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 std::unique_ptr<Module>
33 getLazyIRModule(std::unique_ptr<MemoryBuffer> Buffer, SMDiagnostic &Err,
34                 LLVMContext &Context) {
35   if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
36                 (const unsigned char *)Buffer->getBufferEnd())) {
37     std::string ErrMsg;
38     ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModule(Buffer.get(), Context);
39     if (std::error_code EC = ModuleOrErr.getError()) {
40       Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
41                          EC.message());
42       return nullptr;
43     }
44     // getLazyBitcodeModule takes ownership of the Buffer when successful.
45     Buffer.release();
46     return std::unique_ptr<Module>(ModuleOrErr.get());
47   }
48 
49   return parseAssembly(std::move(Buffer), Err, Context);
50 }
51 
52 std::unique_ptr<Module> llvm::getLazyIRFileModule(StringRef Filename,
53                                                   SMDiagnostic &Err,
54                                                   LLVMContext &Context) {
55   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
56       MemoryBuffer::getFileOrSTDIN(Filename);
57   if (std::error_code EC = FileOrErr.getError()) {
58     Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
59                        "Could not open input file: " + EC.message());
60     return nullptr;
61   }
62 
63   return getLazyIRModule(std::move(FileOrErr.get()), Err, Context);
64 }
65 
66 std::unique_ptr<Module> llvm::parseIR(MemoryBuffer *Buffer, SMDiagnostic &Err,
67                                       LLVMContext &Context) {
68   NamedRegionTimer T(TimeIRParsingName, TimeIRParsingGroupName,
69                      TimePassesIsEnabled);
70   if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
71                 (const unsigned char *)Buffer->getBufferEnd())) {
72     ErrorOr<Module *> ModuleOrErr = parseBitcodeFile(Buffer, Context);
73     if (std::error_code EC = ModuleOrErr.getError()) {
74       Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
75                          EC.message());
76       return nullptr;
77     }
78     return std::unique_ptr<Module>(ModuleOrErr.get());
79   }
80 
81   return parseAssembly(std::unique_ptr<MemoryBuffer>(MemoryBuffer::getMemBuffer(
82                            Buffer->getBuffer(), Buffer->getBufferIdentifier())),
83                        Err, Context);
84 }
85 
86 std::unique_ptr<Module> llvm::parseIRFile(StringRef 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)).release());
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