It causes clang to crash while building Chromium. See https://crbug.com/952230
for reproducer.
> The PrologEpilogInserter need to insert a DW_OP_deref_size before
> prepending a memory location expression to an already implicit
> expression to avoid having the existing expression act on the memory
> address instead of the value behind it.
>
> The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
> big-endian targets need to read the right size as simply truncating a
> larger read would yield the wrong result (LSB bytes are not at the lower
> address).
>
> Differential Revision: https://reviews.llvm.org/D59687
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358281 91177308-0d34-0410-b5e6-96231b3b80d8
The PrologEpilogInserter need to insert a DW_OP_deref_size before
prepending a memory location expression to an already implicit
expression to avoid having the existing expression act on the memory
address instead of the value behind it.
The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
big-endian targets need to read the right size as simply truncating a
larger read would yield the wrong result (LSB bytes are not at the lower
address).
Differential Revision: https://reviews.llvm.org/D59687
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358268 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356451 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356442 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341457 91177308-0d34-0410-b5e6-96231b3b80d8
The replaceAllDbgUsesWith utility helps passes preserve debug info when
replacing one value with another.
This improves upon the existing insertReplacementDbgValues API by:
- Updating debug intrinsics in-place, while preventing use-before-def of
the replacement value.
- Falling back to salvageDebugInfo when a replacement can't be made.
- Moving the responsibiliy for rewriting llvm.dbg.* DIExpressions into
common utility code.
Along with the API change, this teaches replaceAllDbgUsesWith how to
create DIExpressions for three basic integer and pointer conversions:
- The no-op conversion. Applies when the values have the same width, or
have bit-for-bit compatible pointer representations.
- Truncation. Applies when the new value is wider than the old one.
- Zero/sign extension. Applies when the new value is narrower than the
old one.
Testing:
- check-llvm, check-clang, a stage2 `-g -O3` build of clang,
regression/unit testing.
- This resolves a number of mis-sized dbg.value diagnostics from
Debugify.
Differential Revision: https://reviews.llvm.org/D48676
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336451 91177308-0d34-0410-b5e6-96231b3b80d8
For local variables the first DW_OP_deref is consumed by turning the
location kind into a memeory location, but that only makes sense for
values that are in a register to begin with, which cannot happen for
global variables that are attached to a symbol.
rdar://problem/39741860
This reapplies r330970 after fixing an uncovered bug in r331086 and
working around the situation caused by it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331090 91177308-0d34-0410-b5e6-96231b3b80d8
Also make a drive-by-fix of a bug in the subregister scan code that
only triggers with an incomplete or otherwise very irregular machine
description.
rdar://problem/37404493
This re-applies r324972 with an early exit in the case of a complete
failure to make this commit NFC again as intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325041 91177308-0d34-0410-b5e6-96231b3b80d8
Here are the number of additional debug values salvaged in a stage2
build of clang:
63 SALVAGE: MUL
1250 SALVAGE: SDIV
(No values were salvaged from `srem` instructions in this experiment,
but it's a simple case to handle so we might as well.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324976 91177308-0d34-0410-b5e6-96231b3b80d8
Here are the number of additional debug values salvaged in a stage2
build of clang:
1912 SALVAGE: ASHR
405 SALVAGE: LSHR
249 SALVAGE: SHL
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324975 91177308-0d34-0410-b5e6-96231b3b80d8
Also make a drive-by-fix of a bug in the subregister scan code that
only triggers with an incomplete or otherwise very irregular machine
description.
rdar://problem/37404493
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324972 91177308-0d34-0410-b5e6-96231b3b80d8
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318490 91177308-0d34-0410-b5e6-96231b3b80d8
This patch contains fix for reverted commit
rL312318 which was causing failure due to use
of unchecked dyn_cast to CIInit.
Patch by: Nikola Prica.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313870 91177308-0d34-0410-b5e6-96231b3b80d8
This patch provides such debug information for integer
variables whose type is shrinked to bool by providing
dwarf expression which returns either constant initial
value or other value.
Patch by Nikola Prica.
Differential Revision: https://reviews.llvm.org/D35994
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312318 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305386 91177308-0d34-0410-b5e6-96231b3b80d8
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: pcc, echristo, aprantl
Reviewed By: aprantl
Subscribers: fhahn, aprantl, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33892
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305304 91177308-0d34-0410-b5e6-96231b3b80d8
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304864 91177308-0d34-0410-b5e6-96231b3b80d8
1. RegisterClass::getSize() is split into two functions:
- TargetRegisterInfo::getRegSizeInBits(const TargetRegisterClass &RC) const;
- TargetRegisterInfo::getSpillSize(const TargetRegisterClass &RC) const;
2. RegisterClass::getAlignment() is replaced by:
- TargetRegisterInfo::getSpillAlignment(const TargetRegisterClass &RC) const;
This will allow making those values depend on subtarget features in the
future.
Differential Revision: https://reviews.llvm.org/D31783
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301221 91177308-0d34-0410-b5e6-96231b3b80d8
and relax the assertion that prohibited its emission.
This fixes the assertion failure uncovered by r301093.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301209 91177308-0d34-0410-b5e6-96231b3b80d8
- introduced in r300522 and found via the Swift LLDB testsuite.
The fix is to set the location kind to memory whenever an FrameIndex
location is emitted.
rdar://problem/31707602
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300793 91177308-0d34-0410-b5e6-96231b3b80d8
- introduced in r300522 and found via the Swift LLDB testsuite.
The fix is to set the location kind to memory whenever an FrameIndex
location is emitted.
rdar://problem/31707602
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300790 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300522 91177308-0d34-0410-b5e6-96231b3b80d8
If a register location can only be described by a complex expression
(i.e., multiple subregisters) it doesn't safely compose with another
complex expression. For example, it is not possible to apply a
DW_OP_deref operation to multiple DW_OP_pieces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298472 91177308-0d34-0410-b5e6-96231b3b80d8
until the rest of the expression is known.
This is still an NFC refactoring in preparation of a subsequent bugfix.
This reapplies r298388 with a bugfix for non-physical frame registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298471 91177308-0d34-0410-b5e6-96231b3b80d8
If a register location can only be described by a complex expression
(i.e., multiple subregisters) it doesn't safely compose with another
complex expression. For example, it is not possible to apply a
DW_OP_deref operation to multiple DW_OP_pieces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298389 91177308-0d34-0410-b5e6-96231b3b80d8
until the rest of the expression is known.
This is still an NFC refactoring in preparation of a subsequent bugfix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298388 91177308-0d34-0410-b5e6-96231b3b80d8
Citing http://bugs.llvm.org/show_bug.cgi?id=32288
The DWARF generated by LLVM includes this location:
0x55 0x93 0x04 DW_OP_reg5 DW_OP_piece(4) When GCC's DWARF is simply
0x55 (DW_OP_reg5) without the DW_OP_piece. I believe it's reasonable
to assume the DWARF consumer knows which part of a register
logically holds the value (low bytes, high bytes, how many bytes,
etc) for a primitive value like an integer.
This patch gets rid of the redundant DW_OP_piece when a subregister is
at offset 0. It also adds previously missing subregister masking when
a subregister is followed by another operation.
(This reapplies r297960 with two additional testcase updates).
rdar://problem/31069390
https://reviews.llvm.org/D31010
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297965 91177308-0d34-0410-b5e6-96231b3b80d8
Citing http://bugs.llvm.org/show_bug.cgi?id=32288
The DWARF generated by LLVM includes this location:
0x55 0x93 0x04 DW_OP_reg5 DW_OP_piece(4) When GCC's DWARF is simply
0x55 (DW_OP_reg5) without the DW_OP_piece. I believe it's reasonable
to assume the DWARF consumer knows which part of a register
logically holds the value (low bytes, high bytes, how many bytes,
etc) for a primitive value like an integer.
This patch gets rid of the redundant DW_OP_piece when a subregister is
at offset 0. It also adds previously missing subregister masking when
a subregister is followed by another operation.
rdar://problem/31069390
https://reviews.llvm.org/D31010
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297960 91177308-0d34-0410-b5e6-96231b3b80d8
I think it's a hold-over from some previous iteration, but it's never
set to true in LLVM as it exists now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293086 91177308-0d34-0410-b5e6-96231b3b80d8
