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-rw-r--r--contrib/llvm/tools/llvm-link/llvm-link.cpp194
1 files changed, 184 insertions, 10 deletions
diff --git a/contrib/llvm/tools/llvm-link/llvm-link.cpp b/contrib/llvm/tools/llvm-link/llvm-link.cpp
index 369f347..a3238302 100644
--- a/contrib/llvm/tools/llvm-link/llvm-link.cpp
+++ b/contrib/llvm/tools/llvm-link/llvm-link.cpp
@@ -18,10 +18,12 @@
#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"
@@ -43,11 +45,34 @@ static cl::list<std::string> OverridingInputs(
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"));
static cl::opt<bool>
@@ -64,6 +89,10 @@ 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."),
@@ -77,16 +106,21 @@ static cl::opt<bool> PreserveAssemblyUseListOrder(
// 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 std::unique_ptr<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";
- std::unique_ptr<Module> Result = getLazyIRFileModule(FN, Err, Context);
+ std::unique_ptr<Module> Result =
+ getLazyIRFileModule(FN, Err, Context, !MaterializeMetadata);
if (!Result)
Err.print(argv0, errs());
- Result->materializeMetadata();
- UpgradeDebugInfo(*Result);
+ if (MaterializeMetadata) {
+ Result->materializeMetadata();
+ UpgradeDebugInfo(*Result);
+ }
return Result;
}
@@ -112,9 +146,111 @@ static void diagnosticHandler(const DiagnosticInfo &DI) {
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;
+ }
+
+ if (Verbose)
+ errs() << "Importing " << FunctionName << " from " << FileName << "\n";
+
+ 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,
- bool OverrideDuplicateSymbols) {
+ 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()) {
@@ -127,11 +263,36 @@ static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
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(M.get(), OverrideDuplicateSymbols))
+ 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;
@@ -143,18 +304,31 @@ int main(int argc, char **argv) {
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");
auto Composite = make_unique<Module>("llvm-link", Context);
- Linker L(Composite.get(), diagnosticHandler);
+ Linker L(*Composite);
+
+ unsigned Flags = Linker::Flags::None;
+ if (Internalize)
+ Flags |= Linker::Flags::InternalizeLinkedSymbols;
+ if (OnlyNeeded)
+ Flags |= Linker::Flags::LinkOnlyNeeded;
// First add all the regular input files
- if (!linkFiles(argv[0], Context, L, InputFilenames, false))
+ if (!linkFiles(argv[0], Context, L, InputFilenames, Flags))
return 1;
// Next the -override ones.
- if (!linkFiles(argv[0], Context, L, OverridingInputs, true))
+ if (!linkFiles(argv[0], Context, L, OverridingInputs,
+ Flags | Linker::Flags::OverrideFromSrc))
+ 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;
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