1 //===---- IRReader.cpp - Reader for LLVM IR files -------------------------===//
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 #include "llvm/IRReader/IRReader.h"
11 #include "llvm-c/Core.h"
12 #include "llvm-c/IRReader.h"
13 #include "llvm/AsmParser/Parser.h"
14 #include "llvm/Bitcode/ReaderWriter.h"
15 #include "llvm/IR/LLVMContext.h"
16 #include "llvm/IR/Module.h"
17 #include "llvm/Support/MemoryBuffer.h"
18 #include "llvm/Support/SourceMgr.h"
19 #include "llvm/Support/Timer.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include <system_error>
22 
23 using namespace llvm;
24 
25 namespace llvm {
26   extern bool TimePassesIsEnabled;
27 }
28 
29 static const char *const TimeIRParsingGroupName = "LLVM IR Parsing";
30 static const char *const TimeIRParsingName = "Parse IR";
31 
32 static Module *getLazyIRModule(std::unique_ptr<MemoryBuffer> Buffer,
33                                SMDiagnostic &Err, LLVMContext &Context) {
34   if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
35                 (const unsigned char *)Buffer->getBufferEnd())) {
36     std::string ErrMsg;
37     ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModule(Buffer.get(), Context);
38     if (std::error_code EC = ModuleOrErr.getError()) {
39       Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
40                          EC.message());
41       return nullptr;
42     }
43     // getLazyBitcodeModule takes ownership of the Buffer when successful.
44     Buffer.release();
45     return ModuleOrErr.get();
46   }
47 
48   return ParseAssembly(Buffer.release(), nullptr, Err, Context);
49 }
50 
51 Module *llvm::getLazyIRFileModule(const std::string &Filename,
52                                   SMDiagnostic &Err, LLVMContext &Context) {
53   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
54       MemoryBuffer::getFileOrSTDIN(Filename);
55   if (std::error_code EC = FileOrErr.getError()) {
56     Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
57                        "Could not open input file: " + EC.message());
58     return nullptr;
59   }
60 
61   return getLazyIRModule(std::move(FileOrErr.get()), Err, Context);
62 }
63 
64 Module *llvm::ParseIR(MemoryBuffer *Buffer, SMDiagnostic &Err,
65                       LLVMContext &Context) {
66   NamedRegionTimer T(TimeIRParsingName, TimeIRParsingGroupName,
67                      TimePassesIsEnabled);
68   if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
69                 (const unsigned char *)Buffer->getBufferEnd())) {
70     ErrorOr<Module *> ModuleOrErr = parseBitcodeFile(Buffer, Context);
71     Module *M = nullptr;
72     if (std::error_code EC = ModuleOrErr.getError())
73       Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
74                          EC.message());
75     else
76       M = ModuleOrErr.get();
77     // parseBitcodeFile does not take ownership of the Buffer.
78     return M;
79   }
80 
81   return ParseAssembly(MemoryBuffer::getMemBuffer(
82                            Buffer->getBuffer(), Buffer->getBufferIdentifier()),
83                        nullptr, Err, Context);
84 }
85 
86 Module *llvm::ParseIRFile(const std::string &Filename, SMDiagnostic &Err,
87                           LLVMContext &Context) {
88   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
89       MemoryBuffer::getFileOrSTDIN(Filename);
90   if (std::error_code EC = FileOrErr.getError()) {
91     Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
92                        "Could not open input file: " + EC.message());
93     return nullptr;
94   }
95 
96   return ParseIR(FileOrErr.get().get(), Err, Context);
97 }
98 
99 //===----------------------------------------------------------------------===//
100 // C API.
101 //===----------------------------------------------------------------------===//
102 
103 LLVMBool LLVMParseIRInContext(LLVMContextRef ContextRef,
104                               LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutM,
105                               char **OutMessage) {
106   SMDiagnostic Diag;
107 
108   std::unique_ptr<MemoryBuffer> MB(unwrap(MemBuf));
109   *OutM = wrap(ParseIR(MB.get(), Diag, *unwrap(ContextRef)));
110 
111   if(!*OutM) {
112     if (OutMessage) {
113       std::string buf;
114       raw_string_ostream os(buf);
115 
116       Diag.print(nullptr, os, false);
117       os.flush();
118 
119       *OutMessage = strdup(buf.c_str());
120     }
121     return 1;
122   }
123 
124   return 0;
125 }
126