[LLVMSymbolize] Move ModuleInfo into a separate class (SymbolizableModule).

Summary:
This is mostly NFC. It is a first step in cleaning up LLVMSymbolize
library. It removes "ModuleInfo" class which bundles together ObjectFile
and its debug info context in favor of:
  * abstract SymbolizableModule in public headers;
  * SymbolizableObjectFile subclass in implementation.

Additionally, SymbolizableObjectFile is now created via factory, so we
can properly detect object parsing error at this stage instead of keeping
the broken half-parsed object. As a next step, we would be able to
propagate the error all the way back to the library user.

Further improvements might include:
  * factoring out the logic of finding appropriate file with debug info
    for a given object file, and caching all parsed object files into a
    separate class [A].
  * factoring out DILineInfo rendering [B].
This would make what is now a heavyweight "LLVMSymbolizer" a relatively
straightforward class, that calls into [A] to turn filepath into a
SymbolizableModule, delegates actual symbolization to concrete SymbolizableModule
implementation, and lets [C] render the result.

Reviewers: dblaikie, echristo, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14099

llvm-svn: 251662

1 files changed, 80 insertions, 0 deletions

diff --git a/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.h b/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.h
new file mode 100644
index 00000000000..7c138d3e468
--- /dev/null
+++ b/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.h
@@ -0,0 +1,80 @@
+//===-- SymbolizableObjectFile.h -------------------------------- C++ -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the SymbolizableObjectFile class.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_LIB_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEOBJECTFILE_H
+#define LLVM_LIB_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEOBJECTFILE_H
+
+#include "llvm/DebugInfo/Symbolize/SymbolizableModule.h"
+#include <map>
+
+namespace llvm {
+class DataExtractor;
+}
+
+namespace llvm {
+namespace symbolize {
+
+class SymbolizableObjectFile : public SymbolizableModule {
+public:
+  static ErrorOr<std::unique_ptr<SymbolizableObjectFile>>
+  create(object::ObjectFile *Obj, std::unique_ptr<DIContext> DICtx);
+
+  DILineInfo symbolizeCode(uint64_t ModuleOffset, FunctionNameKind FNKind,
+                           bool UseSymbolTable) const override;
+  DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset,
+                                      FunctionNameKind FNKind,
+                                      bool UseSymbolTable) const override;
+  bool symbolizeData(uint64_t ModuleOffset, std::string &Name, uint64_t &Start,
+                     uint64_t &Size) const override;
+
+  // Return true if this is a 32-bit x86 PE COFF module.
+  bool isWin32Module() const override;
+
+  // Returns the preferred base of the module, i.e. where the loader would place
+  // it in memory assuming there were no conflicts.
+  uint64_t getModulePreferredBase() const override;
+
+private:
+  bool getNameFromSymbolTable(object::SymbolRef::Type Type, uint64_t Address,
+                              std::string &Name, uint64_t &Addr,
+                              uint64_t &Size) const;
+  // For big-endian PowerPC64 ELF, OpdAddress is the address of the .opd
+  // (function descriptor) section and OpdExtractor refers to its contents.
+  std::error_code addSymbol(const object::SymbolRef &Symbol,
+                            uint64_t SymbolSize,
+                            DataExtractor *OpdExtractor = nullptr,
+                            uint64_t OpdAddress = 0);
+  std::error_code addCoffExportSymbols(const object::COFFObjectFile *CoffObj);
+
+  object::ObjectFile *Module;
+  std::unique_ptr<DIContext> DebugInfoContext;
+
+  struct SymbolDesc {
+    uint64_t Addr;
+    // If size is 0, assume that symbol occupies the whole memory range up to
+    // the following symbol.
+    uint64_t Size;
+    friend bool operator<(const SymbolDesc &s1, const SymbolDesc &s2) {
+      return s1.Addr < s2.Addr;
+    }
+  };
+  std::map<SymbolDesc, StringRef> Functions;
+  std::map<SymbolDesc, StringRef> Objects;
+
+  SymbolizableObjectFile(object::ObjectFile *Obj,
+                         std::unique_ptr<DIContext> DICtx);
+};
+
+}  // namespace symbolize
+}  // namespace llvm
+
+#endif  // LLVM_LIB_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEOBJECTFILE_H