Add basic support for .debug_ranges section to LLVM's DebugInfo library.

This section (introduced in DWARF-3) is used to define instruction address
ranges for functions that are not contiguous and can't be described
by low_pc/high_pc attributes (this is the usual case for inlined subroutines).
The patch is the first step to support fetching complete inlining info from DWARF.

Reviewed by Benjamin Kramer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162657 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 51 insertions, 0 deletions

diff --git a/lib/DebugInfo/DWARFDebugRangeList.h b/lib/DebugInfo/DWARFDebugRangeList.h
new file mode 100644
index 0000000000..b8d334f7ba
--- /dev/null
+++ b/lib/DebugInfo/DWARFDebugRangeList.h
@@ -0,0 +1,51 @@
+//===-- DWARFDebugRangeList.h -----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_DWARFDEBUGRANGELIST_H
+#define LLVM_DEBUGINFO_DWARFDEBUGRANGELIST_H
+
+#include "llvm/Support/DataExtractor.h"
+#include <vector>
+
+namespace llvm {
+
+class raw_ostream;
+
+class DWARFDebugRangeList {
+public:
+  struct RangeListEntry {
+    // A beginning address offset. This address offset has the size of an
+    // address and is relative to the applicable base address of the
+    // compilation unit referencing this range list. It marks the beginning
+    // of an address range.
+    uint64_t StartAddress;
+    // An ending address offset. This address offset again has the size of
+    // an address and is relative to the applicable base address of the
+    // compilation unit referencing this range list. It marks the first
+    // address past the end of the address range. The ending address must
+    // be greater than or equal to the beginning address.
+    uint64_t EndAddress;
+  };
+
+private:
+  // Offset in .debug_ranges section.
+  uint32_t Offset;
+  uint8_t AddressSize;
+  std::vector<RangeListEntry> Entries;
+
+public:
+  DWARFDebugRangeList() { clear(); }
+  void clear();
+  void dump(raw_ostream &OS) const;
+  bool extract(DataExtractor data, uint32_t *offset_ptr);
+};
+
+}  // namespace llvm
+
+#endif  // LLVM_DEBUGINFO_DWARFDEBUGRANGELIST_H