[llvm] r233120 - Reset the CFA offset at the start of every FDE.

[Rafael Espindola]

Author: rafael
Date: Tue Mar 24 16:47:31 2015
New Revision: 233120

URL: http://llvm.org/viewvc/llvm-project?rev=233120&view=rev
Log:
Reset the CFA offset at the start of every FDE.

This fixes PR21515.

Modified:
    llvm/trunk/lib/MC/MCDwarf.cpp
    llvm/trunk/test/MC/ELF/cfi-adjust-cfa-offset.s

Modified: llvm/trunk/lib/MC/MCDwarf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCDwarf.cpp?rev=233120&r1=233119&r2=233120&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCDwarf.cpp (original)
+++ llvm/trunk/lib/MC/MCDwarf.cpp Tue Mar 24 16:47:31 2015
@@ -999,11 +999,13 @@ static void EmitPersonality(MCStreamer &
 namespace {
   class FrameEmitterImpl {
     int CFAOffset;
+    int InitialCFAOffset;
     bool IsEH;
     const MCSymbol *SectionStart;
   public:
     FrameEmitterImpl(bool isEH)
-        : CFAOffset(0), IsEH(isEH), SectionStart(nullptr) {}
+        : CFAOffset(0), InitialCFAOffset(0), IsEH(isEH), SectionStart(nullptr) {
+    }
 
     void setSectionStart(const MCSymbol *Label) { SectionStart = Label; }
 
@@ -1345,6 +1347,8 @@ const MCSymbol &FrameEmitterImpl::EmitCI
     EmitCFIInstructions(streamer, Instructions, nullptr);
   }
 
+  InitialCFAOffset = CFAOffset;
+
   // Padding
   streamer.EmitValueToAlignment(IsEH ? 4 : MAI->getPointerSize());
 
@@ -1360,6 +1364,8 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCOb
   MCSymbol *fdeEnd = context.CreateTempSymbol();
   const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
 
+  CFAOffset = InitialCFAOffset;
+
   // Length
   const MCExpr *Length = MakeStartMinusEndExpr(streamer, *fdeStart, *fdeEnd, 0);
   emitAbsValue(streamer, Length, 4);

Modified: llvm/trunk/test/MC/ELF/cfi-adjust-cfa-offset.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ELF/cfi-adjust-cfa-offset.s?rev=233120&r1=233119&r2=233120&view=diff
==============================================================================
--- llvm/trunk/test/MC/ELF/cfi-adjust-cfa-offset.s (original)
+++ llvm/trunk/test/MC/ELF/cfi-adjust-cfa-offset.s Tue Mar 24 16:47:31 2015
@@ -11,6 +11,16 @@ f:
 	ret
 	.cfi_endproc
 
+        .cfi_startproc
+	nop
+	.cfi_adjust_cfa_offset 4
+	.cfi_endproc
+
+        .cfi_startproc
+	nop
+	.cfi_adjust_cfa_offset 4
+	.cfi_endproc
+
 // CHECK:        Section {
 // CHECK:          Index: 4
 // CHECK-NEXT:     Name: .eh_frame
@@ -20,7 +30,7 @@ f:
 // CHECK-NEXT:     ]
 // CHECK-NEXT:     Address: 0x0
 // CHECK-NEXT:     Offset: 0x50
-// CHECK-NEXT:     Size: 56
+// CHECK-NEXT:     Size: 96
 // CHECK-NEXT:     Link: 0
 // CHECK-NEXT:     Info: 0
 // CHECK-NEXT:     AddressAlignment: 8
@@ -29,9 +39,11 @@ f:
 // CHECK-NEXT:     ]
 // CHECK-NEXT:     SectionData (
 // CHECK-NEXT:       0000: 14000000 00000000 037A5200 01781001
-// CHECK-NEXT:       0010: 1B0C0708 90010000 1C000000 1C000000
+// CHECK-NEXT:       0010: 1B0C0708 90010000 18000000 1C000000
 // CHECK-NEXT:       0020: 00000000 0A000000 00440E10 410E1444
-// CHECK-NEXT:       0030: 0E080000 00000000
+// CHECK-NEXT:       0030: 0E080000 10000000 38000000 00000000
+// CHECK-NEXT:       0040: 01000000 00410E0C 14000000 4C000000
+// CHECK-NEXT:       0050: 00000000 01000000 00410E0C 00000000
 // CHECK-NEXT:     )
 // CHECK-NEXT:   }
 // CHECK-NEXT:   Section {
@@ -41,13 +53,15 @@ f:
 // CHECK-NEXT:     Flags [
 // CHECK-NEXT:     ]
 // CHECK-NEXT:     Address: 0x0
-// CHECK-NEXT:     Offset: 0x3A0
-// CHECK-NEXT:     Size: 24
+// CHECK-NEXT:     Offset: 0x3C8
+// CHECK-NEXT:     Size: 72
 // CHECK-NEXT:     Link: 7
 // CHECK-NEXT:     Info: 4
 // CHECK-NEXT:     AddressAlignment: 8
 // CHECK-NEXT:     EntrySize: 24
 // CHECK-NEXT:     Relocations [
 // CHECK-NEXT:       0x20 R_X86_64_PC32 .text 0x0
+// CHECK-NEXT:       0x3C R_X86_64_PC32 .text 0x
+// CHECK-NEXT:       0x50 R_X86_64_PC32 .text 0x
 // CHECK-NEXT:     ]
 // CHECK:        }