129 Commits

Author SHA1 Message Date
Daniel Paoliello
050bb26174
[llvm] Implement S_INLINEES debug symbol (#67490)
The `S_INLINEES` debug symbol is used to record all the functions that
are directly inlined within the current function (nested inlining is
ignored).

This change implements support for emitting the `S_INLINEES` debug
symbol in LLVM, and cleans up how the `S_INLINEES` and `S_CALLEES` debug
symbols are dumped.
2023-09-27 14:06:22 -07:00
Daniel Paoliello
0c5c7b52f0 Emit the CodeView S_ARMSWITCHTABLE debug symbol for jump tables
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:

* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).

Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.

Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)

This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D149367
2023-08-31 12:06:50 -07:00
Arthur Eubanks
0a4fc4ac1c Revert "Emit the CodeView S_ARMSWITCHTABLE debug symbol for jump tables"
This reverts commit 8d0c3db388143f4e058b5f513a70fd5d089d51c3.

Causes crashes, see comments in https://reviews.llvm.org/D149367.

Some follow-up fixes are also reverted:

This reverts commit 636269f4fca44693bfd787b0a37bb0328ffcc085.
This reverts commit 5966079cf4d4de0285004eef051784d0d9f7a3a6.
This reverts commit e7294dbc85d24a08c716d9babbe7f68390cf219b.
2023-08-25 18:34:15 -07:00
Daniel Paoliello
8d0c3db388 Emit the CodeView S_ARMSWITCHTABLE debug symbol for jump tables
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:

* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).

Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.

Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)

This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D149367
2023-08-25 10:19:17 -07:00
Elliot Goodrich
b0abd4893f [llvm] Add missing StringExtras.h includes
In preparation for removing the `#include "llvm/ADT/StringExtras.h"`
from the header to source file of `llvm/Support/Error.h`, first add in
all the missing includes that were previously included transitively
through this header.
2023-06-25 15:42:22 +01:00
Daniel Paoliello
f8499d5709 Emit the correct flags for the PROC CodeView Debug Symbol
The S_LPROC32_ID and S_GPROC32_ID CodeView Debug Symbols have a flags
field which LLVM has had the values for (in the ProcSymFlags enum) but
has never actually set.

These flags are used by Microsoft-internal tooling that leverages debug
information to do binary analysis.

Modified LLVM to set the correct flags:

- ProcSymFlags::HasOptimizedDebugInfo - always set, as this indicates that
debug info is present for optimized builds (if debug info is not emitted
for optimized builds, then LLVM won't emit a debug symbol at all).
- ProcSymFlags::IsNoReturn and ProcSymFlags::IsNoInline - set if the
function has the NoReturn or NoInline attributes respectively.
- ProcSymFlags::HasFP - set if the function requires a frame pointer (per
TargetFrameLowering::hasFP).

Per discussion in review, XFAIL'ing lldb test until someone working on
lldb has a chance to look at it.

Differential Revision: https://reviews.llvm.org/D148761
2023-05-16 10:58:10 -07:00
Muhammad Omair Javaid
6b22608a1d Revert "Emit the correct flags for the PROC CodeView Debug Symbol"
This reverts commit e48826e016e2f427f3b7b1274166aa9aa0ea7f4f.

https://lab.llvm.org/buildbot/#/builders/219/builds/2520

ldb-shell :: SymbolFile/PDB/function-nested-block.test

Differential Revision: https://reviews.llvm.org/D148761
2023-05-15 23:38:07 +04:00
Daniel Paoliello
e48826e016 Emit the correct flags for the PROC CodeView Debug Symbol
The S_LPROC32_ID and S_GPROC32_ID CodeView Debug Symbols have a flags
field which LLVM has had the values for (in the ProcSymFlags enum) but
has never actually set.

These flags are used by Microsoft-internal tooling that leverages debug
information to do binary analysis.

Modified LLVM to set the correct flags:

- ProcSymFlags::HasOptimizedDebugInfo - always set, as this indicates that
debug info is present for optimized builds (if debug info is not emitted
for optimized builds, then LLVM won't emit a debug symbol at all).
- ProcSymFlags::IsNoReturn and ProcSymFlags::IsNoInline - set if the
function has the NoReturn or NoInline attributes respectively.
- ProcSymFlags::HasFP - set if the function requires a frame pointer (per
TargetFrameLowering::hasFP).

Differential Revision: https://reviews.llvm.org/D148761
2023-05-03 18:20:16 -07:00
Tobias Hieta
2298a44ccd
[CodeView] Add support for local S_CONSTANT records
CodeView doesn't have the ability to represent variables
in other ways than as in registers or memory values, but
LLVM very often transforms simple values into constants,
consider this program:

int f () { int i = 123; return i; }

LLVM will transform `i` into a constant value and just
leave behind a llvm.dbg.value, this can't be represented
as a S_LOCAL record in CodeView. But we can represent it
as a S_CONSTANT record.

This patch checks if the location of a debug value is null,
then we will insert a S_CONSTANT record instead of a S_LOCAL
value with the flag "OptimizedAway".

In lld we then output the S_CONSTANT in the right scope, before
they where always inserted in the global stream, now we check
the scope before inserting it.

This has shown to improve debugging for our developers
internally.

Fixes to llvm/llvm-project#55958

Reviewed By: aganea

Differential Revision: https://reviews.llvm.org/D138995
2022-12-06 10:34:01 +01:00
Kazu Hirata
32aa35b504 Drop empty string literals from static_assert (NFC)
Identified with modernize-unary-static-assert.
2022-09-03 11:17:47 -07:00
Zequan Wu
9886046289 [CodeView] Combine variable def ranges that are continuous.
It saves about 1.13% size for chrome.dll.pdb on chrome official build.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D125721
2022-05-20 12:12:14 -07:00
Alexandre Ganea
a282ea4898 Reland - [CodeView] Emit S_OBJNAME record
Reland integrates build fixes & further review suggestions.

Thanks to @zturner for the initial S_OBJNAME patch!

Differential Revision: https://reviews.llvm.org/D43002
2021-12-21 19:02:14 -05:00
Alexandre Ganea
5bb5142e80 Revert [CodeView] Emit S_OBJNAME record
Also revert all subsequent fixes:
- abd1cbf5e543f0f114d2742e109ead7d7ddbf9c4 [Clang] Disable debug-info-objname.cpp test on Unix until I sort out the issue.
- 00ec441253048f5e30540ea26bb0a28c42a5fc18 [Clang] debug-info-objname.cpp test: explictly encode a x86 target when using %clang_cl to avoid falling back to a native CPU triple.
- cd407f6e52b09cce2bef24c74b7f36fedc94991b [Clang] Fix build by restricting debug-info-objname.cpp test to x86.
2021-12-21 19:02:14 -05:00
Alexandre Ganea
f44e3fbadd [CodeView] Emit S_OBJNAME record
Thanks to @zturner for the initial patch!

Differential Revision: https://reviews.llvm.org/D43002
2021-12-21 09:26:36 -05:00
Chih-Ping Chen
2ed29d87ef [CodeView] Fortran debug info emission in Code View.
Differential Revision: https://reviews.llvm.org/D112826
2021-11-02 15:06:21 -04:00
Matheus Izvekov
f84c70a379 [CodeView] Saturate values bigger than supported by APInt.
This fixes an assert firing when compiling code which involves 128 bit
integrals.

This would trigger runtime checks similar to this:
```
Assertion failed: getMinSignedBits() <= 64 && "Too many bits for int64_t", file llvm/include/llvm/ADT/APInt.h, line 1646
```

To get around this, we just saturate those big values.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D105320
2021-07-26 22:15:26 +02:00
Kazu Hirata
e785379aff [CodeView] Remove unused declaration collectInlineSiteChildren (NFC)
The function definition was removed on Sep 7, 2016 in commit
a9f4cc9510546f5728258524d344a3e03e43500b.  The declaration seems to be
unused since then.
2020-11-30 22:28:26 -08:00
Jameson Nash
a0ad066ce4 make the AsmPrinterHandler array public
This lets external consumers customize the output, similar to how
AssemblyAnnotationWriter lets the caller define callbacks when printing
IR. The array of handlers already existed, this just cleans up the code
so that it can be exposed publically.

Replaces https://reviews.llvm.org/D74158

Differential Revision: https://reviews.llvm.org/D89613
2020-11-03 10:02:09 -05:00
Amy Huang
7669f3c0f6 Recommit "[CodeView] Emit static data members as S_CONSTANTs."
We used to only emit static const data members in CodeView as
S_CONSTANTS when they were used; this patch makes it so they are always emitted.

This changes CodeViewDebug.cpp to find the static const members from the
class debug info instead of creating DIGlobalVariables in the IR
whenever a static const data member is used.

Bug: https://bugs.llvm.org/show_bug.cgi?id=47580

Differential Revision: https://reviews.llvm.org/D89072

This reverts commit 504615353f31136dd6bf7a971b6c236fd70582be.
2020-10-28 16:35:59 -07:00
Amy Huang
504615353f Revert "[CodeView] Emit static data members as S_CONSTANTs."
Seems like there's an assert in here that we shouldn't be running into.

This reverts commit 515973222ed29abe49f241e89edb6854f44162d4.
2020-10-27 11:29:58 -07:00
Amy Huang
515973222e [CodeView] Emit static data members as S_CONSTANTs.
We used to only emit static const data members in CodeView as
S_CONSTANTS when they were used; this patch makes it so they are always emitted.

I changed CodeViewDebug.cpp to find the static const members from the
class debug info instead of creating DIGlobalVariables in the IR
whenever a static const data member is used.

Bug: https://bugs.llvm.org/show_bug.cgi?id=47580

Differential Revision: https://reviews.llvm.org/D89072
2020-10-26 15:30:35 -07:00
Reid Kleckner
47cc6db928 Re-land [Debug][CodeView] Emit fully qualified names for globals
This reverts commit 525a591f0f48b9d54018bf5245f2abee09c9c1c8.

Fixed an issue with pointers to members based on typedefs. In this case,
LLVM would emit a second UDT. I fixed it by not passing the class type
to getTypeIndex when the base type is not a function type. lowerType
only uses the class type for direct function types. This suggests if we
have a PMF with a function typedef, there may be an issue, but that can
be solved separately.
2020-05-18 17:31:00 -07:00
Hans Wennborg
525a591f0f Revert 76c5f277f2 "Re-land [Debug][CodeView] Emit fully qualified names for globals"
> Before this patch, S_[L|G][THREAD32|DATA32] records were emitted with a simple name, not the fully qualified name (namespace + class scope).
>
> Differential Revision: https://reviews.llvm.org/D79447

This causes asserts in Chromium builds:

CodeViewDebug.cpp:2997: void llvm::CodeViewDebug::emitDebugInfoForUDTs(const std::vector<std::pair<std::string, const DIType *>> &):
Assertion `OriginalSize == UDTs.size()' failed.

I will follow up on the Phabricator issue.
2020-05-18 11:26:30 +02:00
Alexandre Ganea
76c5f277f2 Re-land [Debug][CodeView] Emit fully qualified names for globals
Before this patch, S_[L|G][THREAD32|DATA32] records were emitted with a simple name, not the fully qualified name (namespace + class scope).

Differential Revision: https://reviews.llvm.org/D79447
2020-05-15 10:37:09 -04:00
Amy Huang
2b8c6acc39 Reland "[codeview] Reference types in type parent scopes"
Summary:
Original description (https://reviews.llvm/org/D69924)
Without this change, when a nested tag type of any kind (enum, class,
struct, union) is used as a variable type, it is emitted without
emitting the parent type. In CodeView, parent types point to their inner
types, and inner types do not point back to their parents. We already
walk over all of the parent scopes to build the fully qualified name.
This change simply requests their type indices as we go along to enusre
they are all emitted.

Now, while walking over the parent scopes, add the types to
DeferredCompleteTypes, since they might already be in the process of
being emitted.

Fixes PR43905

Reviewers: rnk, amccarth

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78249
2020-04-16 12:08:52 -07:00
Hans Wennborg
ff3b513495 Revert d91ed80 "[codeview] Reference types in type parent scopes"
This triggered asserts in the Chromium build, see https://crbug.com/1022729 for
details and reproducer.

> Without this change, when a nested tag type of any kind (enum, class,
> struct, union) is used as a variable type, it is emitted without
> emitting the parent type. In CodeView, parent types point to their inner
> types, and inner types do not point back to their parents. We already
> walk over all of the parent scopes to build the fully qualified name.
> This change simply requests their type indices as we go along to enusre
> they are all emitted.
>
> Fixes PR43905
>
> Reviewers: akhuang, amccarth
>
> Differential Revision: https://reviews.llvm.org/D69924
2019-11-08 11:30:33 +01:00
Reid Kleckner
d91ed80e97 [codeview] Reference types in type parent scopes
Without this change, when a nested tag type of any kind (enum, class,
struct, union) is used as a variable type, it is emitted without
emitting the parent type. In CodeView, parent types point to their inner
types, and inner types do not point back to their parents. We already
walk over all of the parent scopes to build the fully qualified name.
This change simply requests their type indices as we go along to enusre
they are all emitted.

Fixes PR43905

Reviewers: akhuang, amccarth

Differential Revision: https://reviews.llvm.org/D69924
2019-11-07 13:58:01 -08:00
Amy Huang
742043047c Recommit "Add a heap alloc site marker field to the ExtraInfo in MachineInstrs"
Summary:
Fixes some things from original commit at https://reviews.llvm.org/D69136. The main
change is that the heap alloc marker is always stored as ExtraInfo in the machine
instruction instead of in the PointerSumType because it cannot hold more than
4 pointer types.

Add instruction marker to MachineInstr ExtraInfo. This does almost the
same thing as Pre/PostInstrSymbols, except that it doesn't create a label until
printing instructions. This allows for labels to be put around instructions that
are deleted/duplicated somewhere.
Use this marker to track heap alloc site call instructions.

Reviewers: rnk

Subscribers: MatzeB, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69536
2019-10-28 16:59:32 -07:00
Amy Huang
64c1f6602a Revert "Add an instruction marker field to the ExtraInfo in MachineInstrs."
Reverting commit b85b4e5a6f8579c137fecb59a4d75d7bfb111f79 due to some
buildbot failures/ out of memory errors.
2019-10-25 12:41:34 -07:00
Amy Huang
b85b4e5a6f Add an instruction marker field to the ExtraInfo in MachineInstrs.
Summary:
Add instruction marker to MachineInstr ExtraInfo. This does almost the
same thing as Pre/PostInstrSymbols, except that it doesn't create a label until
printing instructions. This allows for labels to be put around instructions that
are deleted/duplicated somewhere.

Also undo the workaround in r375137.

Reviewers: rnk

Subscribers: MatzeB, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69136
2019-10-25 09:21:10 -07:00
Amy Huang
f332fe642c [COFF] Change a variable type to be const in the HeapAllocSite map.
llvm-svn: 366479
2019-07-18 18:22:52 +00:00
Amy Huang
c2029068bc Emit global variables as S_CONSTANT records for codeview debug info.
Summary:
This emits S_CONSTANT records for global variables.
Currently this emits records for the global variables already being tracked in the
LLVM IR metadata, which are just constant global variables; we'll also want S_CONSTANTs
for static data members and enums.

Related to https://bugs.llvm.org/show_bug.cgi?id=41615

Reviewers: rnk

Subscribers: aprantl, hiraditya, llvm-commits, thakis

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61926

llvm-svn: 360948
2019-05-16 22:28:52 +00:00
Fangrui Song
da82ce99b7 [DebugInfo] Delete TypedDINodeRef
TypedDINodeRef<T> is a redundant wrapper of Metadata * that is actually a T *.

Accordingly, change DI{Node,Scope,Type}Ref uses to DI{Node,Scope,Type} * or their const variants.
This allows us to delete many resolve() calls that clutter the code.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D61369

llvm-svn: 360108
2019-05-07 02:06:37 +00:00
Amy Huang
68c9199493 Recommitting r358783 and r358786 "[MS] Emit S_HEAPALLOCSITE debug info" with fixes for buildbot error (undefined assembler label).
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.

Reviewers: rnk

Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D61083

llvm-svn: 359149
2019-04-24 23:02:48 +00:00
Amy Huang
fc79ab9857 Revert "[MS] Emit S_HEAPALLOCSITE debug info" because of ToTWin64(db)
buildbot failure.

This reverts commit d07d6d617713bececf57f3547434dd52f0f13f9e and
c774f687b6880484a126ed3e3d737e74c926f0ae.

llvm-svn: 359034
2019-04-23 21:12:58 +00:00
Amy Huang
c774f687b6 [MS] Emit S_HEAPALLOCSITE debug info
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.

Reviewers: hans, rnk

Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D60800

llvm-svn: 358783
2019-04-19 21:09:11 +00:00
David Stenberg
6feef56d1b [DebugInfo] Rename DbgValueHistoryMap::{InstrRange -> Entry}, NFC
Summary:
In an upcoming commit the history map will be changed so that it
contains explicit entries for instructions that clobber preceding debug
values, rather than Begin- End range pairs, so generalize the name to
"Entry".

Also, prefix the iterator variable names in buildLocationList() with
"E". In an upcoming commit the entry will have query functions such as
"isD(e)b(u)gValue", which could at a glance make one confuse it for
iterations over MachineInstrs, so make the iterator names a bit more
distinct to avoid that.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59939

llvm-svn: 358060
2019-04-10 09:07:43 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Reid Kleckner
c168c6f86f [codeview] Check if this 'this' type of a method is a pointer
Fixes crash reported after r347354 for frontends that don't always emit
'this' pointers for methods. Now we will silently produce debug info
that makes functions like this look like static methods, which seems
reasonable.

llvm-svn: 350073
2018-12-26 21:52:17 +00:00
Brock Wyma
b17464e4e8 [CodeView] Emit global variables within lexical scopes to limit visibility
Emit static locals within the correct lexical scope so variables with the same
name will not confuse the debugger into getting the wrong value.

Differential Revision: https://reviews.llvm.org/D55336

llvm-svn: 349777
2018-12-20 17:33:45 +00:00
Yonghong Song
61b189e06f [DebugInfo] Move several private headers to include directory
This patch moved the following files in lib/CodeGen/AsmPrinter/
  AsmPrinterHandler.h
  DbgEntityHistoryCalculator.h
  DebugHandlerBase.h
to include/llvm/CodeGen directory.

Such a change will enable Target to extend DebugHandlerBase
and emit Target specific debug info sections.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D55755

llvm-svn: 349564
2018-12-18 23:10:17 +00:00
Reid Kleckner
5bf71d1127 [codeview] Add begin/endSymbolRecord helpers, NFC
Previously beginning a symbol record was excessively verbose. Now it's a
bit simpler. This follows the same pattern as begin/endCVSubsection.

llvm-svn: 349205
2018-12-14 22:40:28 +00:00
Zachary Turner
c68f895702 [CodeView] Add support for ref-qualified member functions.
When you have a member function with a ref-qualifier, for example:

struct Foo {
  void Func() &;
  void Func2() &&;
};

clang-cl was not emitting this information. Doing so is a bit
awkward, because it's not a property of the LF_MFUNCTION type, which
is what you'd expect. Instead, it's a property of the this pointer
which is actually an LF_POINTER. This record has an attributes
bitmask on it, and our handling of this bitmask was all wrong. We
had some parts of the bitmask defined incorrectly, but importantly
for this bug, we didn't know about these extra 2 bits that represent
the ref qualifier at all.

Differential Revision: https://reviews.llvm.org/D54667

llvm-svn: 347354
2018-11-20 22:13:43 +00:00
Reid Kleckner
755577168a [codeview] Expose -gcodeview-ghash for global type hashing
Summary:
Experience has shown that the functionality is useful. It makes linking
optimized clang with debug info for me a lot faster, 20s to 13s. The
type merging phase of PDB writing goes from 10s to 3s.

This removes the LLVM cl::opt and replaces it with a metadata flag.

After this change, users can do the following to use ghash:
- add -gcodeview-ghash to compiler flags
- replace /DEBUG with /DEBUG:GHASH in linker flags

Reviewers: zturner, hans, thakis, takuto.ikuta

Subscribers: aprantl, hiraditya, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D54370

llvm-svn: 347072
2018-11-16 18:47:41 +00:00
Reid Kleckner
2bcb288ade [codeview] Let the X86 backend tell us the VFRAME offset adjustment
Use MachineFrameInfo's OffsetAdjustment field to pass this information
from the target to CodeViewDebug.cpp. The X86 backend doesn't use it for
any other purpose.

This fixes PR38857 in the case where there is a non-aligned quantity of
CSRs and a non-aligned quantity of locals.

llvm-svn: 346062
2018-11-03 00:41:52 +00:00
Reid Kleckner
810687cb57 [codeview] Emit S_BUILDINFO and LF_BUILDINFO with cwd and source file
Summary: We can fill in the command line and compiler path later if we want.

Reviewers: zturner

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D53179

llvm-svn: 344393
2018-10-12 18:19:06 +00:00
Aaron Smith
802b033d78 [CodeView] Emit function options for subprogram and member functions
Summary:
Use the newly added DebugInfo (DI) Trivial flag, which indicates if a C++ record is trivial or not, to determine Codeview::FunctionOptions.

Clang and MSVC generate slightly different Codeview for C++ records. For example, here is the C++ code for a class with a defaulted ctor,

       class C {
       public:
         C() = default;
       };

Clang will produce a LF for the defaulted ctor while MSVC does not. For more details, refer to FIXMEs in the test cases in "function-options.ll" included with this set of changes.


Reviewers: zturner, rnk, llvm-commits, aleksandr.urakov

Reviewed By: rnk

Subscribers: Hui, JDevlieghere

Differential Revision: https://reviews.llvm.org/D45123

llvm-svn: 343626
2018-10-02 20:21:05 +00:00
Reid Kleckner
d5e4ec74e3 [codeview] Fix 32-bit x86 variable locations in realigned stack frames
Add the .cv_fpo_stackalign directive so that we can define $T0, or the
VFRAME virtual register, with it. This was overlooked in the initial
implementation because unlike MSVC, we push CSRs before allocating stack
space, so this value is only needed to describe local variable
locations. Variables that the compiler now addresses via ESP are instead
described as being stored at offsets from VFRAME, which for us is ESP
after alignment in the prologue.

This adds tests that show that we use the VFRAME register properly in
our S_DEFRANGE records, and that we emit the correct FPO data to define
it.

Fixes PR38857

llvm-svn: 343603
2018-10-02 16:43:52 +00:00
Reid Kleckner
9ea2c01264 [codeview] Emit S_FRAMEPROC and use S_DEFRANGE_FRAMEPOINTER_REL
Summary:
Before this change, LLVM would always describe locals on the stack as
being relative to some specific register, RSP, ESP, EBP, ESI, etc.
Variables in stack memory are pretty common, so there is a special
S_DEFRANGE_FRAMEPOINTER_REL symbol for them. This change uses it to
reduce the size of our debug info.

On top of the size savings, there are cases on 32-bit x86 where local
variables are addressed from ESP, but ESP changes across the function.
Unlike in DWARF, there is no FPO data to describe the stack adjustments
made to push arguments onto the stack and pop them off after the call,
which makes it hard for the debugger to find the local variables in
frames further up the stack.

To handle this, CodeView has a special VFRAME register, which
corresponds to the $T0 variable set by our FPO data in 32-bit.  Offsets
to local variables are instead relative to this value.

This is part of PR38857.

Reviewers: hans, zturner, javed.absar

Subscribers: aprantl, hiraditya, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D52217

llvm-svn: 343543
2018-10-01 21:59:45 +00:00
Reid Kleckner
b3d456a79e [codeview] Remove dead code
llvm-svn: 342285
2018-09-14 21:14:08 +00:00