Split findUnwindSectionByPhdr by targets--arm eabi and others.

[saugustine]

Summary

Hopefully NFC, but this is trickier to determine.

[saugustine]

Fix small clang-tidy complaint.

[saugustine]

The clang-tidy and clang-format failures are all pre-existing, but that is hard to tell from the refactor.

I have fixed the "auto cbdata" -> "auto *cbdata", complaint, because that seems likely to cause confusion to the future readers. But the rest is a rabbit hole of old code that existed long before the style guide, and cleaning that up will make this code not match the surrounding file.

[MaskRay]

The title is

Split findUnwindSectionByPhdr by targets--arm eabi and others.

However, the patch just changes 2 auto to auto *? Is there any missing change in this patch?

The two auto * should be safe.

[saugustine]

Update for clang tidy.

libunwind/src/AddressSpace.hpp

LocalAddressSpace::getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
 
   if (encoding & DW_EH_PE_indirect)
     result = getP(result);
 
   return result;
 }
 
 #if defined(_LIBUNWIND_ARM_EHABI) || defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
+
+#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
+
 struct _LIBUNWIND_HIDDEN dl_iterate_cb_data {
   LocalAddressSpace *addressSpace;
   UnwindInfoSections *sects;
   uintptr_t targetAddr;
 };
+#endif  // defined(_LIBUNWIND_ARM_EHABI) || defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
+
+#if defined(_LIBUNWIND_ARM_EHABI)
 
 static int findUnwindSectionByPhdr(struct dl_phdr_info *pinfo, size_t, void *data) {
-  auto cbdata = static_cast<dl_iterate_cb_data *>(data);
+  auto *cbdata = static_cast<dl_iterate_cb_data *>(data);
   bool found_obj = false;
   bool found_hdr = false;
 
   assert(cbdata);
   assert(cbdata->sects);
 
   if (cbdata->targetAddr < pinfo->dlpi_addr) {
     return false;
   }
 
-#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
-
   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
+  for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) {
+    const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i];
+    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)
+        found_obj = true;
+    } else 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;
+      found_hdr = true;
+    }
+  }
+  return found_obj && found_hdr;
+}
+
+#else // defined(_LIBUNWIND_ARM_EHABI)
+
+static int findUnwindSectionByPhdr(struct dl_phdr_info *pinfo, size_t, void *data) {
+  auto *cbdata = static_cast<dl_iterate_cb_data *>(data);
+  bool found_obj = false;
+  bool found_hdr = false;
+
+  assert(cbdata);
+  assert(cbdata->sects);
+
+  if (cbdata->targetAddr < pinfo->dlpi_addr) {
+    return false;
+  }
+
+  Elf_Addr image_base = pinfo->dlpi_addr;
 
-  #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
-    #if !defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
-     #error "_LIBUNWIND_SUPPORT_DWARF_UNWIND requires _LIBUNWIND_SUPPORT_DWARF_INDEX on this platform."
-   #endif
   size_t object_length;
 
   for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) {
     const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i];
     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) {
static int findUnwindSectionByPhdr(struct dl_phdr_info *pinfo, size_t, void *data) {
   }
 
   if (found_obj && found_hdr) {
     cbdata->sects->dwarf_section_length = object_length;
     return true;
   } else {
     return false;
   }
- #else // defined(_LIBUNWIND_ARM_EHABI)
-  for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) {
-    const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i];
-    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)
-        found_obj = true;
-    } else 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;
-      found_hdr = true;
-    }
-  }
-  return found_obj && found_hdr;
-  #endif
-}
-
-#endif  // defined(_LIBUNWIND_ARM_EHABI) || defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
+#endif  // defined(_LIBUNWIND_ARM_EHABI
 
 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)