Don't produce a "DW_CFA_advance_loc 0".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122609 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 93a447ceae577a205d567d4766f81fb599722733..f3ba2bbb82fcc212f5223e8daf5b82c9d04191af 100644 (file)
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -780,7 +780,8 @@ void MCDwarfFrameEmitter::EmitAdvanceLoc(MCStreamer &Streamer,
 void MCDwarfFrameEmitter::EncodeAdvanceLoc(uint64_t AddrDelta,
                                            raw_ostream &OS) {
   // FIXME: Assumes the code alignment factor is 1.
-  if (isUIntN(6, AddrDelta)) {
+  if (AddrDelta == 0) {
+  } else if (isUIntN(6, AddrDelta)) {
     uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta;
     OS << Opcode;
   } else if (isUInt<8>(AddrDelta)) {

diff --git a/test/MC/ELF/cfi-zero-addr-delta.s b/test/MC/ELF/cfi-zero-addr-delta.s
new file mode 100644 (file)
index 0000000..5585e29
--- /dev/null
+++ b/test/MC/ELF/cfi-zero-addr-delta.s
@@ -0,0 +1,48 @@
+// RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o - | elf-dump  --dump-section-data | FileCheck %s
+
+// Test that we don't produce a DW_CFA_advance_loc 0
+
+f:
+       .cfi_startproc
+        nop
+       .cfi_def_cfa_offset 16
+        nop
+       .cfi_remember_state
+       .cfi_def_cfa_offset 8
+        nop
+       .cfi_restore_state
+        nop
+       .cfi_endproc
+
+// CHECK:      (('sh_name', 0x00000012) # '.eh_frame'
+// CHECK-NEXT:  ('sh_type', 0x00000001)
+// CHECK-NEXT:  ('sh_flags', 0x00000002)
+// CHECK-NEXT:  ('sh_addr', 0x00000000)
+// CHECK-NEXT:  ('sh_offset', 0x00000048)
+// CHECK-NEXT:  ('sh_size', 0x00000038)
+// CHECK-NEXT:  ('sh_link', 0x00000000)
+// CHECK-NEXT:  ('sh_info', 0x00000000)
+// CHECK-NEXT:  ('sh_addralign', 0x00000008)
+// CHECK-NEXT:  ('sh_entsize', 0x00000000)
+// CHECK-NEXT:  ('_section_data', '14000000 00000000 017a5200 01781001 1b0c0708 90010000 1c000000 1c000000 00000000 04000000 00410e10 410a0e08 410b0000 00000000')
+// CHECK-NEXT: ),
+
+// CHECK:      (('sh_name', 0x00000036) # '.rela.eh_frame'
+// CHECK-NEXT:  ('sh_type', 0x00000004)
+// CHECK-NEXT:  ('sh_flags', 0x00000000)
+// CHECK-NEXT:  ('sh_addr', 0x00000000)
+// CHECK-NEXT:  ('sh_offset', 0x00000160)
+// CHECK-NEXT:  ('sh_size', 0x00000018)
+// CHECK-NEXT:  ('sh_link', 0x00000006)
+// CHECK-NEXT:  ('sh_info', 0x00000004)
+// CHECK-NEXT:  ('sh_addralign', 0x00000008)
+// CHECK-NEXT:  ('sh_entsize', 0x00000018)
+// CHECK-NEXT:  ('_relocations', [
+// CHECK-NEXT:   # Relocation 0x00000000
+// CHECK-NEXT:   (('r_offset', 0x00000020)
+// CHECK-NEXT:    ('r_sym', 0x00000002)
+// CHECK-NEXT:    ('r_type', 0x00000002)
+// CHECK-NEXT:    ('r_addend', 0x00000000)
+// CHECK-NEXT:   ),
+// CHECK-NEXT:  ])
+// CHECK-NEXT: ),