Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block" & dependent patches

Try to revert D113741 once again.

This also reverts 0ac75e82fff93a80ca401d3db3541e8d1d9098f

Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block" & dependent patches

Try to revert D113741 once again.

This also reverts 0ac75e82fff93a80ca401d3db3541e8d1d9098f9 (D114705)
as it causes LLDB's lldb-api.lang/cpp/nsimport.TestCppNsImport.py test
failure w/o D113741.

This reverts commit f9607d45f399e2afc39ec16222ea68b4e0831564.

Differential Revision: https://reviews.llvm.org/D116225

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Revert "Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block" & dependent patches"

This has broke following LLDB buildbots:

https://lab.llvm.org/buildbot/#/builders/

Revert "Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block" & dependent patches"

This has broke following LLDB buildbots:

https://lab.llvm.org/buildbot/#/builders/17/builds/14984
https://lab.llvm.org/buildbot/#/builders/96/builds/15928
https://lab.llvm.org/buildbot/#/builders/68/builds/23600

This reverts commit 62a6b9e9ab3eb778111e90a34fee1e6a7c64db8a.

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Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block" & dependent patches

This patch causes invalid DWARF to be generated in some cases of LTO +
Split DWARF - follow-

Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block" & dependent patches

This patch causes invalid DWARF to be generated in some cases of LTO +
Split DWARF - follow-up on the original review thread (D113741) contains
further detail and test cases.

This reverts commit 75b622a7959479ccdb758ebe0973061b7b4fcacd.
This reverts commit b6ccca217c35a95b8c2a337a7801b37cb23dbae2.
This reverts commit 514d37441918dd04a2cd4f35c08959d7c3ff096d.

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Reland [DwarfDebug] Support emitting function-local declaration for a lexical block

This is another attempt to make function-local declarations
(like static variables, structs/classes and other) be

Reland [DwarfDebug] Support emitting function-local declaration for a lexical block

This is another attempt to make function-local declarations
(like static variables, structs/classes and other) be correctly
emitted within a lexical (bracketed) block.

Fixes https://bugs.llvm.org/show_bug.cgi?id=19238.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D113741

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Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block"

This reverts commits
* ee691970a9a85470948ada623c31f0ab8773617c (D113741),
* 79d3132998b2828be8f7d2ec411f91fb11b

Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block"

This reverts commits
* ee691970a9a85470948ada623c31f0ab8773617c (D113741),
* 79d3132998b2828be8f7d2ec411f91fb11b3e01f (D114705)

due to lldb and dexter test failures.

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[DwarfDebug] Support emitting function-local declaration for a lexical block

This is another attempt to make function-local declarations
(like static variables, structs/classes and other) be correct

[DwarfDebug] Support emitting function-local declaration for a lexical block

This is another attempt to make function-local declarations
(like static variables, structs/classes and other) be correctly
emitted within a lexical (bracketed) block.

Fixes https://bugs.llvm.org/show_bug.cgi?id=19238.

Differential Revision: https://reviews.llvm.org/D113741

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DwarfFile.h - remove unnecessary includes. NFCI.

Use forward declarations where possible, move includes down to DwarfFile.cpp and avoid duplicate includes.

Reapply "NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List"

Move these data structures closer together so their emission code can
eventually share more of its implemen

Reapply "NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List"

Move these data structures closer together so their emission code can
eventually share more of its implementation.

Was an egregious bug (completely untested, evidently) where I hadn't
inverted a DWARFv5 test as needed, so it was doing the exact opposite of
what was required & thus tried to emit a DWARFv5 range list header in
DWARFv4.

Reapply 8e04896288d22ed8bef7ac367923374f96b753d6 which was
reverted in a8154e5e0c83d2f0f65f3b4fb1a0bc68785bd975.

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Temporarily revert "NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List"
as it was causing bot and build failures.

This reverts commit 8e04896288d22ed8bef7ac367923374f96

Temporarily revert "NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List"
as it was causing bot and build failures.

This reverts commit 8e04896288d22ed8bef7ac367923374f96b753d6.

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NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List

Move these data structures closer together so their emission code can
eventually share more of its implementation.

DebugInfo: Move loclist base address from DwarfFile to DebugLocStream

There's no need to have more than one of these (there can be two
DwarfFiles - one for the .o, one for the .dwo - but only one lo

DebugInfo: Move loclist base address from DwarfFile to DebugLocStream

There's no need to have more than one of these (there can be two
DwarfFiles - one for the .o, one for the .dwo - but only one loc/loclist
section (either in the .o or the .dwo) & certainly one per
DebugLocStream, which is currently singular in DwarfDebug)

llvm-svn: 375183

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DebugInfo: Simplify RangeSpan to be a plain struct

This is an effort to make RangeSpan and DebugLocStream::Entry more
similar to share code for their emission (to reuse the more complicated
code for

DebugInfo: Simplify RangeSpan to be a plain struct

This is an effort to make RangeSpan and DebugLocStream::Entry more
similar to share code for their emission (to reuse the more complicated
code for using (& choosing when to use) base address selection entries,
etc).

It didn't seem like this struct was worth the complexity of
encapsulation - when the members could be initialized by the ctor to any
value (no validation) and the type is assignable (so there's no
mutability or other constraint being implemented by its interface).

llvm-svn: 373533

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[AsmPrinter] Delete unused RangeSpanList::addRange

llvm-svn: 358068

[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an a

[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.

The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.

For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.

This is a recommit of r356442 with trivial fixes for the failing tests.

Differential Revision: https://reviews.llvm.org/D56587

llvm-svn: 356451

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Revert "[DebugInfo] Introduce DW_OP_LLVM_convert"

This reverts commit 1cf4b593a7ebd666fc6775f3bd38196e8e65fafe.

Build bots found failing tests not detected locally.

Failing Tests (3):
LLVM :: De

Revert "[DebugInfo] Introduce DW_OP_LLVM_convert"

This reverts commit 1cf4b593a7ebd666fc6775f3bd38196e8e65fafe.

Build bots found failing tests not detected locally.

Failing Tests (3):
LLVM :: DebugInfo/Generic/convert-debugloc.ll
LLVM :: DebugInfo/Generic/convert-inlined.ll
LLVM :: DebugInfo/Generic/convert-linked.ll

llvm-svn: 356444

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[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an a

[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.

The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.

For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.

Differential Revision: https://reviews.llvm.org/D56587

llvm-svn: 356442

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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 ne

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

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NFC: DebugInfo: Track the origin CU rather than just the base address for range lists

Turns out knowing more than just the base address might be useful -
specifically a future change to respect a DI

NFC: DebugInfo: Track the origin CU rather than just the base address for range lists

Turns out knowing more than just the base address might be useful -
specifically a future change to respect a DICompileUnit flag for the use
of base address specifiers in DWARF < 5.

llvm-svn: 346380

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[Codegen] - Implement basic .debug_loclists section emission (DWARF5).

.debug_loclists is the DWARF 5 version of the .debug_loc.
With that patch, it will be emitted when DWARF 5 is used.

Differenti

[Codegen] - Implement basic .debug_loclists section emission (DWARF5).

.debug_loclists is the DWARF 5 version of the .debug_loc.
With that patch, it will be emitted when DWARF 5 is used.

Differential revision: https://reviews.llvm.org/D53365

llvm-svn: 345377

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DebugInfo: Use address pool forms in debug_rnglists

Save no relocations by reusing addresses from the address pool.

llvm-svn: 344836

Revert BTF commit series.

The initial patch was not reviewed, and does not have any tests;
it should not have been merged.

This reverts 344395, 344390, 344387, 344385, 344381, 344376,
and 344366.

Revert BTF commit series.

The initial patch was not reviewed, and does not have any tests;
it should not have been merged.

This reverts 344395, 344390, 344387, 344385, 344381, 344376,
and 344366.

llvm-svn: 344405

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[BPF] Don't include linux/types.h and fix style

llvm-svn: 344381

[BPF] Add BTF generation for BPF target

BTF is the debug format for BPF, a kernel virtual machine
and widely used for tracing, networking and security, etc ([1]).

Currently only instruction streams

[BPF] Add BTF generation for BPF target

BTF is the debug format for BPF, a kernel virtual machine
and widely used for tracing, networking and security, etc ([1]).

Currently only instruction streams are passed to kernel,
the kernel verifier verifies them before execution. In order to
provide better visibility of bpf programs to user space
tools, some debug information, e.g., function names and
debug line information are desirable for kernel so tools
can get such information with better annotation
for jited instructions for performance or other reasons.

The dwarf is too complicated in kernel and for BPF.
Hence, BTF is designed to be the debug format for BPF ([2]).
Right now, pahole supports BTF for types, which
are generated based on dwarf sections in the ELF file.

In order to annotate performance metrics for jited bpf insns,
it is necessary to pass debug line info to the kernel.
Furthermore, we want to pass the actual code to the
kernel because of the following reasons:

. bpf program typically is small so storage overhead
should be small.
. in bpf land, it is totally possible that
an application loads the bpf program into the
kernel and then that application quits, so
holding debug info by the user space application
is not practical.
. having source codes directly kept by kernel
would ease deployment since the original source
code does not need ship on every hosts and
kernel-devel package does not need to be
deployed even if kernel headers are used.

The only reliable time to get the source code is
during compilation time. This will result in both more
accurate information and easier deployment as
stated in the above.

Another consideration is for JIT. The project like bcc
use MCJIT to compile a C program into bpf insns and
load them to the kernel ([3]). The generated BTF sections
will be readily available for such cases as well.

This patch implemented generation of BTF info in llvm
compiler. The BTF related sections will be generated
when both -target bpf and -g are specified. Two sections
are generated:
.BTF contains all the type and string information, and
.BTF.ext contains the func_info and line_info.

The separation is related to how two sections are used
differently in bpf loader, e.g., linux libbpf ([4]).
The .BTF section can be loaded into the kernel directly
while .BTF.ext needs loader manipulation before loading
to the kernel. The format of the each section is roughly
defined in llvm:include/llvm/MC/MCBTFContext.h and
from the implementation in llvm:lib/MC/MCBTFContext.cpp.
A later example also shows the contents in each section.

The type and func_info are gathered during CodeGen/AsmPrinter
by traversing dwarf debug_info. The line_info is
gathered in MCObjectStreamer before writing to
the object file. After all the information is gathered,
the two sections are emitted in MCObjectStreamer::finishImpl.

With cmake CMAKE_BUILD_TYPE=Debug, the compiler can
dump out all the tables except insn offset, which
will be resolved later as relocation records.
The debug type "btf" is used for BTFContext dump.

Dwarf tests the debug info generation with
llvm-dwarfdump to decode the binary sections and
check whether the result is expected. Currently
we do not have such a tool yet. We will implement
btf dump functionality in bpftool ([5]) as the bpftool is
considered the recommended tool for bpf introspection.
The implementation for type and func_info is tested
with linux kernel test cases. The line_info is visually
checked with dump from linux kernel libbpf ([4]) and
checked with readelf dumping section raw data.

Note that the .BTF and .BTF.ext information will not
be emitted to assembly code and there is no assembler
support for BTF either.

In the below, with a clang/llvm built with CMAKE_BUILD_TYPE=Debug,
Each table contents are shown for a simple C program.

-bash-4.2$ cat -n test.c
1 struct A {
2 int a;
3 char b;
4 };
5
6 int test(struct A *t) {
7 return t->a;
8 }
-bash-4.2$ clang -O2 -target bpf -g -mllvm -debug-only=btf -c test.c
Type Table:
[1] FUNC name_off=1 info=0x0c000001 size/type=2
param_type=3
[2] INT name_off=12 info=0x01000000 size/type=4
desc=0x01000020
[3] PTR name_off=0 info=0x02000000 size/type=4
[4] STRUCT name_off=16 info=0x04000002 size/type=8
name_off=18 type=2 bit_offset=0
name_off=20 type=5 bit_offset=32
[5] INT name_off=22 info=0x01000000 size/type=1
desc=0x02000008

String Table:
0 :
1 : test
6 : .text
12 : int
16 : A
18 : a
20 : b
22 : char
27 : test.c
34 : int test(struct A *t) {
58 : return t->a;

FuncInfo Table:
sec_name_off=6
insn_offset=<Omitted> type_id=1

LineInfo Table:
sec_name_off=6
insn_offset=<Omitted> file_name_off=27 line_off=34 line_num=6 column_num=0
insn_offset=<Omitted> file_name_off=27 line_off=58 line_num=7 column_num=3
-bash-4.2$ readelf -S test.o
......
[12] .BTF PROGBITS 0000000000000000 0000028d
00000000000000c1 0000000000000000 0 0 1
[13] .BTF.ext PROGBITS 0000000000000000 0000034e
0000000000000050 0000000000000000 0 0 1
[14] .rel.BTF.ext REL 0000000000000000 00000648
0000000000000030 0000000000000010 16 13 8
......
-bash-4.2$

The latest linux kernel ([6]) can already support .BTF with type information.
The [7] has the reference implementation in linux kernel side
to support .BTF.ext func_info. The .BTF.ext line_info support is not
implemented yet. If you have difficulty accessing [6], you can
manually do the following to access the code:

git clone https://github.com/yonghong-song/bpf-next-linux.git
cd bpf-next-linux
git checkout btf

The change will push to linux kernel soon once this patch is landed.

References:
[1]. https://www.kernel.org/doc/Documentation/networking/filter.txt
[2]. https://lwn.net/Articles/750695/
[3]. https://github.com/iovisor/bcc
[4]. https://github.com/torvalds/linux/tree/master/tools/lib/bpf
[5]. https://github.com/torvalds/linux/tree/master/tools/bpf/bpftool
[6]. https://github.com/torvalds/linux
[7]. https://github.com/yonghong-song/bpf-next-linux/tree/btf

Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Yonghong Song <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>

Differential Revision: https://reviews.llvm.org/D52950

llvm-svn: 344366

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[DebugInfo] Generate DWARF debug information for labels. (Fix leak problems)

There are two forms for label debug information in DWARF format.

1. Labels in a non-inlined function:

DW_TAG_label
DW

[DebugInfo] Generate DWARF debug information for labels. (Fix leak problems)

There are two forms for label debug information in DWARF format.

1. Labels in a non-inlined function:

DW_TAG_label
DW_AT_name
DW_AT_decl_file
DW_AT_decl_line
DW_AT_low_pc

2. Labels in an inlined function:

DW_TAG_label
DW_AT_abstract_origin
DW_AT_low_pc

We will collect label information from DBG_LABEL. Before every DBG_LABEL,
we will generate a temporary symbol to denote the location of the label.
The symbol could be used to get DW_AT_low_pc afterwards. So, we create a
mapping between 'inlined label' and DBG_LABEL MachineInstr in DebugHandlerBase.
The DBG_LABEL in the mapping is used to query the symbol before it.

The AbstractLabels in DwarfCompileUnit is used to process labels in inlined
functions.

We also keep a mapping between scope and labels in DwarfFile to help to
generate correct tree structure of DIEs.

It also generates label debug information under global isel.

Differential Revision: https://reviews.llvm.org/D45556

llvm-svn: 340039

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Revert "[DebugInfo] Generate DWARF debug information for labels. (Fix leak problems)"

This reverts commit cb8c5e417d55141f3f079a8a876e786f44308336 / r339676.

This causing a test to fail in http://g

Revert "[DebugInfo] Generate DWARF debug information for labels. (Fix leak problems)"

This reverts commit cb8c5e417d55141f3f079a8a876e786f44308336 / r339676.

This causing a test to fail in http://green.lab.llvm.org/green/job/clang-stage1-configure-RA/48406/

LLVM :: DebugInfo/Generic/debug-label.ll

llvm-svn: 339700

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