"frame variable" and "target variable" are trying to emulate the expression parser when doing things like:
(lldb) frame variable &my_struct.my_bitfield
And since the expression parser doesn't allow this, we shouldn't allow "frame variable" or "target variable" to succeed.
<rdar://problem/27208607>
llvm-svn: 274703
Currently, the DataExtractor::GetMaxU64Bitfield and GetMaxS64Bitfield
routines assume the incoming "bitfield_bit_offset" parameter uses
little-endian bit numbering, i.e. a bitfield_bit_offset 0 refers to
a bitfield whose least-significant bit coincides with the least-
significant bit of the surrounding integer.
On many big-endian systems, however, the big-endian bit numbering
is used for bit fields. Here, a bitfield_bit_offset 0 refers to
a bitfield whose most-significant bit conincides with the most-
significant bit of the surrounding integer.
Now, in principle LLDB could arbitrarily choose which semantics of
bitfield_bit_offset to use. However, there are two problems with
the current approach:
- When parsing DWARF, LLDB decodes bit offsets in little-endian
bit numbering on LE systems, but in big-endian bit numbering
on BE systems. Passing those offsets later on into the
DataExtractor routines gives incorrect results on BE.
- In the interim, LLDB's type layer combines byte and bit offsets
into a single number. I.e. instead of recording bitfields by
specifying the byte offset and byte size of the surrounding
integer *plus* the bit offset of the bit field within that field,
it simply records a single bit offset number.
Now, note that converting from byte offset + bit offset to a
single offset value and back is well-defined if we either use
little-endian byte order *and* little-endian bit numbering,
or use big-endian byte order *and* big-endian bit numbering.
Any other combination will yield incorrect results.
Therefore, the simplest approach would seem to be to always use
the bit numbering that matches the system byte order. This makes
storing a single bit offset valid, and makes the existing DWARF
code correct. The only place to fix is to teach DataExtractor
to use big-endian bit numbering on big endian systems.
However, there is only additional caveat: we also get bit offsets
from LLDB synthetic bitfields. While the exact semantics of those
doesn't seem to be well-defined, from test cases it appears that
the intent was for the user-provided synthetic bitfield offset to
always use little-endian bit numbering. Therefore, on a big-endian
system we now have to convert those to big-endian bit numbering
to remain consistent.
Differential Revision: http://reviews.llvm.org/D18982
llvm-svn: 266312
When the parent of an expression is anonymous, skip adding '.' or '->' before the expression name.
Differential Revision: http://reviews.llvm.org/D18005
llvm-svn: 263166
This patch adds support for printing global static const variables which are given a DW_AT_const_value DWARF tag by clang.
Fix for bug https://llvm.org/bugs/show_bug.cgi?id=25653
Reviewers: clayborg, tberghammer
Subscribers: emaste, lldb-commits
Differential Revision: http://reviews.llvm.org/D15576
llvm-svn: 255887
This latter determination may or may not be possible on a per-language basis; and neither is mandatory to implement for any language
Use this knowledge in the ValueObjectPrinter to generalize the notion of IsObjCNil() and the respective printout
llvm-svn: 252663
In this way, when a language needs to tell itself things that are not bound to a type but to a value (imagine a base-class relation, this is not about the type, but about the ValueObject), it can do so in a clean and general fashion
The interpretation of the values of the flags is, of course, up to the language that owns the value (the value object's runtime language, that is)
llvm-svn: 252503
Summary:
Along with this, support for an optional argument to the "num_children"
method of a Python synthetic child provider has also been added. These have
been added with the following use case in mind:
Synthetic child providers currently have a method "has_children" and
"num_children". While the former is good enough to know if there are
children, it does not give any insight into how many children there are.
Though the latter serves this purpose, calculating the number for children
of a data structure could be an O(N) operation if the data structure has N
children. The new method added in this change provide a middle ground.
One can call GetNumChildren(K) to know if a child exists at an index K
which can be as large as the callers tolerance can be. If the caller wants
to know about children beyond K, it can make an other call with 2K. If the
synthetic child provider maintains state about it counting till K
previosly, then the next call is only an O(K) operation. Infact, all
calls made progressively with steps of K will be O(K) operations.
Reviewers: vharron, clayborg, granata.enrico
Subscribers: labath, lldb-commits
Differential Revision: http://reviews.llvm.org/D13778
llvm-svn: 250930
The ClangExpressionVariable::CreateVariableInList functions looked cute, but
caused more confusion than they solved. I removed them, and instead made sure
that there are adequate facilities for easily adding newly-constructed
ExpressionVariables to lists.
I also made some of the constructors that are common be generic, so that it's
possible to construct expression variables from generic places (like the ABI and
ValueObject) without having to know the specifics about the class.
llvm-svn: 249095
Also added some target-level search functions so that persistent variables and
symbols can be searched for without hand-iterating across the map of
TypeSystems.
llvm-svn: 249027
the corresponding TypeSystem. This makes sense because what kind of data there
is -- and how it can be looked up -- depends on the language.
Functionality that is common to all type systems is factored out into
PersistentExpressionState.
llvm-svn: 248934
There are still a bunch of dependencies on the plug-in, but this helps to
identify them.
There are also a few more bits we need to move (and abstract, for example the
ClangPersistentVariables).
llvm-svn: 248612
Greg Clayton
Enrico Granata
Ulrich Weigand
Marianne Mailhot-Sarrasin
Ewan Crawford
Davide Italiano
Jim Ingham
Siva Chandra
Sean Callanan