[LLVM][DWARF] Make some effort to avoid duplicates in .debug_ranges. (#106614)

Inlining and zero-cost abstractions tend to produce volumes of debug
info with identical ranges. When built with full

[LLVM][DWARF] Make some effort to avoid duplicates in .debug_ranges. (#106614)

Inlining and zero-cost abstractions tend to produce volumes of debug
info with identical ranges. When built with full debugging information
(the equivalent of -g2) librustc_driver.so has 2.1 million entries in
.debug_ranges. But only 1.1 million of those entries are unique. While
in principle all duplicates could be eliminated with a hashtable,
checking to see if the new range is exactly identical to the previous
range and skipping a new addition if it is is sufficient to eliminate
99.99% of the duplicates. This reduces the size of librustc_driver.so's
.debug_ranges section by 35%, or the overall binary size a little more
than 1%.

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Revert "[LLVM][DWARF] Add support for monolithic types in .debug_names (#68131)"

This reverts commit 9bbd2bf654634cd95dd0be7948ec8402c3c76e1e.

Accidental commit: https://github.com/llvm/llvm-projec

Revert "[LLVM][DWARF] Add support for monolithic types in .debug_names (#68131)"

This reverts commit 9bbd2bf654634cd95dd0be7948ec8402c3c76e1e.

Accidental commit: https://github.com/llvm/llvm-project/pull/68131#issuecomment-1749430207

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[LLVM][DWARF] Add support for monolithic types in .debug_names (#68131)

Added support for Type Units in monolithic DWARF in .debug_names.

[AsmPrinter] Fix an unused variable warning

This patch fixes:

llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp:109:10: error: unused
variable 'Ret' [-Werror,-Wunused-variable]

[NFC][AsmPrinter] Remove dead multi-MMI handling from DwarfFile::addScopeVariable

Differential Revision: https://reviews.llvm.org/D158676

[llvm] Use x.empty() instead of llvm::empty(x) (NFC)

I'm planning to deprecate and eventually remove llvm::empty.

I thought about replacing llvm::empty(x) with std::empty(x), but it
turns out that

[llvm] Use x.empty() instead of llvm::empty(x) (NFC)

I'm planning to deprecate and eventually remove llvm::empty.

I thought about replacing llvm::empty(x) with std::empty(x), but it
turns out that all uses can be converted to x.empty(). That is, no
use requires the ability of std::empty to accept C arrays and
std::initializer_list.

Differential Revision: https://reviews.llvm.org/D133677

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[MC] De-capitalize SwitchSection. NFC

Add SwitchSection to return switchSection. The API will be removed soon.

Cleanup includes: DebugInfo & CodeGen

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121332

[CodeGen][Debuginfo][NFC] Refactor DIE values SizeOf method to not depend on AsmPrinter.

SizeOf() method of DIE values(unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const)
depends on AsmPr

[CodeGen][Debuginfo][NFC] Refactor DIE values SizeOf method to not depend on AsmPrinter.

SizeOf() method of DIE values(unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const)
depends on AsmPrinter. AsmPrinter is too specific class here. This patch removes dependency
on AsmPrinter and use dwarf::FormParams structure instead. It allows calculate DIE values
size without using AsmPrinter. That refactoring is useful for D96035([dsymutil][DWARFlinker]
implement separate multi-thread processing for compile units.)

Differential Revision: https://reviews.llvm.org/D116997

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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.

[DebugInfo] Make offsets of dwarf units 64-bit (19/19).

In the case of LTO, several DWARF units can be emitted in one section.
For an extremely large application, they may exceed the limit of 4GiB
f

[DebugInfo] Make offsets of dwarf units 64-bit (19/19).

In the case of LTO, several DWARF units can be emitted in one section.
For an extremely large application, they may exceed the limit of 4GiB
for 32-bit offsets. As it is now possible to emit 64-bit debugging info,
the patch enables storing the larger offsets.

Differential Revision: https://reviews.llvm.org/D87026

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[DebugInfo] Fix emitting DWARF64 compilation units (5/19).

The patch also adds a method to choose an appropriate DWARF form
to represent section offsets according to the version and the format
of pr

[DebugInfo] Fix emitting DWARF64 compilation units (5/19).

The patch also adds a method to choose an appropriate DWARF form
to represent section offsets according to the version and the format
of producing debug info.

Differential Revision: https://reviews.llvm.org/D87014

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[MC] De-capitalize another set of MCStreamer::Emit* functions

Emit{ValueTo,Code}Alignment Emit{DTP,TP,GP}* EmitSymbolValue etc

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: Split DWARF + gmlt + no-split-dwarf-inlining shouldn't emit anything to the .dwo file

This configuration (due to r349207) was intended not to emit any DWO CU,
but a degenerate CU was stil

DebugInfo: Split DWARF + gmlt + no-split-dwarf-inlining shouldn't emit anything to the .dwo file

This configuration (due to r349207) was intended not to emit any DWO CU,
but a degenerate CU was still being emitted - containing a header and a
DW_TAG_compile_unit with no attributes.

Under that situation, emit nothing to the .dwo file. (since this is a
dynamic property of the input the .dwo file is still emitted, just with
nothing in it (so a valid, but empty, ELF file) - if some other CU
didn't satisfy this criteria, its DWO CU would still go there, etc)

llvm-svn: 353771

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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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Recommit r348806: DebugInfo: Use symbol difference for CU length to simplify assembly reading/editing

Mucking about simplifying a test case ( https://reviews.llvm.org/D55261 ) I stumbled across some

Recommit r348806: DebugInfo: Use symbol difference for CU length to simplify assembly reading/editing

Mucking about simplifying a test case ( https://reviews.llvm.org/D55261 ) I stumbled across something I've hit before - that LLVM's (GCC's does too, FWIW) assembly output includes a hardcode length for a DWARF unit in its header. Instead we could emit a label difference - making the assembly easier to read/edit (though potentially at a slight (I haven't tried to observe it) performance cost of delaying/sinking the length computation into the MC layer).

Fix: Predicated all the changes (including creating the labels, even if they aren't used/needed) behind the NVPTX useSectionsAsReferences, avoiding emitting labels in NVPTX where ptxas can't parse them.

Reviewers: JDevlieghere, probinson, ABataev

Differential Revision: https://reviews.llvm.org/D55281

llvm-svn: 349430

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DebugInfo: Avoid using split DWARF when the split unit would be empty.

In ThinLTO many split CUs may be effectively empty because of the lack
of support for cross-unit references in split DWARF.

Us

DebugInfo: Avoid using split DWARF when the split unit would be empty.

In ThinLTO many split CUs may be effectively empty because of the lack
of support for cross-unit references in split DWARF.

Using a split unit in those cases is just a waste/overhead - and turned
out to be one contributor to a significant symbolizer performance issue
when global variable debug info was being imported (see r348416 for the
primary fix) due to symbolizers seeing CUs with no ranges, assuming
there might still be addresses covered and walking into the split CU to
see if there are any ranges (when that split CU was in a DWP file, that
meant loading the DWP and its index, the index was extra large because
of all these fractured/empty CUs... and so was very expensive to load).

(the 3rd fix which will follow, is to assume that a CU with no ranges is
empty rather than merely missing its CU level range data - and to not
walk into its DIEs (split or otherwise) in search of address information
that is generally not present)

llvm-svn: 349207

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Revert "debuginfo: Use symbol difference for CU length to simplify assembly reading/editing"

Temporarily reverts commit r348806 due to strange asm compilation issues in certain modes (combination of

Revert "debuginfo: Use symbol difference for CU length to simplify assembly reading/editing"

Temporarily reverts commit r348806 due to strange asm compilation issues in certain modes (combination of asan+cuda+other things). Will provide repro soon.

llvm-svn: 348898

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debuginfo: Use symbol difference for CU length to simplify assembly reading/editing

Mucking about simplifying a test case ( https://reviews.llvm.org/D55261 ) I stumbled across something I've hit bef

debuginfo: Use symbol difference for CU length to simplify assembly reading/editing

Mucking about simplifying a test case ( https://reviews.llvm.org/D55261 ) I stumbled across something I've hit before - that LLVM's (GCC's does too, FWIW) assembly output includes a hardcode length for a DWARF unit in its header. Instead we could emit a label difference - making the assembly easier to read/edit (though potentially at a slight (I haven't tried to observe it) performance cost of delaying/sinking the length computation into the MC layer).

Reviewers: JDevlieghere, probinson, ABataev

Differential Revision: https://reviews.llvm.org/D55281

llvm-svn: 348806

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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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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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