[DWARF] Fixing a bug in DWARF v5 string offsets tables where the length encoded the...

length excluding the table header. Instead it must encode the contribution length minus the length
field itself.

Reviewer: JDevliegehere

Differential Revision: https://reviews.llvm.org/D45922

llvm-svn: 332030

diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h
index 7f028c3..ac0809f 100644 (file)
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h
@@ -169,6 +169,7 @@ struct BaseAddress {
 /// Represents a unit's contribution to the string offsets table.
 struct StrOffsetsContributionDescriptor {
   uint64_t Base = 0;
+  /// The contribution size not including the header.
   uint64_t Size = 0;
   /// Format and version.
   dwarf::FormParams FormParams = {0, 0, dwarf::DwarfFormat::DWARF32};

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
index a3ea96b..f3a3cbd 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
@@ -36,9 +36,9 @@ void DwarfFile::emitStringOffsetsTableHeader(MCSection *Section) {
   // FIXME: DWARF64
   // We are emitting the header for a contribution to the string offsets
   // table. The header consists of an entry with the contribution's
-  // size (not including the size of the header), the DWARF version and
+  // size (not including the size of the length field), the DWARF version and
   // 2 bytes of padding.
-  Asm->emitInt32(StrPool.size() * EntrySize);
+  Asm->emitInt32(StrPool.size() * EntrySize + 4);
   Asm->emitInt16(Asm->getDwarfVersion());
   Asm->emitInt16(0);
   // Define the symbol that marks the start of the contribution. It is

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 6fbe55b..8488fe8 100644 (file)
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -172,7 +172,11 @@ static void dumpDWARFv5StringOffsetsSection(
       OS << (ContributionHeader - Offset) << "\n";
     }
     OS << format("0x%8.8x: ", (uint32_t)ContributionHeader);
-    OS << "Contribution size = " << Contribution->Size
+    // In DWARF v5 the contribution size in the descriptor does not equal
+    // the originally encoded length (it does not contain the length of the
+    // version field and the padding, a total of 4 bytes). Add them back in
+    // for reporting.
+    OS << "Contribution size = " << (Contribution->Size + (Version < 5 ? 0 : 4))
        << ", Format = " << (Format == DWARF32 ? "DWARF32" : "DWARF64")
        << ", Version = " << Version << "\n";
 

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index d54275d..2d456b4 100644 (file)
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -517,7 +517,9 @@ parseDWARF64StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
   uint64_t Size = DA.getU64(&Offset);
   uint8_t Version = DA.getU16(&Offset);
   (void)DA.getU16(&Offset); // padding
-  return StrOffsetsContributionDescriptor(Offset, Size, Version, DWARF64);
+  // The encoded length includes the 2-byte version field and the 2-byte
+  // padding, so we need to subtract them out when we populate the descriptor.
+  return StrOffsetsContributionDescriptor(Offset, Size - 4, Version, DWARF64);
   //return Optional<StrOffsetsContributionDescriptor>(Descriptor);
 }
 
@@ -532,7 +534,10 @@ parseDWARF32StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
     return Optional<StrOffsetsContributionDescriptor>();
   uint8_t Version = DA.getU16(&Offset);
   (void)DA.getU16(&Offset); // padding
-  return StrOffsetsContributionDescriptor(Offset, ContributionSize, Version, DWARF32);
+  // The encoded length includes the 2-byte version field and the 2-byte
+  // padding, so we need to subtract them out when we populate the descriptor.
+  return StrOffsetsContributionDescriptor(Offset, ContributionSize - 4, Version,
+                                          DWARF32);
   //return Optional<StrOffsetsContributionDescriptor>(Descriptor);
 }
 

diff --git a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-3.s b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-3.s
index 0ff6fdb..07c7cfd 100644 (file)
--- a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-3.s
+++ b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-3.s
@@ -71,7 +71,7 @@ CU1_5_end:
         .long str_CU1_dir
 .debug_str_offsets_segment0_end:
 # CU2's contribution
-        .long .debug_str_offsets_segment1_end-.debug_str_offsets_base1
+        .long .debug_str_offsets_segment1_end-.debug_str_offsets_base1+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base1:
@@ -80,7 +80,7 @@ CU1_5_end:
         .long str_CU2_dir
 .debug_str_offsets_segment1_end:
 # The TU's contribution
-        .long .debug_str_offsets_segment2_end-.debug_str_offsets_base2
+        .long .debug_str_offsets_segment2_end-.debug_str_offsets_base2+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base2:

diff --git a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-4.s b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-4.s
index 36ac712..d4d5657 100644 (file)
--- a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-4.s
+++ b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-4.s
@@ -42,7 +42,7 @@ CU1_5_end:
 # CU1's contribution
 # The length is not a multiple of 4. Check that we don't read off the
 # end.
-        .long .debug_str_offsets_segment0_end-.debug_str_offsets_base0
+        .long .debug_str_offsets_segment0_end-.debug_str_offsets_base0+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base0:

diff --git a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-6.s b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-6.s
index 28c4a41..0a35c5e 100644 (file)
--- a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-6.s
+++ b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-invalid-6.s
@@ -70,7 +70,7 @@ CU2_5_end:
 
         .section .debug_str_offsets,"",@progbits
 # CU1's contribution
-        .long .debug_str_offsets_segment1_end-.debug_str_offsets_base0
+        .long .debug_str_offsets_segment1_end-.debug_str_offsets_base0+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base0:
@@ -80,7 +80,7 @@ CU2_5_end:
 .debug_str_offsets_segment0_end:
 # CU2's contribution
 # Overlapping with CU1's contribution
-        .long .debug_str_offsets_segment1_end-.debug_str_offsets_base1
+        .long .debug_str_offsets_segment1_end-.debug_str_offsets_base1+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base1:

diff --git a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-macho.s b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-macho.s
index f8f48ea..b2b5104 100644 (file)
--- a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-macho.s
+++ b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets-macho.s
@@ -31,7 +31,7 @@ str_Variable3:
 
        .section        __DWARF,__debug_str_offs,regular,debug
 Ldebug_str_offsets:
-        .long Ldebug_str_offsets_segment0_end-Ldebug_str_offsets_base0
+        .long Ldebug_str_offsets_segment0_end-Ldebug_str_offsets_base0+4
         .short 5    # DWARF version
         .short 0    # Padding
 Ldebug_str_offsets_base0:
@@ -47,7 +47,7 @@ Ldebug_str_offsets_segment0_end:
         .long 0
 # CU2's contribution (DWARF64 format)
         .long 0xffffffff
-        .quad Ldebug_str_offsets_segment1_end-Ldebug_str_offsets_base1
+        .quad Ldebug_str_offsets_segment1_end-Ldebug_str_offsets_base1+4
         .short 5    # DWARF version
         .short 0    # Padding
 Ldebug_str_offsets_base1:
@@ -56,7 +56,7 @@ Ldebug_str_offsets_base1:
         .quad str_CU2_dir
 Ldebug_str_offsets_segment1_end:
 # The TU's contribution
-        .long Ldebug_str_offsets_segment2_end-Ldebug_str_offsets_base2
+        .long Ldebug_str_offsets_segment2_end-Ldebug_str_offsets_base2+4
         .short 5    # DWARF version
         .short 0    # Padding
 Ldebug_str_offsets_base2:
@@ -250,7 +250,7 @@ TU_5_end:
 # 
 # The .debug_str_offsets section
 # COMMON:      .debug_str_offsets contents:
-# COMMON-NEXT: 0x00000000: Contribution size = 28, Format = DWARF32, Version = 5
+# COMMON-NEXT: 0x00000000: Contribution size = 32, Format = DWARF32, Version = 5
 # COMMON-NEXT: 0x00000008: 00000000 "Handmade DWARF producer"
 # COMMON-NEXT: 0x0000000c: 00000018 "Compile_Unit_1"
 # COMMON-NEXT: 0x00000010: 00000027 "/home/test/CU1"
@@ -259,10 +259,10 @@ TU_5_end:
 # COMMON-NEXT: 0x0000001c: 00000075 "MyVar2"
 # COMMON-NEXT: 0x00000020: 0000007c "MyVar3"
 # COMMON-NEXT: 0x00000024: Gap, length = 4
-# COMMON-NEXT: 0x00000028: Contribution size = 24, Format = DWARF64, Version = 5
+# COMMON-NEXT: 0x00000028: Contribution size = 28, Format = DWARF64, Version = 5
 # COMMON-NEXT: 0x00000038: 00000000 "Handmade DWARF producer"
 # COMMON-NEXT: 0x00000040: 00000036 "Compile_Unit_2"
 # COMMON-NEXT: 0x00000048: 00000045 "/home/test/CU2"
-# COMMON-NEXT: 0x00000050: Contribution size = 8, Format = DWARF32, Version = 5
+# COMMON-NEXT: 0x00000050: Contribution size = 12, Format = DWARF32, Version = 5
 # COMMON-NEXT: 0x00000058: 00000054 "Type_Unit"
 # COMMON-NEXT: 0x0000005c: 0000005e "MyStruct"

diff --git a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets.s b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets.s
index 363775a..749f4f1 100644 (file)
--- a/llvm/test/DebugInfo/X86/dwarfdump-str-offsets.s
+++ b/llvm/test/DebugInfo/X86/dwarfdump-str-offsets.s
@@ -32,7 +32,7 @@ str_Variable3:
 # Every unit contributes to the string_offsets table.
         .section .debug_str_offsets,"",@progbits
 # CU1's contribution
-        .long .debug_str_offsets_segment0_end-.debug_str_offsets_base0
+        .long .debug_str_offsets_segment0_end-.debug_str_offsets_base0+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base0:
@@ -48,7 +48,7 @@ str_Variable3:
         .long 0
 # CU2's contribution in DWARF64 format
         .long 0xffffffff
-        .quad .debug_str_offsets_segment1_end-.debug_str_offsets_base1
+        .quad .debug_str_offsets_segment1_end-.debug_str_offsets_base1+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base1:
@@ -57,7 +57,7 @@ str_Variable3:
         .quad str_CU2_dir
 .debug_str_offsets_segment1_end:
 # The TU's contribution
-        .long .debug_str_offsets_segment2_end-.debug_str_offsets_base2
+        .long .debug_str_offsets_segment2_end-.debug_str_offsets_base2+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_str_offsets_base2:
@@ -79,7 +79,7 @@ dwo_str_TU_5_type:
 
         .section .debug_str_offsets.dwo,"",@progbits
 # One contribution only in a .dwo file
-        .long .debug_dwo_str_offsets_segment0_end-.debug_dwo_str_offsets_base0
+        .long .debug_dwo_str_offsets_segment0_end-.debug_dwo_str_offsets_base0+4
         .short 5    # DWARF version
         .short 0    # Padding
 .debug_dwo_str_offsets_base0:
@@ -358,7 +358,7 @@ TU_split_5_end:
 # 
 # The .debug_str_offsets section
 # COMMON:      .debug_str_offsets contents:
-# COMMON-NEXT: 0x00000000: Contribution size = 28, Format = DWARF32, Version = 5
+# COMMON-NEXT: 0x00000000: Contribution size = 32, Format = DWARF32, Version = 5
 # COMMON-NEXT: 0x00000008: 00000000 "Handmade DWARF producer"
 # COMMON-NEXT: 0x0000000c: 00000018 "Compile_Unit_1"
 # COMMON-NEXT: 0x00000010: 00000027 "/home/test/CU1"
@@ -367,16 +367,16 @@ TU_split_5_end:
 # COMMON-NEXT: 0x0000001c: 00000075 "MyVar2"
 # COMMON-NEXT: 0x00000020: 0000007c "MyVar3"
 # COMMON-NEXT: Gap, length = 4
-# COMMON-NEXT: 0x00000028: Contribution size = 24, Format = DWARF64, Version = 5
+# COMMON-NEXT: 0x00000028: Contribution size = 28, Format = DWARF64, Version = 5
 # COMMON-NEXT: 0x00000038: 00000000 "Handmade DWARF producer"
 # COMMON-NEXT: 0x00000040: 00000036 "Compile_Unit_2"
 # COMMON-NEXT: 0x00000048: 00000045 "/home/test/CU2"
-# COMMON-NEXT: 0x00000050: Contribution size = 8, Format = DWARF32, Version = 5
+# COMMON-NEXT: 0x00000050: Contribution size = 12, Format = DWARF32, Version = 5
 # COMMON-NEXT: 0x00000058: 00000054 "Type_Unit"
 # COMMON-NEXT: 0x0000005c: 0000005e "MyStruct"
 # 
 # SPLIT:       .debug_str_offsets.dwo contents:
-# SPLIT-NEXT:  0x00000000: Contribution size = 20, Format = DWARF32, Version = 5
+# SPLIT-NEXT:  0x00000000: Contribution size = 24, Format = DWARF32, Version = 5
 # SPLIT-NEXT:  0x00000008: 00000000 "Handmade split DWARF producer"
 # SPLIT-NEXT:  0x0000000c: 0000001e "V5_split_compile_unit"
 # SPLIT-NEXT:  0x00000010: 00000034 "/home/test/splitCU"

diff --git a/llvm/test/DebugInfo/X86/string-offsets-multiple-cus.ll b/llvm/test/DebugInfo/X86/string-offsets-multiple-cus.ll
index 4900687..2f479fa 100644 (file)
--- a/llvm/test/DebugInfo/X86/string-offsets-multiple-cus.ll
+++ b/llvm/test/DebugInfo/X86/string-offsets-multiple-cus.ll
@@ -94,7 +94,7 @@
 ; Check the .debug_str_offsets section header and make sure the referenced string
 ; has the correct offset.
 ; BOTH:           .debug_str_offsets contents:
-; BOTH-NEXT:      0x00000000: Contribution size = 80, Format = DWARF32, Version = 5
+; BOTH-NEXT:      0x00000000: Contribution size = 84, Format = DWARF32, Version = 5
 ; BOTH-NEXT:      0x[[CU1_STROFF]]:
 ; BOTH-NEXT:      {{.*:}}
 ; BOTH-NEXT:      {{.*:}}

diff --git a/llvm/test/DebugInfo/X86/string-offsets-table.ll b/llvm/test/DebugInfo/X86/string-offsets-table.ll
index e2b856f..2234853 100644 (file)
--- a/llvm/test/DebugInfo/X86/string-offsets-table.ll
+++ b/llvm/test/DebugInfo/X86/string-offsets-table.ll
@@ -44,7 +44,7 @@
 ; Verify that the .debug_str_offsets section is there and that it starts
 ; with an 8-byte header, followed by offsets into the .debug_str section.
 ; MONOLITHIC:          .debug_str_offsets contents:
-; MONOLITHIC-NEXT:     Contribution size = 32, Format = DWARF32, Version = 5
+; MONOLITHIC-NEXT:     Contribution size = 36, Format = DWARF32, Version = 5
 ; MONOLITHIC-NEXT:     0x00000008: 00000000
 ; MONOLITHIC-NEXT:     0x0000000c: [[STRING2]]
 ; MONOLITHIC-NEXT:     0x00000010: [[STRING3]]
@@ -91,11 +91,11 @@
 ; Check the string offsets sections in both the main and the .dwo files and
 ; verify that the extracted string offsets are referenced correctly.
 ; SPLIT:      .debug_str_offsets contents:
-; SPLIT-NEXT: 0x00000000: Contribution size = 8, Format = DWARF32, Version = 5
+; SPLIT-NEXT: 0x00000000: Contribution size = 12, Format = DWARF32, Version = 5
 ; SPLIT-NEXT: 0x00000008: 00000000{{.*}}
 ; SPLIT-NEXT: 0x0000000c: [[STRING2SPLIT]]
 ; SPLIT:      .debug_str_offsets.dwo contents:
-; SPLIT-NEXT: 0x00000000: Contribution size = 32, Format = DWARF32, Version = 5
+; SPLIT-NEXT: 0x00000000: Contribution size = 36, Format = DWARF32, Version = 5
 ; SPLIT-NEXT: 0x00000008: 00000000{{.*}}
 ; SPLIT-NEXT: 0x0000000c: [[STRING2DWO]]{{.*}}
 ; SPLIT-NEXT: 0x00000010: [[STRING3DWO]]