From ad86d0ceb5e225978c5dd25a316018ca6873527b Mon Sep 17 00:00:00 2001 From: Pavel Labath Date: Fri, 6 Apr 2018 08:49:57 +0000 Subject: [PATCH] [debug_loc] Fix typo in DWARFExpression constructor Summary: The positions of the DwarfVersion and AddressSize arguments were reversed, which caused parsing for dwarf opcodes which contained address-size-dependent operands (such as DW_OP_addr). Amusingly enough, none of the address-size asserts fired, as dwarf version was always 4, which is a valid address size. I ran into this when constructing weird inputs for the DWARF verifier. I I add a test case as hand-written dwarf -- I am not sure how to trigger this differently, as having a DW_OP_addr inside a location list is a fairly non-standard thing to do. Fixing this error exposed a bug in the debug_loc.dwo parser, which was always being constructed with an address size of 0. I fix that as well by following the pattern in the non-dwo parser of picking up the address size from the first compile unit (which is technically not correct, but probably good enough in practice). Reviewers: JDevlieghere, aprantl, dblaikie Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D45324 llvm-svn: 329381 --- lib/DebugInfo/DWARF/DWARFContext.cpp | 10 +++- lib/DebugInfo/DWARF/DWARFDebugLoc.cpp | 2 +- .../llvm-dwarfdump/X86/debug_loc-OP_addr.s | 58 +++++++++++++++++++ 3 files changed, 66 insertions(+), 4 deletions(-) create mode 100644 test/tools/llvm-dwarfdump/X86/debug_loc-OP_addr.s diff --git a/lib/DebugInfo/DWARF/DWARFContext.cpp b/lib/DebugInfo/DWARF/DWARFContext.cpp index b3564f030eb..e9f4df6f27c 100644 --- a/lib/DebugInfo/DWARF/DWARFContext.cpp +++ b/lib/DebugInfo/DWARF/DWARFContext.cpp @@ -672,7 +672,7 @@ const DWARFDebugLoc *DWARFContext::getDebugLoc() { return Loc.get(); Loc.reset(new DWARFDebugLoc); - // assume all compile units have the same address byte size + // Assume all compile units have the same address byte size. if (getNumCompileUnits()) { DWARFDataExtractor LocData(*DObj, DObj->getLocSection(), isLittleEndian(), getCompileUnitAtIndex(0)->getAddressByteSize()); @@ -685,9 +685,13 @@ const DWARFDebugLocDWO *DWARFContext::getDebugLocDWO() { if (LocDWO) return LocDWO.get(); - DataExtractor LocData(DObj->getLocDWOSection().Data, isLittleEndian(), 0); LocDWO.reset(new DWARFDebugLocDWO()); - LocDWO->parse(LocData); + // Assume all compile units have the same address byte size. + if (getNumCompileUnits()) { + DataExtractor LocData(DObj->getLocDWOSection().Data, isLittleEndian(), + getCompileUnitAtIndex(0)->getAddressByteSize()); + LocDWO->parse(LocData); + } return LocDWO.get(); } diff --git a/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp b/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp index 02d17b278b4..90f3b45af37 100644 --- a/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp +++ b/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp @@ -33,7 +33,7 @@ static void dumpExpression(raw_ostream &OS, ArrayRef Data, const MCRegisterInfo *MRI) { DWARFDataExtractor Extractor(StringRef(Data.data(), Data.size()), IsLittleEndian, AddressSize); - DWARFExpression(Extractor, AddressSize, dwarf::DWARF_VERSION).print(OS, MRI); + DWARFExpression(Extractor, dwarf::DWARF_VERSION, AddressSize).print(OS, MRI); } void DWARFDebugLoc::LocationList::dump(raw_ostream &OS, bool IsLittleEndian, diff --git a/test/tools/llvm-dwarfdump/X86/debug_loc-OP_addr.s b/test/tools/llvm-dwarfdump/X86/debug_loc-OP_addr.s new file mode 100644 index 00000000000..7715558cf2f --- /dev/null +++ b/test/tools/llvm-dwarfdump/X86/debug_loc-OP_addr.s @@ -0,0 +1,58 @@ +# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj | llvm-dwarfdump - | FileCheck %s +# +# CHECK: DW_TAG_variable +# CHECK-NEXT: DW_AT_name ("a") +# CHECK-NEXT: DW_AT_location +# CHECK-NEXT: [0x0000000000000000, 0x0000000000000001): DW_OP_addr 0xdeadbeefbaadf00d + + .section .debug_str,"MS",@progbits,1 +.Linfo_producer: + .asciz "hand-written DWARF" +.Lname_a: + .asciz "a" + + .section .debug_loc,"",@progbits +.Ldebug_loc0: + .quad 0 + .quad 1 + .short .Lloc0_end-.Lloc0_start # Loc expr size +.Lloc0_start: + .byte 3 # DW_OP_addr + .quad 0xdeadbeefbaadf00d +.Lloc0_end: + .quad 0 + .quad 0 + + .section .debug_abbrev,"",@progbits + .byte 1 # Abbreviation Code + .byte 17 # DW_TAG_compile_unit + .byte 1 # DW_CHILDREN_yes + .byte 37 # DW_AT_producer + .byte 14 # DW_FORM_strp + .byte 0 # EOM(1) + .byte 0 # EOM(2) + .byte 5 # Abbreviation Code + .byte 52 # DW_TAG_variable + .byte 0 # DW_CHILDREN_no + .byte 3 # DW_AT_name + .byte 14 # DW_FORM_strp + .byte 2 # DW_AT_location + .byte 23 # DW_FORM_sec_offset + .byte 0 # EOM(1) + .byte 0 # EOM(2) + .byte 0 # EOM(3) + + .section .debug_info,"",@progbits +.Lcu_begin0: + .long .Lcu_end0-.Lcu_start0 # Length of Unit +.Lcu_start0: + .short 4 # DWARF version number + .long .debug_abbrev # Offset Into Abbrev. Section + .byte 8 # Address Size (in bytes) + .byte 1 # Abbrev [1] DW_TAG_compile_unit + .long .Linfo_producer # DW_AT_producer + .byte 5 # Abbrev [5] DW_TAG_variable + .long .Lname_a # DW_AT_name + .long .Ldebug_loc0 # DW_AT_location + .byte 0 # End Of Children Mark +.Lcu_end0: