Support for DW_FORM_implicit_const DWARFv5 feature.
When this form is used attribute value goes to .debug_abbrev section (as SLEB).
As this form would break any debug tool which doesn't support DWARFv5
it is guarded by dwarf version check. Attempt to use this form with
dwarf version <= 4 is considered a fatal error.

Differential Revision: https://reviews.llvm.org/D28456


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291599 91177308-0d34-0410-b5e6-96231b3b80d8

Switch functions that returned bool and filled in a DWARFFormValue arg with ones that return Optional<DWARFFormValue>

Differential Revision: https://reviews.llvm.org/D27737



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289611 91177308-0d34-0410-b5e6-96231b3b80d8

This patch gets a DWARF parsing speed improvement by having DWARFAbbreviationDeclaration instances know if they have a fixed byte size. If an abbreviation has a fixed byte size that can be calculated given a DWARFUnit, then parsing a DIE becomes two steps: parse ULEB128 abbrev code, and then add constant size to the offset.

This patch also adds a fixed byte size to each DWARFAbbreviationDeclaration::AttributeSpec so that attributes can quickly skip their values if needed without the need to lookup the fixed for size.

Notable improvements:

- DWARFAbbreviationDeclaration::findAttributeIndex() now returns an Optional<uint32_t> instead of a uint32_t and we no longer have to look for the magic -1U return value
- Optional<uint32_t> DWARFAbbreviationDeclaration::findAttributeIndex(dwarf::Attribute attr) const;
- DWARFAbbreviationDeclaration now has a getAttributeValue() function that extracts an attribute value given a DIE offset that takes advantage of the DWARFAbbreviationDeclaration::AttributeSpec::ByteSize
- bool DWARFAbbreviationDeclaration::getAttributeValue(const uint32_t DIEOffset, const dwarf::Attribute Attr, const DWARFUnit &U, DWARFFormValue &FormValue) const;
- A DWARFAbbreviationDeclaration instance can return a fixed byte size for itself so DWARF parsing is faster:
- Optional<size_t> DWARFAbbreviationDeclaration::getFixedAttributesByteSize(const DWARFUnit &U) const;
- Any functions that used to take a "const DWARFUnit *U" that would crash if U was NULL now take a "const DWARFUnit &U" and are only called with a valid DWARFUnit

Differential Revision: https://reviews.llvm.org/D26567



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286924 91177308-0d34-0410-b5e6-96231b3b80d8

Switch all DWARF variables for tags, attributes and forms over to use the llvm::dwarf enumerations instead of using raw uint16_t values. This allows easier debugging as users can see the values of the enumerations in the variables view that will show the enumeration string instead of just a number.

https://reviews.llvm.org/D26013



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285309 91177308-0d34-0410-b5e6-96231b3b80d8

This reverts commit r283285 and re-commit r283275 with
a fix for format("%s", Str); where Str is a StringRef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283298 91177308-0d34-0410-b5e6-96231b3b80d8

One test seems randomly broken: DebugInfo/X86/gnu-public-names.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283285 91177308-0d34-0410-b5e6-96231b3b80d8

This reverts commit r283278 and re-commit r283275 with
the update to fix the build on the LLDB side.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283281 91177308-0d34-0410-b5e6-96231b3b80d8

This reverts commit r283275, it broke LLDB Android debug server.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283278 91177308-0d34-0410-b5e6-96231b3b80d8

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283275 91177308-0d34-0410-b5e6-96231b3b80d8

In preparation for adding PDB support to LLVM, this moves the
DWARF parsing code to its own subdirectory under DebugInfo, and
renames LLVMDebugInfo to LLVMDebugInfoDWARF.

This is purely a mechanical / build system change.

Differential Revision: http://reviews.llvm.org/D7269
Reviewed by: Eric Christopher

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227586 91177308-0d34-0410-b5e6-96231b3b80d8

dsymutil needs access to DWARF specific inforamtion, the small DIContext
wrapper isn't sufficient. Other DWARF consumers might want to use it too
(I'm looking at you lldb).

Differential Revision: http://reviews.llvm.org/D6694

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224594 91177308-0d34-0410-b5e6-96231b3b80d8

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203915 91177308-0d34-0410-b5e6-96231b3b80d8

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203914 91177308-0d34-0410-b5e6-96231b3b80d8

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203766 91177308-0d34-0410-b5e6-96231b3b80d8

DWARFAbbreviationDeclaration: remove dead code, refactor parsing code and make it more robust. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193770 91177308-0d34-0410-b5e6-96231b3b80d8

Rename the 'Attributes' class to 'Attribute'. It's going to represent a single attribute in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170502 91177308-0d34-0410-b5e6-96231b3b80d8

Thanks Nick!

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139777 91177308-0d34-0410-b5e6-96231b3b80d8

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139646 91177308-0d34-0410-b5e6-96231b3b80d8

This introduces a new library to LLVM: libDebugInfo. It will provide debug information
parsing to LLVM. Much of the design and some of the code is taken from the LLDB project.

It also contains an llvm-dwarfdump tool that can dump the abbrevs and DIEs from an
object file. It can be used to write tests for DWARF input and output easily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139627 91177308-0d34-0410-b5e6-96231b3b80d8