This change simplifies code that has to deal with
DIGlobalVariableExpression and mirrors how we treat DIExpressions in
debug info intrinsics. Before this change there were two ways of
representing empty expressions on globals, a nullptr and an empty
!DIExpression().
If someone needs to upgrade out-of-tree testcases:
perl -pi -e 's/(!DIGlobalVariableExpression\(var: ![0-9]*)\)/\1, expr: !DIExpression())/g' <MYTEST.ll>
will catch 95%.
llvm-svn: 312144
DIImportedEntity has a line number, but not a file field. To determine
the decl_line/decl_file we combine the line number from the
DIImportedEntity with the file from the DIImportedEntity's scope. This
does not work correctly when the parent scope is a DINamespace or a
DIModule, both of which do not have a source file.
This patch adds a file field to DIImportedEntity to unambiguously
identify the source location of the using/import declaration. Most
testcase updates are mechanical, the interesting one is the removal of
the FIXME in test/DebugInfo/Generic/namespace.ll.
This fixes PR33822. See https://bugs.llvm.org/show_bug.cgi?id=33822
for more context.
<rdar://problem/33357889>
https://bugs.llvm.org/show_bug.cgi?id=33822
Differential Revision: https://reviews.llvm.org/D35583
llvm-svn: 308398
Summary:
This patch is part of 3 patches that together form a single patch, but must be introduced in stages in order not to break things.
The way that LLVM interprets DW_OP_plus in DIExpression nodes is basically that of the DW_OP_plus_uconst operator since LLVM expects an unsigned constant operand. This unnecessarily restricts the DW_OP_plus operator, preventing it from being used to describe the evaluation of runtime values on the expression stack. These patches try to align the semantics of DW_OP_plus and DW_OP_minus with that of the DWARF definition, which pops two elements off the expression stack, performs the operation and pushes the result back on the stack.
This is done in three stages:
• The first patch (LLVM) adds support for DW_OP_plus_uconst.
• The second patch (Clang) contains changes all its uses from DW_OP_plus to DW_OP_plus_uconst.
• The third patch (LLVM) changes the semantics of DW_OP_plus and DW_OP_minus to be in line with its DWARF meaning. This patch includes the bitcode upgrade from legacy DIExpressions.
Patch by Sander de Smalen.
Reviewers: echristo, pcc, aprantl
Reviewed By: aprantl
Subscribers: fhahn, javed.absar, aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D33894
llvm-svn: 305386
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.
I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.
This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.
Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).
llvm-svn: 304787
Fixes the issue highlighted in
http://lists.llvm.org/pipermail/cfe-dev/2014-June/037500.html.
The DW_AT_decl_file and DW_AT_decl_line attributes on namespaces can
prevent LLVM from uniquing types that are in the same namespace. They
also don't carry any meaningful information.
rdar://problem/17484998
Differential Revision: https://reviews.llvm.org/D32648
llvm-svn: 301706
DISubprogram currently has 10 pointer operands, several of which are
often nullptr. This patch reduces the amount of memory allocated by
DISubprogram by rearranging the operands such that containing type,
template params, and thrown types come last, and are only allocated
when they are non-null (or followed by non-null operands).
This patch also eliminates the entirely unused DisplayName operand.
This saves up to 4 pointer operands per DISubprogram. (I tried
measuring the effect on peak memory usage on an LTO link of an X86
llc, but the results were very noisy).
This reapplies r301498 with an attempted workaround for g++.
Differential Revision: https://reviews.llvm.org/D32560
llvm-svn: 301501
DISubprogram currently has 10 pointer operands, several of which are
often nullptr. This patch reduces the amount of memory allocated by
DISubprogram by rearranging the operands such that containing type,
template params, and thrown types come last, and are only allocated
when they are non-null (or followed by non-null operands).
This patch also eliminates the entirely unused DisplayName operand.
This saves up to 4 pointer operands per DISubprogram. (I tried
measuring the effect on peak memory usage on an LTO link of an X86
llc, but the results were very noisy).
llvm-svn: 301498
For Swift we would like to be able to encode the error types that a
function may throw, so the debugger can display them alongside the
function's return value when finish-ing a function.
DWARF defines DW_TAG_thrown_type (intended to be used for C++ throw()
declarations) that is a perfect fit for this purpose. This patch wires
up support for DW_TAG_thrown_type in LLVM by adding a list of thrown
types to DISubprogram.
To offset the cost of the extra pointer, there is a follow-up patch
that turns DISubprogram into a variable-length node.
rdar://problem/29481673
Differential Revision: https://reviews.llvm.org/D32559
llvm-svn: 301489
The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
- describe a variable in a register
- consist of only a DW_OP_reg
2. Memory location descriptions
- describe the address of a variable
3. Implicit location descriptions
- describe the value of a variable
- end with DW_OP_stack_value & friends
The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident. This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.
This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.
There are two major changes in this patch:
I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.
When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
DBG_VALUE, [RBP-8] --> DW_OP_fbreg -8
DBG_VALUE, RAX --> DW_OP_reg0 +0
DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0
All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.
https://bugs.llvm.org/show_bug.cgi?id=32382
<rdar://problem/31205000>
Differential Revision: https://reviews.llvm.org/D31439
llvm-svn: 300522
This is a follow-up to https://reviews.llvm.org/D29349. It turns out
that NeedUpgradeToDIGlobalVariableExpression is always necessary when
we encountered a version==0 record because it may always be referenced
via a list of globals in a DICompileUnit. My tests weren't good enough
to catch this though. To trigger this case, we need much older bitcode
produced by LLVM around version 3.7.
<rdar://problem/30404262>
Differential Revision: https://reviews.llvm.org/D29693
llvm-svn: 294488
The bitcode upgrade for DIGlobalVariable unconditionally wrapped
DIGlobalVariables in a DIGlobalVariableExpression. When a
DIGlobalVariable is referenced by a DIImportedEntity, however, this is
wrong. This patch fixes the bitcode upgrade by deferring the creation
of DIGlobalVariableExpressions until we know the context of the
DIGlobalVariable.
<rdar://problem/30134279>
Differential Revision: https://reviews.llvm.org/D29349
llvm-svn: 294318
Summary:
MetadataLoader::MetadataLoaderImpl::parseOneMetadata uses
the following construct in a number of places:
```
MetadataList.assignValue(<...>, NextMetadataNo++);
```
There, NextMetadataNo gets incremented, and since the order
of arguments evaluation is not specified, that can happen
before or after other arguments are evaluated.
In a few cases the other arguments indirectly use NextMetadataNo.
For instance, it's
```
MetadataList.assignValue(
GET_OR_DISTINCT(DIModule,
(Context, getMDOrNull(Record[1]),
getMDString(Record[2]), getMDString(Record[3]),
getMDString(Record[4]), getMDString(Record[5]))),
NextMetadataNo++);
```
getMDOrNull calls getMD that uses NextMetadataNo:
```
MetadataList.getMetadataFwdRef(NextMetadataNo);
```
Therefore, the order of evaluation becomes important. That caused
a very subtle LLD crash that only happens if compiled with GCC or
if LLD is built with LTO. In the case if LLD is compiled with Clang
and regular linking mode, everything worked as intended.
This change extracts incrementing of NextMetadataNo outside of
the arguments list to guarantee the correct order of evaluation.
For the record, this has taken 3 days to track to the origin. It all
started with a ThinLTO bot in Chrome not being able to link a target
if debug info is enabled.
Reviewers: pcc, mehdi_amini
Reviewed By: mehdi_amini
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D29204
llvm-svn: 293291
CFI is using intrinsics that takes MDString as arguments, and this
was broken during lazy-loading of metadata.
Differential Revision: https://reviews.llvm.org/D28916
llvm-svn: 292641
Summary:
Without this, we're stressing the RAUW of unique nodes,
which is a costly operation. This is intended to limit
the number of RAUW, and is very effective on the total
link-time of opt with ThinLTO, before:
real 4m4.587s user 15m3.401s sys 0m23.616s
after:
real 3m25.261s user 12m22.132s sys 0m24.152s
Reviewers: tejohnson, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28751
llvm-svn: 292420
The change in r291362 was too agressive. We still need to flush at the
end of the block because function local metadata can introduce fwd
ref as well.
(Bootstrap with ThinLTO was broken)
llvm-svn: 291379
Summary:
The issue happens with:
%0 = ....., !tbaa !0
%1 = ....., !tbaa !1
With !0 that references !1.
In this case when loading !0 we generates a temporary for the
operand !1. We now flush it immediately and trigger the load of
!1 before moving on. If we don't we get the temporary when
attaching to %1. This is usually not an issue except that we
eagerly try to update TBAA MDNodes, which is obviously not possible
if we only have a temporary.
Differential Revision: https://reviews.llvm.org/D28423
llvm-svn: 291362
Summary:
This is a relatively simple scheme: we use the index emitted in the
bitcode to avoid loading all the global metadata. Instead we load
the index with their position in the bitcode so that we can load each
of them individually. Materializing the global metadata block in this
condition only triggers loading the named metadata, and the ones
referenced from there (transitively). When materializing a function,
metadata from the global block are loaded lazily as they are
referenced.
Two main current limitations are:
1) Global values other than functions are not materialized on demand,
so we need to eagerly load METADATA_GLOBAL_DECL_ATTACHMENT records
(and their transitive dependencies).
2) When we load a single metadata, we don't recurse on the operands,
instead we use a placeholder or a temporary metadata. Unfortunately
tepmorary nodes are very expensive. This is why we don't have it
always enabled and only for importing.
These two limitations can be lifted in a subsequent improvement if
needed.
With this change, the total link time of opt with ThinLTO and Debug
Info enabled is going down from 282s to 224s (~20%).
Reviewers: pcc, tejohnson, dexonsmith
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28113
llvm-svn: 291027
As per post-commit review for r289993 (D27775), we can only safely
import a type as a decl if it has an Identifier, as the Name alone
is not enough to be unique across modules.
llvm-svn: 290915
This makes it explicit what is the exact list to handle, and it
looks much more easy to manipulate and understand that the
previous custom tracking of min/max to express the range where
to look for.
Differential Revision: https://reviews.llvm.org/D28089
llvm-svn: 290507
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 290153
Summary:
When reading the metadata bitcode, create a type declaration when
possible for composite types when we are importing. Doing this in
the bitcode reader saves memory. Also it works naturally in the case
when the type ODR map contains a definition for the same composite type
because it was used in the importing module (buildODRType will
automatically use the existing definition and not create a type
declaration).
For Chromium built with -g2, this reduces the aggregate size of the
generated native object files by 66% (from 31G to 10G). It reduced
the time through the ThinLTO link and backend phases by about 20% on
my machine.
Reviewers: mehdi_amini, dblaikie, aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27775
llvm-svn: 289993
This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).
Sorry for the churn!
llvm-svn: 289982
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 289920
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 289902
Summary:
I'm planning on changing the way we load metadata to enable laziness.
I'm getting lost in this gigantic files, and gigantic class that is the bitcode
reader. This is a first toward splitting it in a few coarse components that
are more easily understandable.
Reviewers: pcc, tejohnson
Subscribers: mgorny, llvm-commits, dexonsmith
Differential Revision: https://reviews.llvm.org/D27646
llvm-svn: 289461
Peter Collingbourne