1 //===---- IRReader.cpp - Reader for LLVM IR files -------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/IRReader/IRReader.h"
10 #include "llvm-c/IRReader.h"
11 #include "llvm/AsmParser/Parser.h"
12 #include "llvm/Bitcode/BitcodeReader.h"
13 #include "llvm/IR/LLVMContext.h"
14 #include "llvm/IR/Module.h"
15 #include "llvm/Support/MemoryBuffer.h"
16 #include "llvm/Support/SourceMgr.h"
17 #include "llvm/Support/Timer.h"
18 #include "llvm/Support/raw_ostream.h"
19 #include <optional>
20 #include <system_error>
21 
22 using namespace llvm;
23 
24 namespace llvm {
25   extern bool TimePassesIsEnabled;
26 }
27 
28 const char TimeIRParsingGroupName[] = "irparse";
29 const char TimeIRParsingGroupDescription[] = "LLVM IR Parsing";
30 const char TimeIRParsingName[] = "parse";
31 const char TimeIRParsingDescription[] = "Parse IR";
32 
33 std::unique_ptr<Module>
34 llvm::getLazyIRModule(std::unique_ptr<MemoryBuffer> Buffer, SMDiagnostic &Err,
35                       LLVMContext &Context, bool ShouldLazyLoadMetadata) {
36   if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
37                 (const unsigned char *)Buffer->getBufferEnd())) {
38     Expected<std::unique_ptr<Module>> ModuleOrErr = getOwningLazyBitcodeModule(
39         std::move(Buffer), Context, ShouldLazyLoadMetadata);
40     if (Error E = ModuleOrErr.takeError()) {
41       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
42         Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
43                            EIB.message());
44       });
45       return nullptr;
46     }
47     return std::move(ModuleOrErr.get());
48   }
49 
50   return parseAssembly(Buffer->getMemBufferRef(), Err, Context);
51 }
52 
53 std::unique_ptr<Module> llvm::getLazyIRFileModule(StringRef Filename,
54                                                   SMDiagnostic &Err,
55                                                   LLVMContext &Context,
56                                                   bool ShouldLazyLoadMetadata) {
57   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
58       MemoryBuffer::getFileOrSTDIN(Filename);
59   if (std::error_code EC = FileOrErr.getError()) {
60     Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
61                        "Could not open input file: " + EC.message());
62     return nullptr;
63   }
64 
65   return getLazyIRModule(std::move(FileOrErr.get()), Err, Context,
66                          ShouldLazyLoadMetadata);
67 }
68 
69 std::unique_ptr<Module> llvm::parseIR(MemoryBufferRef Buffer, SMDiagnostic &Err,
70                                       LLVMContext &Context,
71                                       ParserCallbacks Callbacks) {
72   NamedRegionTimer T(TimeIRParsingName, TimeIRParsingDescription,
73                      TimeIRParsingGroupName, TimeIRParsingGroupDescription,
74                      TimePassesIsEnabled);
75   if (isBitcode((const unsigned char *)Buffer.getBufferStart(),
76                 (const unsigned char *)Buffer.getBufferEnd())) {
77     Expected<std::unique_ptr<Module>> ModuleOrErr =
78         parseBitcodeFile(Buffer, Context, Callbacks);
79     if (Error E = ModuleOrErr.takeError()) {
80       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
81         Err = SMDiagnostic(Buffer.getBufferIdentifier(), SourceMgr::DK_Error,
82                            EIB.message());
83       });
84       return nullptr;
85     }
86     return std::move(ModuleOrErr.get());
87   }
88 
89   return parseAssembly(Buffer, Err, Context, nullptr,
90                        Callbacks.DataLayout.value_or(
91                            [](StringRef, StringRef) { return std::nullopt; }));
92 }
93 
94 std::unique_ptr<Module> llvm::parseIRFile(StringRef Filename, SMDiagnostic &Err,
95                                           LLVMContext &Context,
96                                           ParserCallbacks Callbacks) {
97   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
98       MemoryBuffer::getFileOrSTDIN(Filename, /*IsText=*/true);
99   if (std::error_code EC = FileOrErr.getError()) {
100     Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
101                        "Could not open input file: " + EC.message());
102     return nullptr;
103   }
104 
105   return parseIR(FileOrErr.get()->getMemBufferRef(), Err, Context, Callbacks);
106 }
107 
108 //===----------------------------------------------------------------------===//
109 // C API.
110 //===----------------------------------------------------------------------===//
111 
112 LLVMBool LLVMParseIRInContext(LLVMContextRef ContextRef,
113                               LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutM,
114                               char **OutMessage) {
115   SMDiagnostic Diag;
116 
117   std::unique_ptr<MemoryBuffer> MB(unwrap(MemBuf));
118   *OutM =
119       wrap(parseIR(MB->getMemBufferRef(), Diag, *unwrap(ContextRef)).release());
120 
121   if(!*OutM) {
122     if (OutMessage) {
123       std::string buf;
124       raw_string_ostream os(buf);
125 
126       Diag.print(nullptr, os, false);
127       os.flush();
128 
129       *OutMessage = strdup(buf.c_str());
130     }
131     return 1;
132   }
133 
134   return 0;
135 }
136