12 Commits

Author SHA1 Message Date
Sean Callanan
ed185ab5c7 Fixed two problems when reading constant/register
variables in the ValueObject code:

  - Report an error if the variable does not have
    a valid address.

  - Return the contents of the data to GetData(),
    even if the value is constant.

<rdar://problem/13690855>

llvm-svn: 179876
2013-04-19 19:47:32 +00:00
Sean Callanan
1582ee6840 This commit changes the way LLDB executes user
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
2013-04-18 22:06:33 +00:00
Sean Callanan
14b1bae5ee Flipped the big switch: LLDB now uses the new
Materializer for all expressions that need to
run in the target.  This includes the following
changes:

- Removed a bunch of (de-)materialization code
  from ClangExpressionDeclMap and assumed the
  presence of a Materializer where we previously
  had a fallback.

- Ensured that an IRMemoryMap is passed into
  ClangExpressionDeclMap::Materialize().

- Fixed object ownership on LLVMContext; it is
  now owned by the IRExecutionUnit, since the
  Module and the ExecutionEngine both depend on
  its existence.

- Fixed a few bugs in IRMemoryMap and the
  Materializer that showed up during testing.

llvm-svn: 179649
2013-04-16 23:25:35 +00:00
Sean Callanan
2d37e5a5a5 Added logging to each entity in the Materializer
to make debugging easier when things go wrong.

llvm-svn: 179576
2013-04-15 22:48:23 +00:00
Sean Callanan
b5717e00c8 Added support for registers to the Materializer.
Also improved logging and error handling in a few
spots in the Materializer.

llvm-svn: 179557
2013-04-15 20:51:24 +00:00
Sean Callanan
b024d87822 Audited the existing Materializer code to ensure
that it works in the absence of a process.  Codepaths
in the Materializer now use the best execution context
scope available to them.

llvm-svn: 179539
2013-04-15 17:12:47 +00:00
Sean Callanan
2f1edcd758 Added symbol materialization support to the new
Materializer.

llvm-svn: 179445
2013-04-13 02:25:02 +00:00
Sean Callanan
458ae1c6eb Now that ValueObjects permit writing, made the
Materializer use that API when dematerializing
variables.

llvm-svn: 179443
2013-04-13 02:06:42 +00:00
Sean Callanan
f8043fa527 Implemented materialization and dematerialization
for variables in the new Materializer.  This is
much easier now that the ValueObject API is solid.

I still have to implement reading bytes into a
ValueObject, but committing what I have so far.

This code is not yet used, so there will be fixes
when I switch the expression parser over to use the
new Materializer.

llvm-svn: 179416
2013-04-12 21:40:34 +00:00
Sean Callanan
35005f768e Replicated the materialization logic for persistent
variables in the Materializer.  We don't use this
code yet, but will soon once the other materializers
are online.

llvm-svn: 179390
2013-04-12 18:10:34 +00:00
Sean Callanan
3dd6a42306 Hand over the job of laying out the argument structure
to the Materializer.  Materialization is still done by
the ClangExpressionDeclMap; this will be the next thing
to move.

Also fixed a layout bug that this uncovered.

llvm-svn: 179318
2013-04-11 21:16:36 +00:00
Sean Callanan
96d2730a7b Added a Materializer class that contains
information about each variable that needs to
be materialized for an expression to work.  The
next step is to migrate all materialization code
from ClangExpressionDeclMap to Materializer, and
to use it for variable materialization.

llvm-svn: 179245
2013-04-11 00:09:05 +00:00