1 //===- lib/Linker/LinkItems.cpp - Link LLVM objects and libraries ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Reid Spencer and is distributed under the
6 // University of Illinois Open Source 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/Module.h"
17 #include "llvm/Support/MemoryBuffer.h"
18 #include "llvm/Bitcode/ReaderWriter.h"
22 // LinkItems - This function is the main entry point into linking. It takes a
23 // list of LinkItem which indicates the order the files should be linked and
24 // how each file should be treated (plain file or with library search). The
25 // function only links bitcode and produces a result list of items that are
28 Linker::LinkInItems(const ItemList& Items, ItemList& NativeItems) {
29 // Clear the NativeItems just in case
32 // For each linkage item ...
33 for (ItemList::const_iterator I = Items.begin(), E = Items.end();
36 // Link in the library suggested.
37 bool is_native = false;
38 if (LinkInLibrary(I->first, is_native))
41 NativeItems.push_back(*I);
43 // Link in the file suggested
44 bool is_native = false;
45 if (LinkInFile(sys::Path(I->first), is_native))
48 NativeItems.push_back(*I);
52 // At this point we have processed all the link items provided to us. Since
53 // we have an aggregated module at this point, the dependent libraries in
54 // that module should also be aggregated with duplicates eliminated. This is
55 // now the time to process the dependent libraries to resolve any remaining
58 for (Module::lib_iterator I = Composite->lib_begin(),
59 E = Composite->lib_end(); I != E; ++I) {
60 if(LinkInLibrary(*I, is_native))
63 NativeItems.push_back(std::make_pair(*I, true));
70 /// LinkInLibrary - links one library into the HeadModule.
72 bool Linker::LinkInLibrary(const std::string& Lib, bool& is_native) {
74 // Determine where this library lives.
75 sys::Path Pathname = FindLib(Lib);
76 if (Pathname.isEmpty())
77 return warning("Cannot find library '" + Lib + "'");
79 // If its an archive, try to link it in
81 Pathname.getMagicNumber(Magic, 64);
82 switch (sys::IdentifyFileType(Magic.c_str(), 64)) {
83 default: assert(0 && "Bad file type identification");
84 case sys::Unknown_FileType:
85 return warning("Supposed library '" + Lib + "' isn't a library.");
87 case sys::Bitcode_FileType:
89 if (LinkInFile(Pathname, is_native))
93 case sys::Archive_FileType:
94 if (LinkInArchive(Pathname, is_native))
95 return error("Cannot link archive '" + Pathname.toString() + "'");
98 case sys::ELF_Relocatable_FileType:
99 case sys::ELF_SharedObject_FileType:
100 case sys::Mach_O_Object_FileType:
101 case sys::Mach_O_FixedVirtualMemorySharedLib_FileType:
102 case sys::Mach_O_DynamicallyLinkedSharedLib_FileType:
103 case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType:
104 case sys::COFF_FileType:
111 /// LinkLibraries - takes the specified library files and links them into the
112 /// main bitcode object file.
115 /// Libraries - The list of libraries to link into the module.
118 /// FALSE - No error.
121 bool Linker::LinkInLibraries(const std::vector<std::string> &Libraries) {
123 // Process the set of libraries we've been provided.
124 bool is_native = false;
125 for (unsigned i = 0; i < Libraries.size(); ++i)
126 if (LinkInLibrary(Libraries[i], is_native))
129 // At this point we have processed all the libraries provided to us. Since
130 // we have an aggregated module at this point, the dependent libraries in
131 // that module should also be aggregated with duplicates eliminated. This is
132 // now the time to process the dependent libraries to resolve any remaining
134 const Module::LibraryListType& DepLibs = Composite->getLibraries();
135 for (Module::LibraryListType::const_iterator I = DepLibs.begin(),
136 E = DepLibs.end(); I != E; ++I)
137 if (LinkInLibrary(*I, is_native))
143 /// LinkInFile - opens a bitcode file and links in all objects which
144 /// provide symbols that are currently undefined.
147 /// File - The pathname of the bitcode file.
150 /// ErrorMessage - A C++ string detailing what error occurred, if any.
153 /// TRUE - An error occurred.
154 /// FALSE - No errors.
156 bool Linker::LinkInFile(const sys::Path &File, bool &is_native) {
159 // Check for a file of name "-", which means "read standard input"
160 if (File.toString() == "-") {
161 std::auto_ptr<Module> M;
162 if (MemoryBuffer *Buffer = MemoryBuffer::getSTDIN()) {
163 M.reset(ParseBitcodeFile(Buffer, &Error));
166 if (!LinkInModule(M.get(), &Error))
169 Error = "standard input is empty";
170 return error("Cannot link stdin: " + Error);
173 // Make sure we can at least read the file
175 return error("Cannot find linker input '" + File.toString() + "'");
177 // If its an archive, try to link it in
179 File.getMagicNumber(Magic, 64);
180 switch (sys::IdentifyFileType(Magic.c_str(), 64)) {
181 default: assert(0 && "Bad file type identification");
182 case sys::Unknown_FileType:
183 return warning("Ignoring file '" + File.toString() +
184 "' because does not contain bitcode.");
186 case sys::Archive_FileType:
187 // A user may specify an ar archive without -l, perhaps because it
188 // is not installed as a library. Detect that and link the archive.
189 verbose("Linking archive file '" + File.toString() + "'");
190 if (LinkInArchive(File, is_native))
194 case sys::Bitcode_FileType: {
195 verbose("Linking bitcode file '" + File.toString() + "'");
196 std::auto_ptr<Module> M(LoadObject(File));
198 return error("Cannot load file '" + File.toString() + "': " + Error);
199 if (LinkInModule(M.get(), &Error))
200 return error("Cannot link file '" + File.toString() + "': " + Error);
202 verbose("Linked in file '" + File.toString() + "'");
206 case sys::ELF_Relocatable_FileType:
207 case sys::ELF_SharedObject_FileType:
208 case sys::Mach_O_Object_FileType:
209 case sys::Mach_O_FixedVirtualMemorySharedLib_FileType:
210 case sys::Mach_O_DynamicallyLinkedSharedLib_FileType:
211 case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType:
212 case sys::COFF_FileType:
219 /// LinkFiles - takes a module and a list of files and links them all together.
220 /// It locates the file either in the current directory, as its absolute
221 /// or relative pathname, or as a file somewhere in LLVM_LIB_SEARCH_PATH.
224 /// Files - A vector of sys::Path indicating the LLVM bitcode filenames
225 /// to be linked. The names can refer to a mixture of pure LLVM
226 /// bitcode files and archive (ar) formatted files.
229 /// FALSE - No errors.
230 /// TRUE - Some error occurred.
232 bool Linker::LinkInFiles(const std::vector<sys::Path> &Files) {
234 for (unsigned i = 0; i < Files.size(); ++i)
235 if (LinkInFile(Files[i], is_native))