Adding new LTO APIs to parse metadata nodes and extract linker options and

dependent libraries from a bitcode module.

Differential Revision: http://llvm-reviews.chandlerc.com/D2343



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199759 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm-c/lto.h

@@ -40,7 +40,7 @@ typedef bool lto_bool_t;
  * @{
  */
 
-#define LTO_API_VERSION 7
+#define LTO_API_VERSION 8
 
 /**
  * \since prior to LTO_API_VERSION=3
@@ -246,6 +246,43 @@ lto_module_get_symbol_name(lto_module_t mod, unsigned int index);
 extern lto_symbol_attributes
 lto_module_get_symbol_attribute(lto_module_t mod, unsigned int index);
 
+
+/**
+ * Returns the number of dependent libraries in the object module.
+ *
+ * \since LTO_API_VERSION=8
+ */
+extern unsigned int
+lto_module_get_num_deplibs(lto_module_t mod);
+
+
+/**
+ * Returns the ith dependent library in the module.
+ *
+ * \since LTO_API_VERSION=8
+ */
+extern const char*
+lto_module_get_deplib(lto_module_t mod, unsigned int index);
+
+
+/**
+ * Returns the number of linker options in the object module.
+ *
+ * \since LTO_API_VERSION=8
+ */
+extern unsigned int
+lto_module_get_num_linkeropts(lto_module_t mod);
+
+
+/**
+ * Returns the ith linker option in the module.
+ *
+ * \since LTO_API_VERSION=8
+ */
+extern const char*
+lto_module_get_linkeropt(lto_module_t mod, unsigned int index);
+
+
 /**
  * Diagnostic severity.
  *

include/llvm/CodeGen/TargetLoweringObjectFileImpl.h

@@ -80,6 +80,10 @@ class TargetLoweringObjectFileMachO : public TargetLoweringObjectFile {
 public:
   virtual ~TargetLoweringObjectFileMachO() {}
 
+  /// getDepLibFromLinkerOpt - Extract the dependent library name from a linker
+  /// option string. Returns StringRef() if the option does not specify a library.
+  virtual StringRef getDepLibFromLinkerOpt(StringRef LinkerOption) const;
+
   /// emitModuleFlags - Emit the module flags that specify the garbage
   /// collection information.
   virtual void emitModuleFlags(MCStreamer &Streamer,
@@ -129,6 +133,10 @@ public:
   SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
                          Mangler *Mang, const TargetMachine &TM) const;
 
+  /// getDepLibFromLinkerOpt - Extract the dependent library name from a linker
+  /// option string. Returns StringRef() if the option does not specify a library.
+  virtual StringRef getDepLibFromLinkerOpt(StringRef LinkerOption) const;
+
   /// emitModuleFlags - Emit Obj-C garbage collection and linker options.  Only
   /// linker option emission is implemented for COFF.
   virtual void emitModuleFlags(MCStreamer &Streamer,

include/llvm/LTO/LTOModule.h

@@ -51,6 +51,9 @@ private:
   llvm::OwningPtr<llvm::Module>           _module;
   llvm::OwningPtr<llvm::TargetMachine>    _target;
   llvm::MCObjectFileInfo ObjFileInfo;
+  StringSet                               _linkeropt_strings;
+  std::vector<const char *>               _deplibs;
+  std::vector<const char *>               _linkeropts;
   std::vector<NameAndAttributes>          _symbols;
 
   // _defines and _undefines only needed to disambiguate tentative definitions
@@ -129,6 +132,30 @@ public:
     return NULL;
   }
 
+  /// getDependentLibraryCount - Get the number of dependent libraries
+  uint32_t getDependentLibraryCount() {
+    return _deplibs.size();
+  }
+
+  /// getDependentLibrary - Get the dependent library at the specified index.
+  const char *getDependentLibrary(uint32_t index) {
+    if (index < _deplibs.size())
+      return _deplibs[index];
+    return NULL;
+  }
+
+  /// getLinkerOptCount - Get the number of linker options
+  uint32_t getLinkerOptCount() {
+    return _linkeropts.size();
+  }
+
+  /// getLinkerOpt - Get the linker option at the specified index.
+  const char *getLinkerOpt(uint32_t index) {
+    if (index < _linkeropts.size())
+      return _linkeropts[index];
+    return NULL;
+  }
+
   /// getLLVVMModule - Return the Module.
   llvm::Module *getLLVVMModule() { return _module.get(); }
 
@@ -138,6 +165,10 @@ public:
   }
 
 private:
+  /// parseMetadata - Parse metadata from the module
+  // FIXME: it only parses "Linker Options" metadata at the moment
+  void parseMetadata();
+
   /// parseSymbols - Parse the symbols from the module and model-level ASM and
   /// add them to either the defined or undefined lists.
   bool parseSymbols(std::string &errMsg);

include/llvm/Target/TargetLoweringObjectFile.h

@@ -57,6 +57,12 @@ public:
                                     const TargetMachine &TM,
                                     const MCSymbol *Sym) const;
 
+  /// getDepLibFromLinkerOpt - Extract the dependent library name from a linker
+  /// option string. Returns StringRef() if the option does not specify a library.
+  virtual StringRef getDepLibFromLinkerOpt(StringRef LinkerOption) const {
+    return StringRef();
+  }
+
   /// emitModuleFlags - Emit the module flags that the platform cares about.
   virtual void emitModuleFlags(MCStreamer &,
                                ArrayRef<Module::ModuleFlagEntry>,

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

@@ -402,6 +402,16 @@ TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) {
 //                                 MachO
 //===----------------------------------------------------------------------===//
 
+/// getDepLibFromLinkerOpt - Extract the dependent library name from a linker
+/// option string. Returns StringRef() if the option does not specify a library.
+StringRef TargetLoweringObjectFileMachO::
+getDepLibFromLinkerOpt(StringRef LinkerOption) const {
+  const char *LibCmd = "-l";
+  if (LinkerOption.startswith(LibCmd))
+    return LinkerOption.substr(strlen(LibCmd));
+  return StringRef();
+}
+
 /// emitModuleFlags - Perform code emission for module flags.
 void TargetLoweringObjectFileMachO::
 emitModuleFlags(MCStreamer &Streamer,
@@ -774,6 +784,14 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
   return DataSection;
 }
 
+StringRef TargetLoweringObjectFileCOFF::
+getDepLibFromLinkerOpt(StringRef LinkerOption) const {
+  const char *LibCmd = "/DEFAULTLIB:";
+  if (LinkerOption.startswith(LibCmd))
+    return LinkerOption.substr(strlen(LibCmd));
+  return StringRef();
+}
+
 void TargetLoweringObjectFileCOFF::
 emitModuleFlags(MCStreamer &Streamer,
                 ArrayRef<Module::ModuleFlagEntry> ModuleFlags,

lib/LTO/LTOModule.cpp

@@ -18,6 +18,7 @@
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Metadata.h"
 #include "llvm/IR/Module.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
@@ -37,6 +38,8 @@
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/system_error.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Transforms/Utils/GlobalStatus.h"
 using namespace llvm;
@@ -177,6 +180,8 @@ LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer,
     return NULL;
   }
 
+  Ret->parseMetadata();
+
   return Ret;
 }
 
@@ -798,3 +803,27 @@ bool LTOModule::parseSymbols(std::string &errMsg) {
 
   return false;
 }
+
+/// parseMetadata - Parse metadata from the module
+void LTOModule::parseMetadata() {
+  // Linker Options
+  if (Value *Val = _module->getModuleFlag("Linker Options")) {
+    MDNode *LinkerOptions = cast<MDNode>(Val);
+    for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
+      MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
+      for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
+        MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
+        StringRef Op = _linkeropt_strings.
+            GetOrCreateValue(MDOption->getString()).getKey();
+        StringRef DepLibName = _target->getTargetLowering()->
+            getObjFileLowering().getDepLibFromLinkerOpt(Op);
+        if (!DepLibName.empty())
+          _deplibs.push_back(DepLibName.data());
+        else if (!Op.empty())
+          _linkeropts.push_back(Op.data());
+      }
+    }
+  }
+
+  // Add other interesting metadata here.
+}

tools/lto/lto.cpp

@@ -193,6 +193,28 @@ lto_symbol_attributes lto_module_get_symbol_attribute(lto_module_t mod,
   return mod->getSymbolAttributes(index);
 }
 
+/// lto_module_get_num_deplibs - Returns the number of dependent libraries in
+/// the object module.
+unsigned int lto_module_get_num_deplibs(lto_module_t mod) {
+  return mod->getDependentLibraryCount();
+}
+
+/// lto_module_get_deplib - Returns the ith dependent library in the module.
+const char* lto_module_get_deplib(lto_module_t mod, unsigned int index) {
+  return mod->getDependentLibrary(index);
+}
+
+/// lto_module_get_num_linkeropts - Returns the number of linker options in the
+/// object module.
+unsigned int lto_module_get_num_linkeropts(lto_module_t mod) {
+  return mod->getLinkerOptCount();
+}
+
+/// lto_module_get_linkeropt - Returns the ith linker option in the module.
+const char* lto_module_get_linkeropt(lto_module_t mod, unsigned int index) {
+  return mod->getLinkerOpt(index);
+}
+
 /// Set a diagnostic handler.
 void lto_codegen_set_diagnostic_handler(lto_code_gen_t cg,
                                         lto_diagnostic_handler_t diag_handler,

tools/lto/lto.exports

@@ -5,6 +5,10 @@ lto_module_create
 lto_module_create_from_fd
 lto_module_create_from_fd_at_offset
 lto_module_create_from_memory
+lto_module_get_deplib
+lto_module_get_linkeropt
+lto_module_get_num_deplibs
+lto_module_get_num_linkeropts
 lto_module_get_num_symbols
 lto_module_get_symbol_attribute
 lto_module_get_symbol_name