Commit Graph

13 Commits

Author SHA1 Message Date
James Y Knight 693d39dd12 Remove irrelevant references to legacy git repositories from
compiler identification lines in test-cases.

(Doing so only because it's then easier to search for references which
are actually important and need fixing.)

llvm-svn: 351200
2019-01-15 16:18:52 +00:00
David Stenberg 33b192d72b [DebugInfo] Omit location list entries with empty ranges
Summary:
This fixes PR39710. In that case we emitted a location list looking like
this:

.Ldebug_loc0:
        .quad   .Lfunc_begin0-.Lfunc_begin0
        .quad   .Lfunc_begin0-.Lfunc_begin0
        .short  1                       # Loc expr size
        .byte   85                      # DW_OP_reg5
        .quad   .Lfunc_begin0-.Lfunc_begin0
        .quad   .Lfunc_end0-.Lfunc_begin0
        .short  1                       # Loc expr size
        .byte   85                      # super-register DW_OP_reg5
        .quad   0
        .quad   0

As seen, the first entry's beginning and ending addresses evalute to 0,
which meant that the entry inadvertently became an "end of list" entry,
resulting in the location list ending sooner than expected.

To fix this, omit all entries with empty ranges. Location list entries
with empty ranges do not have any effect, as specified by DWARF, so we
might as well drop them:

"A location list entry (but not a base address selection or end of list
 entry) whose beginning and ending addresses are equal has no effect
 because the size of the range covered by such an entry is zero."

Reviewers: davide, aprantl, dblaikie

Reviewed By: aprantl

Subscribers: javed.absar, JDevlieghere, llvm-commits

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D55919

llvm-svn: 350698
2019-01-09 09:58:59 +00:00
Jonas Devlieghere 965b598b2a [DebugInfo] Normalize common kinds of DWARF sub-expressions.
Normalize common kinds of DWARF sub-expressions to make debug info
encoding a bit more compact:

  DW_OP_constu [X < 32] -> DW_OP_litX
  DW_OP_constu [all ones] -> DW_OP_lit0, DW_OP_not (64-bit only)

Differential revision: https://reviews.llvm.org/D51640

llvm-svn: 341457
2018-09-05 10:18:36 +00:00
Shiva Chen 2c864551df [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841
2018-05-09 02:40:45 +00:00
Jonas Devlieghere 6f24c8778c [DebugInfo] Unify dumping of address ranges
Summary:
This patch unifies the printing of address ranges as [0x0, 0x1).

rdar://34822059

Reviewers: aprantl, dblaikie

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D42056

llvm-svn: 322543
2018-01-16 11:17:57 +00:00
Adrian Prantl 16aa4cf7ef llvm-dwarfdump: Make -brief the default and add a -verbose option instead.
Differential Revision: https://reviews.llvm.org/D37717

llvm-svn: 312972
2017-09-11 23:05:20 +00:00
Adrian Prantl 7bc1b28291 llvm-dwarfdump: Replace -debug-dump=sect option with individual options.
As discussed on llvm-dev in
http://lists.llvm.org/pipermail/llvm-dev/2017-September/117301.html
this changes the command line interface of llvm-dwarfdump to match the
one used by the dwarfdump utility shipping on macOS. In addition to
being shorter to type this format also has the advantage of allowing
more than one section to be specified at the same time.

In a nutshell, with this change

  $ llvm-dwarfdump --debug-dump=info
  $ llvm-dwarfdump --debug-dump=apple-objc

becomes

  $ dwarfdump --debug-info --apple-objc

Differential Revision: https://reviews.llvm.org/D37714

llvm-svn: 312970
2017-09-11 22:59:45 +00:00
Reid Kleckner a058736c9c [dwarfdump] Pretty print location expressions and location lists
Summary:
Based on Fred's patch here: https://reviews.llvm.org/D6771

I can't seem to commandeer the old review, so I'm creating a new one.

With that change the locations exrpessions are pretty printed inline in the
DIE tree. The output looks like this for debug_loc entries:

    DW_AT_location [DW_FORM_data4]        (0x00000000
       0x0000000000000001 - 0x000000000000000b: DW_OP_consts +3
       0x000000000000000b - 0x0000000000000012: DW_OP_consts +7
       0x0000000000000012 - 0x000000000000001b: DW_OP_reg0 RAX, DW_OP_piece 0x4
       0x000000000000001b - 0x0000000000000024: DW_OP_breg5 RDI+0)

And like this for debug_loc.dwo entries:
    DW_AT_location [DW_FORM_sec_offset]   (0x00000000
      Addr idx 2 (w/ length 190): DW_OP_consts +0, DW_OP_stack_value
      Addr idx 3 (w/ length 23): DW_OP_reg0 RAX, DW_OP_piece 0x4)

Simple locations without ranges are printed inline:

   DW_AT_location [DW_FORM_block1]       (DW_OP_reg4 RSI, DW_OP_piece 0x4, DW_OP_bit_piece 0x20 0x0)

The debug_loc(.dwo) dumping in changed accordingly to factor the code.

Reviewers: dblaikie, aprantl, friss

Subscribers: mgorny, javed.absar, hiraditya, llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D37123

llvm-svn: 312042
2017-08-29 21:41:21 +00:00
Adrian Prantl abe04759a6 Remove the obsolete offset parameter from @llvm.dbg.value
There is no situation where this rarely-used argument cannot be
substituted with a DIExpression and removing it allows us to simplify
the DWARF backend. Note that this patch does not yet remove any of
the newly dead code.

rdar://problem/33580047
Differential Revision: https://reviews.llvm.org/D35951

llvm-svn: 309426
2017-07-28 20:21:02 +00:00
Adrian Prantl 941fa7588b [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

llvm-svn: 288683
2016-12-05 18:04:47 +00:00
Adrian Prantl 75819aedf6 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00
Adrian Prantl b8089516a5 testcase gardening: update the emissionKind enum to the new syntax. (NFC)
llvm-svn: 265081
2016-04-01 00:16:49 +00:00
Keno Fischer bc0cb11eb2 [DwarfDebug] Don't merge DebugLocEntries if their pieces overlap
Summary:
Later in DWARF emission we check that DebugLocEntries have
non-overlapping pieces, so we should create any such entries
by merging here.

Fixes PR26163.

Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D16249

llvm-svn: 257979
2016-01-16 01:15:32 +00:00