[DebugInfo] Fix printing CIE offsets in EH FDEs.

While the value of the CIE pointer field in a DWARF FDE record is an offset to the corresponding CIE record from the beginning of the section, for EH FDE records it is relative to the current offset. Previously, we did not make that distinction when dumped both kinds of FDE records and just printed the same value for the CIE pointer field and the CIE offset; that was acceptable for DWARF FDEs but was wrong for EH FDEs. This patch fixes the issue by explicitly printing the offset of the linked CIE object. Differential Revision: https://reviews.llvm.org/D74613
llvm · Feb 25, 2020 · bd2df13 · bd2df13
1 parent dcd89b3
commit bd2df13
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Showing 11 changed files with 39 additions and 18 deletions.
diff --git a/lld/test/ELF/eh-frame-hdr-augmentation.s b/lld/test/ELF/eh-frame-hdr-augmentation.s
@@ -19,7 +19,7 @@
 // CHECK-NEXT: DW_CFA_nop:
 // CHECK-NEXT: DW_CFA_nop:
 
-// CHECK:      00000020 00000014 00000024 FDE cie=00000024 pc=00001014...00001014
+// CHECK:      00000020 00000014 00000024 FDE cie=00000000 pc=00001014...00001014
 // CHECK-NEXT:   LSDA Address: 000000000000100b
 // CHECK-NEXT:   DW_CFA_nop:
 // CHECK-NEXT:   DW_CFA_nop:

diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h
@@ -223,14 +223,14 @@ class CIE : public FrameEntry {
 /// DWARF Frame Description Entry (FDE)
 class FDE : public FrameEntry {
 public:
-  FDE(uint64_t Offset, uint64_t Length, int64_t LinkedCIEOffset,
+  FDE(uint64_t Offset, uint64_t Length, uint64_t CIEPointer,
       uint64_t InitialLocation, uint64_t AddressRange, CIE *Cie,
       Optional<uint64_t> LSDAAddress, Triple::ArchType Arch)
       : FrameEntry(FK_FDE, Offset, Length,
                    Cie ? Cie->getCodeAlignmentFactor() : 0,
                    Cie ? Cie->getDataAlignmentFactor() : 0,
                    Arch),
-        LinkedCIEOffset(LinkedCIEOffset), InitialLocation(InitialLocation),
+        CIEPointer(CIEPointer), InitialLocation(InitialLocation),
         AddressRange(AddressRange), LinkedCIE(Cie), LSDAAddress(LSDAAddress) {}
 
   ~FDE() override = default;
@@ -246,8 +246,11 @@ class FDE : public FrameEntry {
   static bool classof(const FrameEntry *FE) { return FE->getKind() == FK_FDE; }
 
 private:
-  /// The following fields are defined in section 6.4.1 of the DWARF standard v3
-  const uint64_t LinkedCIEOffset;
+  /// The following fields are defined in section 6.4.1 of the DWARFv3 standard.
+  /// Note that CIE pointers in EH FDEs, unlike DWARF FDEs, contain relative
+  /// offsets to the linked CIEs. See the following link for more info:
+  /// https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
+  const uint64_t CIEPointer;
   const uint64_t InitialLocation;
   const uint64_t AddressRange;
   const CIE *LinkedCIE;

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
@@ -313,10 +313,14 @@ void CIE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const {
 }
 
 void FDE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const {
-  OS << format("%08x %08x %08x FDE ", (uint32_t)Offset, (uint32_t)Length,
-               (int32_t)LinkedCIEOffset);
-  OS << format("cie=%08x pc=%08x...%08x\n", (int32_t)LinkedCIEOffset,
-               (uint32_t)InitialLocation,
+  OS << format("%08x %08x %08x", (uint32_t)Offset, (uint32_t)Length,
+               (uint32_t)CIEPointer)
+     << " FDE cie=";
+  if (LinkedCIE)
+    OS << format("%08x", (uint32_t)(LinkedCIE->getOffset()));
+  else
+    OS << "<invalid offset>";
+  OS << format(" pc=%08x...%08x\n", (uint32_t)InitialLocation,
                (uint32_t)InitialLocation + (uint32_t)AddressRange);
   if (LSDAAddress)
     OS << format("  LSDA Address: %016" PRIx64 "\n", *LSDAAddress);

diff --git a/llvm/test/DebugInfo/RISCV/eh-frame.s b/llvm/test/DebugInfo/RISCV/eh-frame.s
@@ -28,7 +28,7 @@ func:
 # CHECK:   Augmentation data:     1B
 # CHECK:   DW_CFA_def_cfa: reg2 +0
 #
-# CHECK: 00000014 00000010 00000018 FDE cie=00000018 pc=00000000...00000004
+# CHECK: 00000014 00000010 00000018 FDE cie=00000000 pc=00000000...00000004
 # CHECK:   DW_CFA_nop:
 # CHECK:   DW_CFA_nop:
 # CHECK:   DW_CFA_nop:
diff --git a/llvm/test/DebugInfo/X86/debug_frame-invalid-cie-offset.s b/llvm/test/DebugInfo/X86/debug_frame-invalid-cie-offset.s
@@ -0,0 +1,14 @@
+# RUN: llvm-mc -triple i386-unknown-linux %s -filetype=obj -o - | \
+# RUN:  llvm-dwarfdump -debug-frame - | \
+# RUN:  FileCheck %s
+
+# CHECK: .debug_frame contents:
+# CHECK: 00000000 0000000c 12345678 FDE cie=<invalid offset> pc=00010000...00010010
+
+    .section .debug_frame,"",@progbits
+    .long   .LFDE0end-.LFDE0id  # Length
+.LFDE0id:
+    .long   0x12345678          # CIE pointer (invalid)
+    .long   0x00010000          # Initial location
+    .long   0x00000010          # Address range
+.LFDE0end:
diff --git a/llvm/test/MC/Mips/eh-frame.s b/llvm/test/MC/Mips/eh-frame.s
@@ -67,7 +67,7 @@ func:
 // DWARF32-EMPTY:
 // DWARF32-NEXT:     DW_CFA_def_cfa_register: reg29
 //
-// DWARF32: 00000014 00000010 00000018 FDE cie=00000018 pc=00000000...00000000
+// DWARF32: 00000014 00000010 00000018 FDE cie=00000000 pc=00000000...00000000
 // DWARF32-NEXT:     DW_CFA_nop:
 // DWARF32-NEXT:     DW_CFA_nop:
 // DWARF32-NEXT:     DW_CFA_nop:
@@ -89,8 +89,8 @@ func:
 // DWARF64-NEXT:     DW_CFA_def_cfa_register: reg29
 // DWARF64_PIC-NEXT: DW_CFA_nop:
 //
-// DWARF64_ABS:      00000014 00000018 00000018 FDE cie=00000018 pc=00000000...00000000
-// DWARF64_PIC:      00000014 00000010 00000018 FDE cie=00000018 pc=00000000...00000000
+// DWARF64_ABS:      00000014 00000018 00000018 FDE cie=00000000 pc=00000000...00000000
+// DWARF64_PIC:      00000014 00000010 00000018 FDE cie=00000000 pc=00000000...00000000
 // DWARF64-NEXT:     DW_CFA_nop:
 // DWARF64-NEXT:     DW_CFA_nop:
 // DWARF64-NEXT:     DW_CFA_nop:
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_frame_GNU_args_size.s b/llvm/test/tools/llvm-dwarfdump/X86/debug_frame_GNU_args_size.s
@@ -2,7 +2,7 @@
 # RUN: llvm-dwarfdump -v %t | FileCheck %s
 
 # CHECK:      .eh_frame contents:
-# CHECK:        00000018 00000010 0000001c FDE cie=0000001c pc=00000000...00000000
+# CHECK:        00000018 00000010 0000001c FDE cie=00000000 pc=00000000...00000000
 # CHECK-NEXT:     DW_CFA_GNU_args_size: +16
 # CHECK-NEXT:     DW_CFA_nop:
 

diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_frame_offset.test b/llvm/test/tools/llvm-dwarfdump/X86/debug_frame_offset.test
@@ -8,7 +8,7 @@ CHECK-NOT: pc
 RUN: llvm-dwarfdump %p/../../dsymutil/Inputs/basic1.macho.x86_64.o \
 RUN:   -eh-frame=0x00000018 | FileCheck %s --check-prefix=EH
 EH: .eh_frame contents:
-EH-NEXT: 00000018 00000024 0000001c FDE cie=0000001c pc=fffffd00...fffffd24
+EH-NEXT: 00000018 00000024 0000001c FDE cie=00000000 pc=fffffd00...fffffd24
 EH-NEXT:   DW_CFA_advance_loc: 1
 EH-NOT: pc
 EH-NOT: CIE
diff --git a/llvm/test/tools/llvm-objdump/eh_frame-arm64.test b/llvm/test/tools/llvm-objdump/eh_frame-arm64.test
@@ -12,7 +12,7 @@
 
 # CHECK:   DW_CFA_def_cfa: reg31 +0
 
-# CHECK: 00000014 00000020 00000018 FDE cie=00000018 pc=ffffffe4...00000004
+# CHECK: 00000014 00000020 00000018 FDE cie=00000000 pc=ffffffe4...00000004
 # CHECK:   DW_CFA_advance_loc: 8
 # CHECK:   DW_CFA_def_cfa_offset: +16
 # CHECK:   DW_CFA_offset: reg30 -8

diff --git a/llvm/test/tools/llvm-objdump/eh_frame-coff.test b/llvm/test/tools/llvm-objdump/eh_frame-coff.test
@@ -16,7 +16,7 @@
 # CHECK:   DW_CFA_nop:
 # CHECK:   DW_CFA_nop:
 
-# CHECK: 00000020 0000001c 00000024 FDE cie=00000024 pc=00401410...00401488
+# CHECK: 00000020 0000001c 00000024 FDE cie=00000000 pc=00401410...00401488
 # CHECK:   LSDA Address: 0000000000406000
 # CHECK:   DW_CFA_advance_loc: 1
 # CHECK:   DW_CFA_def_cfa_offset: +8

diff --git a/llvm/test/tools/llvm-objdump/eh_frame-mipsel.test b/llvm/test/tools/llvm-objdump/eh_frame-mipsel.test
@@ -12,7 +12,7 @@
 
 # CHECK:   DW_CFA_def_cfa: reg29 +0
 
-# CHECK: 0000001c 00000018 00000020 FDE cie=00000020 pc=00400890...004008dc
+# CHECK: 0000001c 00000018 00000020 FDE cie=00000000 pc=00400890...004008dc
 # CHECK:   DW_CFA_advance_loc: 4
 # CHECK:   DW_CFA_def_cfa_offset: +24
 # CHECK:   DW_CFA_advance_loc: 4