Merge clang, llvm, lld, lldb, compiler-rt and libc++ 5.0.0 release.

MFC r309126 (by emaste):

  Correct lld llvm-tblgen dependency file name

MFC r309169:

  Get rid of separate Subversion mergeinfo properties for llvm-dwarfdump
  and llvm-lto.  The mergeinfo confuses Subversion enormously, and these
  directories will just use the mergeinfo for llvm itself.

MFC r312765:

  Pull in r276136 from upstream llvm trunk (by Wei Mi):

    Use ValueOffsetPair to enhance value reuse during SCEV expansion.

    In D12090, the ExprValueMap was added to reuse existing value during
    SCEV expansion. However, const folding and sext/zext distribution can
    make the reuse still difficult.

    A simplified case is: suppose we know S1 expands to V1 in
    ExprValueMap, and
      S1 = S2 + C_a
      S3 = S2 + C_b
    where C_a and C_b are different SCEVConstants. Then we'd like to
    expand S3 as V1 - C_a + C_b instead of expanding S2 literally. It is
    helpful when S2 is a complex SCEV expr and S2 has no entry in
    ExprValueMap, which is usually caused by the fact that S3 is
    generated from S1 after const folding.

    In order to do that, we represent ExprValueMap as a mapping from SCEV
    to ValueOffsetPair. We will save both S1->{V1, 0} and S2->{V1, C_a}
    into the ExprValueMap when we create SCEV for V1. When S3 is
    expanded, it will first expand S2 to V1 - C_a because of S2->{V1,
    C_a} in the map, then expand S3 to V1 - C_a + C_b.

    Differential Revision: https://reviews.llvm.org/D21313

  This should fix assertion failures when building OpenCV >= 3.1.

  PR:		215649

MFC r312831:

  Revert r312765 for now, since it causes assertions when building
  lang/spidermonkey24.

  Reported by:	antoine
  PR:		215649

MFC r316511 (by jhb):

  Add an implementation of __ffssi2() derived from __ffsdi2().

  Newer versions of GCC include an __ffssi2() symbol in libgcc and the
  compiler can emit calls to it in generated code.  This is true for at
  least GCC 6.2 when compiling world for mips and mips64.

  Reviewed by:	jmallett, dim
  Sponsored by:	DARPA / AFRL
  Differential Revision:	https://reviews.freebsd.org/D10086

MFC r318601 (by adrian):

  [libcompiler-rt] add bswapdi2/bswapsi2

  This is required for mips gcc 6.3 userland to build/run.

  Reviewed by:	emaste, dim
  Approved by:	emaste
  Differential Revision:	https://reviews.freebsd.org/D10838

MFC r318884 (by emaste):

  lldb: map TRAP_CAP to a trace trap

  In the absense of a more specific handler for TRAP_CAP (generated by
  ENOTCAPABLE or ECAPMODE while in capability mode) treat it as a trace
  trap.

  Example usage (testing the bug in PR219173):

  % proccontrol -m trapcap lldb usr.bin/hexdump/obj/hexdump -- -Cv -s 1 /bin/ls
  ...
  (lldb) run
  Process 12980 launching
  Process 12980 launched: '.../usr.bin/hexdump/obj/hexdump' (x86_64)
  Process 12980 stopped
  * thread #1, stop reason = trace
      frame #0: 0x0000004b80c65f1a libc.so.7`__sys_lseek + 10
  ...

  In the future we should have LLDB control the trapcap procctl itself
  (as it does with ASLR), as well as report a specific stop reason.
  This change eliminates an assertion failure from LLDB for now.

MFC r319796:

  Remove a few unneeded files from libllvm, libclang and liblldb.

MFC r319885 (by emaste):

  lld: ELF: Fix ICF crash on absolute symbol relocations.

  If two sections contained relocations to absolute symbols with the same
  value we would crash when trying to access their sections. Add a check that
  both symbols point to sections before accessing their sections, and treat
  absolute symbols as equal if their values are equal.

  Obtained from:	LLD commit r292578

MFC r319918:

  Revert r319796 for now, it can cause undefined references when linking
  in some circumstances.

  Reported by:	Shawn Webb <shawn.webb@hardenedbsd.org>

MFC r319957 (by emaste):

  lld: Add armelf emulation mode

  Obtained from:	LLD r305375

MFC r321369:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 (trunk r308421).  Upstream has branched for the 5.0.0 release,
  which should be in about a month.  Please report bugs and regressions,
  so we can get them into the release.

  Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
  support to build; see UPDATING for more information.

MFC r321420:

  Add a few more object files to liblldb, which should solve errors when
  linking the lldb executable in some cases.  In particular, when the
  -ffunction-sections -fdata-sections options are turned off, or
  ineffective.

  Reported by:	Shawn Webb, Mark Millard

MFC r321433:

  Cleanup stale Options.inc files from the previous libllvm build for
  clang 4.0.0.  Otherwise, these can get included before the two newly
  generated ones (which are different) for clang 5.0.0.

  Reported by:	Mark Millard

MFC r321439 (by bdrewery):

  Move llvm Options.inc hack from r321433 for NO_CLEAN to lib/clang/libllvm.

  The files are only ever generated to .OBJDIR, not to WORLDTMP (as a
  sysroot) and are only ever included from a compilation.  So using
  a beforebuild target here removes the file before the compilation
  tries to include it.

MFC r321664:

  Pull in r308891 from upstream llvm trunk (by Benjamin Kramer):

    [CodeGenPrepare] Cut off FindAllMemoryUses if there are too many uses.

    This avoids excessive compile time. The case I'm looking at is
    Function.cpp from an old version of LLVM that still had the giant
    memcmp string matcher in it. Before r308322 this compiled in about 2
    minutes, after it, clang takes infinite* time to compile it. With
    this patch we're at 5 min, which is still bad but this is a
    pathological case.

    The cut off at 20 uses was chosen by looking at other cut-offs in LLVM
    for user scanning. It's probably too high, but does the job and is
    very unlikely to regress anything.

    Fixes PR33900.

    * I'm impatient and aborted after 15 minutes, on the bug report it was
      killed after 2h.

  Pull in r308986 from upstream llvm trunk (by Simon Pilgrim):

    [X86][CGP] Reduce memcmp() expansion to 2 load pairs (PR33914)

    D35067/rL308322 attempted to support up to 4 load pairs for memcmp
    inlining which resulted in regressions for some optimized libc memcmp
    implementations (PR33914).

    Until we can match these more optimal cases, this patch reduces the
    memcmp expansion to a maximum of 2 load pairs (which matches what we
    do for -Os).

    This patch should be considered for the 5.0.0 release branch as well

    Differential Revision: https://reviews.llvm.org/D35830

  These fix a hang (or extremely long compile time) when building older
  LLVM ports.

  Reported by:    antoine
  PR:             219139

MFC r321719:

  Pull in r309503 from upstream clang trunk (by Richard Smith):

    PR33902: Invalidate line number cache when adding more text to
    existing buffer.

    This led to crashes as the line number cache would report a bogus
    line number for a line of code, and we'd try to find a nonexistent
    column within the line when printing diagnostics.

  This fixes an assertion when building the graphics/champlain port.

  Reported by:	antoine, kwm
  PR:		219139

MFC r321723:

  Upgrade our copies of clang, llvm, lld and lldb to r309439 from the
  upstream release_50 branch.  This is just after upstream's 5.0.0-rc1.

MFC r322320:

  Upgrade our copies of clang, llvm and libc++ to r310316 from the
  upstream release_50 branch.

MFC r322326 (by emaste):

  lldb: Make i386-*-freebsd expression work on JIT path

  * Enable i386 ABI creation for freebsd
  * Added an extra argument in ABISysV_i386::PrepareTrivialCall for mmap
    syscall
  * Unlike linux, the last argument of mmap is actually 64-bit(off_t).
    This requires us to push an additional word for the higher order bits.
  * Prior to this change, ktrace dump will show mmap failures due to
    invalid argument coming from the 6th mmap argument.

  Submitted by:	Karnajit Wangkhem
  Differential Revision:	https://reviews.llvm.org/D34776

MFC r322360 (by emaste):

  lldb: Report inferior signals as signals, not exceptions, on FreeBSD

  This is the FreeBSD equivalent of LLVM r238549.

  This serves 2 purposes:

  * LLDB should handle inferior process signals SIGSEGV/SIGILL/SIGBUS/
    SIGFPE the way it is suppose to be handled. Prior to this fix these
    signals will neither create a coredump, nor exit from the debugger
    or work for signal handling scenario.
  * eInvalidCrashReason need not report "unknown crash reason" if we have
    a valid si_signo

  llvm.org/pr23699

  Patch by Karnajit Wangkhem

  Differential Revision:  https://reviews.llvm.org/D35223

  Submitted by:	Karnajit Wangkhem
  Obtained from:	LLVM r310591

MFC r322474 (by emaste):

  lld: Add `-z muldefs` option.

  Obtained from:	LLVM r310757

MFC r322740:

  Upgrade our copies of clang, llvm, lld and libc++ to r311219 from the
  upstream release_50 branch.

MFC r322855:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r311606 from
  the upstream release_50 branch.

  As of this version, lib/msun's trig test should also work correctly
  again (see bug 220989 for more information).

  PR:		220989

MFC r323112:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r312293 from
  the upstream release_50 branch.  This corresponds to 5.0.0 rc4.

  As of this version, the cad/stepcode port should now compile in a more
  reasonable time on i386 (see bug 221836 for more information).

  PR:		221836

MFC r323245:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 release (upstream r312559).

  Release notes for llvm, clang and lld will be available here soon:
  <http://releases.llvm.org/5.0.0/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/clang/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/lld/docs/ReleaseNotes.html>

  Relnotes:	yes

(cherry picked from commit 12cd91cf4c6b96a24427c0de5374916f2808d263)

1 files changed, 342 insertions, 353 deletions

diff --git a/contrib/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp b/contrib/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
index dc9310d..83a7792 100644
--- a/contrib/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
+++ b/contrib/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
@@ -1,4 +1,4 @@
-//===-- DWARFFormValue.cpp ------------------------------------------------===//
+//===- DWARFFormValue.cpp -------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,264 +7,240 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "SyntaxHighlighting.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/None.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
+#include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/Dwarf.h"
+#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
+#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
-#include <cassert>
+#include <cinttypes>
+#include <cstdint>
 #include <limits>
+
 using namespace llvm;
 using namespace dwarf;
 using namespace syntax;
 
 static const DWARFFormValue::FormClass DWARF4FormClasses[] = {
-  DWARFFormValue::FC_Unknown,       // 0x0
-  DWARFFormValue::FC_Address,       // 0x01 DW_FORM_addr
-  DWARFFormValue::FC_Unknown,       // 0x02 unused
-  DWARFFormValue::FC_Block,         // 0x03 DW_FORM_block2
-  DWARFFormValue::FC_Block,         // 0x04 DW_FORM_block4
-  DWARFFormValue::FC_Constant,      // 0x05 DW_FORM_data2
-  // --- These can be FC_SectionOffset in DWARF3 and below:
-  DWARFFormValue::FC_Constant,      // 0x06 DW_FORM_data4
-  DWARFFormValue::FC_Constant,      // 0x07 DW_FORM_data8
-  // ---
-  DWARFFormValue::FC_String,        // 0x08 DW_FORM_string
-  DWARFFormValue::FC_Block,         // 0x09 DW_FORM_block
-  DWARFFormValue::FC_Block,         // 0x0a DW_FORM_block1
-  DWARFFormValue::FC_Constant,      // 0x0b DW_FORM_data1
-  DWARFFormValue::FC_Flag,          // 0x0c DW_FORM_flag
-  DWARFFormValue::FC_Constant,      // 0x0d DW_FORM_sdata
-  DWARFFormValue::FC_String,        // 0x0e DW_FORM_strp
-  DWARFFormValue::FC_Constant,      // 0x0f DW_FORM_udata
-  DWARFFormValue::FC_Reference,     // 0x10 DW_FORM_ref_addr
-  DWARFFormValue::FC_Reference,     // 0x11 DW_FORM_ref1
-  DWARFFormValue::FC_Reference,     // 0x12 DW_FORM_ref2
-  DWARFFormValue::FC_Reference,     // 0x13 DW_FORM_ref4
-  DWARFFormValue::FC_Reference,     // 0x14 DW_FORM_ref8
-  DWARFFormValue::FC_Reference,     // 0x15 DW_FORM_ref_udata
-  DWARFFormValue::FC_Indirect,      // 0x16 DW_FORM_indirect
-  DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset
-  DWARFFormValue::FC_Exprloc,       // 0x18 DW_FORM_exprloc
-  DWARFFormValue::FC_Flag,          // 0x19 DW_FORM_flag_present
-};
-
-namespace {
-
-/// A helper class that can be used in DWARFFormValue.cpp functions that need
-/// to know the byte size of DW_FORM values that vary in size depending on the
-/// DWARF version, address byte size, or DWARF32 or DWARF64.
-class FormSizeHelper {
-  uint16_t Version;
-  uint8_t AddrSize;
-  llvm::dwarf::DwarfFormat Format;
-
-public:
-  FormSizeHelper(uint16_t V, uint8_t A, llvm::dwarf::DwarfFormat F)
-  : Version(V), AddrSize(A), Format(F) {}
-  uint8_t getAddressByteSize() const { return AddrSize; }
-  uint8_t getRefAddrByteSize() const {
-    if (Version == 2)
-      return AddrSize;
-    return getDwarfOffsetByteSize();
-  }
-  uint8_t getDwarfOffsetByteSize() const {
-    switch (Format) {
-      case dwarf::DwarfFormat::DWARF32:
-        return 4;
-      case dwarf::DwarfFormat::DWARF64:
-        return 8;
-    }
-    llvm_unreachable("Invalid Format value");
-  }
+    DWARFFormValue::FC_Unknown,  // 0x0
+    DWARFFormValue::FC_Address,  // 0x01 DW_FORM_addr
+    DWARFFormValue::FC_Unknown,  // 0x02 unused
+    DWARFFormValue::FC_Block,    // 0x03 DW_FORM_block2
+    DWARFFormValue::FC_Block,    // 0x04 DW_FORM_block4
+    DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2
+    // --- These can be FC_SectionOffset in DWARF3 and below:
+    DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4
+    DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8
+    // ---
+    DWARFFormValue::FC_String,        // 0x08 DW_FORM_string
+    DWARFFormValue::FC_Block,         // 0x09 DW_FORM_block
+    DWARFFormValue::FC_Block,         // 0x0a DW_FORM_block1
+    DWARFFormValue::FC_Constant,      // 0x0b DW_FORM_data1
+    DWARFFormValue::FC_Flag,          // 0x0c DW_FORM_flag
+    DWARFFormValue::FC_Constant,      // 0x0d DW_FORM_sdata
+    DWARFFormValue::FC_String,        // 0x0e DW_FORM_strp
+    DWARFFormValue::FC_Constant,      // 0x0f DW_FORM_udata
+    DWARFFormValue::FC_Reference,     // 0x10 DW_FORM_ref_addr
+    DWARFFormValue::FC_Reference,     // 0x11 DW_FORM_ref1
+    DWARFFormValue::FC_Reference,     // 0x12 DW_FORM_ref2
+    DWARFFormValue::FC_Reference,     // 0x13 DW_FORM_ref4
+    DWARFFormValue::FC_Reference,     // 0x14 DW_FORM_ref8
+    DWARFFormValue::FC_Reference,     // 0x15 DW_FORM_ref_udata
+    DWARFFormValue::FC_Indirect,      // 0x16 DW_FORM_indirect
+    DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset
+    DWARFFormValue::FC_Exprloc,       // 0x18 DW_FORM_exprloc
+    DWARFFormValue::FC_Flag,          // 0x19 DW_FORM_flag_present
 };
 
-} // end anonymous namespace
-
-template <class T>
-static Optional<uint8_t> getFixedByteSize(dwarf::Form Form, const T *U) {
+Optional<uint8_t>
+DWARFFormValue::getFixedByteSize(dwarf::Form Form,
+                                 const DWARFFormParams Params) {
   switch (Form) {
-    case DW_FORM_addr:
-      if (U)
-        return U->getAddressByteSize();
-      return None;
+  case DW_FORM_addr:
+    assert(Params.Version && Params.AddrSize && "Invalid Params for form");
+    return Params.AddrSize;
+
+  case DW_FORM_block:          // ULEB128 length L followed by L bytes.
+  case DW_FORM_block1:         // 1 byte length L followed by L bytes.
+  case DW_FORM_block2:         // 2 byte length L followed by L bytes.
+  case DW_FORM_block4:         // 4 byte length L followed by L bytes.
+  case DW_FORM_string:         // C-string with null terminator.
+  case DW_FORM_sdata:          // SLEB128.
+  case DW_FORM_udata:          // ULEB128.
+  case DW_FORM_ref_udata:      // ULEB128.
+  case DW_FORM_indirect:       // ULEB128.
+  case DW_FORM_exprloc:        // ULEB128 length L followed by L bytes.
+  case DW_FORM_strx:           // ULEB128.
+  case DW_FORM_addrx:          // ULEB128.
+  case DW_FORM_loclistx:       // ULEB128.
+  case DW_FORM_rnglistx:       // ULEB128.
+  case DW_FORM_GNU_addr_index: // ULEB128.
+  case DW_FORM_GNU_str_index:  // ULEB128.
+    return None;
 
-    case DW_FORM_block:          // ULEB128 length L followed by L bytes.
-    case DW_FORM_block1:         // 1 byte length L followed by L bytes.
-    case DW_FORM_block2:         // 2 byte length L followed by L bytes.
-    case DW_FORM_block4:         // 4 byte length L followed by L bytes.
-    case DW_FORM_string:         // C-string with null terminator.
-    case DW_FORM_sdata:          // SLEB128.
-    case DW_FORM_udata:          // ULEB128.
-    case DW_FORM_ref_udata:      // ULEB128.
-    case DW_FORM_indirect:       // ULEB128.
-    case DW_FORM_exprloc:        // ULEB128 length L followed by L bytes.
-    case DW_FORM_strx:           // ULEB128.
-    case DW_FORM_addrx:          // ULEB128.
-    case DW_FORM_loclistx:       // ULEB128.
-    case DW_FORM_rnglistx:       // ULEB128.
-    case DW_FORM_GNU_addr_index: // ULEB128.
-    case DW_FORM_GNU_str_index:  // ULEB128.
-      return None;
+  case DW_FORM_ref_addr:
+    assert(Params.Version && Params.AddrSize && "Invalid Params for form");
+    return Params.getRefAddrByteSize();
 
-    case DW_FORM_ref_addr:
-      if (U)
-        return U->getRefAddrByteSize();
-      return None;
+  case DW_FORM_flag:
+  case DW_FORM_data1:
+  case DW_FORM_ref1:
+  case DW_FORM_strx1:
+  case DW_FORM_addrx1:
+    return 1;
 
-    case DW_FORM_flag:
-    case DW_FORM_data1:
-    case DW_FORM_ref1:
-      return 1;
+  case DW_FORM_data2:
+  case DW_FORM_ref2:
+  case DW_FORM_strx2:
+  case DW_FORM_addrx2:
+    return 2;
 
-    case DW_FORM_data2:
-    case DW_FORM_ref2:
-      return 2;
+  case DW_FORM_strx3:
+    return 3;
 
-    case DW_FORM_data4:
-    case DW_FORM_ref4:
-      return 4;
+  case DW_FORM_data4:
+  case DW_FORM_ref4:
+  case DW_FORM_ref_sup4:
+  case DW_FORM_strx4:
+  case DW_FORM_addrx4:
+    return 4;
 
-    case DW_FORM_strp:
-    case DW_FORM_GNU_ref_alt:
-    case DW_FORM_GNU_strp_alt:
-    case DW_FORM_line_strp:
-    case DW_FORM_sec_offset:
-    case DW_FORM_strp_sup:
-    case DW_FORM_ref_sup:
-      if (U)
-        return U->getDwarfOffsetByteSize();
-      return None;
+  case DW_FORM_strp:
+  case DW_FORM_GNU_ref_alt:
+  case DW_FORM_GNU_strp_alt:
+  case DW_FORM_line_strp:
+  case DW_FORM_sec_offset:
+  case DW_FORM_strp_sup:
+    assert(Params.Version && Params.AddrSize && "Invalid Params for form");
+    return Params.getDwarfOffsetByteSize();
 
-    case DW_FORM_data8:
-    case DW_FORM_ref8:
-    case DW_FORM_ref_sig8:
-      return 8;
+  case DW_FORM_data8:
+  case DW_FORM_ref8:
+  case DW_FORM_ref_sig8:
+  case DW_FORM_ref_sup8:
+    return 8;
 
-    case DW_FORM_flag_present:
-      return 0;
+  case DW_FORM_flag_present:
+    return 0;
 
-    case DW_FORM_data16:
-      return 16;
+  case DW_FORM_data16:
+    return 16;
 
-    case DW_FORM_implicit_const:
-      // The implicit value is stored in the abbreviation as a SLEB128, and
-      // there no data in debug info.
-      return 0;
+  case DW_FORM_implicit_const:
+    // The implicit value is stored in the abbreviation as a SLEB128, and
+    // there no data in debug info.
+    return 0;
 
-    default:
-      llvm_unreachable("Handle this form in this switch statement");
+  default:
+    llvm_unreachable("Handle this form in this switch statement");
   }
   return None;
 }
 
-template <class T>
-static bool skipFormValue(dwarf::Form Form, const DataExtractor &DebugInfoData,
-                          uint32_t *OffsetPtr, const T *U) {
+bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData,
+                               uint32_t *OffsetPtr,
+                               const DWARFFormParams Params) {
   bool Indirect = false;
   do {
     switch (Form) {
-        // Blocks of inlined data that have a length field and the data bytes
-        // inlined in the .debug_info.
-      case DW_FORM_exprloc:
-      case DW_FORM_block: {
-        uint64_t size = DebugInfoData.getULEB128(OffsetPtr);
-        *OffsetPtr += size;
-        return true;
-      }
-      case DW_FORM_block1: {
-        uint8_t size = DebugInfoData.getU8(OffsetPtr);
-        *OffsetPtr += size;
-        return true;
-      }
-      case DW_FORM_block2: {
-        uint16_t size = DebugInfoData.getU16(OffsetPtr);
-        *OffsetPtr += size;
-        return true;
-      }
-      case DW_FORM_block4: {
-        uint32_t size = DebugInfoData.getU32(OffsetPtr);
-        *OffsetPtr += size;
+    // Blocks of inlined data that have a length field and the data bytes
+    // inlined in the .debug_info.
+    case DW_FORM_exprloc:
+    case DW_FORM_block: {
+      uint64_t size = DebugInfoData.getULEB128(OffsetPtr);
+      *OffsetPtr += size;
+      return true;
+    }
+    case DW_FORM_block1: {
+      uint8_t size = DebugInfoData.getU8(OffsetPtr);
+      *OffsetPtr += size;
+      return true;
+    }
+    case DW_FORM_block2: {
+      uint16_t size = DebugInfoData.getU16(OffsetPtr);
+      *OffsetPtr += size;
+      return true;
+    }
+    case DW_FORM_block4: {
+      uint32_t size = DebugInfoData.getU32(OffsetPtr);
+      *OffsetPtr += size;
+      return true;
+    }
+
+    // Inlined NULL terminated C-strings.
+    case DW_FORM_string:
+      DebugInfoData.getCStr(OffsetPtr);
+      return true;
+
+    case DW_FORM_addr:
+    case DW_FORM_ref_addr:
+    case DW_FORM_flag_present:
+    case DW_FORM_data1:
+    case DW_FORM_data2:
+    case DW_FORM_data4:
+    case DW_FORM_data8:
+    case DW_FORM_flag:
+    case DW_FORM_ref1:
+    case DW_FORM_ref2:
+    case DW_FORM_ref4:
+    case DW_FORM_ref8:
+    case DW_FORM_ref_sig8:
+    case DW_FORM_ref_sup4:
+    case DW_FORM_ref_sup8:
+    case DW_FORM_strx1:
+    case DW_FORM_strx2:
+    case DW_FORM_strx4:
+    case DW_FORM_addrx1:
+    case DW_FORM_addrx2:
+    case DW_FORM_addrx4:
+    case DW_FORM_sec_offset:
+    case DW_FORM_strp:
+    case DW_FORM_strp_sup:
+    case DW_FORM_line_strp:
+    case DW_FORM_GNU_ref_alt:
+    case DW_FORM_GNU_strp_alt:
+      if (Optional<uint8_t> FixedSize =
+              DWARFFormValue::getFixedByteSize(Form, Params)) {
+        *OffsetPtr += *FixedSize;
         return true;
       }
+      return false;
 
-        // Inlined NULL terminated C-strings.
-      case DW_FORM_string:
-        DebugInfoData.getCStr(OffsetPtr);
-        return true;
+    // signed or unsigned LEB 128 values.
+    case DW_FORM_sdata:
+      DebugInfoData.getSLEB128(OffsetPtr);
+      return true;
 
-      case DW_FORM_addr:
-      case DW_FORM_ref_addr:
-      case DW_FORM_flag_present:
-      case DW_FORM_data1:
-      case DW_FORM_data2:
-      case DW_FORM_data4:
-      case DW_FORM_data8:
-      case DW_FORM_flag:
-      case DW_FORM_ref1:
-      case DW_FORM_ref2:
-      case DW_FORM_ref4:
-      case DW_FORM_ref8:
-      case DW_FORM_ref_sig8:
-      case DW_FORM_ref_sup:
-      case DW_FORM_sec_offset:
-      case DW_FORM_strp:
-      case DW_FORM_strp_sup:
-      case DW_FORM_line_strp:
-      case DW_FORM_GNU_ref_alt:
-      case DW_FORM_GNU_strp_alt:
-        if (Optional<uint8_t> FixedSize = ::getFixedByteSize(Form, U)) {
-          *OffsetPtr += *FixedSize;
-          return true;
-        }
-        return false;
+    case DW_FORM_udata:
+    case DW_FORM_ref_udata:
+    case DW_FORM_strx:
+    case DW_FORM_addrx:
+    case DW_FORM_loclistx:
+    case DW_FORM_rnglistx:
+    case DW_FORM_GNU_addr_index:
+    case DW_FORM_GNU_str_index:
+      DebugInfoData.getULEB128(OffsetPtr);
+      return true;
 
-        // signed or unsigned LEB 128 values.
-      case DW_FORM_sdata:
-        DebugInfoData.getSLEB128(OffsetPtr);
-        return true;
+    case DW_FORM_indirect:
+      Indirect = true;
+      Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr));
+      break;
 
-      case DW_FORM_udata:
-      case DW_FORM_ref_udata:
-      case DW_FORM_strx:
-      case DW_FORM_addrx:
-      case DW_FORM_loclistx:
-      case DW_FORM_rnglistx:
-      case DW_FORM_GNU_addr_index:
-      case DW_FORM_GNU_str_index:
-        DebugInfoData.getULEB128(OffsetPtr);
-        return true;
-        
-      case DW_FORM_indirect:
-        Indirect = true;
-        Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr));
-        break;
-        
-      default:
-        return false;
+    default:
+      return false;
     }
   } while (Indirect);
   return true;
 }
 
-Optional<uint8_t> DWARFFormValue::getFixedByteSize(dwarf::Form Form,
-                                                   const DWARFUnit *U) {
-  return ::getFixedByteSize(Form, U);
-}
-
-Optional<uint8_t>
-DWARFFormValue::getFixedByteSize(dwarf::Form Form, uint16_t Version,
-                                 uint8_t AddrSize,
-                                 llvm::dwarf::DwarfFormat Format) {
-  FormSizeHelper FSH(Version, AddrSize, Format);
-  return ::getFixedByteSize(Form, &FSH);
-}
-
 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
   // First, check DWARF4 form classes.
   if (Form < makeArrayRef(DWARF4FormClasses).size() &&
@@ -279,6 +255,11 @@ bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
     return (FC == FC_Address);
   case DW_FORM_GNU_str_index:
   case DW_FORM_GNU_strp_alt:
+  case DW_FORM_strx:
+  case DW_FORM_strx1:
+  case DW_FORM_strx2:
+  case DW_FORM_strx3:
+  case DW_FORM_strx4:
     return (FC == FC_String);
   case DW_FORM_implicit_const:
     return (FC == FC_Constant);
@@ -287,178 +268,170 @@ bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
   }
   // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset.
   // Don't check for DWARF version here, as some producers may still do this
-  // by mistake.
-  return (Form == DW_FORM_data4 || Form == DW_FORM_data8) &&
+  // by mistake. Also accept DW_FORM_strp since this is .debug_str section
+  // offset.
+  return (Form == DW_FORM_data4 || Form == DW_FORM_data8 ||
+          Form == DW_FORM_strp) &&
          FC == FC_SectionOffset;
 }
 
-bool DWARFFormValue::extractValue(const DataExtractor &data, 
-                                  uint32_t *offset_ptr,
-                                  const DWARFUnit *cu) {
-  U = cu;
-  bool indirect = false;
-  bool is_block = false;
+bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
+                                  uint32_t *OffsetPtr, const DWARFUnit *CU) {
+  U = CU;
+  bool Indirect = false;
+  bool IsBlock = false;
   Value.data = nullptr;
   // Read the value for the form into value and follow and DW_FORM_indirect
   // instances we run into
   do {
-    indirect = false;
+    Indirect = false;
     switch (Form) {
     case DW_FORM_addr:
     case DW_FORM_ref_addr: {
       if (!U)
         return false;
-      uint16_t AddrSize =
-          (Form == DW_FORM_addr)
-              ? U->getAddressByteSize()
-              : U->getRefAddrByteSize();
-      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr);
-      if (AI != U->getRelocMap()->end()) {
-        Value.uval = data.getUnsigned(offset_ptr, AddrSize) + AI->second.second;
-      } else
-        Value.uval = data.getUnsigned(offset_ptr, AddrSize);
+      uint16_t Size = (Form == DW_FORM_addr) ? U->getAddressByteSize()
+                                             : U->getRefAddrByteSize();
+      Value.uval = Data.getRelocatedValue(Size, OffsetPtr, &Value.SectionIndex);
       break;
     }
     case DW_FORM_exprloc:
     case DW_FORM_block:
-      Value.uval = data.getULEB128(offset_ptr);
-      is_block = true;
+      Value.uval = Data.getULEB128(OffsetPtr);
+      IsBlock = true;
       break;
     case DW_FORM_block1:
-      Value.uval = data.getU8(offset_ptr);
-      is_block = true;
+      Value.uval = Data.getU8(OffsetPtr);
+      IsBlock = true;
       break;
     case DW_FORM_block2:
-      Value.uval = data.getU16(offset_ptr);
-      is_block = true;
+      Value.uval = Data.getU16(OffsetPtr);
+      IsBlock = true;
       break;
     case DW_FORM_block4:
-      Value.uval = data.getU32(offset_ptr);
-      is_block = true;
+      Value.uval = Data.getU32(OffsetPtr);
+      IsBlock = true;
       break;
     case DW_FORM_data1:
     case DW_FORM_ref1:
     case DW_FORM_flag:
-      Value.uval = data.getU8(offset_ptr);
+    case DW_FORM_strx1:
+    case DW_FORM_addrx1:
+      Value.uval = Data.getU8(OffsetPtr);
       break;
     case DW_FORM_data2:
     case DW_FORM_ref2:
-      Value.uval = data.getU16(offset_ptr);
+    case DW_FORM_strx2:
+    case DW_FORM_addrx2:
+      Value.uval = Data.getU16(OffsetPtr);
+      break;
+    case DW_FORM_strx3:
+      Value.uval = Data.getU24(OffsetPtr);
       break;
     case DW_FORM_data4:
-    case DW_FORM_ref4: {
-      Value.uval = data.getU32(offset_ptr);
-      if (!U)
-        break;
-      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr-4);
-      if (AI != U->getRelocMap()->end())
-        Value.uval += AI->second.second;
+    case DW_FORM_ref4:
+    case DW_FORM_ref_sup4:
+    case DW_FORM_strx4:
+    case DW_FORM_addrx4:
+      Value.uval = Data.getRelocatedValue(4, OffsetPtr);
       break;
-    }
     case DW_FORM_data8:
     case DW_FORM_ref8:
-      Value.uval = data.getU64(offset_ptr);
+    case DW_FORM_ref_sup8:
+      Value.uval = Data.getU64(OffsetPtr);
       break;
     case DW_FORM_sdata:
-      Value.sval = data.getSLEB128(offset_ptr);
+      Value.sval = Data.getSLEB128(OffsetPtr);
       break;
     case DW_FORM_udata:
     case DW_FORM_ref_udata:
-      Value.uval = data.getULEB128(offset_ptr);
+      Value.uval = Data.getULEB128(OffsetPtr);
       break;
     case DW_FORM_string:
-      Value.cstr = data.getCStr(offset_ptr);
+      Value.cstr = Data.getCStr(OffsetPtr);
       break;
     case DW_FORM_indirect:
-      Form = static_cast<dwarf::Form>(data.getULEB128(offset_ptr));
-      indirect = true;
+      Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr));
+      Indirect = true;
       break;
     case DW_FORM_strp:
     case DW_FORM_sec_offset:
     case DW_FORM_GNU_ref_alt:
     case DW_FORM_GNU_strp_alt:
     case DW_FORM_line_strp:
-    case DW_FORM_strp_sup:
-    case DW_FORM_ref_sup: {
+    case DW_FORM_strp_sup: {
       if (!U)
         return false;
-      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr);
-      uint8_t Size = U->getDwarfOffsetByteSize();
-      Value.uval = data.getUnsigned(offset_ptr, Size);
-      if (AI != U->getRelocMap()->end())
-        Value.uval += AI->second.second;
+      Value.uval =
+          Data.getRelocatedValue(U->getDwarfOffsetByteSize(), OffsetPtr);
       break;
     }
     case DW_FORM_flag_present:
       Value.uval = 1;
       break;
     case DW_FORM_ref_sig8:
-      Value.uval = data.getU64(offset_ptr);
+      Value.uval = Data.getU64(OffsetPtr);
       break;
     case DW_FORM_GNU_addr_index:
     case DW_FORM_GNU_str_index:
-      Value.uval = data.getULEB128(offset_ptr);
+    case DW_FORM_strx:
+      Value.uval = Data.getULEB128(OffsetPtr);
       break;
     default:
-      return false;
+      // DWARFFormValue::skipValue() will have caught this and caused all
+      // DWARF DIEs to fail to be parsed, so this code is not be reachable.
+      llvm_unreachable("unsupported form");
     }
-  } while (indirect);
+  } while (Indirect);
 
-  if (is_block) {
-    StringRef str = data.getData().substr(*offset_ptr, Value.uval);
+  if (IsBlock) {
+    StringRef Str = Data.getData().substr(*OffsetPtr, Value.uval);
     Value.data = nullptr;
-    if (!str.empty()) {
-      Value.data = reinterpret_cast<const uint8_t *>(str.data());
-      *offset_ptr += Value.uval;
+    if (!Str.empty()) {
+      Value.data = reinterpret_cast<const uint8_t *>(Str.data());
+      *OffsetPtr += Value.uval;
     }
   }
 
   return true;
 }
 
-bool DWARFFormValue::skipValue(DataExtractor DebugInfoData,
-                               uint32_t *offset_ptr, const DWARFUnit *U) const {
-  return DWARFFormValue::skipValue(Form, DebugInfoData, offset_ptr, U);
-}
-
-bool DWARFFormValue::skipValue(dwarf::Form form, DataExtractor DebugInfoData,
-                               uint32_t *offset_ptr, const DWARFUnit *U) {
-  return skipFormValue(form, DebugInfoData, offset_ptr, U);
-}
-
-bool DWARFFormValue::skipValue(dwarf::Form form, DataExtractor DebugInfoData,
-                               uint32_t *offset_ptr, uint16_t Version,
-                               uint8_t AddrSize,
-                               llvm::dwarf::DwarfFormat Format) {
-  FormSizeHelper FSH(Version, AddrSize, Format);
-  return skipFormValue(form, DebugInfoData, offset_ptr, &FSH);
-}
-
-void
-DWARFFormValue::dump(raw_ostream &OS) const {
-  uint64_t uvalue = Value.uval;
-  bool cu_relative_offset = false;
+void DWARFFormValue::dump(raw_ostream &OS) const {
+  uint64_t UValue = Value.uval;
+  bool CURelativeOffset = false;
 
   switch (Form) {
-  case DW_FORM_addr:      OS << format("0x%016" PRIx64, uvalue); break;
+  case DW_FORM_addr:
+    OS << format("0x%016" PRIx64, UValue);
+    break;
   case DW_FORM_GNU_addr_index: {
-    OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
+    OS << format(" indexed (%8.8x) address = ", (uint32_t)UValue);
     uint64_t Address;
     if (U == nullptr)
       OS << "<invalid dwarf unit>";
-    else if (U->getAddrOffsetSectionItem(uvalue, Address))
+    else if (U->getAddrOffsetSectionItem(UValue, Address))
       OS << format("0x%016" PRIx64, Address);
     else
       OS << "<no .debug_addr section>";
     break;
   }
-  case DW_FORM_flag_present: OS << "true"; break;
+  case DW_FORM_flag_present:
+    OS << "true";
+    break;
   case DW_FORM_flag:
-  case DW_FORM_data1:     OS << format("0x%02x", (uint8_t)uvalue); break;
-  case DW_FORM_data2:     OS << format("0x%04x", (uint16_t)uvalue); break;
-  case DW_FORM_data4:     OS << format("0x%08x", (uint32_t)uvalue); break;
+  case DW_FORM_data1:
+    OS << format("0x%02x", (uint8_t)UValue);
+    break;
+  case DW_FORM_data2:
+    OS << format("0x%04x", (uint16_t)UValue);
+    break;
+  case DW_FORM_data4:
+    OS << format("0x%08x", (uint32_t)UValue);
+    break;
   case DW_FORM_ref_sig8:
-  case DW_FORM_data8:     OS << format("0x%016" PRIx64, uvalue); break;
+  case DW_FORM_data8:
+    OS << format("0x%016" PRIx64, UValue);
+    break;
   case DW_FORM_string:
     OS << '"';
     OS.write_escaped(Value.cstr);
@@ -469,83 +442,97 @@ DWARFFormValue::dump(raw_ostream &OS) const {
   case DW_FORM_block1:
   case DW_FORM_block2:
   case DW_FORM_block4:
-    if (uvalue > 0) {
+    if (UValue > 0) {
       switch (Form) {
       case DW_FORM_exprloc:
-      case DW_FORM_block:  OS << format("<0x%" PRIx64 "> ", uvalue);     break;
-      case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue);  break;
-      case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break;
-      case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break;
-      default: break;
+      case DW_FORM_block:
+        OS << format("<0x%" PRIx64 "> ", UValue);
+        break;
+      case DW_FORM_block1:
+        OS << format("<0x%2.2x> ", (uint8_t)UValue);
+        break;
+      case DW_FORM_block2:
+        OS << format("<0x%4.4x> ", (uint16_t)UValue);
+        break;
+      case DW_FORM_block4:
+        OS << format("<0x%8.8x> ", (uint32_t)UValue);
+        break;
+      default:
+        break;
       }
 
-      const uint8_t* data_ptr = Value.data;
-      if (data_ptr) {
-        // uvalue contains size of block
-        const uint8_t* end_data_ptr = data_ptr + uvalue;
-        while (data_ptr < end_data_ptr) {
-          OS << format("%2.2x ", *data_ptr);
-          ++data_ptr;
+      const uint8_t *DataPtr = Value.data;
+      if (DataPtr) {
+        // UValue contains size of block
+        const uint8_t *EndDataPtr = DataPtr + UValue;
+        while (DataPtr < EndDataPtr) {
+          OS << format("%2.2x ", *DataPtr);
+          ++DataPtr;
         }
-      }
-      else
+      } else
         OS << "NULL";
     }
     break;
 
-  case DW_FORM_sdata:     OS << Value.sval; break;
-  case DW_FORM_udata:     OS << Value.uval; break;
-  case DW_FORM_strp: {
-    OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
+  case DW_FORM_sdata:
+    OS << Value.sval;
+    break;
+  case DW_FORM_udata:
+    OS << Value.uval;
+    break;
+  case DW_FORM_strp:
+    OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)UValue);
     dumpString(OS);
     break;
-  }
-  case DW_FORM_GNU_str_index: {
-    OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
+  case DW_FORM_strx:
+  case DW_FORM_strx1:
+  case DW_FORM_strx2:
+  case DW_FORM_strx3:
+  case DW_FORM_strx4:
+  case DW_FORM_GNU_str_index:
+    OS << format(" indexed (%8.8x) string = ", (uint32_t)UValue);
     dumpString(OS);
     break;
-  }
-  case DW_FORM_GNU_strp_alt: {
-    OS << format("alt indirect string, offset: 0x%" PRIx64 "", uvalue);
+  case DW_FORM_GNU_strp_alt:
+    OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue);
     dumpString(OS);
     break;
-  }
   case DW_FORM_ref_addr:
-    OS << format("0x%016" PRIx64, uvalue);
+    OS << format("0x%016" PRIx64, UValue);
     break;
   case DW_FORM_ref1:
-    cu_relative_offset = true;
-    OS << format("cu + 0x%2.2x", (uint8_t)uvalue);
+    CURelativeOffset = true;
+    OS << format("cu + 0x%2.2x", (uint8_t)UValue);
     break;
   case DW_FORM_ref2:
-    cu_relative_offset = true;
-    OS << format("cu + 0x%4.4x", (uint16_t)uvalue);
+    CURelativeOffset = true;
+    OS << format("cu + 0x%4.4x", (uint16_t)UValue);
     break;
   case DW_FORM_ref4:
-    cu_relative_offset = true;
-    OS << format("cu + 0x%4.4x", (uint32_t)uvalue);
+    CURelativeOffset = true;
+    OS << format("cu + 0x%4.4x", (uint32_t)UValue);
     break;
   case DW_FORM_ref8:
-    cu_relative_offset = true;
-    OS << format("cu + 0x%8.8" PRIx64, uvalue);
+    CURelativeOffset = true;
+    OS << format("cu + 0x%8.8" PRIx64, UValue);
     break;
   case DW_FORM_ref_udata:
-    cu_relative_offset = true;
-    OS << format("cu + 0x%" PRIx64, uvalue);
+    CURelativeOffset = true;
+    OS << format("cu + 0x%" PRIx64, UValue);
     break;
   case DW_FORM_GNU_ref_alt:
-    OS << format("<alt 0x%" PRIx64 ">", uvalue);
+    OS << format("<alt 0x%" PRIx64 ">", UValue);
     break;
 
-    // All DW_FORM_indirect attributes should be resolved prior to calling
-    // this function
+  // All DW_FORM_indirect attributes should be resolved prior to calling
+  // this function
   case DW_FORM_indirect:
     OS << "DW_FORM_indirect";
     break;
 
-    // Should be formatted to 64-bit for DWARF64.
+  // Should be formatted to 64-bit for DWARF64.
   case DW_FORM_sec_offset:
-    OS << format("0x%08x", (uint32_t)uvalue);
+    OS << format("0x%08x", (uint32_t)UValue);
     break;
 
   default:
@@ -553,10 +540,10 @@ DWARFFormValue::dump(raw_ostream &OS) const {
     break;
   }
 
-  if (cu_relative_offset) {
+  if (CURelativeOffset) {
     OS << " => {";
     WithColor(OS, syntax::Address).get()
-      << format("0x%8.8" PRIx64, uvalue + (U ? U->getOffset() : 0));
+        << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0));
     OS << "}";
   }
 }
@@ -580,8 +567,10 @@ Optional<const char *> DWARFFormValue::getAsCString() const {
   if (Form == DW_FORM_GNU_strp_alt || U == nullptr)
     return None;
   uint32_t Offset = Value.uval;
-  if (Form == DW_FORM_GNU_str_index) {
-    uint32_t StrOffset;
+  if (Form == DW_FORM_GNU_str_index || Form == DW_FORM_strx ||
+      Form == DW_FORM_strx1 || Form == DW_FORM_strx2 || Form == DW_FORM_strx3 ||
+      Form == DW_FORM_strx4) {
+    uint64_t StrOffset;
     if (!U->getStringOffsetSectionItem(Offset, StrOffset))
       return None;
     Offset = StrOffset;
@@ -633,15 +622,16 @@ Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const {
 }
 
 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const {
-  if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag))
-      || Form == DW_FORM_sdata)
+  if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) ||
+      Form == DW_FORM_sdata)
     return None;
   return Value.uval;
 }
 
 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const {
   if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) ||
-      (Form == DW_FORM_udata && uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval))
+      (Form == DW_FORM_udata &&
+       uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval))
     return None;
   switch (Form) {
   case DW_FORM_data4:
@@ -674,4 +664,3 @@ Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const {
     return None;
   return Value.uval;
 }
-