When emitting the PC range in an FDE, use the same data encoding for both ends

of the range. Fixes PR13581!

llvm-svn: 161739

2 files changed, 34 insertions, 9 deletions

diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 722779aff1b..4c63e434d23 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -1294,20 +1294,17 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCStreamer &streamer,
     streamer.EmitSymbolValue(&cieStart, 4);
   }
 
-  unsigned fdeEncoding = MOFI->getFDEEncoding(UsingCFI);
-  unsigned size = getSizeForEncoding(streamer, fdeEncoding);
-
   // PC Begin
-  unsigned PCBeginEncoding = IsEH ? fdeEncoding :
-    (unsigned)dwarf::DW_EH_PE_absptr;
-  unsigned PCBeginSize = getSizeForEncoding(streamer, PCBeginEncoding);
-  EmitSymbol(streamer, *frame.Begin, PCBeginEncoding, "FDE initial location");
+  unsigned PCEncoding = IsEH ? MOFI->getFDEEncoding(UsingCFI)
+                             : (unsigned)dwarf::DW_EH_PE_absptr;
+  unsigned PCSize = getSizeForEncoding(streamer, PCEncoding);
+  EmitSymbol(streamer, *frame.Begin, PCEncoding, "FDE initial location");
 
   // PC Range
   const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin,
                                               *frame.End, 0);
   if (verboseAsm) streamer.AddComment("FDE address range");
-  streamer.EmitAbsValue(Range, size);
+  streamer.EmitAbsValue(Range, PCSize);
 
   if (IsEH) {
     // Augmentation Data Length
@@ -1330,7 +1327,7 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCStreamer &streamer,
   EmitCFIInstructions(streamer, frame.Instructions, frame.Begin);
 
   // Padding
-  streamer.EmitValueToAlignment(PCBeginSize);
+  streamer.EmitValueToAlignment(PCSize);
 
   return fdeEnd;
 }
diff --git a/llvm/test/MC/ELF/fde.s b/llvm/test/MC/ELF/fde.s
new file mode 100644
index 00000000000..b7fa48b7bc5
--- /dev/null
+++ b/llvm/test/MC/ELF/fde.s
@@ -0,0 +1,28 @@
+# RUN: llvm-mc -filetype=obj %s -o %t.o && llvm-objdump -s %t.o
+# PR13581
+
+# CHECK: Contents of section .debug_frame:
+# CHECK-NEXT:  0000 14000000 ffffffff 01000178 100c0708  ...........x....
+# CHECK-NEXT:  0010 90010000 00000000 1c000000 00000000  ................
+# CHECK-NEXT:  0020 00000000 00000000 11000000 00000000  ................
+# CHECK-NEXT:  0030 410e1086 02430d06                    A....C..
+
+__cxx_global_var_init:                  # @__cxx_global_var_init
+        .cfi_startproc
+.Lfunc_begin0:
+# BB#0:                                 # %entry
+        pushq   %rbp
+.Ltmp2:
+        .cfi_def_cfa_offset 16
+.Ltmp3:
+        .cfi_offset %rbp, -16
+        movq    %rsp, %rbp
+.Ltmp4:
+        .cfi_def_cfa_register %rbp
+.Ltmp5:
+        callq   _Z2rsv@PLT
+        movl    %eax, _ZL1i(%rip)
+        popq    %rbp
+        ret
+        .cfi_endproc
+        .cfi_sections .debug_frame