Commit Graph

39 Commits

Author SHA1 Message Date
Raphael Isemann 958608285e [lldb] Allow LLDB to automatically retry a failed expression with an imported std C++ module
By now LLDB can import the 'std' C++ module to improve expression evaluation,
but there are still a few problems to solve before we can do this by default.
One is that importing the C++ module is slightly slower than normal expression
evaluation (mostly because the disk access and loading the initial lookup data
is quite slow in comparison to the barebone Clang setup the rest of the LLDB
expression evaluator is usually doing). Another problem is that some complicated
types in the standard library aren't fully supported yet by the ASTImporter, so
we end up types that fail to import (which usually appears to the user as if the
type is empty or there is just no result variable).

To still allow people to adopt this mode in their daily debugging, this patch
adds a setting that allows LLDB to automatically retry failed expression with a
loaded C++ module. All success expressions will behave exactly as they would do
before this patch. Failed expressions get a another parse attempt if we find a
usable C++ module in the current execution context. This way we shouldn't have
any performance/parsing regressions in normal debugging workflows, while the
debugging workflows involving STL containers benefit from the C++ module type
info.

This setting is off by default for now with the intention to enable it by
default on macOS soon-ish.

The implementation is mostly just extracting the existing parse logic into its
own function and then calling the parse function again if the first evaluation
failed and we have a C++ module to retry the parsing with.

Reviewed By: shafik, JDevlieghere, aprantl

Differential Revision: https://reviews.llvm.org/D92784
2020-12-10 12:29:17 +01:00
Raphael Isemann 2b37c5b560 [lldb][NFC] Make ClangExpressionSourceCode's wrapping logic more consistent
Summary:
ClangExpressionSourceCode has different ways to wrap the user expression based on
which context the expression is executed in. For example, if we're in a C++ member
function we put the expression inside a fake member function of a fake class to make the
evaluation possible. Similar things are done for Objective-C instance/static methods.
There is also a default wrapping where we put the expression in a normal function
just to make it possible to execute it.

The way we currently define which kind of wrapping the expression needs is based on
the `wrapping_language` we keep passing to the ClangExpressionSourceCode
instance. We repurposed the language type enum for that variable to distinguish the
cases above with the following mapping:
* language = C_plus_plus -> member function wrapping
* language = ObjC -> instance/static method wrapping (`is_static` distinguished between those two).
* language = C -> normal function wrapping
* all other cases like C_plus_plus11, Haskell etc. make our class a no-op that does mostly nothing.

That mapping is currently not documented and just confusing as the `language`
is unrelated to the expression language (and in the ClangUserExpression we even pretend
that it *is* the actual language, but luckily never used it for anything). Some of the code
in ClangExpressionSourceCode is also obviously thinking that this is the actual language of
the expression as it checks for non-existent cases such as `ObjC_plus_plus` which is
not part of the mapping.

This patch makes a new enum to describe the four cases above (with instance/static Objective-C
methods now being their own case). It also make that enum just a member of
ClangExpressionSourceCode instead of having to pass the same value to the class repeatedly.
This gets also rid of all the switch-case-checks for 'unknown' language such as C_plus_plus11 as this
is no longer necessary.

Reviewers: labath, JDevlieghere

Reviewed By: labath

Subscribers: abidh

Differential Revision: https://reviews.llvm.org/D80793
2020-06-01 13:24:30 +02:00
Jonas Devlieghere cdc514e4c6 [lldb] Update header guards to be consistent and compliant with LLVM (NFC)
LLDB has a few different styles of header guards and they're not very
consistent because things get moved around or copy/pasted. This patch
unifies the header guards across LLDB and converts everything to match
LLVM's style.

Differential revision: https://reviews.llvm.org/D74743
2020-02-17 23:15:40 -08:00
Alex Langford 5b0c8dd3a4 [lldb] Delete ClangForward.h
Summary:
I think that there are very few things from clang that actually need forward
declaration, so not having a ClangForward header makes sense.

Differential Revision: https://reviews.llvm.org/D73827
2020-02-03 10:43:12 -08:00
Jonas Devlieghere ad882774fe [LLDB] Fix a bunch of -Wdocumentation warnings 2019-11-13 12:28:10 -08:00
Raphael Isemann 52f3a2faf9 [lldb][NFC] Move LLVM RTTI implementation from enum to static ID variable
Summary:
swift-lldb currently has to patch the ExpressionKind enum to add support for Swift expressions. If we implement LLVM's RTTI
with a static ID variable instead of a centralised enum we can drop that patch.

Reviewers: labath, davide

Reviewed By: labath

Subscribers: JDevlieghere, lldb-commits

Tags: #upstreaming_lldb_s_downstream_patches, #lldb

Differential Revision: https://reviews.llvm.org/D70070
2019-11-12 10:04:32 +01:00
Raphael Isemann 9379d19ff8 [lldb] Decouple importing the std C++ module from the way the program is compiled
Summary:
At the moment, when trying to import the `std` module in LLDB, we look at the imported modules used in the compiled program
and try to infer the Clang configuration we need from the DWARF module-import. That was the initial idea but turned out to
cause a few problems or inconveniences:

* It requires that users compile their programs with C++ modules. Given how experimental C++ modules are makes this feature inaccessible
for many users. Also it means that people can't just get the benefits of this feature for free when we activate it by default
(and we can't just close all the associated bug reports).
* Relying on DWARF's imported module tags (that are only emitted by default on macOS) means this can only be used when using DWARF (and with -glldb on Linux).
* We essentially hardcoded the C standard library paths on some platforms (Linux) or just couldn't support this feature on other platforms (macOS).

This patch drops the whole idea of looking at the imported module DWARF tags and instead just uses the support files of the compilation unit.
If we look at the support files and see file paths that indicate where the C standard library and libc++ are, we can just create the module
configuration this information. This fixes all the problems above which means we can enable all the tests now on Linux, macOS and with other debug information
than what we currently had. The only debug information specific code is now the iteration over external type module when -gmodules is used (as `std` and also the
`Darwin` module are their own external type module with their own files).

The meat of this patch is the CppModuleConfiguration which looks at the file paths from the compilation unit and then figures out the include paths
based on those paths. It's quite conservative in that it only enables modules if we find a single C library and single libc++ library. It's still missing some
test mode where we try to compile an expression before we actually activate the config for the user (which probably also needs some caching mechanism),
but for now it works and makes the feature usable.

Reviewers: aprantl, shafik, jdoerfert

Reviewed By: aprantl

Subscribers: mgorny, abidh, JDevlieghere, lldb-commits

Tags: #c_modules_in_lldb, #lldb

Differential Revision: https://reviews.llvm.org/D67760

llvm-svn: 372716
2019-09-24 10:08:18 +00:00
Raphael Isemann 1442efea9a [lldb] Print better diagnostics for user expressions and modules
Summary:
Currently our expression evaluators only prints very basic errors that are not very useful when writing complex expressions.

For example, in the expression below the user made a type error, but it's not clear from the diagnostic what went wrong:
```
(lldb) expr printf("Modulos are:", foobar%mo1, foobar%mo2, foobar%mo3)
error: invalid operands to binary expression ('int' and 'double')
```

This patch enables full Clang diagnostics in our expression evaluator. After this patch the diagnostics for the expression look like this:

```
(lldb) expr printf("Modulos are:", foobar%mo1, foobar%mo2, foobar%mo3)
error: <user expression 1>:1:54: invalid operands to binary expression ('int' and 'float')
printf("Modulos are:", foobar%mo1, foobar%mo2, foobar%mo3)
                                               ~~~~~~^~~~
```

To make this possible, we now emulate a user expression file within our diagnostics. This prevents that the user is exposed to
our internal wrapper code we inject.

Note that the diagnostics that refer to declarations from the debug information (e.g. 'note' diagnostics pointing to a called function)
will not be improved by this as they don't have any source locations associated with them, so caret or line printing isn't possible.
We instead just suppress these diagnostics as we already do with warnings as they would otherwise just be a context message
without any context (and the original diagnostic in the user expression should be enough to explain the issue).

Fixes rdar://24306342

Reviewers: JDevlieghere, aprantl, shafik, #lldb

Reviewed By: JDevlieghere, #lldb

Subscribers: usaxena95, davide, jingham, aprantl, arphaman, kadircet, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D65646

llvm-svn: 372203
2019-09-18 08:53:35 +00:00
Raphael Isemann 3ad8278737 [lldb][NFC] Make include directories in Clang expression parser a std::string
We never compare these directories (where ConstString would be good) and
essentially just convert this back to a normal string in the end. So we might
as well just use std::string. Also makes it easier to unittest this code
(which was the main motivation for this change).

llvm-svn: 371623
2019-09-11 14:33:11 +00:00
Raphael Isemann b0ca908808 [lldb][NFC] Move Clang-specific flags to ClangUserExpression
LLVMUserExpression doesn't use these variables and they are all specific to Clang.

Also removes m_const_object as this was actually never used by anyone (and Clang
didn't report it as we assigned it in the constructor which seems to count as use).

llvm-svn: 370440
2019-08-30 07:44:29 +00:00
Raphael Isemann b859168ec9 [lldb][NFC] Document options parameter in ClangUserExpression constructor
Somehow this option was only documented in the swift branch.

llvm-svn: 370395
2019-08-29 18:53:20 +00:00
Raphael Isemann 5eb87cf30f [lldb][NFC] Refactor ClangUserExpression::UpdateLanguageForExpr
The UpdateLanguageForExpr should only update the language, but over
time it started to do also do different things related to the generation
of the expression source code. This patch refactors all the source code
generation part into its own function.

llvm-svn: 367922
2019-08-05 20:31:47 +00:00
Raphael Isemann 71569d0d52 Inject only relevant local variables in the expression evaluation context
Summary:
In r259902, LLDB started injecting all the locals in every expression
evaluation. This fixed a bunch of issues, but also caused others, mostly
performance regressions on some codebases. The regressions were bad
enough that we added a setting in r274783 to control the behavior and
we have been shipping with the setting off to avoid the perf regressions.

This patch changes the logic injecting the local variables to only inject
the ones present in the expression typed by the user. The approach is
fairly simple and just scans the typed expression for every local name.
Hopefully this gives us the best of both world as it just realizes the
types of the variables really used by the expression.

Landing this requires the 2 other issues I pointed out today to be addressed
but I wanted to gather comments right away.

Original patch by Frédéric Riss!

Reviewers: jingham, clayborg, friss, shafik

Reviewed By: jingham, clayborg

Subscribers: teemperor, labath, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D46551

llvm-svn: 359773
2019-05-02 10:12:56 +00:00
Jonas Devlieghere 8b3af63b89 [NFC] Remove ASCII lines from comments
A lot of comments in LLDB are surrounded by an ASCII line to delimit the
begging and end of the comment.

Its use is not really consistent across the code base, sometimes the
lines are longer, sometimes they are shorter and sometimes they are
omitted. Furthermore, it looks kind of weird with the 80 column limit,
where the comment actually extends past the line, but not by much.
Furthermore, when /// is used for Doxygen comments, it looks
particularly odd. And when // is used, it incorrectly gives the
impression that it's actually a Doxygen comment.

I assume these lines were added to improve distinguishing between
comments and code. However, given that todays editors and IDEs do a
great job at highlighting comments, I think it's worth to drop this for
the sake of consistency. The alternative is fixing all the
inconsistencies, which would create a lot more churn.

Differential revision: https://reviews.llvm.org/D60508

llvm-svn: 358135
2019-04-10 20:48:55 +00:00
Adrian Prantl 7e34d78da1 Fix an invalid static cast in ClangExpressionParser.cpp
This was found by the green dragon sanitizer bot.

rdar://problem/48536644

Differential Revision: https://reviews.llvm.org/D59314

llvm-svn: 356090
2019-03-13 19:46:30 +00:00
Raphael Isemann 6c0bbfc0c9 Add ability to import std module into expression parser to improve C++ debugging
Summary:
This patch is the MVP version of importing the std module into the expression parser to improve C++ debugging.

What happens in this patch is that we inject a `@import std` into our expression source code. We also
modify our internal Clang instance for parsing this expression to work with modules and debug info
at the same time (which is the main change in terms of LOC). We implicitly build the `std` module on the first use. The
C++ include paths for building are extracted from the debug info, which means that this currently only
works if the program is compiled with `-glldb -fmodules` and uses the std module. The C include paths
are currently specified by LLDB.

I enabled the tests currently only for libc++ and Linux because I could test this locally. I'll enable the tests
for other platforms once this has landed and doesn't break any bots (and I implemented the platform-specific
C include paths for them).

With this patch we can now:
* Build a libc++ as a module and import it into the expression parser.
* Read from the module while also referencing declarations from the debug info. E.g. `std::abs(local_variable)`.

What doesn't work (yet):
* Merging debug info and C++ module declarations. E.g. `std::vector<CustomClass>` doesn't work.
* Pretty much anything that involves the ASTImporter and templated code. As the ASTImporter is used for saving the result declaration, this means that we can't
call yet any function that returns a non-trivial type.
* Use libstdc++ for this, as it requires multiple include paths and Clang only emits one include path per module. Also libstdc++ doesn't support Clang modules without patches.

Reviewers: aprantl, jingham, shafik, friss, davide, serge-sans-paille

Reviewed By: aprantl

Subscribers: labath, mgorny, abidh, jdoerfert, lldb-commits

Tags: #c_modules_in_lldb, #lldb

Differential Revision: https://reviews.llvm.org/D58125

llvm-svn: 355939
2019-03-12 17:09:33 +00:00
Adrian Prantl f05b42e960 Bring Doxygen comment syntax in sync with LLVM coding style.
This changes '@' prefix to '\'.

llvm-svn: 355841
2019-03-11 17:09:29 +00:00
Aleksandr Urakov 40624a085c [Expressions] Add support of expressions evaluation in some object's context
Summary:
This patch adds support of expression evaluation in a context of some object.
Consider the following example:
```
struct S {
  int a = 11;
  int b = 12;
};

int main() {
  S s;
  int a = 1;
  int b = 2;
  // We have stopped here
  return 0;
}
```
This patch allows to do something like that:
```
lldb.frame.FindVariable("s").EvaluateExpression("a + b")
```
and the result will be `33` (not `3`) because fields `a` and `b` of `s` will be
used (not locals `a` and `b`).

This is achieved by replacing of `this` type and object for the expression. This
has some limitations: an expression can be evaluated only for values located in
the debuggee process memory (they must have an address of `eAddressTypeLoad`
type).

Reviewers: teemperor, clayborg, jingham, zturner, labath, davide, spyffe, serge-sans-paille

Reviewed By: jingham

Subscribers: abidh, lldb-commits, leonid.mashinskiy

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D55318

llvm-svn: 353149
2019-02-05 09:14:36 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Jonas Devlieghere ceff6644bb Remove header grouping comments.
This patch removes the comments grouping header includes. They were
added after running IWYU over the LLDB codebase. However they add little
value, are often outdates and burdensome to maintain.

llvm-svn: 346626
2018-11-11 23:17:06 +00:00
Raphael Isemann dababf70e2 Refactor ClangUserExpression::GetLanguageForExpr
Summary:
The `ClangUserExpression::GetLanguageForExpr` method is currently a big
source of sadness, as it's name implies that it's an accessor method, but it actually
is also initializing some variables that we need for parsing. This caused that we
currently call this getter just for it's side effects while ignoring it's return value,
which is confusing for the reader.

This patch renames it to `UpdateLanguageForExpr` and merges all calls to the
method into a single call in `ClangUserExpression::PrepareForParsing` (as calling
this method is anyway mandatory for parsing to succeed)

While looking at the code, I also found that we actually have two language
variables in this class hierarchy. The normal `Language` from the UserExpression
class and the `LanguageForExpr` that we implemented in this subclass. Both
don't seem to actually contain the same value, so we probably should look at this
next.

Reviewers: xbolva00

Reviewed By: xbolva00

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D52561

llvm-svn: 343191
2018-09-27 10:12:54 +00:00
Raphael Isemann bfc5ef6c5b Change type of m_user_expression_start_pos to size_t
AbsPosToLineColumnPos is the only reader of m_user_expression_start_pos
and actually treats it like a size_t. Also the value we store in
m_user_expression_start_pos is originally a size_t, so it makes sense
to change the type of this variable to size_t.

llvm-svn: 342804
2018-09-22 13:33:08 +00:00
Raphael Isemann c11a780ed6 Use a CompletionRequest in the expression command completion [NFC]
The patch was originally written before we had a CompletionRequest,
so it still used a StringList to pass back the completions to
the request.

llvm-svn: 341124
2018-08-30 21:26:32 +00:00
Raphael Isemann 7482973411 Added initial code completion support for the `expr` command
Summary:
This patch adds initial code completion support for the `expr` command.

We now have a completion handler in the expression CommandObject that
essentially just attempts to parse the given user expression with Clang with
an attached code completion consumer. We filter and prepare the
code completions provided by Clang and send them back to the completion
API.

The current completion is limited to variables that are in the current scope.
This includes local variables and all types used by local variables. We however
don't do any completion of symbols that are not used in the local scope (or
in some other way already in the ASTContext).

This is partly because there is not yet any code that manually searches for additiona
information in the debug information. Another cause is that for some reason the existing
code for loading these additional symbols when requested by Clang doesn't seem to work.
This will be fixed in a future patch.

Reviewers: jingham, teemperor

Reviewed By: teemperor

Subscribers: labath, aprantl, JDevlieghere, friss, lldb-commits

Differential Revision: https://reviews.llvm.org/D48465

llvm-svn: 341086
2018-08-30 17:29:37 +00:00
Raphael Isemann ba800e7db5 Refactor ClangUserExpression::Parse [NFC]
Summary:
This patch splits out functionality from the `Parse` method into different methods.
This benefits the code completion work (which should reuse those methods) and makes the
code a bit more readable.

Note that this patch is as minimal as possible. Some of the code in the new methods definitely
needs more refactoring.

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D48339

llvm-svn: 336734
2018-07-10 22:12:39 +00:00
Adrian Prantl d8f460e864 Enable AUTOBRIEF in doxygen configuration.
This brings the LLDB configuration closer to LLVM's and removes visual
clutter in the source code by removing the @brief commands from
comments.

This patch also reflows the paragraphs in all doxygen comments.

See also https://reviews.llvm.org/D46290.

Differential Revision: https://reviews.llvm.org/D46321

llvm-svn: 331373
2018-05-02 16:55:16 +00:00
Adrian Prantl 5435f78046 Move the persistent variable counter into Target
so it can be shared across multiple language plugins.

In a multi-language project it is counterintuitive to have a result
variables reuse numbers just because they are using a different
language plugin in LLDB (but not for example, when they are
Objective-C versus C++, since they are both handled by Clang).

This is NFC on llvm.org except for the Go plugin.

rdar://problem/39299889

Differential Revision: https://reviews.llvm.org/D46083

llvm-svn: 331234
2018-04-30 23:59:15 +00:00
Zachary Turner 97206d5727 Rename Error -> Status.
This renames the LLDB error class to Status, as discussed
on the lldb-dev mailing list.

A change of this magnitude cannot easily be done without
find and replace, but that has potential to catch unwanted
occurrences of common strings such as "Error".  Every effort
was made to find all the obvious things such as the word "Error"
appearing in a string, etc, but it's possible there are still
some lingering occurences left around.  Hopefully nothing too
serious.

llvm-svn: 302872
2017-05-12 04:51:55 +00:00
Zachary Turner c5d7df9035 Convert some Expression parser functions to StringRef.
llvm-svn: 286208
2016-11-08 04:52:16 +00:00
Kate Stone b9c1b51e45 *** This commit represents a complete reformatting of the LLDB source code
*** to conform to clang-format’s LLVM style.  This kind of mass change has
*** two obvious implications:

Firstly, merging this particular commit into a downstream fork may be a huge
effort.  Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit.  The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):

    find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
    find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;

The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.

Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit.  There are alternatives available that will attempt
to look through this change and find the appropriate prior commit.  YMMV.

llvm-svn: 280751
2016-09-06 20:57:50 +00:00
Sean Callanan 00294b34a3 Backend support for top-level Clang epxressions
This patch adds a new ExecutionPolicy, eExecutionPolicyTopLevel, which
tells the expression parser that the expression should be JITted as top
level code but nothing (except static initializers) should be run.  I
have modified the Clang expression parser to recognize this execution
policy.  On top of the existing patches that support storing IR and
maintaining a map of arbitrary Decls, this is mainly just patching up a
few places in the expression parser.

I intend to submit a patch for review that exposes this functionality
through the "expression" command and through the SB API.  That patch
also includes a testcase for all of this.

<rdar://problem/22864976>

llvm-svn: 264095
2016-03-22 21:05:51 +00:00
Sean Callanan 579e70c9b0 Add a DiagnosticManager replace error streams in the expression parser.
We want to do a better job presenting errors that occur when evaluating
expressions. Key to this effort is getting away from a model where all
errors are spat out onto a stream where the client has to take or leave
all of them.

To this end, this patch adds a new class, DiagnosticManager, which
contains errors produced by the compiler or by LLDB as an expression
is created. The DiagnosticManager can dump itself to a log as well as
to a string. Clients will (in the future) be able to filter out the
errors they're interested in by ID or present subsets of these errors
to the user.

This patch is not intended to change the *users* of errors - only to
thread DiagnosticManagers to all the places where streams are used. I
also attempt to standardize our use of errors a bit, removing trailing
newlines and making clients omit 'error:', 'warning:' etc. and instead
pass the Severity flag.

The patch is testsuite-neutral, with modifications to one part of the
MI tests because it relied on "error: error:" being erroneously
printed. This patch fixes the MI variable handling and the testcase.

<rdar://problem/22864976>

llvm-svn: 263859
2016-03-19 00:03:59 +00:00
Jim Ingham 51148e9f94 AddInitialArguments -> AddArguments, and we pass in the struct_address and push it too. All the
callers had to do this by hand and we ended up never actually adding initial arguments and then
reusing them by passing in the struct address separately, so the distinction wasn't needed.

llvm-svn: 252108
2015-11-05 00:24:18 +00:00
Jim Ingham 19a63fc6fa Add the ability to pass an EvaluateExpressionOptions when you make a UserExpression. This
isn't used in this commit but will be in a future commit.

llvm-svn: 251887
2015-11-03 02:11:24 +00:00
Ryan Brown 998c8a1c1c Create an expression parser for Go.
The Go interpreter doesn't JIT or use LLVM, so this also
moves all the JIT related code from UserExpression to a new class LLVMUserExpression.

Differential Revision: http://reviews.llvm.org/D13073

Fix merge

llvm-svn: 251820
2015-11-02 19:30:40 +00:00
Eugene Zelenko 4c3f2b9446 Fix Clang-tidy modernize-use-override warnings in some files in source/Plugins; other minor fixes.
Differential Revision: http://reviews.llvm.org/D13916

llvm-svn: 250872
2015-10-21 01:03:30 +00:00
Bruce Mitchener 804f981fd0 Reduce header inclusion in Expression.
Reviewers: spyffe

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D13333

llvm-svn: 249570
2015-10-07 17:22:54 +00:00
Sean Callanan 9fda9d2177 Add PersistentVariableDelegate to handle language-specific dematerialization.
The concept here is that languages may have different ways of communicating
results.  In particular, languages may have different names for their result
variables and in fact may have multiple types of result variables (e.g.,
error results).  Materializer was tied to one specific model of result handling.

Instead, now UserExpressions can register their own handlers for the result
variables they inject.  This allows language-specific code in Materializer to
be moved into the expression parser plug-in, and it simplifies Materializer.
These delegates are subclasses of PersistentVariableDelegate.

PersistentVariableDelegate can provide the name of the result variable, and is
notified when the result variable is populated.  It can also be used to touch
persistent variables if need be, updating language-specific state.  The
UserExpression owns the delegate and can decide on its result based on
consulting all of its (potentially multiple) delegates.

The user expression itself now makes the determination of what the final result
of the expression is, rather than relying on the Materializer, and I've added a
virtual function to UserExpression to allow this.

llvm-svn: 249233
2015-10-03 09:09:01 +00:00
Sean Callanan 4dbb271fcc Moved more Clang-specific parts of the expression parser into the Clang plugin.
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
2015-09-25 20:35:58 +00:00