Commit Graph

9 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
83902832de Revert "Revert "DI: Fold constant arguments into a single MDString""
This reverts commit r218918, effectively reapplying r218914 after fixing
an Ocaml bindings test and an Asan crash.  The root cause of the latter
was a tightened-up check in `DILexicalBlock::Verify()`, so I'll file a
PR to investigate who requires the loose check (and why).

Original commit message follows.

--

This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219010 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-03 20:01:09 +00:00
Duncan P. N. Exon Smith
32e192aeb3 Revert "DI: Fold constant arguments into a single MDString"
This reverts commit r218914 while I investigate some bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218918 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-02 22:15:31 +00:00
Duncan P. N. Exon Smith
0917b70630 DI: Fold constant arguments into a single MDString
This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218914 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-02 21:56:57 +00:00
Adrian Prantl
02474a32eb Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

Note: I accidentally committed a bogus older version of this patch previously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218787 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 18:55:02 +00:00
Adrian Prantl
10c4265675 Revert r218778 while investigating buldbot breakage.
"Move the complex address expression out of DIVariable and into an extra"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218782 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 18:10:54 +00:00
Adrian Prantl
076fd5dfc1 Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218778 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 17:55:39 +00:00
David Blaikie
c7260209a8 Use DILexicalBlockFile, rather than DILexicalBlock, to track discriminator changes to ensure discriminator changes don't introduce new DWARF DW_TAG_lexical_blocks.
Somewhat unnoticed in the original implementation of discriminators, but
it could cause instructions to end up in new, small,
DW_TAG_lexical_blocks due to the use of DILexicalBlock to track
discriminator changes.

Instead, use DILexicalBlockFile which we already use to track file
changes without introducing new scopes, so it works well to track
discriminator changes in the same way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216239 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 22:45:21 +00:00
Diego Novillo
0a0d620db3 Fix bug 19437 - Only add discriminators for DWARF 4 and above.
Summary:
This prevents the discriminator generation pass from triggering if
the DWARF version being used in the module is prior to 4.

Reviewers: echristo, dblaikie

CC: llvm-commits

Differential Revision: http://reviews.llvm.org/D3413

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206507 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-17 22:33:50 +00:00
Diego Novillo
f05b45fdb2 Pass to emit DWARF path discriminators.
DWARF discriminators are used to distinguish multiple control flow paths
on the same source location. When this happens, instructions across
basic block boundaries will share the same debug location.

This pass detects this situation and creates a new lexical scope to one
of the two instructions. This lexical scope is a child scope of the
original and contains a new discriminator value. This discriminator is
then picked up from MCObjectStreamer::EmitDwarfLocDirective to be
written on the object file.

This fixes http://llvm.org/bugs/show_bug.cgi?id=18270.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202752 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-03 20:06:11 +00:00