Support generation of CFI in .debug_frame format.

.debug_frame section is almost identical to .eh_frame section.
There are only minor differences in the CIE and FDE headers.
The main difference is that .eh_frame is intended to be used
at runtime for exception handling and is therefore allocated
within the running program whereas .debug_frame is not.

This makes .debug_frame easier to remove using standard tools.
"objcopy --strip-debug" removes .debug_frame, but not .eh_frame.
(although objcopy can be still be forced to remove .eh_frame)

Similarly, we might want to separate the CFI to separate debug
file or include it as compressed .gnu_debugdata section.
It is more appropriate to use .debug_frame for this purpose.

Bug:20556771
Change-Id: I9d91a333b9fb37523fd6fafccfad89b21d2477af

1 files changed, 19 insertions, 17 deletions

diff --git a/compiler/dwarf/dwarf_test.cc b/compiler/dwarf/dwarf_test.cc
index edba00aeaa..4971f0ef10 100644
--- a/compiler/dwarf/dwarf_test.cc
+++ b/compiler/dwarf/dwarf_test.cc
@@ -26,6 +26,8 @@
 namespace art {
 namespace dwarf {
 
+constexpr CFIFormat kCFIFormat = DW_DEBUG_FRAME_FORMAT;
+
 // Run the tests only on host since we need objdump.
 #ifndef HAVE_ANDROID_OS
 
@@ -120,30 +122,30 @@ TEST_F(DwarfTest, DebugFrame) {
   DW_CHECK_NEXT("DW_CFA_restore: r5 (ebp)");
 
   DebugFrameOpCodeWriter<> initial_opcodes;
-  WriteEhFrameCIE(is64bit, DW_EH_PE_absptr, Reg(is64bit ? 16 : 8),
-                  initial_opcodes, &eh_frame_data_);
-  std::vector<uintptr_t> eh_frame_patches;
+  WriteDebugFrameCIE(is64bit, DW_EH_PE_absptr, Reg(is64bit ? 16 : 8),
+                     initial_opcodes, kCFIFormat, &debug_frame_data_);
+  std::vector<uintptr_t> debug_frame_patches;
   std::vector<uintptr_t> expected_patches { 28 };  // NOLINT
-  WriteEhFrameFDE(is64bit, 0, 0x01000000, 0x01000000, opcodes.data(),
-                  &eh_frame_data_, &eh_frame_patches);
+  WriteDebugFrameFDE(is64bit, 0, 0x01000000, 0x01000000, opcodes.data(),
+                     kCFIFormat, &debug_frame_data_, &debug_frame_patches);
 
-  EXPECT_EQ(expected_patches, eh_frame_patches);
+  EXPECT_EQ(expected_patches, debug_frame_patches);
   CheckObjdumpOutput(is64bit, "-W");
 }
 
 TEST_F(DwarfTest, DebugFrame64) {
   constexpr bool is64bit = true;
   DebugFrameOpCodeWriter<> initial_opcodes;
-  WriteEhFrameCIE(is64bit, DW_EH_PE_absptr, Reg(16),
-                  initial_opcodes, &eh_frame_data_);
+  WriteDebugFrameCIE(is64bit, DW_EH_PE_absptr, Reg(16),
+                     initial_opcodes, kCFIFormat, &debug_frame_data_);
   DebugFrameOpCodeWriter<> opcodes;
-  std::vector<uintptr_t> eh_frame_patches;
+  std::vector<uintptr_t> debug_frame_patches;
   std::vector<uintptr_t> expected_patches { 32 };  // NOLINT
-  WriteEhFrameFDE(is64bit, 0, 0x0100000000000000, 0x0200000000000000,
-                  opcodes.data(), &eh_frame_data_, &eh_frame_patches);
+  WriteDebugFrameFDE(is64bit, 0, 0x0100000000000000, 0x0200000000000000,
+                     opcodes.data(), kCFIFormat, &debug_frame_data_, &debug_frame_patches);
   DW_CHECK("FDE cie=00000000 pc=100000000000000..300000000000000");
 
-  EXPECT_EQ(expected_patches, eh_frame_patches);
+  EXPECT_EQ(expected_patches, debug_frame_patches);
   CheckObjdumpOutput(is64bit, "-W");
 }
 
@@ -173,11 +175,11 @@ TEST_F(DwarfTest, x86_64_RegisterMapping) {
   DW_CHECK_NEXT("DW_CFA_offset: r14 (r14)");
   DW_CHECK_NEXT("DW_CFA_offset: r15 (r15)");
   DebugFrameOpCodeWriter<> initial_opcodes;
-  WriteEhFrameCIE(is64bit, DW_EH_PE_absptr, Reg(16),
-                  initial_opcodes, &eh_frame_data_);
-  std::vector<uintptr_t> eh_frame_patches;
-  WriteEhFrameFDE(is64bit, 0, 0x0100000000000000, 0x0200000000000000,
-                  opcodes.data(), &eh_frame_data_, &eh_frame_patches);
+  WriteDebugFrameCIE(is64bit, DW_EH_PE_absptr, Reg(16),
+                     initial_opcodes, kCFIFormat, &debug_frame_data_);
+  std::vector<uintptr_t> debug_frame_patches;
+  WriteDebugFrameFDE(is64bit, 0, 0x0100000000000000, 0x0200000000000000,
+                     opcodes.data(), kCFIFormat, &debug_frame_data_, &debug_frame_patches);
 
   CheckObjdumpOutput(is64bit, "-W");
 }