aboutsummaryrefslogtreecommitdiff
path: root/llvm/tools/llvm-as/llvm-as.cpp
blob: 1c869e1739319ede0748040dca1eec283311bfb9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
//===--- llvm-as.cpp - The low-level LLVM assembler -----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//  This utility may be invoked in the following manner:
//   llvm-as --help         - Output information about command line switches
//   llvm-as [options]      - Read LLVM asm from stdin, write bitcode to stdout
//   llvm-as [options] x.ll - Read LLVM asm from the x.ll file, write bitcode
//                            to the x.bc file.
//
//===----------------------------------------------------------------------===//

#include "llvm/AsmParser/Parser.h"
#include "llvm/Bitcode/BitcodeWriter.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/Support/ToolOutputFile.h"
#include <memory>
#include <optional>
using namespace llvm;

cl::OptionCategory AsCat("llvm-as Options");

static cl::opt<std::string> InputFilename(cl::Positional,
                                          cl::desc("<input .llvm file>"),
                                          cl::init("-"));

static cl::opt<std::string> OutputFilename("o",
                                           cl::desc("Override output filename"),
                                           cl::value_desc("filename"),
                                           cl::cat(AsCat));

static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals"),
                           cl::cat(AsCat));

static cl::opt<bool> DisableOutput("disable-output", cl::desc("Disable output"),
                                   cl::init(false), cl::cat(AsCat));

static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"),
                                    cl::init(false), cl::cat(AsCat));

static cl::opt<bool> DumpAsm("d", cl::desc("Print assembly as parsed"),
                             cl::Hidden, cl::cat(AsCat));

static cl::opt<bool>
    DisableVerify("disable-verify", cl::Hidden,
                  cl::desc("Do not run verifier on input LLVM (dangerous!)"),
                  cl::cat(AsCat));

static cl::opt<bool> PreserveBitcodeUseListOrder(
    "preserve-bc-uselistorder",
    cl::desc("Preserve use-list order when writing LLVM bitcode."),
    cl::init(true), cl::Hidden, cl::cat(AsCat));

static cl::opt<std::string> ClDataLayout("data-layout",
                                         cl::desc("data layout string to use"),
                                         cl::value_desc("layout-string"),
                                         cl::init(""), cl::cat(AsCat));

static void WriteOutputFile(const Module *M, const ModuleSummaryIndex *Index) {
  // Infer the output filename if needed.
  if (OutputFilename.empty()) {
    if (InputFilename == "-") {
      OutputFilename = "-";
    } else {
      StringRef IFN = InputFilename;
      OutputFilename = (IFN.ends_with(".ll") ? IFN.drop_back(3) : IFN).str();
      OutputFilename += ".bc";
    }
  }

  std::error_code EC;
  std::unique_ptr<ToolOutputFile> Out(
      new ToolOutputFile(OutputFilename, EC, sys::fs::OF_None));
  if (EC) {
    errs() << EC.message() << '\n';
    exit(1);
  }

  if (Force || !CheckBitcodeOutputToConsole(Out->os())) {
    const ModuleSummaryIndex *IndexToWrite = nullptr;
    // Don't attempt to write a summary index unless it contains any entries or
    // has non-zero flags. The latter is used to assemble dummy index files for
    // skipping modules by distributed ThinLTO backends. Otherwise we get an empty
    // summary section.
    if (Index && (Index->begin() != Index->end() || Index->getFlags()))
      IndexToWrite = Index;
    if (!IndexToWrite || (M && (!M->empty() || !M->global_empty())))
      // If we have a non-empty Module, then we write the Module plus
      // any non-null Index along with it as a per-module Index.
      // If both are empty, this will give an empty module block, which is
      // the expected behavior.
      WriteBitcodeToFile(*M, Out->os(), PreserveBitcodeUseListOrder,
                         IndexToWrite, EmitModuleHash);
    else
      // Otherwise, with an empty Module but non-empty Index, we write a
      // combined index.
      writeIndexToFile(*IndexToWrite, Out->os());
  }

  // Declare success.
  Out->keep();
}

int main(int argc, char **argv) {
  InitLLVM X(argc, argv);
  cl::HideUnrelatedOptions(AsCat);
  cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
  LLVMContext Context;

  // Parse the file now...
  SMDiagnostic Err;
  auto SetDataLayout = [](StringRef, StringRef) -> std::optional<std::string> {
    if (ClDataLayout.empty())
      return std::nullopt;
    return ClDataLayout;
  };
  ParsedModuleAndIndex ModuleAndIndex;
  if (DisableVerify) {
    ModuleAndIndex = parseAssemblyFileWithIndexNoUpgradeDebugInfo(
        InputFilename, Err, Context, nullptr, SetDataLayout);
  } else {
    ModuleAndIndex = parseAssemblyFileWithIndex(InputFilename, Err, Context,
                                                nullptr, SetDataLayout);
  }
  std::unique_ptr<Module> M = std::move(ModuleAndIndex.Mod);
  if (!M.get()) {
    Err.print(argv[0], errs());
    return 1;
  }
  std::unique_ptr<ModuleSummaryIndex> Index = std::move(ModuleAndIndex.Index);

  if (!DisableVerify) {
    std::string ErrorStr;
    raw_string_ostream OS(ErrorStr);
    if (verifyModule(*M.get(), &OS)) {
      errs() << argv[0]
             << ": assembly parsed, but does not verify as correct!\n";
      errs() << OS.str();
      return 1;
    }
    // TODO: Implement and call summary index verifier.
  }

  if (DumpAsm) {
    errs() << "Here's the assembly:\n" << *M.get();
    if (Index.get() && Index->begin() != Index->end())
      Index->print(errs());
  }

  if (!DisableOutput)
    WriteOutputFile(M.get(), Index.get());

  return 0;
}