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(), ErrMsg);
44        // ParseBitcodeFile does not take ownership of the Buffer in the
45        // case of an error.
46        delete Buffer;
47      }
48      return M;
49    }
50
51    return ParseAssembly(Buffer, 0, Err, Context);
52  }
53
54  /// If the given file holds a bitcode image, return a Module
55  /// for it which does lazy deserialization of function bodies.  Otherwise,
56  /// attempt to parse it as LLVM Assembly and return a fully populated
57  /// Module.
58  inline Module *getLazyIRFileModule(const std::string &Filename,
59                                     SMDiagnostic &Err,
60                                     LLVMContext &Context) {
61    OwningPtr<MemoryBuffer> File;
62    if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename.c_str(), File)) {
63      Err = SMDiagnostic(Filename,
64                         "Could not open input file: " + ec.message());
65      return 0;
66    }
67
68    return getLazyIRModule(File.take(), Err, Context);
69  }
70
71  /// If the given MemoryBuffer holds a bitcode image, return a Module
72  /// for it.  Otherwise, attempt to parse it as LLVM Assembly and return
73  /// a Module for it. This function *always* takes ownership of the given
74  /// MemoryBuffer.
75  inline Module *ParseIR(MemoryBuffer *Buffer,
76                         SMDiagnostic &Err,
77                         LLVMContext &Context) {
78    if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
79                  (const unsigned char *)Buffer->getBufferEnd())) {
80      std::string ErrMsg;
81      Module *M = ParseBitcodeFile(Buffer, Context, &ErrMsg);
82      if (M == 0)
83        Err = SMDiagnostic(Buffer->getBufferIdentifier(), ErrMsg);
84      // ParseBitcodeFile does not take ownership of the Buffer.
85      delete Buffer;
86      return M;
87    }
88
89    return ParseAssembly(Buffer, 0, Err, Context);
90  }
91
92  /// If the given file holds a bitcode image, return a Module for it.
93  /// Otherwise, attempt to parse it as LLVM Assembly and return a Module
94  /// for it.
95  inline Module *ParseIRFile(const std::string &Filename,
96                             SMDiagnostic &Err,
97                             LLVMContext &Context) {
98    OwningPtr<MemoryBuffer> File;
99    if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename.c_str(), File)) {
100      Err = SMDiagnostic(Filename,
101                         "Could not open input file: " + ec.message());
102      return 0;
103    }
104
105    return ParseIR(File.take(), Err, Context);
106  }
107
108}
109
110#endif
111