commit 527c9c71f0c6e2f9943ac028e7c050500699a44b
author David Srbecky <dsrbecky@google.com> Fri Apr 17 21:14:10 2015 +0100
committer David Srbecky <dsrbecky@google.com> Tue Apr 21 19:47:42 2015 +0100
tree 09e6794e5b184ce33ca468c972a8ef2faff7f174
parent e7bee3b7d307508243f4a00b5cf8a8867fcaaff5

Generate .eh_frame_hdr section and PT_GNU_EH_FRAME segment.

Fixes issue 20125400 - ART: Need .eh_frame_hdr and PT_GNU_EH_FRAME
for libunwind.

.eh_frame_hdr serves two purposes. Firstly, it can optionally contain
binary search table for fast eh_frame lookup. This is important for
C++ exception handling, but we do not need it so we omit it.
Secondly, it contains a relative .eh_frame pointer which makes it
easier for run-time code to locate the .eh_frame section.
libunwind seems to rely on this relative pointer.

Bug: 20125400
Change-Id: I7c1e3f68d914f70781404c508395831a3296a7da

compiler/dwarf/dwarf_test.h

diff --git a/compiler/dwarf/dwarf_test.h b/compiler/dwarf/dwarf_test.h
index dd5e0c2..cbe700a 100644
--- a/compiler/dwarf/dwarf_test.h
+++ b/compiler/dwarf/dwarf_test.h
@@ -100,30 +100,30 @@
                Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr> builder(
         &code, file.GetFile(), isa, 0, 0, 0, 0, 0, 0, false, false);
     typedef ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> Section;
+    Section debug_info(".debug_info", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+    Section debug_abbrev(".debug_abbrev", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+    Section debug_str(".debug_str", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+    Section debug_line(".debug_line", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+    Section eh_frame(".eh_frame", SHT_PROGBITS, SHF_ALLOC, nullptr, 0, 4, 0);
     if (!debug_info_data_.empty()) {
-      Section debug_info(".debug_info", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
       debug_info.SetBuffer(debug_info_data_);
-      builder.RegisterRawSection(debug_info);
+      builder.RegisterRawSection(&debug_info);
     }
     if (!debug_abbrev_data_.empty()) {
-      Section debug_abbrev(".debug_abbrev", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
       debug_abbrev.SetBuffer(debug_abbrev_data_);
-      builder.RegisterRawSection(debug_abbrev);
+      builder.RegisterRawSection(&debug_abbrev);
     }
     if (!debug_str_data_.empty()) {
-      Section debug_str(".debug_str", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
       debug_str.SetBuffer(debug_str_data_);
-      builder.RegisterRawSection(debug_str);
+      builder.RegisterRawSection(&debug_str);
     }
     if (!debug_line_data_.empty()) {
-      Section debug_line(".debug_line", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
       debug_line.SetBuffer(debug_line_data_);
-      builder.RegisterRawSection(debug_line);
+      builder.RegisterRawSection(&debug_line);
     }
     if (!eh_frame_data_.empty()) {
-      Section eh_frame(".eh_frame", SHT_PROGBITS, SHF_ALLOC, nullptr, 0, 4, 0);
       eh_frame.SetBuffer(eh_frame_data_);
-      builder.RegisterRawSection(eh_frame);
+      builder.RegisterRawSection(&eh_frame);
     }
     builder.Init();
     builder.Write();