X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=tools%2Fllvm-link%2Fllvm-link.cpp;h=a32383028ae248f344228371093680e1efdf2ae7;hb=HEAD;hp=652c414a9d32fe25021e4a938a53760008912c0a;hpb=c1b49b56d4132efa2e06deb8f23508d0de4c8800;p=oota-llvm.git

diff --git a/tools/llvm-link/llvm-link.cpp b/tools/llvm-link/llvm-link.cpp
index 652c414a9d3..a32383028ae 100644
--- a/tools/llvm-link/llvm-link.cpp
+++ b/tools/llvm-link/llvm-link.cpp
@@ -12,13 +12,20 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Linker.h"
-#include "llvm/Analysis/Verifier.h"
+#include "llvm/Linker/Linker.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/AutoUpgrade.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/IR/DiagnosticPrinter.h"
+#include "llvm/IR/FunctionInfo.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
+#include "llvm/Object/FunctionIndexObjectFile.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/PrettyStackTrace.h"
@@ -33,10 +40,38 @@ static cl::list<std::string>
 InputFilenames(cl::Positional, cl::OneOrMore,
                cl::desc("<input bitcode files>"));
 
+static cl::list<std::string> OverridingInputs(
+    "override", cl::ZeroOrMore, cl::value_desc("filename"),
+    cl::desc(
+        "input bitcode file which can override previously defined symbol(s)"));
+
+// Option to simulate function importing for testing. This enables using
+// llvm-link to simulate ThinLTO backend processes.
+static cl::list<std::string> Imports(
+    "import", cl::ZeroOrMore, cl::value_desc("function:filename"),
+    cl::desc("Pair of function name and filename, where function should be "
+             "imported from bitcode in filename"));
+
+// Option to support testing of function importing. The function index
+// must be specified in the case were we request imports via the -import
+// option, as well as when compiling any module with functions that may be
+// exported (imported by a different llvm-link -import invocation), to ensure
+// consistent promotion and renaming of locals.
+static cl::opt<std::string> FunctionIndex("functionindex",
+                                          cl::desc("Function index filename"),
+                                          cl::init(""),
+                                          cl::value_desc("filename"));
+
 static cl::opt<std::string>
 OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
                cl::value_desc("filename"));
 
+static cl::opt<bool>
+Internalize("internalize", cl::desc("Internalize linked symbols"));
+
+static cl::opt<bool>
+OnlyNeeded("only-needed", cl::desc("Link only needed symbols"));
+
 static cl::opt<bool>
 Force("f", cl::desc("Enable binary output on terminals"));
 
@@ -50,78 +85,271 @@ Verbose("v", cl::desc("Print information about actions taken"));
 static cl::opt<bool>
 DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
 
-// LoadFile - Read the specified bitcode file in and return it.  This routine
-// searches the link path for the specified file to try to find it...
+static cl::opt<bool>
+SuppressWarnings("suppress-warnings", cl::desc("Suppress all linking warnings"),
+                 cl::init(false));
+
+static cl::opt<bool>
+    PreserveModules("preserve-modules",
+                    cl::desc("Preserve linked modules for testing"));
+
+static cl::opt<bool> PreserveBitcodeUseListOrder(
+    "preserve-bc-uselistorder",
+    cl::desc("Preserve use-list order when writing LLVM bitcode."),
+    cl::init(true), cl::Hidden);
+
+static cl::opt<bool> PreserveAssemblyUseListOrder(
+    "preserve-ll-uselistorder",
+    cl::desc("Preserve use-list order when writing LLVM assembly."),
+    cl::init(false), cl::Hidden);
+
+// Read the specified bitcode file in and return it. This routine searches the
+// link path for the specified file to try to find it...
 //
-static inline Module *LoadFile(const char *argv0, const std::string &FN,
-                               LLVMContext& Context) {
+static std::unique_ptr<Module> loadFile(const char *argv0,
+                                        const std::string &FN,
+                                        LLVMContext &Context,
+                                        bool MaterializeMetadata = true) {
   SMDiagnostic Err;
   if (Verbose) errs() << "Loading '" << FN << "'\n";
-  Module* Result = 0;
+  std::unique_ptr<Module> Result =
+      getLazyIRFileModule(FN, Err, Context, !MaterializeMetadata);
+  if (!Result)
+    Err.print(argv0, errs());
+
+  if (MaterializeMetadata) {
+    Result->materializeMetadata();
+    UpgradeDebugInfo(*Result);
+  }
+
+  return Result;
+}
+
+static void diagnosticHandler(const DiagnosticInfo &DI) {
+  unsigned Severity = DI.getSeverity();
+  switch (Severity) {
+  case DS_Error:
+    errs() << "ERROR: ";
+    break;
+  case DS_Warning:
+    if (SuppressWarnings)
+      return;
+    errs() << "WARNING: ";
+    break;
+  case DS_Remark:
+  case DS_Note:
+    llvm_unreachable("Only expecting warnings and errors");
+  }
+
+  DiagnosticPrinterRawOStream DP(errs());
+  DI.print(DP);
+  errs() << '\n';
+}
+
+static void diagnosticHandlerWithContext(const DiagnosticInfo &DI, void *C) {
+  diagnosticHandler(DI);
+}
+
+/// Import any functions requested via the -import option.
+static bool importFunctions(const char *argv0, LLVMContext &Context,
+                            Linker &L) {
+  StringMap<std::unique_ptr<DenseMap<unsigned, MDNode *>>>
+      ModuleToTempMDValsMap;
+  for (const auto &Import : Imports) {
+    // Identify the requested function and its bitcode source file.
+    size_t Idx = Import.find(':');
+    if (Idx == std::string::npos) {
+      errs() << "Import parameter bad format: " << Import << "\n";
+      return false;
+    }
+    std::string FunctionName = Import.substr(0, Idx);
+    std::string FileName = Import.substr(Idx + 1, std::string::npos);
+
+    // Load the specified source module.
+    std::unique_ptr<Module> M = loadFile(argv0, FileName, Context, false);
+    if (!M.get()) {
+      errs() << argv0 << ": error loading file '" << FileName << "'\n";
+      return false;
+    }
+
+    if (verifyModule(*M, &errs())) {
+      errs() << argv0 << ": " << FileName
+             << ": error: input module is broken!\n";
+      return false;
+    }
+
+    Function *F = M->getFunction(FunctionName);
+    if (!F) {
+      errs() << "Ignoring import request for non-existent function "
+             << FunctionName << " from " << FileName << "\n";
+      continue;
+    }
+    // We cannot import weak_any functions without possibly affecting the
+    // order they are seen and selected by the linker, changing program
+    // semantics.
+    if (F->hasWeakAnyLinkage()) {
+      errs() << "Ignoring import request for weak-any function " << FunctionName
+             << " from " << FileName << "\n";
+      continue;
+    }
 
-  Result = ParseIRFile(FN, Err, Context);
-  if (Result) return Result;   // Load successful!
+    if (Verbose)
+      errs() << "Importing " << FunctionName << " from " << FileName << "\n";
 
-  Err.print(argv0, errs());
-  return NULL;
+    std::unique_ptr<FunctionInfoIndex> Index;
+    if (!FunctionIndex.empty()) {
+      ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr =
+          llvm::getFunctionIndexForFile(FunctionIndex, diagnosticHandler);
+      std::error_code EC = IndexOrErr.getError();
+      if (EC) {
+        errs() << EC.message() << '\n';
+        return false;
+      }
+      Index = std::move(IndexOrErr.get());
+    }
+
+    // Save the mapping of value ids to temporary metadata created when
+    // importing this function. If we have already imported from this module,
+    // add new temporary metadata to the existing mapping.
+    auto &TempMDVals = ModuleToTempMDValsMap[FileName];
+    if (!TempMDVals)
+      TempMDVals = llvm::make_unique<DenseMap<unsigned, MDNode *>>();
+
+    // Link in the specified function.
+    DenseSet<const GlobalValue *> FunctionsToImport;
+    FunctionsToImport.insert(F);
+    if (L.linkInModule(std::move(M), Linker::Flags::None, Index.get(),
+                       &FunctionsToImport, TempMDVals.get()))
+      return false;
+  }
+
+  // Now link in metadata for all modules from which we imported functions.
+  for (StringMapEntry<std::unique_ptr<DenseMap<unsigned, MDNode *>>> &SME :
+       ModuleToTempMDValsMap) {
+    // Load the specified source module.
+    std::unique_ptr<Module> M = loadFile(argv0, SME.getKey(), Context, true);
+    if (!M.get()) {
+      errs() << argv0 << ": error loading file '" << SME.getKey() << "'\n";
+      return false;
+    }
+
+    if (verifyModule(*M, &errs())) {
+      errs() << argv0 << ": " << SME.getKey()
+             << ": error: input module is broken!\n";
+      return false;
+    }
+
+    // Link in all necessary metadata from this module.
+    if (L.linkInMetadata(*M, SME.getValue().get()))
+      return false;
+  }
+  return true;
+}
+
+static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
+                      const cl::list<std::string> &Files,
+                      unsigned Flags) {
+  // Filter out flags that don't apply to the first file we load.
+  unsigned ApplicableFlags = Flags & Linker::Flags::OverrideFromSrc;
+  for (const auto &File : Files) {
+    std::unique_ptr<Module> M = loadFile(argv0, File, Context);
+    if (!M.get()) {
+      errs() << argv0 << ": error loading file '" << File << "'\n";
+      return false;
+    }
+
+    if (verifyModule(*M, &errs())) {
+      errs() << argv0 << ": " << File << ": error: input module is broken!\n";
+      return false;
+    }
+
+    // If a function index is supplied, load it so linkInModule can treat
+    // local functions/variables as exported and promote if necessary.
+    std::unique_ptr<FunctionInfoIndex> Index;
+    if (!FunctionIndex.empty()) {
+      ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr =
+          llvm::getFunctionIndexForFile(FunctionIndex, diagnosticHandler);
+      std::error_code EC = IndexOrErr.getError();
+      if (EC) {
+        errs() << EC.message() << '\n';
+        return false;
+      }
+      Index = std::move(IndexOrErr.get());
+    }
+
+    if (Verbose)
+      errs() << "Linking in '" << File << "'\n";
+
+    if (L.linkInModule(std::move(M), ApplicableFlags, Index.get()))
+      return false;
+    // All linker flags apply to linking of subsequent files.
+    ApplicableFlags = Flags;
+
+    // If requested for testing, preserve modules by releasing them from
+    // the unique_ptr before the are freed. This can help catch any
+    // cross-module references from e.g. unneeded metadata references
+    // that aren't properly set to null but instead mapped to the source
+    // module version. The bitcode writer will assert if it finds any such
+    // cross-module references.
+    if (PreserveModules)
+      M.release();
+  }
+
+  return true;
 }
 
 int main(int argc, char **argv) {
   // Print a stack trace if we signal out.
   sys::PrintStackTraceOnErrorSignal();
   PrettyStackTraceProgram X(argc, argv);
-  
+
   LLVMContext &Context = getGlobalContext();
+  Context.setDiagnosticHandler(diagnosticHandlerWithContext, nullptr, true);
+
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
 
-  unsigned BaseArg = 0;
-  std::string ErrorMessage;
+  auto Composite = make_unique<Module>("llvm-link", Context);
+  Linker L(*Composite);
 
-  OwningPtr<Module> Composite(LoadFile(argv[0],
-                                       InputFilenames[BaseArg], Context));
-  if (Composite.get() == 0) {
-    errs() << argv[0] << ": error loading file '"
-           << InputFilenames[BaseArg] << "'\n";
-    return 1;
-  }
+  unsigned Flags = Linker::Flags::None;
+  if (Internalize)
+    Flags |= Linker::Flags::InternalizeLinkedSymbols;
+  if (OnlyNeeded)
+    Flags |= Linker::Flags::LinkOnlyNeeded;
 
-  Linker L(Composite.get());
-  for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
-    OwningPtr<Module> M(LoadFile(argv[0], InputFilenames[i], Context));
-    if (M.get() == 0) {
-      errs() << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
-      return 1;
-    }
+  // First add all the regular input files
+  if (!linkFiles(argv[0], Context, L, InputFilenames, Flags))
+    return 1;
 
-    if (Verbose) errs() << "Linking in '" << InputFilenames[i] << "'\n";
+  // Next the -override ones.
+  if (!linkFiles(argv[0], Context, L, OverridingInputs,
+                 Flags | Linker::Flags::OverrideFromSrc))
+    return 1;
 
-    if (L.linkInModule(M.get(), &ErrorMessage)) {
-      errs() << argv[0] << ": link error in '" << InputFilenames[i]
-             << "': " << ErrorMessage << "\n";
-      return 1;
-    }
-  }
+  // Import any functions requested via -import
+  if (!importFunctions(argv[0], Context, L))
+    return 1;
 
   if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite;
 
-  std::string ErrorInfo;
-  tool_output_file Out(OutputFilename.c_str(), ErrorInfo, sys::fs::F_Binary);
-  if (!ErrorInfo.empty()) {
-    errs() << ErrorInfo << '\n';
+  std::error_code EC;
+  tool_output_file Out(OutputFilename, EC, sys::fs::F_None);
+  if (EC) {
+    errs() << EC.message() << '\n';
     return 1;
   }
 
-  if (verifyModule(*Composite)) {
-    errs() << argv[0] << ": linked module is broken!\n";
+  if (verifyModule(*Composite, &errs())) {
+    errs() << argv[0] << ": error: linked module is broken!\n";
     return 1;
   }
 
   if (Verbose) errs() << "Writing bitcode...\n";
   if (OutputAssembly) {
-    Out.os() << *Composite;
+    Composite->print(Out.os(), nullptr, PreserveAssemblyUseListOrder);
   } else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
-    WriteBitcodeToFile(Composite.get(), Out.os());
+    WriteBitcodeToFile(Composite.get(), Out.os(), PreserveBitcodeUseListOrder);
 
   // Declare success.
   Out.keep();