1 //===- lib/Linker/LinkItems.cpp - Link LLVM objects and libraries ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains routines to handle linking together LLVM bitcode files,
11 // and to handle annoying things like static libraries.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Linker.h"
16 #include "llvm/Bitcode/ReaderWriter.h"
17 #include "llvm/Module.h"
18 #include "llvm/Support/ErrorHandling.h"
19 #include "llvm/Support/MemoryBuffer.h"
20 #include "llvm/Support/Path.h"
21 #include "llvm/Support/system_error.h"
24 // LinkItems - This function is the main entry point into linking. It takes a
25 // list of LinkItem which indicates the order the files should be linked and
26 // how each file should be treated (plain file or with library search). The
27 // function only links bitcode and produces a result list of items that are
30 Linker::LinkInItems(const ItemList& Items, ItemList& NativeItems) {
31 // Clear the NativeItems just in case
34 // For each linkage item ...
35 for (ItemList::const_iterator I = Items.begin(), E = Items.end();
38 // Link in the library suggested.
39 bool is_native = false;
40 if (LinkInLibrary(I->first, is_native))
43 NativeItems.push_back(*I);
45 // Link in the file suggested
46 bool is_native = false;
47 if (LinkInFile(sys::Path(I->first), is_native))
50 NativeItems.push_back(*I);
58 /// LinkInLibrary - links one library into the HeadModule.
60 bool Linker::LinkInLibrary(StringRef Lib, bool& is_native) {
62 // Determine where this library lives.
63 sys::Path Pathname = FindLib(Lib);
64 if (Pathname.isEmpty())
65 return error("Cannot find library '" + Lib.str() + "'");
67 // If its an archive, try to link it in
69 Pathname.getMagicNumber(Magic, 64);
70 switch (sys::IdentifyFileType(Magic.c_str(), 64)) {
71 default: llvm_unreachable("Bad file type identification");
72 case sys::Unknown_FileType:
73 return warning("Supposed library '" + Lib.str() + "' isn't a library.");
75 case sys::Bitcode_FileType:
77 if (LinkInFile(Pathname, is_native))
81 case sys::Archive_FileType:
82 if (LinkInArchive(Pathname, is_native))
83 return error("Cannot link archive '" + Pathname.str() + "'");
86 case sys::ELF_Relocatable_FileType:
87 case sys::ELF_SharedObject_FileType:
88 case sys::Mach_O_Object_FileType:
89 case sys::Mach_O_FixedVirtualMemorySharedLib_FileType:
90 case sys::Mach_O_DynamicallyLinkedSharedLib_FileType:
91 case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType:
92 case sys::COFF_FileType:
99 /// LinkLibraries - takes the specified library files and links them into the
100 /// main bitcode object file.
103 /// Libraries - The list of libraries to link into the module.
106 /// FALSE - No error.
109 bool Linker::LinkInLibraries(const std::vector<std::string> &Libraries) {
111 // Process the set of libraries we've been provided.
112 bool is_native = false;
113 for (unsigned i = 0; i < Libraries.size(); ++i)
114 if (LinkInLibrary(Libraries[i], is_native))
120 /// LinkInFile - opens a bitcode file and links in all objects which
121 /// provide symbols that are currently undefined.
124 /// File - The pathname of the bitcode file.
127 /// ErrorMessage - A C++ string detailing what error occurred, if any.
130 /// TRUE - An error occurred.
131 /// FALSE - No errors.
133 bool Linker::LinkInFile(const sys::Path &File, bool &is_native) {
136 // Check for a file of name "-", which means "read standard input"
137 if (File.str() == "-") {
138 std::auto_ptr<Module> M;
139 OwningPtr<MemoryBuffer> Buffer;
141 if (!(ec = MemoryBuffer::getSTDIN(Buffer))) {
142 if (!Buffer->getBufferSize()) {
143 Error = "standard input is empty";
145 M.reset(ParseBitcodeFile(Buffer.get(), Context, &Error));
147 if (!LinkInModule(M.get(), &Error))
151 return error("Cannot link stdin: " + ec.message());
154 // Determine what variety of file it is.
156 if (!File.getMagicNumber(Magic, 64))
157 return error("Cannot find linker input '" + File.str() + "'");
159 switch (sys::IdentifyFileType(Magic.c_str(), 64)) {
160 default: llvm_unreachable("Bad file type identification");
161 case sys::Unknown_FileType:
162 return warning("Ignoring file '" + File.str() +
163 "' because does not contain bitcode.");
165 case sys::Archive_FileType:
166 // A user may specify an ar archive without -l, perhaps because it
167 // is not installed as a library. Detect that and link the archive.
168 if (LinkInArchive(File, is_native))
172 case sys::Bitcode_FileType: {
173 verbose("Linking bitcode file '" + File.str() + "'");
174 std::auto_ptr<Module> M(LoadObject(File));
176 return error("Cannot load file '" + File.str() + "': " + Error);
177 if (LinkInModule(M.get(), &Error))
178 return error("Cannot link file '" + File.str() + "': " + Error);
180 verbose("Linked in file '" + File.str() + "'");
184 case sys::ELF_Relocatable_FileType:
185 case sys::ELF_SharedObject_FileType:
186 case sys::Mach_O_Object_FileType:
187 case sys::Mach_O_FixedVirtualMemorySharedLib_FileType:
188 case sys::Mach_O_DynamicallyLinkedSharedLib_FileType:
189 case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType:
190 case sys::COFF_FileType:
197 /// LinkFiles - takes a module and a list of files and links them all together.
198 /// It locates the file either in the current directory, as its absolute
199 /// or relative pathname, or as a file somewhere in LLVM_LIB_SEARCH_PATH.
202 /// Files - A vector of sys::Path indicating the LLVM bitcode filenames
203 /// to be linked. The names can refer to a mixture of pure LLVM
204 /// bitcode files and archive (ar) formatted files.
207 /// FALSE - No errors.
208 /// TRUE - Some error occurred.
210 bool Linker::LinkInFiles(const std::vector<sys::Path> &Files) {
212 for (unsigned i = 0; i < Files.size(); ++i)
213 if (LinkInFile(Files[i], is_native))