[llvm-commits] CVS: llvm/tools/gccld/gccld.cpp
Chris Lattner
lattner at cs.uiuc.edu
Sat Apr 19 17:45:01 PDT 2003
Changes in directory llvm/tools/gccld:
gccld.cpp updated: 1.25 -> 1.26
---
Log message:
Add first support for linking in .a files correctly and minimally, like a real linker does
---
Diffs of the changes:
Index: llvm/tools/gccld/gccld.cpp
diff -u llvm/tools/gccld/gccld.cpp:1.25 llvm/tools/gccld/gccld.cpp:1.26
--- llvm/tools/gccld/gccld.cpp:1.25 Fri Apr 18 18:38:22 2003
+++ llvm/tools/gccld/gccld.cpp Sat Apr 19 17:44:38 2003
@@ -1,8 +1,7 @@
-//===----------------------------------------------------------------------===//
-// LLVM 'GCCLD' UTILITY
+//===- gccld.cpp - LLVM 'ld' compatible linker ----------------------------===//
//
// This utility is intended to be compatible with GCC, and follows standard
-// system ld conventions. As such, the default output file is ./a.out.
+// system 'ld' conventions. As such, the default output file is ./a.out.
// Additionally, this program outputs a shell script that is used to invoke LLI
// to execute the program. In this manner, the generated executable (a.out for
// example), is directly executable, whereas the bytecode file actually lives in
@@ -25,6 +24,7 @@
#include "Support/Signals.h"
#include <fstream>
#include <memory>
+#include <set>
#include <algorithm>
#include <sys/types.h> // For FileExists
#include <sys/stat.h>
@@ -56,6 +56,10 @@
NoInternalize("disable-internalize",
cl::desc("Do not mark all symbols as internal"));
+ cl::opt<bool>
+ LinkAsLibrary("link-as-library", cl::desc("Link the .bc files together as a"
+ " library, not an executable"));
+
// Compatibility options that are ignored, but support by LD
cl::opt<std::string>
CO3("soname", cl::Hidden, cl::desc("Compatibility option: ignored"));
@@ -71,74 +75,241 @@
return stat(FN.c_str(), &StatBuf) != -1;
}
-// LoadFile - Read the specified bytecode file in and return it. This routine
-// searches the link path for the specified file to try to find it...
-//
-static inline std::auto_ptr<Module> LoadFile(const std::string &FN) {
- std::string Filename = FN;
+
+// LoadObject - Read the specified "object file", which should not search the
+// library path to find it.
+static inline std::auto_ptr<Module> LoadObject(const std::string &FN,
+ std::string &OutErrorMessage) {
+ if (Verbose) std::cerr << "Loading '" << FN << "'\n";
+ if (!FileExists(FN)) {
+ OutErrorMessage = "could not find input file '" + FN + "'!";
+ return std::auto_ptr<Module>();
+ }
+
std::string ErrorMessage;
+ Module *Result = ParseBytecodeFile(FN, &ErrorMessage);
+ if (Result) return std::auto_ptr<Module>(Result);
- unsigned NextLibPathIdx = 0;
- bool FoundAFile = false;
+ OutErrorMessage = "Bytecode file '" + FN + "' corrupt!";
+ if (ErrorMessage.size()) OutErrorMessage += ": " + ErrorMessage;
+ return std::auto_ptr<Module>();
+}
- while (1) {
- if (Verbose) std::cerr << "Loading '" << Filename << "'\n";
- if (FileExists(Filename)) FoundAFile = true;
- Module *Result = ParseBytecodeFile(Filename, &ErrorMessage);
- if (Result) return std::auto_ptr<Module>(Result); // Load successful!
+
+static Module *LoadSingleLibraryObject(const std::string &Filename) {
+ std::string ErrorMessage;
+ std::auto_ptr<Module> M = LoadObject(Filename, ErrorMessage);
+ if (M.get() == 0 && Verbose) {
+ std::cerr << "Error loading '" + Filename + "'";
+ if (!ErrorMessage.empty()) std::cerr << ": " << ErrorMessage;
+ std::cerr << "\n";
+ }
+
+ return M.release();
+}
+
+
+// LoadLibraryFromDirectory - This looks for a .a, .so, or .bc file in a
+// particular directory. It returns true if no library is found, otherwise it
+// puts the loaded modules into the Objects list, and sets isArchive to true if
+// a .a file was loaded.
+//
+static inline bool LoadLibraryFromDirectory(const std::string &LibName,
+ const std::string &Directory,
+ std::vector<Module*> &Objects,
+ bool &isArchive) {
+ if (FileExists(Directory + "lib" + LibName + ".a")) {
+ std::string ErrorMessage;
+ if (Verbose) std::cerr << "Loading '" << Directory << LibName << ".a'\n";
+ if (!ReadArchiveFile(Directory + "lib" + LibName + ".a", Objects,
+ &ErrorMessage)) { // Read the archive file
+ isArchive = true;
+ return false; // Success!
+ }
if (Verbose) {
- std::cerr << "Error opening bytecode file: '" << Filename << "'";
- if (ErrorMessage.size()) std::cerr << ": " << ErrorMessage;
+ std::cerr << "Error loading archive '" + Directory + "lib"+LibName+".a'";
+ if (!ErrorMessage.empty()) std::cerr << ": " << ErrorMessage;
std::cerr << "\n";
}
-
- if (NextLibPathIdx == LibPaths.size()) break;
- Filename = LibPaths[NextLibPathIdx++] + "/" + FN;
}
- if (FoundAFile)
- std::cerr << "Bytecode file '" << FN << "' corrupt! "
- << "Use 'gccld -v ...' for more info.\n";
- else
- std::cerr << "Could not locate bytecode file: '" << FN << "'\n";
- return std::auto_ptr<Module>();
+ if (FileExists(Directory + "lib" + LibName + ".so"))
+ if (Module *M = LoadSingleLibraryObject(Directory + "lib" + LibName+".so")){
+ isArchive = false;
+ Objects.push_back(M);
+ return false;
+ }
+
+ if (FileExists(Directory + "lib" + LibName + ".bc"))
+ if (Module *M = LoadSingleLibraryObject(Directory + "lib" + LibName+".bc")){
+ isArchive = false;
+ Objects.push_back(M);
+ return false;
+ }
+ return true;
}
+// LoadLibrary - This searches for a .a, .so, or .bc file which provides the
+// LLVM bytecode for the library. It returns true if no library is found,
+// otherwise it puts the loaded modules into the Objects list, and sets
+// isArchive to true if a .a file was loaded.
+//
+static inline bool LoadLibrary(const std::string &LibName,
+ std::vector<Module*> &Objects, bool &isArchive,
+ std::string &ErrorMessage) {
+ std::string Directory;
+ unsigned NextLibPathIdx = 0;
-int main(int argc, char **argv) {
- cl::ParseCommandLineOptions(argc, argv, " llvm linker for GCC\n");
+ while (1) {
+ // Try loading from the current directory...
+ if (Verbose) std::cerr << " Looking in directory '" << Directory << "'\n";
+ if (!LoadLibraryFromDirectory(LibName, Directory, Objects, isArchive))
+ return false;
- unsigned BaseArg = 0;
- std::string ErrorMessage;
+ if (NextLibPathIdx == LibPaths.size()) break;
+ Directory = LibPaths[NextLibPathIdx++]+"/";
+ }
- if (!Libraries.empty()) {
- // Sort libraries list...
- std::sort(Libraries.begin(), Libraries.end());
+ ErrorMessage = "error linking library '-l" + LibName+ "': library not found!";
+ return true;
+}
- // Remove duplicate libraries entries...
- Libraries.erase(unique(Libraries.begin(), Libraries.end()),
- Libraries.end());
+static void GetAllDefinedSymbols(Module *M,
+ std::set<std::string> &DefinedSymbols) {
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+}
- // Add all of the libraries to the end of the link line...
- for (unsigned i = 0; i < Libraries.size(); ++i)
- InputFilenames.push_back("lib" + Libraries[i] + ".bc");
+// GetAllUndefinedSymbols - This calculates the set of undefined symbols that
+// still exist in an LLVM module. This is a bit tricky because there may be two
+// symbols with the same name, but different LLVM types that will be resolved to
+// each other, but aren't currently (thus we need to treat it as resolved).
+//
+static void GetAllUndefinedSymbols(Module *M,
+ std::set<std::string> &UndefinedSymbols) {
+ std::set<std::string> DefinedSymbols;
+ UndefinedSymbols.clear(); // Start out empty
+
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ if (I->hasName()) {
+ if (I->isExternal())
+ UndefinedSymbols.insert(I->getName());
+ else if (!I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ }
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ if (I->hasName()) {
+ if (I->isExternal())
+ UndefinedSymbols.insert(I->getName());
+ else if (!I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ }
+
+ // Prune out any defined symbols from the undefined symbols set...
+ for (std::set<std::string>::iterator I = UndefinedSymbols.begin();
+ I != UndefinedSymbols.end(); )
+ if (DefinedSymbols.count(*I))
+ UndefinedSymbols.erase(I++); // This symbol really is defined!
+ else
+ ++I; // Keep this symbol in the undefined symbols list
+}
+
+
+static bool LinkLibrary(Module *M, const std::string &LibName,
+ std::string &ErrorMessage) {
+ std::vector<Module*> Objects;
+ bool isArchive;
+ if (LoadLibrary(LibName, Objects, isArchive, ErrorMessage)) return true;
+
+ // Figure out which symbols are defined by all of the modules in the .a file
+ std::vector<std::set<std::string> > DefinedSymbols;
+ DefinedSymbols.resize(Objects.size());
+ for (unsigned i = 0; i != Objects.size(); ++i)
+ GetAllDefinedSymbols(Objects[i], DefinedSymbols[i]);
+
+ std::set<std::string> UndefinedSymbols;
+ GetAllUndefinedSymbols(M, UndefinedSymbols);
+
+ bool Linked = true;
+ while (Linked) { // While we are linking in object files, loop.
+ Linked = false;
+
+ for (unsigned i = 0; i != Objects.size(); ++i) {
+ // Consider whether we need to link in this module... we only need to
+ // link it in if it defines some symbol which is so far undefined.
+ //
+ const std::set<std::string> &DefSymbols = DefinedSymbols[i];
+
+ bool ObjectRequired = false;
+ for (std::set<std::string>::iterator I = UndefinedSymbols.begin(),
+ E = UndefinedSymbols.end(); I != E; ++I)
+ if (DefSymbols.count(*I)) {
+ if (Verbose)
+ std::cerr << " Found object providing symbol '" << *I << "'...\n";
+ ObjectRequired = true;
+ break;
+ }
+
+ // We DO need to link this object into the program...
+ if (ObjectRequired) {
+ if (LinkModules(M, Objects[i], &ErrorMessage))
+ return true; // Couldn't link in the right object file...
+
+ // Since we have linked in this object, delete it from the list of
+ // objects to consider in this archive file.
+ std::swap(Objects[i], Objects.back());
+ std::swap(DefinedSymbols[i], DefinedSymbols.back());
+ Objects.pop_back();
+ DefinedSymbols.pop_back();
+ --i; // Do not skip an entry
+
+ // The undefined symbols set should have shrunk.
+ GetAllUndefinedSymbols(M, UndefinedSymbols);
+ Linked = true; // We have linked something in!
+ }
+ }
}
+
+ return false;
+}
+
+static int PrintAndReturn(const char *progname, const std::string &Message,
+ const std::string &Extra = "") {
+ std::cerr << progname << Extra << ": " << Message << "\n";
+ return 1;
+}
- std::auto_ptr<Module> Composite(LoadFile(InputFilenames[BaseArg]));
- if (Composite.get() == 0) return 1;
- for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
- std::auto_ptr<Module> M(LoadFile(InputFilenames[i]));
- if (M.get() == 0) return 1;
+int main(int argc, char **argv) {
+ cl::ParseCommandLineOptions(argc, argv, " llvm linker for GCC\n");
+
+ std::string ErrorMessage;
+ std::auto_ptr<Module> Composite(LoadObject(InputFilenames[0], ErrorMessage));
+ if (Composite.get() == 0)
+ return PrintAndReturn(argv[0], ErrorMessage);
+
+ for (unsigned i = 1; i < InputFilenames.size(); ++i) {
+ std::auto_ptr<Module> M(LoadObject(InputFilenames[i], ErrorMessage));
+ if (M.get() == 0)
+ return PrintAndReturn(argv[0], ErrorMessage);
if (Verbose) std::cerr << "Linking in '" << InputFilenames[i] << "'\n";
- if (LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
- std::cerr << argv[0] << ": error linking in '" << InputFilenames[i]
- << "': " << ErrorMessage << "\n";
- return 1;
- }
+ if (LinkModules(Composite.get(), M.get(), &ErrorMessage))
+ return PrintAndReturn(argv[0], ErrorMessage,
+ ": error linking in '" + InputFilenames[i] + "'");
+ }
+
+ // Link in all of the libraries next...
+ for (unsigned i = 0; i != Libraries.size(); ++i) {
+ if (Verbose) std::cerr << "Linking in library: -l" << Libraries[i] << "\n";
+ if (LinkLibrary(Composite.get(), Libraries[i], ErrorMessage))
+ return PrintAndReturn(argv[0], ErrorMessage);
}
// In addition to just linking the input from GCC, we also want to spiff it up
@@ -178,33 +349,33 @@
Passes.add(createGlobalDCEPass());
// Add the pass that writes bytecode to the output file...
- std::ofstream Out((OutputFilename+".bc").c_str());
- if (!Out.good()) {
- std::cerr << argv[0] << ": error opening '" << OutputFilename
- << ".bc' for writing!\n";
- return 1;
- }
+ std::string RealBytecodeOutput = OutputFilename;
+ if (!LinkAsLibrary) RealBytecodeOutput += ".bc";
+ std::ofstream Out(RealBytecodeOutput.c_str());
+ if (!Out.good())
+ return PrintAndReturn(argv[0], "error opening '" + RealBytecodeOutput +
+ "' for writing!");
Passes.add(new WriteBytecodePass(&Out)); // Write bytecode to file...
// Make sure that the Out file gets unlink'd from the disk if we get a SIGINT
- RemoveFileOnSignal(OutputFilename+".bc");
+ RemoveFileOnSignal(RealBytecodeOutput);
// Run our queue of passes all at once now, efficiently.
Passes.run(*Composite.get());
Out.close();
- // Output the script to start the program...
- std::ofstream Out2(OutputFilename.c_str());
- if (!Out2.good()) {
- std::cerr << argv[0] << ": error opening '" << OutputFilename
- << "' for writing!\n";
- return 1;
- }
- Out2 << "#!/bin/sh\nlli -q -abort-on-exception $0.bc $*\n";
- Out2.close();
+ if (!LinkAsLibrary) {
+ // Output the script to start the program...
+ std::ofstream Out2(OutputFilename.c_str());
+ if (!Out2.good())
+ return PrintAndReturn(argv[0], "error opening '" + OutputFilename +
+ "' for writing!");
+ Out2 << "#!/bin/sh\nlli -q -abort-on-exception $0.bc $*\n";
+ Out2.close();
- // Make the script executable...
- chmod(OutputFilename.c_str(), 0755);
+ // Make the script executable...
+ chmod(OutputFilename.c_str(), 0755);
+ }
return 0;
}
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