commit 35e1e6ad4b50f1adbe9f93fe467766f042491896
author Tong Shen <endlessroad@google.com> Wed Jul 30 09:31:22 2014 -0700
committer Tong Shen <endlessroad@google.com> Wed Jul 30 20:19:26 2014 +0000
tree 054e8fe1140fc1144ececa8ad8beda18be9566a2
parent 01a0ebb6b96c32879dcad99d515fc0cd8de2a266

1. Fix CFI for quick compiled code in x86 & x86_64;
2. Emit CFI in .eh_frame instead of .debug_frame.

With CFI, we can correctly unwind past quick generated code.
Now gdb should unwind to main() for both x86 & x86_64 host-side ART.

Note that it does not work with relocation yet.

Testing:
1. art/test/run-test --host --gdb [--64] --no-relocate 005
2. In gdb, run 'b art_quick_invoke_stub', then 'r', then 'c' a few times
3. In gdb, run 'bt'. You should see stack frames down to main()

Change-Id: I5350d4097dc3d360a60cb17c94f1d02b99bc58bb

compiler/elf_writer_quick.cc

diff --git a/compiler/elf_writer_quick.cc b/compiler/elf_writer_quick.cc
index 4274386..1fde12e 100644
--- a/compiler/elf_writer_quick.cc
+++ b/compiler/elf_writer_quick.cc
@@ -106,14 +106,14 @@
   // | .strtab\0               |  (Optional)
   // | .debug_str\0            |  (Optional)
   // | .debug_info\0           |  (Optional)
-  // | .debug_frame\0          |  (Optional)
+  // | .eh_frame\0             |  (Optional)
   // | .debug_abbrev\0         |  (Optional)
   // +-------------------------+  (Optional)
   // | .debug_str              |  (Optional)
   // +-------------------------+  (Optional)
   // | .debug_info             |  (Optional)
   // +-------------------------+  (Optional)
-  // | .debug_frame            |  (Optional)
+  // | .eh_frame               |  (Optional)
   // +-------------------------+  (Optional)
   // | .debug_abbrev           |  (Optional)
   // +-------------------------+
@@ -127,7 +127,7 @@
   // | Elf32_Shdr .shstrtab    |
   // | Elf32_Shdr .debug_str   |  (Optional)
   // | Elf32_Shdr .debug_info  |  (Optional)
-  // | Elf32_Shdr .debug_frame |  (Optional)
+  // | Elf32_Shdr .eh_frame    |  (Optional)
   // | Elf32_Shdr .debug_abbrev|  (Optional)
   // +-------------------------+
 
@@ -844,14 +844,14 @@
     ElfRawSectionBuilder debug_info(".debug_info",   SHT_PROGBITS, 0, nullptr, 0, 1, 0);
     ElfRawSectionBuilder debug_abbrev(".debug_abbrev", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
     ElfRawSectionBuilder debug_str(".debug_str",    SHT_PROGBITS, 0, nullptr, 0, 1, 0);
-    ElfRawSectionBuilder debug_frame(".debug_frame",  SHT_PROGBITS, 0, nullptr, 0, 4, 0);
-    debug_frame.SetBuffer(*compiler_driver_->GetCallFrameInformation());
+    ElfRawSectionBuilder eh_frame(".eh_frame",  SHT_PROGBITS, SHF_ALLOC, nullptr, 0, 4, 0);
+    eh_frame.SetBuffer(*compiler_driver_->GetCallFrameInformation());
 
     FillInCFIInformation(oat_writer, debug_info.GetBuffer(),
                          debug_abbrev.GetBuffer(), debug_str.GetBuffer());
     builder.RegisterRawSection(debug_info);
     builder.RegisterRawSection(debug_abbrev);
-    builder.RegisterRawSection(debug_frame);
+    builder.RegisterRawSection(eh_frame);
     builder.RegisterRawSection(debug_str);
   }