)
Add a new source buffer to this source manager.
Definition: SourceMgr.h:144
llvm::cl::value_desc
Definition: CommandLine.h:421
Main.h
TGParser.h
llvm::RecordKeeper::saveInputFilename
void saveInputFilename(std::string Filename)
Definition: Record.h:1910
OutputFilename
static cl::opt< std::string > OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"), cl::init("-"))
llvm::sys::fs::status
std::error_code status(const Twine &path, file_status &result, bool follow=true)
Get file status as if by POSIX stat().
llvm::ErrorOr
Represents either an error or a value T.
Definition: ErrorOr.h:56
llvm::cl::desc
Definition: CommandLine.h:412
llvm::raw_string_ostream::str
std::string & str()
Returns the string's reference.
Definition: raw_ostream.h:646
Record.h
llvm::TGParser::ParseFile
bool ParseFile()
ParseFile - Main entrypoint for parsing a tblgen file.
Definition: TGParser.cpp:3830
NoWarnOnUnusedTemplateArgs
static cl::opt< bool > NoWarnOnUnusedTemplateArgs("no-warn-on-unused-template-args", cl::desc("Disable unused template argument warnings."))
DependFilename
static cl::opt< std::string > DependFilename("d", cl::desc("Dependency filename"), cl::value_desc("filename"), cl::init(""))
llvm::cl::list
Definition: CommandLine.h:1608