Previously, the options for a breakopint or its
locations stored only the text of the breakpoint
condition (ironically, they used ClangUserExpression
as a glorified std::string) and, each time the condition
had to be evaluated in the StopInfo code, the expression
parser would be invoked via a static method to parse and
then execute the expression.
I made several changes here:
- Each breakpoint location now has its own
ClangUserExpressionSP containing a version of
the breakpoint expression compiled for that exact
location.
- Whenever the breakpoint is hit, the breakpoint
condition expression is simply re-run to determine
whether to stop.
- If the process changes (e.g., it's re-run) or
the source code of the expression changes (we use
a hash so as to avoid doing string comparisons)
the ClangUserExpressionSP is re-generated.
This should improve performance of breakpoint
conditions significantly, and takes advantage of
the recent expression re-use work.
llvm-svn: 179838
Adding another CU-wide list, in this case of imported_modules (since they
should be relatively rare, it seemed better to add a list where each element
had a "context" value, rather than add a (usually empty) list to every scope).
This takes care of DW_TAG_imported_module, but to fully address PR14606 we'll
need to expand this to cover DW_TAG_imported_declaration too.
llvm-svn: 179836
When the SlotIndexes pass was introduced it was intended to support insertion
of code during register allocation. Removal of code was a minor consideration
(and raised the question of what to do about dangling SlotIndex objects pointing
to the erased index), so I opted to keep all indexes around indefinitely and
simply null out those that weren't being used.
Nowadays people are moving more code around (e.g. via HandleMove), which means
more zombie indexes. I want to start killing off indexes when we're done with
them to reclaim the resources they use up.
llvm-svn: 179834
and made attempts to allocate memory in the process
fall back to FindSpace and just allocate memory on
the host (but with real-looking pointers, hence
FindSpace) if the process doesn't allow allocation.
This allows expressions to run on processes that don't
support allocation, like core files.
This introduces an extremely rare potential problem:
If all of the following are true:
- The Process doesn't support allocation;
- the user writes an expression that refers to an
address that does not yet map to anything, or is
dynamically generated (e.g., the result of calling
a function); and
- the randomly-selected address for the static data
for that specific expression runs into the
address the user was expecting to work with;
then dereferencing the pointer later results
in the user seeing something unexpected. This is
unlikely but possible; as a future piece of work,
we should have processes be able to hint to the
expression parser where it can allocate temporary data
of this kind.
llvm-svn: 179827
variant/dialect. Addresses a FIXME in the emitMnemonicAliases function.
Use and test case to come shortly.
rdar://13688439 and part of PR13340.
llvm-svn: 179804
Many PPC instructions have a so-called 'record form' which stores to a specific
condition register the result of comparing the result of the instruction with
zero (always as a signed comparison). For integer operations on PPC64, this is
always a 64-bit comparison.
This implementation is derived from the implementation in the ARM backend;
there are some differences because PPC condition registers are allocatable
virtual registers (although the record forms always use a specific one), and we
look for a matching subtraction instruction after the compare (but before the
first use) in addition to before it.
llvm-svn: 179802
expressions.
Previously, ClangUserExpression assumed that if
there was a constant result for an expression
then it could be determined during parsing. In
particular, the IRInterpreter ran while parser
state (in particular, ClangExpressionDeclMap)
was present. This approach is flawed, because
the IRInterpreter actually is capable of using
external variables, and hence the result might
be different each run. Until now, we papered
over this flaw by re-parsing the expression each
time we ran it.
I have rewritten the IRInterpreter to be
completely independent of the ClangExpressionDeclMap.
Instead of special-casing external variable lookup,
which ties the IRInterpreter closely to LLDB,
we now interpret the exact same IR that the JIT
would see. This IR assumes that materialization
has occurred; hence the recent implementation of the
Materializer, which does not require parser state
(in the form of ClangExpressionDeclMap) to be
present.
Materialization, interpretation, and dematerialization
are now all independent of parsing. This means that
in theory we can parse expressions once and run them
many times. I have three outstanding tasks before
shutting this down:
- First, I will ensure that all of this works with
core files. Core files have a Process but do not
allow allocating memory, which currently confuses
materialization.
- Second, I will make expression breakpoint
conditions remember their ClangUserExpression and
re-use it.
- Third, I will tear out all the redundant code
(for example, materialization logic in
ClangExpressionDeclMap) that is no longer used.
While implementing this fix, I also found a bug in
IRForTarget's handling of floating-point constants.
This should be fixed.
llvm-svn: 179801
Semantics of parameters named Index and Idx were inconsistent between
"include/llvm/IR/Attributes.h", "lib/IR/AttributeImpl.h" and
"lib/IR/Attributes.cpp": sometimes these were fixed 1-based indexes of IR
parameters (or AttributeSet::ReturnIndex for IR return values or
AttributeSet::FunctionIndex for IR functions), other times they were the
internal slot for storage in the underlying AttributeSetImpl. I renamed usage of
the former to "Index" and usage of the latter to "Slot" ("Slot" was already
being used consistently for the latter in a subset of cases)
Patch by Stephen Lin!
llvm-svn: 179791
Alexey Samsonov