The only tests we have for the DWARF parser are the tests that use llvm-dwarfdump and expect output from textual dumps.
More DWARF parser modification are coming in the next few weeks and I wanted to add tests that can verify that we can encode and decode all form types, as well as test some other basic DWARF APIs where we ask DIE objects for their children and siblings.
DwarfGenerator.cpp was added in the lib/CodeGen directory. This file contains the code necessary to easily create DWARF for tests:
dwarfgen::Generator DG;
Triple Triple("x86_64--");
bool success = DG.init(Triple, Version);
if (!success)
return;
dwarfgen::CompileUnit &CU = DG.addCompileUnit();
dwarfgen::DIE CUDie = CU.getUnitDIE();
CUDie.addAttribute(DW_AT_name, DW_FORM_strp, "/tmp/main.c");
CUDie.addAttribute(DW_AT_language, DW_FORM_data2, DW_LANG_C);
dwarfgen::DIE SubprogramDie = CUDie.addChild(DW_TAG_subprogram);
SubprogramDie.addAttribute(DW_AT_name, DW_FORM_strp, "main");
SubprogramDie.addAttribute(DW_AT_low_pc, DW_FORM_addr, 0x1000U);
SubprogramDie.addAttribute(DW_AT_high_pc, DW_FORM_addr, 0x2000U);
dwarfgen::DIE IntDie = CUDie.addChild(DW_TAG_base_type);
IntDie.addAttribute(DW_AT_name, DW_FORM_strp, "int");
IntDie.addAttribute(DW_AT_encoding, DW_FORM_data1, DW_ATE_signed);
IntDie.addAttribute(DW_AT_byte_size, DW_FORM_data1, 4);
dwarfgen::DIE ArgcDie = SubprogramDie.addChild(DW_TAG_formal_parameter);
ArgcDie.addAttribute(DW_AT_name, DW_FORM_strp, "argc");
// ArgcDie.addAttribute(DW_AT_type, DW_FORM_ref4, IntDie);
ArgcDie.addAttribute(DW_AT_type, DW_FORM_ref_addr, IntDie);
StringRef FileBytes = DG.generate();
MemoryBufferRef FileBuffer(FileBytes, "dwarf");
auto Obj = object::ObjectFile::createObjectFile(FileBuffer);
EXPECT_TRUE((bool)Obj);
DWARFContextInMemory DwarfContext(*Obj.get());
This code is backed by the AsmPrinter code that emits DWARF for the actual compiler.
While adding unit tests it was discovered that DIEValue that used DIEEntry as their values had bugs where DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref8, and DW_FORM_ref_udata forms were not supported. These are all now supported. Added support for DW_FORM_string so we can emit inlined C strings.
Centralized the code to unique abbreviations into a new DIEAbbrevSet class and made both the dwarfgen::Generator and the llvm::DwarfFile classes use the new class.
Fixed comments in the llvm::DIE class so that the Offset is known to be the compile/type unit offset.
DIEInteger now supports more DW_FORM values.
There are also unit tests that cover:
Encoding and decoding all form types and values
Encoding and decoding all reference types (DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref4, DW_FORM_ref8, DW_FORM_ref_udata, DW_FORM_ref_addr) including cross compile unit references with that go forward one compile unit and backward on compile unit.
Differential Revision: https://reviews.llvm.org/D27326
llvm-svn: 289010
Summary: The code we use to read PDBs assumed that streams we ask it to read exist, and would read memory outside a vector and crash if this wasn't the case. This would, for example, cause llvm-pdbdump to crash on PDBs generated by lld. This patch handles such cases more gracefully: the PDB reading code in LLVM now reports errors when asked to get a stream that is not present, and llvm-pdbdump will report missing streams and continue processing streams that are present.
Reviewers: ruiu, zturner
Subscribers: thakis, amccarth
Differential Revision: https://reviews.llvm.org/D27325
llvm-svn: 288722
PDBFileBuilder supports two different ways to create files.
One is PDBFileBuilder::commit. That function takes a filename
and write a result to the file. The other is PDBFileBuilder::build.
That returns a new PDBFile object.
This patch removes the latter because no one is using it and
in a real life situation we are very unlikely to need it.
Even if you need it, it'd be easy to write a new PDB to a memory
buffer and read it back.
Removing PDBFileBuilder::build enables us to remove other classes
build transitively.
Differential Revision: https://reviews.llvm.org/D26987
llvm-svn: 287697
This is required by DbiStream, but DbiStreamBuilder didn't align
these substreams, so the output of DbiSTreamBuilder couldn't be
read by DbiStream.
Test will be added to LLD.
llvm-svn: 287067
These numbers are intended to be capped at 65535, but
`std::max<uint16_t>(UINT16_MAX, N)` always returns N for any N because
the expression is the same as `std::max((uint16_t)UINT16_MAX, (uint16_t)N)`.
llvm-svn: 287060
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
llvm-svn: 286924
This patch defines a new function to add a SectionContribs stream
to a PDB file. Unlike SectionMap, SectionContribs contains a list
of input sections as opposed to output sections.
Note that this patch needs improving because currently we do not
set Module field in SectionContribs entries. In a follow-up patch,
I'll add Modules and then fix it after that.
Differential Revision: https://reviews.llvm.org/D26210
llvm-svn: 286677
https://reviews.llvm.org/D26526
- Fixed DW_FORM_strp to be correctly sized and extracted for DWARF64
- Added some missing strp variants as well
- Fixed comment typo
llvm-svn: 286603
In preparation for a follow on patch that improves DWARF parsing speed, clean up DWARFFormValue so that we have can get the fixed byte size of a form value given a DWARFUnit or given the version, address byte size and dwarf32/64.
This patch cleans up code so that everyone is using one of the new DWARFFormValue functions:
static Optional<uint8_t> DWARFFormValue::getFixedByteSize(dwarf::Form Form, const DWARFUnit *U = nullptr);
static Optional<uint8_t> DWARFFormValue::getFixedByteSize(dwarf::Form Form, uint16_t Version, uint8_t AddrSize, bool Dwarf32);
This patch changes DWARFFormValue::skipValue() to rely on the output of DWARFFormValue::getFixedByteSize(...) instead of duplicating the code in each function. This will reduce the number of changes we need to make to DWARF to fewer places in DWARFFormValue when we add support for new form.
This patch also starts to support DWARF64 so that we can get correct byte sizes for forms that vary according the DWARF 32/64.
To reduce the code duplication a new FormSizeHelper pure virtual class was created that can be created as a FormSizeHelperDWARFUnit when you have a DWARFUnit, or FormSizeHelperManual where you manually specify the DWARF version, address byte size and DWARF32/DWARF64. There is now a single implementation of a function that gets the fixed byte size (instead of two where one took a DWARFUnit and one took the DWARF version, address byte size and DWARFFormat enum) and one function to skip the form values.
https://reviews.llvm.org/D26526
llvm-svn: 286597
Previously support had been added for using CodeViewRecordIO
to read (deserialize) CodeView type records. This patch adds
support for writing those same records. With this patch,
reading and writing of CodeView type records finally uses a single
codepath.
Differential Revision: https://reviews.llvm.org/D26253
llvm-svn: 286304
Using a pattern similar to that of YamlIO, this allows
us to have a single codepath for translating codeview
records to and from serialized byte streams. The
current patch only hooks this up to the reading of
CodeView type records. A subsequent patch will hook
it up for writing of CodeView type records, and then a
third patch will hook up the reading and writing of
CodeView symbols.
Differential Revision: https://reviews.llvm.org/D26040
llvm-svn: 285836
This change enables LLD to construct a Section Map stream in a PDB file.
I do not understand all these fields in the Section Map yet, but it seems
like a copy of a COFF section header in another format.
With this patch, DbiStreamBuilder can emit a Section Map which
llvm-pdbdump can dump.
Differential Revision: https://reviews.llvm.org/D26112
llvm-svn: 285606
Modifying DWARFFormValue to remember the DWARFUnit that it was encoded with can simplify the usage of instances of this class. Previously users would have to try and pass in the same DWARFUnit that was used to decode the form value and there was a possibility that a different DWARFUnit might be supplied to the functions that extract values (strings, CU relative references, addresses) and cause problems. This fixes this potential issue by storing the DWARFUnit inside the DWARFFormValue so that this mistake can't be made. Instances of DWARFFormValue are not stored permanently and are used as temporary values, so the increase in size of an instance of DWARFFormValue isn't a big deal. This makes decoding form values more bullet proof and is a change that will be used by future modifications.
https://reviews.llvm.org/D26052
llvm-svn: 285594
Summary:
Fixes PR28281.
MSVC lists indirect virtual base classes in the field list of a class,
using LF_IVBCLASS records. This change makes LLVM emit such records
when processing DW_TAG_inheritance tags with the DIFlagVirtual and
(newly introduced) DIFlagIndirect tags.
Reviewers: rnk, ruiu, zturner
Differential Revision: https://reviews.llvm.org/D25578
llvm-svn: 285130
Summary: This adds support for dumping the globals stream from PDB files using llvm-pdbdump, similar to the support we have for the publics stream.
Reviewers: ruiu, zturner
Subscribers: beanz, mgorny, modocache
Differential Revision: https://reviews.llvm.org/D25801
llvm-svn: 284861
This was all using ArrayRef<>s before which presents a problem
when you want to serialize to or deserialize from an actual
PDB stream. An ArrayRef<> is really just a special case of
what can be handled with StreamInterface though (e.g. by using
a ByteStream), so changing this to use StreamInterface allows
us to plug in a PDB stream and get all the record serialization
and deserialization for free on a MappedBlockStream.
Subsequent patches will try to remove TypeTableBuilder and
TypeRecordBuilder in favor of class that operate on
Streams as well, which should allow us to completely merge
the reading and writing codepaths for both types and symbols.
Differential Revision: https://reviews.llvm.org/D25831
llvm-svn: 284762
This is just a quick utility handy for getting rough summaries of types
in a given object or dwo file. I've been using it to investigate the
amount of type info redundancy across a project build, for example.
llvm-svn: 284537
In the MS ABI, the frontend is supposed to MD5 such pathologically long
names. LLVM should still defend itself from long names, though.
Fixes part of PR29098.
llvm-svn: 284136
The previous commit was failing because we filled empty slots of
the debug stream index with kInvalidStreamIndex. It should've been 0.
llvm-svn: 283925
Previously, there is no way to create a stream other than pre-defined
special stream such as DBI or IPI. This patch adds a new method,
addDbgStream, to add a debug stream to a PDB file.
Differential Revision: https://reviews.llvm.org/D25356
llvm-svn: 283823
This is the first step towards round-tripping symbol information,
and thusly being able to write symbol information to a PDB.
This patch writes the symbol information for each compiland to
the Yaml when running in pdb2yaml mode. There's still some loose
ends, such as what to do about relocations (necessary in order to
print linkage names), how to print enums with friendly names, and
how to give the dumper access to the StringTable, but this is a
good first start.
llvm-svn: 283641
Type visitor code had already been refactored previously to
decouple the visitor and the visitor callback interface. This
was necessary for having the flexibility to visit in different
ways (for example, dumping to yaml, reading from yaml, dumping
to ScopedPrinter, etc).
This patch merely implements the same visitation pattern for
symbol records that has already been implemented for type records.
llvm-svn: 283609
When we create a PDB file using PDBFileBuilder, the information
in the superblock, such as the size of the resulting file, is not
available.
Previously, PDBFileBuilder::initialize took a superblock assuming
that all the members of the struct are correct. That is useful when
you want to restore the exact information from a YAML file, but
that's probably the only use case in which that is useful.
When we are creating a PDB file on the fly, we have to backfill the
members.
This patch redefines PDBFileBuilder::initialize to take only a
block size. Now all the other members are left as default values,
so that they'll be updated when commit() is called.
Differential Revision: https://reviews.llvm.org/D25108
llvm-svn: 282944
WritableStream needs the exact file size to open a file, but
until we fix the final layout of a PDB file, we don't know the
size of the file.
This patch changes the parameter type of PDBFileBuilder::commit
to solve that chiecken-and-egg problem. Now the function opens
a file after fixing the layout, so it can create a file with the
exact size.
Differential Revision: https://reviews.llvm.org/D25107
llvm-svn: 282940
The IPI stream is structurally identical to the TPI stream, but it
contains different record types. So we just re-use the TPI writing
code.
llvm-svn: 281638
We were inadvertently adding the size of the hash value stream to
the size of the TPI stream, even though the hash value stream is
an entirely separate stream.
llvm-svn: 281636
The `CVType` had two redundant fields which were confusing and
error-prone to fill out. By treating member records as a distinct
type from leaf records, we are able to simplify this quite a bit.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D24432
llvm-svn: 281556
Greg Clayton