Currently this is an LLVM extension to the COFF spec which is
experimental and intended to speed up linking. For now it is
behind a hidden cl::opt flag, but in the future we can move it
to a "real" cc1 flag and have the driver pass it through whenever
it is appropriate.
The patch to actually make use of this section in lld will come
in a followup.
Differential Revision: https://reviews.llvm.org/D40917
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320649 91177308-0d34-0410-b5e6-96231b3b80d8
The motivation behind this patch is that future directions require us to
be able to compute the hash value of records independently of actually
using them for de-duplication.
The current structure of TypeSerializer / TypeTableBuilder being a
single entry point that takes an unserialized type record, and then
hashes and de-duplicates it is not flexible enough to allow this.
At the same time, the existing TypeSerializer is already extremely
complex for this very reason -- it tries to be too many things. In
addition to serializing, hashing, and de-duplicating, ti also supports
splitting up field list records and adding continuations. All of this
functionality crammed into this one class makes it very complicated to
work with and hard to maintain.
To solve all of these problems, I've re-written everything from scratch
and split the functionality into separate pieces that can easily be
reused. The end result is that one class TypeSerializer is turned into 3
new classes SimpleTypeSerializer, ContinuationRecordBuilder, and
TypeTableBuilder, each of which in isolation is simple and
straightforward.
A quick summary of these new classes and their responsibilities are:
- SimpleTypeSerializer : Turns a non-FieldList leaf type into a series of
bytes. Does not do any hashing. Every time you call it, it will
re-serialize and return bytes again. The same instance can be re-used
over and over to avoid re-allocations, and in exchange for this
optimization the bytes returned by the serializer only live until the
caller attempts to serialize a new record.
- ContinuationRecordBuilder : Turns a FieldList-like record into a series
of fragments. Does not do any hashing. Like SimpleTypeSerializer,
returns references to privately owned bytes, so the storage is
invalidated as soon as the caller tries to re-use the instance. Works
equally well for LF_FIELDLIST as it does for LF_METHODLIST, solving a
long-standing theoretical limitation of the previous implementation.
- TypeTableBuilder : Accepts sequences of bytes that the user has already
serialized, and inserts them by de-duplicating with a hash table. For
the sake of convenience and efficiency, this class internally stores a
SimpleTypeSerializer so that it can accept unserialized records. The
same is not true of ContinuationRecordBuilder. The user is required to
create their own instance of ContinuationRecordBuilder.
Differential Revision: https://reviews.llvm.org/D40518
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319198 91177308-0d34-0410-b5e6-96231b3b80d8
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318490 91177308-0d34-0410-b5e6-96231b3b80d8
This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.
This fixes a link error with modular codegeneration builds - where a
header and its implementation are circularly dependent and so need to be
in the same library, not split between two like this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317379 91177308-0d34-0410-b5e6-96231b3b80d8
Change the map key from DIFile* to the absolute path string. Computing
the absolute path isn't expensive because we already have a map that
caches the full path keyed on DIFile*.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317041 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This adds a set of new directives that describe 32-bit x86 prologues.
The directives are limited and do not expose the full complexity of
codeview FPO data. They are merely a convenience for the compiler to
generate more readable assembly so we don't need to generate tons of
labels in CodeGen. If our prologue emission changes in the future, we
can change the set of available directives to suit our needs. These are
modelled after the .seh_ directives, which use a different format that
interacts with exception handling.
The directives are:
.cv_fpo_proc _foo
.cv_fpo_pushreg ebp/ebx/etc
.cv_fpo_setframe ebp/esi/etc
.cv_fpo_stackalloc 200
.cv_fpo_endprologue
.cv_fpo_endproc
.cv_fpo_data _foo
I tried to follow the implementation of ARM EHABI CFI directives by
sinking most directives out of MCStreamer and into X86TargetStreamer.
This helps avoid polluting non-X86 code with WinCOFF specific logic.
I used cdb to confirm that this can show locals in parent CSRs in a few
cases, most importantly the one where we use ESI as a frame pointer,
i.e. the one in http://crbug.com/756153#c28
Once we have cdb integration in debuginfo-tests, we can add integration
tests there.
Reviewers: majnemer, hans
Subscribers: aemerson, mgorny, kristof.beyls, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D38776
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315513 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r313431 and brings back r313374 with a fix to write
checksums as binary data and not ASCII hex strings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313657 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit 6389e7aa724ea7671d096f4770f016c3d86b0d54.
There is a bug in this implementation where the string value of the
checksum is outputted, instead of the actual hex bytes. Therefore the
checksum is incorrect, and this prevent pdbs from being loaded by visual
studio. Revert this until the checksum is emitted correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313431 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we used a size of '1' for VLAs because we weren't sure what
MSVC did. However, MSVC does support declaring an array without a size,
for which it emits an array type with a size of zero. Clang emits the
same DI metadata for VLAs and arrays without bound, so we would describe
arrays without bound as having one element. This lead to Microsoft
debuggers only printing a single element.
Emitting a size of zero appears to cause these debuggers to search the
symbol information to find a definition of the variable with accurate
array bounds.
Fixes http://crbug.com/763580
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313203 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
To improve CodeView quality for static member functions, we need to make the
static explicit. In addition to a small change in LLVM's CodeViewDebug to
return the appropriate MethodKind, this requires a small change in Clang to
note the staticness in the debug info metadata.
Subscribers: aprantl, hiraditya
Differential Revision: https://reviews.llvm.org/D37715
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313192 91177308-0d34-0410-b5e6-96231b3b80d8
S_UDT records are basically the "bridge" between the debugger's
expression evaluator and the type information. If you type
(Foo*)nullptr into the watch window, the debugger looks for an
S_UDT record named Foo. If it can find one, it displays your type.
Otherwise you get an error.
We have always understood this to mean that if you have code like
this:
struct A {
int X;
};
struct B {
typedef A AT;
AT Member;
};
that you will get 3 S_UDT records. "A", "B", and "B::AT". Because
if you were to type (B::AT*)nullptr into the debugger, it would
need to find an S_UDT record named "B::AT".
But "B::AT" is actually the S_UDT record that would be generated
if B were a namespace, not a struct. So the debugger needs to be
able to distinguish this case. So what it does is:
1. Look for an S_UDT named "B::AT". If it finds one, it knows
that AT is in a namespace.
2. If it doesn't find one, split at the scope resolution operator,
and look for an S_UDT named B. If it finds one, look up the type
for B, and then look for AT as one of its members.
With this algorithm, S_UDT records for nested typedefs are not just
unnecessary, but actually wrong!
The results of implementing this in clang are dramatic. It cuts
our /DEBUG:FASTLINK PDB sizes by more than 50%, and we go from
being ~20% larger than MSVC PDBs on average, to ~40% smaller.
It also slightly speeds up link time. We get about 10% faster
links than without this patch.
Differential Revision: https://reviews.llvm.org/D37410
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312583 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This intrinsic represents a label with a list of associated metadata
strings. It is modelled as reading and writing inaccessible memory so
that it won't be removed as dead code. I think the intention is that the
annotation strings should appear at most once in the debug info, so I
marked it noduplicate. We are allowed to inline code with annotations as
long as we strip the annotation, but that can be done later.
Reviewers: majnemer
Subscribers: eraman, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D36904
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312569 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Hopefully this also clarifies exactly when and why we're rewriting
certiain S_LOCALs using reference types: We're using the reference type
to stand in for a zero-offset load.
Reviewers: inglorion
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37309
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312247 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
DbgVariableLocation::extractFromMachineInstruction originally
returned a boolean indicating success. This change makes it return
an Optional<DbgVariableLocation> so we cannot try to access the fields
of the struct if they aren't valid.
Reviewers: aprantl, rnk, zturner
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37279
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312143 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Some variables show up in Visual Studio as "optimized out" even in -O0
-Od builds. This change fixes two issues that would cause this to
happen. The first issue is that not all DIExpressions we generate were
recognized by the CodeView writer. This has been addressed by adding
support for DW_OP_constu, DW_OP_minus, and DW_OP_plus. The second
issue is that we had no way to encode DW_OP_deref in CodeView. We get
around that by changinge the type we encode in the debug info to be
a reference to the type in the source code.
This fixes PR34261.
The reland adds two extra checks to the original: It checks if the
DbgVariableLocation is valid before checking any of its fields, and
it only emits ranges with nonzero registers.
Reviewers: aprantl, rnk, zturner
Reviewed By: rnk
Subscribers: mgorny, llvm-commits, aprantl, hiraditya
Differential Revision: https://reviews.llvm.org/D36907
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312034 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a problem introduced 311957, where the compiler would crash
with "fatal error: error in backend: unknown codeview register".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311969 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Some variables show up in Visual Studio as "optimized out" even in -O0
-Od builds. This change fixes two issues that would cause this to
happen. The first issue is that not all DIExpressions we generate were
recognized by the CodeView writer. This has been addressed by adding
support for DW_OP_constu, DW_OP_minus, and DW_OP_plus. The second
issue is that we had no way to encode DW_OP_deref in CodeView. We get
around that by changinge the type we encode in the debug info to be
a reference to the type in the source code.
This fixes PR34261.
Reviewers: aprantl, rnk, zturner
Reviewed By: rnk
Subscribers: mgorny, llvm-commits, aprantl, hiraditya
Differential Revision: https://reviews.llvm.org/D36907
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311957 91177308-0d34-0410-b5e6-96231b3b80d8
S_UDT symbols are the debugger's "index" for all the structs,
typedefs, classes, and enums in a program. If any of those
structs/classes don't have a complete declaration, or if there
is a typedef to something that doesn't have a complete definition,
then emitting the S_UDT is unhelpful because it doesn't give
the debugger enough information to do anything useful. On the
other hand, it results in a huge size blow-up in the resulting
PDB, which is exacerbated by an order of magnitude when linking
with /DEBUG:FASTLINK.
With this patch, we drop S_UDT records for types that refer either
directly or indirectly (e.g. through a typedef, pointer, etc) to
a class/struct/union/enum without a complete definition. This
brings us about 50% of the way towards parity with /DEBUG:FASTLINK
PDBs generated from cl-compiled object files.
Differential Revision: https://reviews.llvm.org/D37162
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311904 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we limited ourselves to only emitting nested classes, but we
need other kinds of types as well.
This fixes the Visual Studio STL visualizers, so that users can
visualize std::string and other objects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310410 91177308-0d34-0410-b5e6-96231b3b80d8
In the last half-dozen commits to LLVM I removed code that became dead
after removing the offset parameter from llvm.dbg.value gradually
proceeding from IR towards the backend. Before I can move on to
DwarfDebug and friends there is one last side-called offset I need to
remove: This patch modifies PrologEpilogInserter's use of the
DBG_VALUE's offset argument to use a DIExpression instead. Because the
PrologEpilogInserter runs at the Machine level I had to play a little
trick with a named llvm.dbg.mir node to get the DIExpressions to print
in MIR dumps (which print the llvm::Module followed by the
MachineFunction dump).
I also had to add rudimentary DwarfExpression support to CodeView and
as a side-effect also fixed a bug (CodeViewDebug::collectVariableInfo
was supposed to give up on variables with complex DIExpressions, but
would fail to do so for fragments, which are also modeled as
DIExpressions).
With this last holdover removed we will have only one canonical way of
representing offsets to debug locations which will simplify the code
in DwarfDebug (and future versions of CodeViewDebug once it starts
handling more complex expressions) and make it easier to reason about.
This patch is NFC-ish: All test case changes are for assembler
comments and the binary output does not change.
rdar://problem/33580047
Differential Revision: https://reviews.llvm.org/D36125
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309751 91177308-0d34-0410-b5e6-96231b3b80d8
When the first instruction of a basic block has no location (consider a
LEA materializing the address of an alloca for a call), we want to start
the line table for the block with the first valid source location in the
block. We need to ignore DBG_VALUE instructions during this scan to get
decent line tables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309628 91177308-0d34-0410-b5e6-96231b3b80d8
If the instructions at the beginning of the block have no location,
we're better off using the location of the first instruction in the
current basic block. At the very least, that instruction post-dominates
this one, whereas if we don't emit a .cv_loc directive, we end up using
the potentially invalid location that falls through from the previous
block.
We could probably do better here by emitting some kind of ".cv_loc end"
directive that stops the line table entry of the previous .cv_loc
directive from bleeding out of its basic block. This would improve the
line table when an entire MBB has no valid location info.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306889 91177308-0d34-0410-b5e6-96231b3b80d8
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304864 91177308-0d34-0410-b5e6-96231b3b80d8
Previously, every time we wanted to serialize a field list record, we
would create a new copy of FieldListRecordBuilder, which would in turn
create a temporary instance of TypeSerializer, which itself had a
std::vector<> that was about 128K in size. So this 128K allocation was
happening every time. We can re-use the same instance over and over, we
just have to clear its internal hash table and seen records list between
each run. This saves us from the constant re-allocations.
This is worth an ~18.5% speed increase (3.75s -> 3.05s) in my tests.
Differential Revision: https://reviews.llvm.org/D33506
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303919 91177308-0d34-0410-b5e6-96231b3b80d8
MachineInstructions that don't generate any code (such as
IMPLICIT_DEFs) should not generate any debug info either.
Fixes PR33107.
https://bugs.llvm.org/show_bug.cgi?id=33107
This reapplies r303566 without any modifications. The stage2 build
failures persisted even after reverting this patch, and looking back
through history, it looks like these tests are flaky.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303575 91177308-0d34-0410-b5e6-96231b3b80d8
This was originally reverted because it was a breaking a bunch
of bots and the breakage was not surfacing on Windows. After much
head-scratching this was ultimately traced back to a bug in the
lit test runner related to its pipe handling. Now that the bug
in lit is fixed, Windows correctly reports these test failures,
and as such I have finally (hopefully) fixed all of them in this
patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303446 91177308-0d34-0410-b5e6-96231b3b80d8
This is a squash of ~5 reverts of, well, pretty much everything
I did today. Something is seriously broken with lit on Windows
right now, and as a result assertions that fire in tests are
triggering failures. I've been breaking non-Windows bots all
day which has seriously confused me because all my tests have
been passing, and after running lit with -a to view the output
even on successful runs, I find out that the tool is crashing
and yet lit is still reporting it as a success!
At this point I don't even know where to start, so rather than
leave the tree broken for who knows how long, I will get this
back to green, and then once lit is fixed on Windows, hopefully
hopefully fix the remaining set of problems for real.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303409 91177308-0d34-0410-b5e6-96231b3b80d8
Right now we have multiple notions of things that represent collections of
types. Most commonly used are TypeDatabase, which is supposed to keep
mappings from TypeIndex to type name when reading a type stream, which
happens when reading PDBs. And also TypeTableBuilder, which is used to
build up a collection of types dynamically which we will later serialize
(i.e. when writing PDBs).
But often you just want to do some operation on a collection of types, and
you may want to do the same operation on any kind of collection. For
example, you might want to merge two TypeTableBuilders or you might want
to merge two type streams that you loaded from various files.
This dichotomy between reading and writing is responsible for a lot of the
existing code duplication and overlapping responsibilities in the existing
CodeView library classes. For example, after building up a
TypeTableBuilder with a bunch of type records, if we want to dump it we
have to re-invent a bunch of extra glue because our dumper takes a
TypeDatabase or a CVTypeArray, which are both incompatible with
TypeTableBuilder.
This patch introduces an abstract base class called TypeCollection which
is shared between the various type collection like things. Wherever we
previously stored a TypeDatabase& in some common class, we now store a
TypeCollection&.
The advantage of this is that all the details of how the collection are
implemented, such as lazy deserialization of partial type streams, is
completely transparent and you can just treat any collection of types the
same regardless of where it came from.
Differential Revision: https://reviews.llvm.org/D33293
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303388 91177308-0d34-0410-b5e6-96231b3b80d8
There is often a lot of boilerplate code required to visit a type
record or type stream. The #1 use case is that you have a sequence
of bytes that represent one or more records, and you want to
deserialize each one, switch on it, and call a callback with the
deserialized record that the user can examine. Currently this
requires at least 6 lines of code:
codeview::TypeVisitorCallbackPipeline Pipeline;
Pipeline.addCallbackToPipeline(Deserializer);
Pipeline.addCallbackToPipeline(MyCallbacks);
codeview::CVTypeVisitor Visitor(Pipeline);
consumeError(Visitor.visitTypeRecord(Record));
With this patch, it becomes one line of code:
consumeError(codeview::visitTypeRecord(Record, MyCallbacks));
This is done by having the deserialization happen internally inside
of the visitTypeRecord function. Since this is occasionally not
desirable, the function provides a 3rd parameter that can be used
to change this behavior.
Hopefully this can significantly reduce the barrier to entry
to using the visitation infrastructure.
Differential Revision: https://reviews.llvm.org/D33245
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303271 91177308-0d34-0410-b5e6-96231b3b80d8
This function gives the wrong answer on some non-ELF platforms in some
cases. The function that does the right thing lives in Mangler.h. To try to
discourage people from using this function, give it a different name.
Differential Revision: https://reviews.llvm.org/D33162
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303134 91177308-0d34-0410-b5e6-96231b3b80d8
Fixes inalloca parameters, which previously all pointed to the same
offset. Extend the test to use llvm-readobj so that we can test the
offset in a readable way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302578 91177308-0d34-0410-b5e6-96231b3b80d8
Most of the time we know exactly how many type records we
have in a list, and we want to use the visitor to deserialize
them into actual records in a database. Previously we were
just using push_back() every time without reserving the space
up front in the vector. This is obviously terrible from a
performance standpoint, and it's not uncommon to have PDB
files with half a million type records, where the performance
degredation was quite noticeable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302302 91177308-0d34-0410-b5e6-96231b3b80d8
Compiler emitted synthetic types may not have an associated DIFile
(translation unit). In such a case, when generating CodeView debug type
information, we would attempt to compute an absolute filepath which
would result in a segfault due to a NULL DIFile*. If there is no source
file associated with the type, elide the type index entry for the type
and record the type information. This actually results in higher
fidelity debug information than clang/C2 as of this writing.
Resolves PR32668!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302085 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we wrote line information and file checksum
information, but we did not write information about inlinee
lines and functions. This patch adds support for that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301936 91177308-0d34-0410-b5e6-96231b3b80d8
We have a lot of very similarly named classes related to
dealing with module debug info. This patch has NFC, it just
renames some classes to be more descriptive (albeit slightly
more to type). The mapping from old to new class names is as
follows:
Old | New
ModInfo | DbiModuleDescriptor
ModuleSubstream | ModuleDebugFragment
ModStream | ModuleDebugStream
With the corresponding Builder classes renamed accordingly.
Differential Revision: https://reviews.llvm.org/D32506
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301555 91177308-0d34-0410-b5e6-96231b3b80d8
DISubprogram currently has 10 pointer operands, several of which are
often nullptr. This patch reduces the amount of memory allocated by
DISubprogram by rearranging the operands such that containing type,
template params, and thrown types come last, and are only allocated
when they are non-null (or followed by non-null operands).
This patch also eliminates the entirely unused DisplayName operand.
This saves up to 4 pointer operands per DISubprogram. (I tried
measuring the effect on peak memory usage on an LTO link of an X86
llc, but the results were very noisy).
This reapplies r301498 with an attempted workaround for g++.
Differential Revision: https://reviews.llvm.org/D32560
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301501 91177308-0d34-0410-b5e6-96231b3b80d8
