1//===---- llvm/Support/IRReader.h - Reader for LLVM IR files ----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines functions for reading LLVM IR. They support both
11// Bitcode and Assembly, automatically detecting the input format.
12//
13// These functions must be defined in a header file in order to avoid
14// library dependencies, since they reference both Bitcode and Assembly
15// functions.
16//
17//===----------------------------------------------------------------------===//
18
19#ifndef LLVM_SUPPORT_IRREADER_H
20#define LLVM_SUPPORT_IRREADER_H
21
22#include "llvm/ADT/OwningPtr.h"
23#include "llvm/Assembly/Parser.h"
24#include "llvm/Bitcode/ReaderWriter.h"
25#include "llvm/Support/MemoryBuffer.h"
26#include "llvm/Support/SourceMgr.h"
27#include "llvm/Support/system_error.h"
28
29namespace llvm {
30
31  /// If the given MemoryBuffer holds a bitcode image, return a Module for it
32  /// which does lazy deserialization of function bodies.  Otherwise, attempt to
33  /// parse it as LLVM Assembly and return a fully populated Module. This
34  /// function *always* takes ownership of the given MemoryBuffer.
35  inline Module *getLazyIRModule(MemoryBuffer *Buffer,
36                                 SMDiagnostic &Err,
37                                 LLVMContext &Context) {
38    if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
39                  (const unsigned char *)Buffer->getBufferEnd())) {
40      std::string ErrMsg;
41      Module *M = getLazyBitcodeModule(Buffer, Context, &ErrMsg);
42      if (M == 0) {
43        Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
44                           ErrMsg);
45        // ParseBitcodeFile does not take ownership of the Buffer in the
46        // case of an error.
47        delete Buffer;
48      }
49      return M;
50    }
51
52    return ParseAssembly(Buffer, 0, Err, Context);
53  }
54
55  /// If the given file holds a bitcode image, return a Module
56  /// for it which does lazy deserialization of function bodies.  Otherwise,
57  /// attempt to parse it as LLVM Assembly and return a fully populated
58  /// Module.
59  inline Module *getLazyIRFileModule(const std::string &Filename,
60                                     SMDiagnostic &Err,
61                                     LLVMContext &Context) {
62    OwningPtr<MemoryBuffer> File;
63    if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename.c_str(), File)) {
64      Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
65                         "Could not open input file: " + ec.message());
66      return 0;
67    }
68
69    return getLazyIRModule(File.take(), Err, Context);
70  }
71
72  /// If the given MemoryBuffer holds a bitcode image, return a Module
73  /// for it.  Otherwise, attempt to parse it as LLVM Assembly and return
74  /// a Module for it. This function *always* takes ownership of the given
75  /// MemoryBuffer.
76  inline Module *ParseIR(MemoryBuffer *Buffer,
77                         SMDiagnostic &Err,
78                         LLVMContext &Context) {
79    if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
80                  (const unsigned char *)Buffer->getBufferEnd())) {
81      std::string ErrMsg;
82      Module *M = ParseBitcodeFile(Buffer, Context, &ErrMsg);
83      if (M == 0)
84        Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
85                           ErrMsg);
86      // ParseBitcodeFile does not take ownership of the Buffer.
87      delete Buffer;
88      return M;
89    }
90
91    return ParseAssembly(Buffer, 0, Err, Context);
92  }
93
94  /// If the given file holds a bitcode image, return a Module for it.
95  /// Otherwise, attempt to parse it as LLVM Assembly and return a Module
96  /// for it.
97  inline Module *ParseIRFile(const std::string &Filename,
98                             SMDiagnostic &Err,
99                             LLVMContext &Context) {
100    OwningPtr<MemoryBuffer> File;
101    if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename.c_str(), File)) {
102      Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
103                         "Could not open input file: " + ec.message());
104      return 0;
105    }
106
107    return ParseIR(File.take(), Err, Context);
108  }
109
110}
111
112#endif
113