Implement dependent library processing and search paths for them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16287 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-link/llvm-link.cpp

@@ -20,6 +20,8 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileUtilities.h"
 #include "llvm/System/Signals.h"
+#include "llvm/System/Path.h"
+#include "llvm/ADT/SetVector.h"
 #include <fstream>
 #include <iostream>
 #include <memory>
@@ -46,30 +48,56 @@ static cl::list<std::string>
 LibPaths("L", cl::desc("Specify a library search path"), cl::ZeroOrMore,
          cl::value_desc("directory"), cl::Prefix);
 
+static cl::list<std::string>
+Libraries("l", cl::desc("Specify library names to link with"), cl::ZeroOrMore,
+          cl::Prefix, cl::value_desc("library name"));
+
+// GetModule - This function is just factored out of the functions below
+static inline Module* GetModule(const sys::Path& Filename) {
+  if (Verbose) std::cerr << "Loading '" << Filename.c_str() << "'\n";
+  std::string ErrorMessage;
+  if (Filename.exists()) {
+    Module* Result = ParseBytecodeFile(Filename.get(), &ErrorMessage);
+    if (Result) return Result;   // Load successful!
+
+    if (Verbose) {
+      std::cerr << "Error opening bytecode file: '" << Filename.c_str() << "'";
+      if (ErrorMessage.size()) std::cerr << ": " << ErrorMessage;
+      std::cerr << "\n";
+    }
+  } else {
+    std::cerr << "Bytecode file: '" << Filename.c_str() 
+              << "' does not exist.\n";
+  }
+  return 0;
+}
+
 // 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;
-  std::string ErrorMessage;
+  sys::Path Filename;
+  if (!Filename.set_file(FN)) {
+    std::cerr << "Invalid file name: '" << Filename.c_str() << "'\n";
+    return std::auto_ptr<Module>();
+  }
+
+  if (Module* Result = GetModule(Filename)) 
+    return std::auto_ptr<Module>(Result);
 
-  unsigned NextLibPathIdx = 0;
   bool FoundAFile = false;
 
-  while (1) {
-    if (Verbose) std::cerr << "Loading '" << Filename << "'\n";
-    if (getFileSize(Filename) != -1) FoundAFile = true;
-    Module *Result = ParseBytecodeFile(Filename, &ErrorMessage);
-    if (Result) return std::auto_ptr<Module>(Result);   // Load successful!
-
-    if (Verbose) {
-      std::cerr << "Error opening bytecode file: '" << Filename << "'";
-      if (ErrorMessage.size()) std::cerr << ": " << ErrorMessage;
-      std::cerr << "\n";
+  for (unsigned i = 0; i < LibPaths.size(); i++) {
+    if (!Filename.set_directory(LibPaths[i])) {
+      std::cerr << "Invalid library path: '" << LibPaths[i] << "'\n";
+    } else if (!Filename.append_file(FN)) {
+      std::cerr << "Invalid library path: '" << LibPaths[i]
+                << "/" << FN.c_str() << "'\n";
+    } else if (Filename.exists()) {
+      FoundAFile = true;
+      if (Module *Result = GetModule(Filename))
+        return std::auto_ptr<Module>(Result);   // Load successful!
     }
-    
-    if (NextLibPathIdx == LibPaths.size()) break;
-    Filename = LibPaths[NextLibPathIdx++] + "/" + FN;
   }
 
   if (FoundAFile)
@@ -80,8 +108,79 @@ static inline std::auto_ptr<Module> LoadFile(const std::string &FN) {
   return std::auto_ptr<Module>();
 }
 
+sys::Path GetPathForLinkageItem(const std::string& link_item,
+                                const std::string& dir) {
+  sys::Path fullpath;
+  fullpath.set_directory(dir);
 
+  // Try *.o
+  fullpath.append_file(link_item);
+  fullpath.append_suffix("o");
+  if (fullpath.readable()) 
+    return fullpath;
 
+  // Try *.bc
+  fullpath.elide_suffix();
+  fullpath.append_suffix("bc");
+  if (fullpath.readable()) 
+    return fullpath;
+
+  // Try *.so
+  fullpath.elide_suffix();
+  fullpath.append_suffix(sys::Path::GetDLLSuffix());
+  if (fullpath.readable())
+    return fullpath;
+
+  // Try lib*.a
+  fullpath.set_directory(dir);
+  fullpath.append_file(std::string("lib") + link_item);
+  fullpath.append_suffix("a");
+  if (fullpath.readable())
+    return fullpath;
+
+  // Didn't find one.
+  fullpath.clear();
+  return fullpath;
+}
+
+static inline bool LoadLibrary(const std::string &FN, Module*& Result) {
+  Result = 0;
+  sys::Path Filename;
+  if (!Filename.set_file(FN)) {
+    return false;
+  }
+
+  if (Filename.readable() && Filename.is_bytecode_file()) {
+    if (Result = GetModule(Filename))
+      return true;
+  }
+
+  bool foundAFile = false;
+
+  for (unsigned I = 0; I < LibPaths.size(); I++) {
+    sys::Path path = GetPathForLinkageItem(FN,LibPaths[I]);
+    if (!path.is_empty()) {
+      if (path.is_bytecode_file()) {
+        if (Result = GetModule(path)) {
+          return true;
+        } else {
+          // We found file but its not a valid bytecode file so we 
+          // return false and leave Result null.
+          return false;
+        }
+      } else {
+        // We found a file, but its not a bytecode file so we return
+        // false and leave Result null.
+        return false;
+      }
+    }
+  }
+
+  // We didn't find a file so we leave Result null and return
+  // false to indicate that the library should be just left in the
+  // emitted module as resolvable at runtime.
+  return false;
+}
 
 int main(int argc, char **argv) {
   cl::ParseCommandLineOptions(argc, argv, " llvm linker\n");
@@ -101,12 +200,40 @@ int main(int argc, char **argv) {
     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]
+      std::cerr << argv[0] << ": link error in '" << InputFilenames[i]
                 << "': " << ErrorMessage << "\n";
       return 1;
     }
   }
 
+  // Get the list of dependent libraries from the composite module
+  const Module::LibraryListType& libs = Composite.get()->getLibraries();
+
+  // Iterate over the list of dependent libraries, linking them in as we
+  // find them
+  Module::LibraryListType::const_iterator I = libs.begin();
+  while (I != libs.end()) {
+    Module* Mod = 0;
+    if (LoadLibrary(*I,Mod)) {
+      if (Mod != 0) {
+        std::auto_ptr<Module> M(Mod);
+        if (LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
+          std::cerr << argv[0] << ": link error in '" << *I
+                << "': " << ErrorMessage << "\n";
+          return 1;
+        }
+      } else {
+        std::cerr << argv[0] << ": confused loading library '" << *I
+          << "'. Aborting\n";
+        return 2;
+      }
+    }
+    ++I;
+  }
+
+  // TODO: Iterate over the -l list and link in any modules containing
+  // global symbols that have not been resolved so far.
+
   if (DumpAsm) std::cerr << "Here's the assembly:\n" << Composite.get();
 
   std::ostream *Out = &std::cout;  // Default to printing to stdout...