Restoring authorship annotation for <orivej@yandex-team.ru>. Commit 2 of 2.

1 files changed, 334 insertions, 334 deletions

diff --git a/contrib/libs/libunwind/src/AddressSpace.hpp b/contrib/libs/libunwind/src/AddressSpace.hpp
index d15d5302a7..0c4dfeb4e6 100644
--- a/contrib/libs/libunwind/src/AddressSpace.hpp
+++ b/contrib/libs/libunwind/src/AddressSpace.hpp
@@ -1,8 +1,8 @@
 //===----------------------------------------------------------------------===//
 //
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
-// See https://llvm.org/LICENSE.txt for license information. 
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //
 // Abstracts accessing local vs remote address spaces.
@@ -17,125 +17,125 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "libunwind.h" 
-#include "config.h" 
-#include "dwarf2.h" 
-#include "EHHeaderParser.hpp" 
-#include "Registers.hpp" 
- 
-#ifndef _LIBUNWIND_USE_DLADDR 
-  #if !defined(_LIBUNWIND_IS_BAREMETAL) && !defined(_WIN32) 
-    #define _LIBUNWIND_USE_DLADDR 1 
-  #else 
-    #define _LIBUNWIND_USE_DLADDR 0 
-  #endif 
-#endif 
- 
-#if _LIBUNWIND_USE_DLADDR 
+#include "libunwind.h"
+#include "config.h"
+#include "dwarf2.h"
+#include "EHHeaderParser.hpp"
+#include "Registers.hpp"
+
+#ifndef _LIBUNWIND_USE_DLADDR
+  #if !defined(_LIBUNWIND_IS_BAREMETAL) && !defined(_WIN32)
+    #define _LIBUNWIND_USE_DLADDR 1
+  #else
+    #define _LIBUNWIND_USE_DLADDR 0
+  #endif
+#endif
+
+#if _LIBUNWIND_USE_DLADDR
 #include <dlfcn.h>
-#if defined(__ELF__) && defined(_LIBUNWIND_LINK_DL_LIB) 
-#pragma comment(lib, "dl") 
+#if defined(__ELF__) && defined(_LIBUNWIND_LINK_DL_LIB)
+#pragma comment(lib, "dl")
+#endif
+#endif
+
+#if defined(_LIBUNWIND_ARM_EHABI)
+struct EHABIIndexEntry {
+  uint32_t functionOffset;
+  uint32_t data;
+};
 #endif
-#endif 
-
-#if defined(_LIBUNWIND_ARM_EHABI) 
-struct EHABIIndexEntry { 
-  uint32_t functionOffset; 
-  uint32_t data; 
-}; 
-#endif 
- 
+
 #ifdef __APPLE__
 
-  struct dyld_unwind_sections 
-  { 
-    const struct mach_header*   mh; 
-    const void*                 dwarf_section; 
-    uintptr_t                   dwarf_section_length; 
-    const void*                 compact_unwind_section; 
-    uintptr_t                   compact_unwind_section_length; 
-  }; 
+  struct dyld_unwind_sections
+  {
+    const struct mach_header*   mh;
+    const void*                 dwarf_section;
+    uintptr_t                   dwarf_section_length;
+    const void*                 compact_unwind_section;
+    uintptr_t                   compact_unwind_section_length;
+  };
+
+  // In 10.7.0 or later, libSystem.dylib implements this function.
+  extern "C" bool _dyld_find_unwind_sections(void *, dyld_unwind_sections *);
 
-  // In 10.7.0 or later, libSystem.dylib implements this function. 
-  extern "C" bool _dyld_find_unwind_sections(void *, dyld_unwind_sections *); 
+#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_LIBUNWIND_IS_BAREMETAL)
 
-#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_LIBUNWIND_IS_BAREMETAL) 
- 
 // When statically linked on bare-metal, the symbols for the EH table are looked
 // up without going through the dynamic loader.
 
-// The following linker script may be used to produce the necessary sections and symbols. 
-// Unless the --eh-frame-hdr linker option is provided, the section is not generated 
-// and does not take space in the output file. 
-// 
-//   .eh_frame : 
-//   { 
-//       __eh_frame_start = .; 
-//       KEEP(*(.eh_frame)) 
-//       __eh_frame_end = .; 
-//   } 
-// 
-//   .eh_frame_hdr : 
-//   { 
-//       KEEP(*(.eh_frame_hdr)) 
-//   } 
-// 
-//   __eh_frame_hdr_start = SIZEOF(.eh_frame_hdr) > 0 ? ADDR(.eh_frame_hdr) : 0; 
-//   __eh_frame_hdr_end = SIZEOF(.eh_frame_hdr) > 0 ? . : 0; 
- 
-extern char __eh_frame_start; 
-extern char __eh_frame_end; 
- 
-#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 
-extern char __eh_frame_hdr_start; 
-extern char __eh_frame_hdr_end; 
-#endif 
- 
-#elif defined(_LIBUNWIND_ARM_EHABI) && defined(_LIBUNWIND_IS_BAREMETAL) 
- 
-// When statically linked on bare-metal, the symbols for the EH table are looked 
-// up without going through the dynamic loader. 
-extern char __exidx_start; 
-extern char __exidx_end; 
- 
-#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_WIN32) 
- 
-#include <windows.h> 
-#include <psapi.h> 
- 
-#elif defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) ||                               \ 
-      defined(_LIBUNWIND_USE_DL_UNWIND_FIND_EXIDX) 
- 
-#include <link.h> 
- 
+// The following linker script may be used to produce the necessary sections and symbols.
+// Unless the --eh-frame-hdr linker option is provided, the section is not generated
+// and does not take space in the output file.
+//
+//   .eh_frame :
+//   {
+//       __eh_frame_start = .;
+//       KEEP(*(.eh_frame))
+//       __eh_frame_end = .;
+//   }
+//
+//   .eh_frame_hdr :
+//   {
+//       KEEP(*(.eh_frame_hdr))
+//   }
+//
+//   __eh_frame_hdr_start = SIZEOF(.eh_frame_hdr) > 0 ? ADDR(.eh_frame_hdr) : 0;
+//   __eh_frame_hdr_end = SIZEOF(.eh_frame_hdr) > 0 ? . : 0;
+
+extern char __eh_frame_start;
+extern char __eh_frame_end;
+
+#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
+extern char __eh_frame_hdr_start;
+extern char __eh_frame_hdr_end;
+#endif
+
+#elif defined(_LIBUNWIND_ARM_EHABI) && defined(_LIBUNWIND_IS_BAREMETAL)
+
+// When statically linked on bare-metal, the symbols for the EH table are looked
+// up without going through the dynamic loader.
+extern char __exidx_start;
+extern char __exidx_end;
+
+#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_WIN32)
+
+#include <windows.h>
+#include <psapi.h>
+
+#elif defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) ||                               \
+      defined(_LIBUNWIND_USE_DL_UNWIND_FIND_EXIDX)
+
+#include <link.h>
+
 #endif
 
 namespace libunwind {
 
 /// Used by findUnwindSections() to return info about needed sections.
 struct UnwindInfoSections {
-#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) ||                                \ 
-    defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) ||                              \ 
-    defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) 
-  // No dso_base for SEH. 
+#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) ||                                \
+    defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) ||                              \
+    defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
+  // No dso_base for SEH.
   uintptr_t       dso_base;
 #endif
-#if defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) 
+#if defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
   size_t          text_segment_length;
-#endif 
-#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 
+#endif
+#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
   uintptr_t       dwarf_section;
   size_t          dwarf_section_length;
 #endif
-#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 
+#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
   uintptr_t       dwarf_index_section;
   size_t          dwarf_index_section_length;
 #endif
-#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 
+#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
   uintptr_t       compact_unwind_section;
   size_t          compact_unwind_section_length;
 #endif
-#if defined(_LIBUNWIND_ARM_EHABI) 
+#if defined(_LIBUNWIND_ARM_EHABI)
   uintptr_t       arm_section;
   size_t          arm_section_length;
 #endif
@@ -145,10 +145,10 @@ struct UnwindInfoSections {
 /// LocalAddressSpace is used as a template parameter to UnwindCursor when
 /// unwinding a thread in the same process.  The wrappers compile away,
 /// making local unwinds fast.
-class _LIBUNWIND_HIDDEN LocalAddressSpace { 
+class _LIBUNWIND_HIDDEN LocalAddressSpace {
 public:
-  typedef uintptr_t pint_t; 
-  typedef intptr_t  sint_t; 
+  typedef uintptr_t pint_t;
+  typedef intptr_t  sint_t;
   uint8_t         get8(pint_t addr) {
     uint8_t val;
     memcpy(&val, (void *)addr, sizeof(val));
@@ -180,7 +180,7 @@ public:
     return val;
   }
   uintptr_t       getP(pint_t addr);
-  uint64_t        getRegister(pint_t addr); 
+  uint64_t        getRegister(pint_t addr);
   static uint64_t getULEB128(pint_t &addr, pint_t end);
   static int64_t  getSLEB128(pint_t &addr, pint_t end);
 
@@ -195,21 +195,21 @@ public:
 };
 
 inline uintptr_t LocalAddressSpace::getP(pint_t addr) {
-#if __SIZEOF_POINTER__ == 8 
+#if __SIZEOF_POINTER__ == 8
+  return get64(addr);
+#else
+  return get32(addr);
+#endif
+}
+
+inline uint64_t LocalAddressSpace::getRegister(pint_t addr) {
+#if __SIZEOF_POINTER__ == 8 || defined(__mips64)
   return get64(addr);
 #else
   return get32(addr);
 #endif
 }
 
-inline uint64_t LocalAddressSpace::getRegister(pint_t addr) { 
-#if __SIZEOF_POINTER__ == 8 || defined(__mips64) 
-  return get64(addr); 
-#else 
-  return get32(addr); 
-#endif 
-} 
- 
 /// Read a ULEB128 into a 64-bit word.
 inline uint64_t LocalAddressSpace::getULEB128(pint_t &addr, pint_t end) {
   const uint8_t *p = (uint8_t *)addr;
@@ -246,11 +246,11 @@ inline int64_t LocalAddressSpace::getSLEB128(pint_t &addr, pint_t end) {
     if (p == pend)
       _LIBUNWIND_ABORT("truncated sleb128 expression");
     byte = *p++;
-    result |= (uint64_t)(byte & 0x7f) << bit; 
+    result |= (uint64_t)(byte & 0x7f) << bit;
     bit += 7;
   } while (byte & 0x80);
   // sign extend negative numbers
-  if ((byte & 0x40) != 0 && bit < 64) 
+  if ((byte & 0x40) != 0 && bit < 64)
     result |= (-1ULL) << bit;
   addr = (pint_t) p;
   return result;
@@ -348,163 +348,163 @@ LocalAddressSpace::getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
   return result;
 }
 
-#if defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) 
- 
-// The ElfW() macro for pointer-size independent ELF header traversal is not 
-// provided by <link.h> on some systems (e.g., FreeBSD). On these systems the 
-// data structures are just called Elf_XXX. Define ElfW() locally. 
-#if !defined(ElfW) 
-  #define ElfW(type) Elf_##type 
-#endif 
-#if !defined(Elf_Half) 
-  typedef ElfW(Half) Elf_Half; 
-#endif 
-#if !defined(Elf_Phdr) 
-  typedef ElfW(Phdr) Elf_Phdr; 
-#endif 
-#if !defined(Elf_Addr) 
-  typedef ElfW(Addr) Elf_Addr; 
-#endif 
- 
-static Elf_Addr calculateImageBase(struct dl_phdr_info *pinfo) { 
-  Elf_Addr image_base = pinfo->dlpi_addr; 
-#if defined(__ANDROID__) && __ANDROID_API__ < 18 
-  if (image_base == 0) { 
-    // Normally, an image base of 0 indicates a non-PIE executable. On 
-    // versions of Android prior to API 18, the dynamic linker reported a 
-    // dlpi_addr of 0 for PIE executables. Compute the true image base 
-    // using the PT_PHDR segment. 
-    // See https://github.com/android/ndk/issues/505. 
-    for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) { 
-      const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i]; 
-      if (phdr->p_type == PT_PHDR) { 
-        image_base = reinterpret_cast<Elf_Addr>(pinfo->dlpi_phdr) - 
-          phdr->p_vaddr; 
-        break; 
-      } 
-    } 
-  } 
-#endif 
-  return image_base; 
-} 
- 
-struct _LIBUNWIND_HIDDEN dl_iterate_cb_data { 
-  LocalAddressSpace *addressSpace; 
-  UnwindInfoSections *sects; 
-  uintptr_t targetAddr; 
-}; 
- 
-#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE) 
-#include "FrameHeaderCache.hpp" 
- 
-// Typically there is one cache per process, but when libunwind is built as a 
-// hermetic static library, then each shared object may have its own cache. 
-static FrameHeaderCache TheFrameHeaderCache; 
-#endif 
- 
-static bool checkAddrInSegment(const Elf_Phdr *phdr, size_t image_base, 
-                               dl_iterate_cb_data *cbdata) { 
-  if (phdr->p_type == PT_LOAD) { 
-    uintptr_t begin = image_base + phdr->p_vaddr; 
-    uintptr_t end = begin + phdr->p_memsz; 
-    if (cbdata->targetAddr >= begin && cbdata->targetAddr < end) { 
-      cbdata->sects->dso_base = begin; 
-      cbdata->sects->text_segment_length = phdr->p_memsz; 
-      return true; 
-    } 
-  } 
-  return false; 
-} 
- 
-static bool checkForUnwindInfoSegment(const Elf_Phdr *phdr, size_t image_base, 
-                                      dl_iterate_cb_data *cbdata) { 
-#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 
-  if (phdr->p_type == PT_GNU_EH_FRAME) { 
-    EHHeaderParser<LocalAddressSpace>::EHHeaderInfo hdrInfo; 
-    uintptr_t eh_frame_hdr_start = image_base + phdr->p_vaddr; 
-    cbdata->sects->dwarf_index_section = eh_frame_hdr_start; 
-    cbdata->sects->dwarf_index_section_length = phdr->p_memsz; 
-    if (EHHeaderParser<LocalAddressSpace>::decodeEHHdr( 
-            *cbdata->addressSpace, eh_frame_hdr_start, phdr->p_memsz, 
-            hdrInfo)) { 
-      // .eh_frame_hdr records the start of .eh_frame, but not its size. 
-      // Rely on a zero terminator to find the end of the section. 
-      cbdata->sects->dwarf_section = hdrInfo.eh_frame_ptr; 
+#if defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
+
+// The ElfW() macro for pointer-size independent ELF header traversal is not
+// provided by <link.h> on some systems (e.g., FreeBSD). On these systems the
+// data structures are just called Elf_XXX. Define ElfW() locally.
+#if !defined(ElfW)
+  #define ElfW(type) Elf_##type
+#endif
+#if !defined(Elf_Half)
+  typedef ElfW(Half) Elf_Half;
+#endif
+#if !defined(Elf_Phdr)
+  typedef ElfW(Phdr) Elf_Phdr;
+#endif
+#if !defined(Elf_Addr)
+  typedef ElfW(Addr) Elf_Addr;
+#endif
+
+static Elf_Addr calculateImageBase(struct dl_phdr_info *pinfo) {
+  Elf_Addr image_base = pinfo->dlpi_addr;
+#if defined(__ANDROID__) && __ANDROID_API__ < 18
+  if (image_base == 0) {
+    // Normally, an image base of 0 indicates a non-PIE executable. On
+    // versions of Android prior to API 18, the dynamic linker reported a
+    // dlpi_addr of 0 for PIE executables. Compute the true image base
+    // using the PT_PHDR segment.
+    // See https://github.com/android/ndk/issues/505.
+    for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) {
+      const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i];
+      if (phdr->p_type == PT_PHDR) {
+        image_base = reinterpret_cast<Elf_Addr>(pinfo->dlpi_phdr) -
+          phdr->p_vaddr;
+        break;
+      }
+    }
+  }
+#endif
+  return image_base;
+}
+
+struct _LIBUNWIND_HIDDEN dl_iterate_cb_data {
+  LocalAddressSpace *addressSpace;
+  UnwindInfoSections *sects;
+  uintptr_t targetAddr;
+};
+
+#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE)
+#include "FrameHeaderCache.hpp"
+
+// Typically there is one cache per process, but when libunwind is built as a
+// hermetic static library, then each shared object may have its own cache.
+static FrameHeaderCache TheFrameHeaderCache;
+#endif
+
+static bool checkAddrInSegment(const Elf_Phdr *phdr, size_t image_base,
+                               dl_iterate_cb_data *cbdata) {
+  if (phdr->p_type == PT_LOAD) {
+    uintptr_t begin = image_base + phdr->p_vaddr;
+    uintptr_t end = begin + phdr->p_memsz;
+    if (cbdata->targetAddr >= begin && cbdata->targetAddr < end) {
+      cbdata->sects->dso_base = begin;
+      cbdata->sects->text_segment_length = phdr->p_memsz;
+      return true;
+    }
+  }
+  return false;
+}
+
+static bool checkForUnwindInfoSegment(const Elf_Phdr *phdr, size_t image_base,
+                                      dl_iterate_cb_data *cbdata) {
+#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
+  if (phdr->p_type == PT_GNU_EH_FRAME) {
+    EHHeaderParser<LocalAddressSpace>::EHHeaderInfo hdrInfo;
+    uintptr_t eh_frame_hdr_start = image_base + phdr->p_vaddr;
+    cbdata->sects->dwarf_index_section = eh_frame_hdr_start;
+    cbdata->sects->dwarf_index_section_length = phdr->p_memsz;
+    if (EHHeaderParser<LocalAddressSpace>::decodeEHHdr(
+            *cbdata->addressSpace, eh_frame_hdr_start, phdr->p_memsz,
+            hdrInfo)) {
+      // .eh_frame_hdr records the start of .eh_frame, but not its size.
+      // Rely on a zero terminator to find the end of the section.
+      cbdata->sects->dwarf_section = hdrInfo.eh_frame_ptr;
       cbdata->sects->dwarf_section_length = SIZE_MAX;
-      return true; 
-    } 
-  } 
-  return false; 
-#elif defined(_LIBUNWIND_ARM_EHABI) 
-  if (phdr->p_type == PT_ARM_EXIDX) { 
-    uintptr_t exidx_start = image_base + phdr->p_vaddr; 
-    cbdata->sects->arm_section = exidx_start; 
-    cbdata->sects->arm_section_length = phdr->p_memsz; 
-    return true; 
-  } 
-  return false; 
-#else 
-#error Need one of _LIBUNWIND_SUPPORT_DWARF_INDEX or _LIBUNWIND_ARM_EHABI 
-#endif 
-} 
- 
-static int findUnwindSectionsByPhdr(struct dl_phdr_info *pinfo, 
-                                    size_t pinfo_size, void *data) { 
-  auto cbdata = static_cast<dl_iterate_cb_data *>(data); 
-  if (pinfo->dlpi_phnum == 0 || cbdata->targetAddr < pinfo->dlpi_addr) 
-    return 0; 
-#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE) 
-  if (TheFrameHeaderCache.find(pinfo, pinfo_size, data)) 
-    return 1; 
-#else 
-  // Avoid warning about unused variable. 
-  (void)pinfo_size; 
-#endif 
- 
-  Elf_Addr image_base = calculateImageBase(pinfo); 
- 
-  // Most shared objects seen in this callback function likely don't contain the 
-  // target address, so optimize for that. Scan for a matching PT_LOAD segment 
-  // first and bail when it isn't found. 
-  bool found_text = false; 
-  for (Elf_Half i = 0; i < pinfo->dlpi_phnum; ++i) { 
-    if (checkAddrInSegment(&pinfo->dlpi_phdr[i], image_base, cbdata)) { 
-      found_text = true; 
-      break; 
-    } 
-  } 
-  if (!found_text) 
-    return 0; 
- 
-  // PT_GNU_EH_FRAME and PT_ARM_EXIDX are usually near the end. Iterate 
-  // backward. 
-  bool found_unwind = false; 
-  for (Elf_Half i = pinfo->dlpi_phnum; i > 0; i--) { 
-    const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i - 1]; 
-    if (checkForUnwindInfoSegment(phdr, image_base, cbdata)) { 
-      found_unwind = true; 
-      break; 
-    } 
-  } 
-  if (!found_unwind) 
-    return 0; 
- 
-#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE) 
-  TheFrameHeaderCache.add(cbdata->sects); 
-#endif 
-  return 1; 
-} 
- 
-#endif  // defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) 
- 
- 
+      return true;
+    }
+  }
+  return false;
+#elif defined(_LIBUNWIND_ARM_EHABI)
+  if (phdr->p_type == PT_ARM_EXIDX) {
+    uintptr_t exidx_start = image_base + phdr->p_vaddr;
+    cbdata->sects->arm_section = exidx_start;
+    cbdata->sects->arm_section_length = phdr->p_memsz;
+    return true;
+  }
+  return false;
+#else
+#error Need one of _LIBUNWIND_SUPPORT_DWARF_INDEX or _LIBUNWIND_ARM_EHABI
+#endif
+}
+
+static int findUnwindSectionsByPhdr(struct dl_phdr_info *pinfo,
+                                    size_t pinfo_size, void *data) {
+  auto cbdata = static_cast<dl_iterate_cb_data *>(data);
+  if (pinfo->dlpi_phnum == 0 || cbdata->targetAddr < pinfo->dlpi_addr)
+    return 0;
+#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE)
+  if (TheFrameHeaderCache.find(pinfo, pinfo_size, data))
+    return 1;
+#else
+  // Avoid warning about unused variable.
+  (void)pinfo_size;
+#endif
+
+  Elf_Addr image_base = calculateImageBase(pinfo);
+
+  // Most shared objects seen in this callback function likely don't contain the
+  // target address, so optimize for that. Scan for a matching PT_LOAD segment
+  // first and bail when it isn't found.
+  bool found_text = false;
+  for (Elf_Half i = 0; i < pinfo->dlpi_phnum; ++i) {
+    if (checkAddrInSegment(&pinfo->dlpi_phdr[i], image_base, cbdata)) {
+      found_text = true;
+      break;
+    }
+  }
+  if (!found_text)
+    return 0;
+
+  // PT_GNU_EH_FRAME and PT_ARM_EXIDX are usually near the end. Iterate
+  // backward.
+  bool found_unwind = false;
+  for (Elf_Half i = pinfo->dlpi_phnum; i > 0; i--) {
+    const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i - 1];
+    if (checkForUnwindInfoSegment(phdr, image_base, cbdata)) {
+      found_unwind = true;
+      break;
+    }
+  }
+  if (!found_unwind)
+    return 0;
+
+#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE)
+  TheFrameHeaderCache.add(cbdata->sects);
+#endif
+  return 1;
+}
+
+#endif  // defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
+
+
 inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr,
                                                   UnwindInfoSections &info) {
 #ifdef __APPLE__
   dyld_unwind_sections dyldInfo;
   if (_dyld_find_unwind_sections((void *)targetAddr, &dyldInfo)) {
     info.dso_base                      = (uintptr_t)dyldInfo.mh;
- #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 
+ #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
     info.dwarf_section                 = (uintptr_t)dyldInfo.dwarf_section;
     info.dwarf_section_length          = (size_t)dyldInfo.dwarf_section_length;
  #endif
@@ -512,84 +512,84 @@ inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr,
     info.compact_unwind_section_length = (size_t)dyldInfo.compact_unwind_section_length;
     return true;
   }
-#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_LIBUNWIND_IS_BAREMETAL) 
-  info.dso_base = 0; 
+#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_LIBUNWIND_IS_BAREMETAL)
+  info.dso_base = 0;
   // Bare metal is statically linked, so no need to ask the dynamic loader
   info.dwarf_section_length = (size_t)(&__eh_frame_end - &__eh_frame_start);
-  info.dwarf_section =        (uintptr_t)(&__eh_frame_start); 
-  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: section %p length %p", 
-                             (void *)info.dwarf_section, (void *)info.dwarf_section_length); 
-#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 
-  info.dwarf_index_section =        (uintptr_t)(&__eh_frame_hdr_start); 
+  info.dwarf_section =        (uintptr_t)(&__eh_frame_start);
+  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: section %p length %p",
+                             (void *)info.dwarf_section, (void *)info.dwarf_section_length);
+#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
+  info.dwarf_index_section =        (uintptr_t)(&__eh_frame_hdr_start);
   info.dwarf_index_section_length = (size_t)(&__eh_frame_hdr_end - &__eh_frame_hdr_start);
-  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: index section %p length %p", 
-                             (void *)info.dwarf_index_section, (void *)info.dwarf_index_section_length); 
-#endif 
-  if (info.dwarf_section_length) 
-    return true; 
-#elif defined(_LIBUNWIND_ARM_EHABI) && defined(_LIBUNWIND_IS_BAREMETAL) 
-  // Bare metal is statically linked, so no need to ask the dynamic loader 
+  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: index section %p length %p",
+                             (void *)info.dwarf_index_section, (void *)info.dwarf_index_section_length);
+#endif
+  if (info.dwarf_section_length)
+    return true;
+#elif defined(_LIBUNWIND_ARM_EHABI) && defined(_LIBUNWIND_IS_BAREMETAL)
+  // Bare metal is statically linked, so no need to ask the dynamic loader
   info.arm_section =        (uintptr_t)(&__exidx_start);
   info.arm_section_length = (size_t)(&__exidx_end - &__exidx_start);
-  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: section %p length %p", 
-                             (void *)info.arm_section, (void *)info.arm_section_length); 
-  if (info.arm_section && info.arm_section_length) 
-    return true; 
-#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_WIN32) 
-  HMODULE mods[1024]; 
-  HANDLE process = GetCurrentProcess(); 
-  DWORD needed; 
- 
-  if (!EnumProcessModules(process, mods, sizeof(mods), &needed)) { 
-    DWORD err = GetLastError(); 
-    _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: EnumProcessModules failed, " 
-                               "returned error %d", (int)err); 
-    return false; 
-  } 
- 
-  for (unsigned i = 0; i < (needed / sizeof(HMODULE)); i++) { 
-    PIMAGE_DOS_HEADER pidh = (PIMAGE_DOS_HEADER)mods[i]; 
-    PIMAGE_NT_HEADERS pinh = (PIMAGE_NT_HEADERS)((BYTE *)pidh + pidh->e_lfanew); 
-    PIMAGE_FILE_HEADER pifh = (PIMAGE_FILE_HEADER)&pinh->FileHeader; 
-    PIMAGE_SECTION_HEADER pish = IMAGE_FIRST_SECTION(pinh); 
-    bool found_obj = false; 
-    bool found_hdr = false; 
- 
-    info.dso_base = (uintptr_t)mods[i]; 
-    for (unsigned j = 0; j < pifh->NumberOfSections; j++, pish++) { 
-      uintptr_t begin = pish->VirtualAddress + (uintptr_t)mods[i]; 
-      uintptr_t end = begin + pish->Misc.VirtualSize; 
-      if (!strncmp((const char *)pish->Name, ".text", 
-                   IMAGE_SIZEOF_SHORT_NAME)) { 
-        if (targetAddr >= begin && targetAddr < end) 
-          found_obj = true; 
-      } else if (!strncmp((const char *)pish->Name, ".eh_frame", 
-                          IMAGE_SIZEOF_SHORT_NAME)) { 
-        info.dwarf_section = begin; 
-        info.dwarf_section_length = pish->Misc.VirtualSize; 
-        found_hdr = true; 
-      } 
-      if (found_obj && found_hdr) 
-        return true; 
-    } 
-  } 
-  return false; 
-#elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32) 
-  // Don't even bother, since Windows has functions that do all this stuff 
-  // for us. 
-  (void)targetAddr; 
-  (void)info; 
-  return true; 
-#elif defined(_LIBUNWIND_USE_DL_UNWIND_FIND_EXIDX) 
+  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: section %p length %p",
+                             (void *)info.arm_section, (void *)info.arm_section_length);
+  if (info.arm_section && info.arm_section_length)
+    return true;
+#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_WIN32)
+  HMODULE mods[1024];
+  HANDLE process = GetCurrentProcess();
+  DWORD needed;
+
+  if (!EnumProcessModules(process, mods, sizeof(mods), &needed)) {
+    DWORD err = GetLastError();
+    _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: EnumProcessModules failed, "
+                               "returned error %d", (int)err);
+    return false;
+  }
+
+  for (unsigned i = 0; i < (needed / sizeof(HMODULE)); i++) {
+    PIMAGE_DOS_HEADER pidh = (PIMAGE_DOS_HEADER)mods[i];
+    PIMAGE_NT_HEADERS pinh = (PIMAGE_NT_HEADERS)((BYTE *)pidh + pidh->e_lfanew);
+    PIMAGE_FILE_HEADER pifh = (PIMAGE_FILE_HEADER)&pinh->FileHeader;
+    PIMAGE_SECTION_HEADER pish = IMAGE_FIRST_SECTION(pinh);
+    bool found_obj = false;
+    bool found_hdr = false;
+
+    info.dso_base = (uintptr_t)mods[i];
+    for (unsigned j = 0; j < pifh->NumberOfSections; j++, pish++) {
+      uintptr_t begin = pish->VirtualAddress + (uintptr_t)mods[i];
+      uintptr_t end = begin + pish->Misc.VirtualSize;
+      if (!strncmp((const char *)pish->Name, ".text",
+                   IMAGE_SIZEOF_SHORT_NAME)) {
+        if (targetAddr >= begin && targetAddr < end)
+          found_obj = true;
+      } else if (!strncmp((const char *)pish->Name, ".eh_frame",
+                          IMAGE_SIZEOF_SHORT_NAME)) {
+        info.dwarf_section = begin;
+        info.dwarf_section_length = pish->Misc.VirtualSize;
+        found_hdr = true;
+      }
+      if (found_obj && found_hdr)
+        return true;
+    }
+  }
+  return false;
+#elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
+  // Don't even bother, since Windows has functions that do all this stuff
+  // for us.
+  (void)targetAddr;
+  (void)info;
+  return true;
+#elif defined(_LIBUNWIND_USE_DL_UNWIND_FIND_EXIDX)
   int length = 0;
-  info.arm_section = 
-      (uintptr_t)dl_unwind_find_exidx((_Unwind_Ptr)targetAddr, &length); 
+  info.arm_section =
+      (uintptr_t)dl_unwind_find_exidx((_Unwind_Ptr)targetAddr, &length);
   info.arm_section_length = (size_t)length * sizeof(EHABIIndexEntry);
   if (info.arm_section && info.arm_section_length)
     return true;
-#elif defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) 
+#elif defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
   dl_iterate_cb_data cb_data = {this, &info, targetAddr};
-  int found = dl_iterate_phdr(findUnwindSectionsByPhdr, &cb_data); 
+  int found = dl_iterate_phdr(findUnwindSectionsByPhdr, &cb_data);
   return static_cast<bool>(found);
 #endif
 
@@ -607,7 +607,7 @@ inline bool LocalAddressSpace::findOtherFDE(pint_t targetAddr, pint_t &fde) {
 inline bool LocalAddressSpace::findFunctionName(pint_t addr, char *buf,
                                                 size_t bufLen,
                                                 unw_word_t *offset) {
-#if _LIBUNWIND_USE_DLADDR 
+#if _LIBUNWIND_USE_DLADDR
   Dl_info dyldInfo;
   if (dladdr((void *)addr, &dyldInfo)) {
     if (dyldInfo.dli_sname != NULL) {
@@ -616,11 +616,11 @@ inline bool LocalAddressSpace::findFunctionName(pint_t addr, char *buf,
       return true;
     }
   }
-#else 
-  (void)addr; 
-  (void)buf; 
-  (void)bufLen; 
-  (void)offset; 
+#else
+  (void)addr;
+  (void)buf;
+  (void)bufLen;
+  (void)offset;
 #endif
   return false;
 }