Commit Graph

114 Commits

Author SHA1 Message Date
Yang Fan 6e26e49edf [analyzer] NFC: Fix wrong parameter name in printFormattedEntry.
Parameters were in a different order in the header and in the implementation.

Fix surrounding comments a bit.

Differential Revision: https://reviews.llvm.org/D86691
2020-08-27 12:15:26 -07:00
Aaron Ballman 7339fca25f Revert "Convert a reachable llvm_unreachable into an assert."
This reverts commit 4a0267e3ad.
2020-03-24 16:06:14 -04:00
Aaron Ballman 4a0267e3ad Convert a reachable llvm_unreachable into an assert. 2020-03-10 14:22:21 -04:00
Csaba Dabis a079a42708 [analyzer] Analysis: Silence checkers
Summary:
This patch introduces a new `analyzer-config` configuration:
`-analyzer-config silence-checkers`
which could be used to silence the given checkers.

It accepts a semicolon separated list, packed into quotation marks, e.g:
`-analyzer-config silence-checkers="core.DivideZero;core.NullDereference"`

It could be used to "disable" core checkers, so they model the analysis as
before, just if some of them are too noisy it prevents to emit reports.

This patch also adds support for that new option to the scan-build.
Passing the option `-disable-checker core.DivideZero` to the scan-build
will be transferred to `-analyzer-config silence-checkers=core.DivideZero`.

Reviewed By: NoQ, Szelethus

Differential Revision: https://reviews.llvm.org/D66042

llvm-svn: 369078
2019-08-16 01:53:14 +00:00
Kristof Umann e8df27d925 [analyzer] Add a new frontend flag to display all checker options
Add the new frontend flag -analyzer-checker-option-help to display all
checker/package options.

Differential Revision: https://reviews.llvm.org/D57858

llvm-svn: 361552
2019-05-23 20:47:28 +00:00
Kristof Umann 83cc1b35d1 [analyzer] Remove the default value arg from getChecker*Option
Since D57922, the config table contains every checker option, and it's default
value, so having it as an argument for getChecker*Option is redundant.

By the time any of the getChecker*Option function is called, we verified the
value in CheckerRegistry (after D57860), so we can confidently assert here, as
any irregularities detected at this point must be a programmer error. However,
in compatibility mode, verification won't happen, so the default value must be
restored.

This implies something else, other than adding removing one more potential point
of failure -- debug.ConfigDumper will always contain valid values for
checker/package options!

Differential Revision: https://reviews.llvm.org/D59195

llvm-svn: 361042
2019-05-17 15:52:13 +00:00
Kristof Umann 30b2307da8 [analyzer] Insert checker options into AnalyzerOption::ConfigTable
The more entries we have in AnalyzerOptions::ConfigTable, the more helpful
debug.ConfigDumper is. With this patch, I'm pretty confident that it'll now emit
the entire state of the analyzer, minus the frontend flags.

It would be nice to reserve the config table specifically to checker options
only, as storing the regular analyzer configs is kinda redundant.

Differential Revision: https://reviews.llvm.org/D57922

llvm-svn: 361006
2019-05-17 09:29:44 +00:00
Kristof Umann 9f7fc9838a [analyzer] Don't display implementation checkers under -analyzer-checker-help, but do under the new flag -analyzer-checker-help-hidden
During my work on analyzer dependencies, I created a great amount of new
checkers that emitted no diagnostics at all, and were purely modeling some
function or another.

However, the user shouldn't really disable/enable these by hand, hence this
patch, which hides these by default. I intentionally chose not to hide alpha
checkers, because they have a scary enough name, in my opinion, to cause no
surprise when they emit false positives or cause crashes.

The patch introduces the Hidden bit into the TableGen files (you may remember
it before I removed it in D53995), and checkers that are either marked as
hidden, or are in a package that is marked hidden won't be displayed under
-analyzer-checker-help. -analyzer-checker-help-hidden, a new flag meant for
developers only, displays the full list.

Differential Revision: https://reviews.llvm.org/D60925

llvm-svn: 359720
2019-05-01 19:56:47 +00:00
Kristof Umann 088b1c9cdc [analyzer] Enable subcheckers to possess checker options
Under the term "subchecker", I mean checkers that do not have a checker class on
their own, like unix.MallocChecker to unix.DynamicMemoryModeling.

Since a checker object was required in order to retrieve checker options,
subcheckers couldn't possess options on their own.

This patch is also an excuse to change the argument order of getChecker*Option,
it always bothered me, now it resembles the actual command line argument
(checkername:option=value).

Differential Revision: https://reviews.llvm.org/D57579

llvm-svn: 355297
2019-03-04 00:28:16 +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
Aaron Ballman 2f234cbfb0 Allow direct navigation to static analysis checker documentation through SARIF exports.
This adds anchors to all of the documented checks so that you can directly link to a check by a stable name. This is useful because the SARIF file format has a field for specifying a URI to documentation for a rule and some viewers, like CodeSonar, make use of this information. These links are then exposed through the SARIF exporter.

llvm-svn: 349812
2018-12-20 20:20:20 +00:00
Kristof Umann 549f9cd46f [analyzer] Evaluate all non-checker config options before analysis
In earlier patches regarding AnalyzerOptions, a lot of effort went into
gathering all config options, and changing the interface so that potential
misuse can be eliminited.

Up until this point, AnalyzerOptions only evaluated an option when it was
querried. For example, if we had a "-no-false-positives" flag, AnalyzerOptions
would store an Optional field for it that would be None up until somewhere in
the code until the flag's getter function is called.

However, now that we're confident that we've gathered all configs, we can
evaluate off of them before analysis, so we can emit a error on invalid input
even if that prticular flag will not matter in that particular run of the
analyzer. Another very big benefit of this is that debug.ConfigDumper will now
show the value of all configs every single time.

Also, almost all options related class have a similar interface, so uniformity
is also a benefit.

The implementation for errors on invalid input will be commited shorty.

Differential Revision: https://reviews.llvm.org/D53692

llvm-svn: 348031
2018-11-30 20:44:00 +00:00
Kristof Umann 35fc356fec [analyzer] Drastically simplify the tblgen files used for checkers
Interestingly, only about the quarter of the emitter file is used, the DescFile
entry hasn't ever been touched [1], and the entire concept of groups is a
mystery, so I removed them.

[1] http://lists.llvm.org/pipermail/cfe-dev/2018-October/059664.html

Differential Revision: https://reviews.llvm.org/D53995

llvm-svn: 346680
2018-11-12 17:49:51 +00:00
Kristof Umann 0a1f91c80c [analyzer] Restrict AnalyzerOptions' interface so that non-checker objects have to be registered
One of the reasons why AnalyzerOptions is so chaotic is that options can be
retrieved from the command line whenever and wherever. This allowed for some
options to be forgotten for a looooooong time. Have you ever heard of
"region-store-small-struct-limit"? In order to prevent this in the future, I'm
proposing to restrict AnalyzerOptions' interface so that only checker options
can be retrieved without special getters. I would like to make every option be
accessible only through a getter, but checkers from plugins are a thing, so I'll
have to figure something out for that.

This also forces developers who'd like to add a new option to register it
properly in the .def file.

This is done by

* making the third checker pointer parameter non-optional, and checked by an
  assert to be non-null.
* I added new, but private non-checkers option initializers, meant only for
  internal use,
* Renamed these methods accordingly (mind the consistent name for once with
  getBooleanOption!):
  - getOptionAsString -> getCheckerStringOption,
  - getOptionAsInteger -> getCheckerIntegerOption
* The 3 functions meant for initializing data members (with the not very
  descriptive getBooleanOption, getOptionAsString and getOptionAsUInt names)
  were renamed to be overloads of the getAndInitOption function name.
* All options were in some way retrieved via getCheckerOption. I removed it, and
  moved the logic to getStringOption and getCheckerStringOption. This did cause
  some code duplication, but that's the only way I could do it, now that checker
  and non-checker options are separated. Note that the non-checker version
  inserts the new option to the ConfigTable with the default value, but the
  checker version only attempts to find already existing entries. This is how
  it always worked, but this is clunky and I might end reworking that too, so we
  can eventually get a ConfigTable that contains the entire configuration of the
  analyzer.

Differential Revision: https://reviews.llvm.org/D53483

llvm-svn: 346113
2018-11-05 03:50:37 +00:00
Kristof Umann e390633d46 [analyzer][NFC] Collect all -analyzer-config options in a .def file
I'm in the process of refactoring AnalyzerOptions. The main motivation behind
here is to emit warnings if an invalid -analyzer-config option is given from the
command line, and be able to list them all.

In this patch, I'm moving all analyzer options to a def file, and move 2 enums
to global namespace.

Differential Revision: https://reviews.llvm.org/D53277

llvm-svn: 345986
2018-11-02 15:50:44 +00:00
Kristof Umann c83b0dda49 [analyzer][NFC] Fix some incorrect uses of -analyzer-config options
I'm in the process of refactoring AnalyzerOptions. The main motivation behind
here is to emit warnings if an invalid -analyzer-config option is given from
the command line, and be able to list them all.

In this patch, I found some flags that should've been used as checker options,
or have absolutely no mention of in AnalyzerOptions, or are nonexistent.

- NonLocalizedStringChecker now uses its "AggressiveReport" flag as a checker
    option
- lib/StaticAnalyzer/Frontend/ModelInjector.cpp now accesses the "model-path"
    option through a getter in AnalyzerOptions
- -analyzer-config path-diagnostics-alternate=false is not a thing, I removed it,
- lib/StaticAnalyzer/Checkers/AllocationDiagnostics.cpp and
    lib/StaticAnalyzer/Checkers/AllocationDiagnostics.h are weird, they actually
    only contain an option getter. I deleted them, and fixed RetainCountChecker
    to get it's "leak-diagnostics-reference-allocation" option as a checker option,
- "region-store-small-struct-limit" has a proper getter now.

Differential Revision: https://reviews.llvm.org/D53276

llvm-svn: 345985
2018-11-02 15:48:10 +00:00
Kristof Umann 7d6d9eb688 [analyzer][PlistMacroExpansion] Part 1.: New expand-macros flag
This is the first part of the implementation of the inclusion of macro
expansions into the plist output. It adds a new flag that adds a new
"macro_expansions" entry to each report that has PathDiagnosticPieces that were
expanded from a macro. While there's an entry for each macro expansion, both
the name of the macro and what it expands to is missing, and will be implemented
in followup patches.

Differential Revision: https://reviews.llvm.org/D52742

llvm-svn: 345724
2018-10-31 14:54:27 +00:00
Kristof Umann ca8a05ac34 [analyzer][NFC] Fix inconsistencies in AnalyzerOptions
I'm in the process of refactoring AnalyzerOptions. The main motivation behind
here is to emit warnings if an invalid -analyzer-config option is given from the
command line, and be able to list them all.

This first NFC patch contains small modifications to make AnalyzerOptions.cpp a
little more consistent.

Differential Revision: https://reviews.llvm.org/D53274

llvm-svn: 344870
2018-10-21 18:19:32 +00:00
George Karpenkov d1dd5c3a88 [analyzer] Experiment with an iteration order only based on location, and not using the stack frame
Differential Revision: https://reviews.llvm.org/D53058

llvm-svn: 344313
2018-10-11 22:59:59 +00:00
George Karpenkov a393e68b27 [analyzer] Move analyzer-eagerly-assume to AnalyzerOptions, enable by default
Differential Revision: https://reviews.llvm.org/D51251

llvm-svn: 340963
2018-08-29 20:29:17 +00:00
Adam Balogh dcde8acc32 [Analyzer] Quick Fix for exponential execution time when simpilifying complex additive expressions
Patch https://reviews.llvm.org/rC329780 not only rearranges comparisons but
also binary expressions. This latter behavior is not protected by the analyzer
option. Hower, since no complexity threshold is enforced to the symbols this
may result in exponential execution time if the expressions are too complex:
https://bugs.llvm.org/show_bug.cgi?id=38208. For a quick fix we extended the
analyzer option to also cover the additive cases.

This is only a temporary fix, the final solution should be enforcing the
complexity threshold to the symbols.

Differential Revision: https://reviews.llvm.org/D49536

llvm-svn: 337678
2018-07-23 10:50:20 +00:00
Mikhail R. Gadelha ddd4229cc4 [analyzer] Memoize complexity of SymExpr
Summary:
This patch introduces a new member to SymExpr, which stores the symbol complexity, avoiding recalculating it every time computeComplexity() is called.

Also, increase the complexity of conjured Symbols by one, so it's clear that it has a greater complexity than its underlying symbols.

Reviewers: NoQ, george.karpenkov

Reviewed By: NoQ, george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D49232

llvm-svn: 337472
2018-07-19 17:03:12 +00:00
Mikhail R. Gadelha e254b0f8c7 [analyzer] Fix constraint being dropped when analyzing a program without taint tracking enabled
Summary:
This patch removes the constraint dropping when taint tracking is disabled.

It also voids the crash reported in D28953 by treating a SymSymExpr with non pointer symbols as an opaque expression.

Updated the regressions and verifying the big projects now; I'll update here when they're done.

Based on the discussion on the mailing list and the patches by @ddcc.

Reviewers: george.karpenkov, NoQ, ddcc, baloghadamsoftware

Reviewed By: george.karpenkov

Subscribers: delcypher, llvm-commits, rnkovacs, xazax.hun, szepet, a.sidorin, ddcc

Differential Revision: https://reviews.llvm.org/D48650

llvm-svn: 337167
2018-07-16 13:14:46 +00:00
Mikhail R. Gadelha 237d42bfa5 [analyzer] Add option to set maximum symbol complexity threshold
Summary:
This adds an option, max-symbol-complexity, so an user can set the maximum symbol complexity threshold.

Note that the current behaviour is equivalent to max complexity = 0, when taint analysis is not enabled and tests show that in a number of tests, having complexity = 25 yields the same results as complexity = 10000.

This patch was extracted and modified from Dominic Chen's patch, D35450.

Reviewers: george.karpenkov, NoQ, ddcc

Reviewed By: george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D49093

llvm-svn: 336671
2018-07-10 13:46:05 +00:00
Artem Dergachev ff267df0de [CFG] [analyzer] Add construction contexts that explain pre-C++17 copy elision.
Before C++17 copy elision was optional, even if the elidable copy/move
constructor had arbitrary side effects. The elidable constructor is present
in the AST, but marked as elidable.

In these cases CFG now contains additional information that allows its clients
to figure out if a temporary object is only being constructed so that to pass
it to an elidable constructor. If so, it includes a reference to the elidable
constructor's construction context, so that the client could elide the
elidable constructor and construct the object directly at its final destination.

Differential Revision: https://reviews.llvm.org/D47616

llvm-svn: 335795
2018-06-28 00:04:54 +00:00
Mikhail R. Gadelha 8cd2ee1f24 [analyzer] False positive refutation with Z3
Summary: This is a prototype of a bug reporter visitor that invalidates bug reports by re-checking constraints of certain states on the bug path using the Z3 constraint manager backend. The functionality is available under the `crosscheck-with-z3` analyzer config flag.

Reviewers: george.karpenkov, NoQ, dcoughlin, rnkovacs

Reviewed By: george.karpenkov

Subscribers: rnkovacs, NoQ, george.karpenkov, dcoughlin, xbolva00, ddcc, mikhail.ramalho, MTC, fhahn, whisperity, baloghadamsoftware, szepet, a.sidorin, gsd, dkrupp, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D45517

llvm-svn: 333903
2018-06-04 14:40:44 +00:00
Adam Balogh 2bbccca9f7 [Analyzer] SValBuilder Comparison Rearrangement (with Restrictions and Analyzer Option)
Since the range-based constraint manager (default) is weak in handling comparisons where symbols are on both sides it is wise to rearrange them to have symbols only on the left side. Thus e.g. A + n >= B + m becomes A - B >= m - n which enables the constraint manager to store a range m - n .. MAX_VALUE for the symbolic expression A - B. This can be used later to check whether e.g. A + k == B + l can be true, which is also rearranged to A - B == l - k so the constraint manager can check whether l - k is in the range (thus greater than or equal to m - n).

The restriction in this version is the the rearrangement happens only if both the symbols and the concrete integers are within the range [min/4 .. max/4] where min and max are the minimal and maximal values of their type.

The rearrangement is not enabled by default. It has to be enabled by using -analyzer-config aggressive-relational-comparison-simplification=true.

Co-author of this patch is Artem Dergachev (NoQ).

Differential Revision: https://reviews.llvm.org/D41938

llvm-svn: 329780
2018-04-11 06:21:12 +00:00
Artem Dergachev 3761e7a4be [analyzer] Enable temporary object destructor inlining by default.
When a temporary is constructed with a proper construction context, it should
be safe to inline the destructor. We have added suppressions for some of the
common false positives caused by such inlining, so there should be - and from my
observations there indeed is - more benefit than harm from enabling destructor
inlining.

Differential Revision: https://reviews.llvm.org/D44721

llvm-svn: 328258
2018-03-22 22:05:53 +00:00
Maxim Ostapenko debca45e45 [analyzer] Add scope information to CFG
This patch adds two new CFG elements CFGScopeBegin and CFGScopeEnd that indicate
when a local scope begins and ends respectively. We use first VarDecl declared
in a scope to uniquely identify it and add CFGScopeBegin and CFGScopeEnd elements
into corresponding basic blocks.

Differential Revision: https://reviews.llvm.org/D16403

llvm-svn: 327258
2018-03-12 12:26:15 +00:00
Eugene Zelenko 6a58efdf76 [StaticAnalyzer] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 326856
2018-03-07 00:17:48 +00:00
Artem Dergachev 61199443fe [analyzer] Enable cfg-temporary-dtors by default.
Don't enable c++-temp-dtor-inlining by default yet, due to this reference
counting pointe problem.

Otherwise the new mode seems stable and allows us to incrementally fix C++
problems in much less hacky ways.

Differential Revision: https://reviews.llvm.org/D43804

llvm-svn: 326461
2018-03-01 18:53:13 +00:00
Ilya Biryukov 8b9b3bd07c Resubmit [analyzer] Support for naive cross translation unit analysis
Originally submitted as r326323 and r326324.
Reverted in r326432.

Reverting the commit was a mistake.
The breakage was due to invalid build files in our internal buildsystem,
CMakeLists did not have any cyclic dependencies.

llvm-svn: 326439
2018-03-01 14:54:16 +00:00
Ilya Biryukov d49e75afbd Revert "[analyzer] Support for naive cross translation unit analysis"
Also revert "[analyzer] Fix a compiler warning"
This reverts commits r326323 and r326324.

Reason: the commits introduced a cyclic dependency in the build graph.
This happens to work with cmake, but breaks out internal integrate.

llvm-svn: 326432
2018-03-01 12:43:39 +00:00
Gabor Horvath eb0584bee4 [analyzer] Support for naive cross translation unit analysis
The aim of this patch is to be minimal to enable incremental development of
the feature on the top of the tree. This patch should be an NFC when the
feature is turned off. It is turned off by default and still considered as
experimental.

Technical details are available in the EuroLLVM Talk: 
http://llvm.org/devmtg/2017-03//2017/02/20/accepted-sessions.html#7

Note that the initial prototype was done by A. Sidorin et al.: http://lists.llvm.org/pipermail/cfe-dev/2015-October/045730.html

Contributions to the measurements and the new version of the code: Peter Szecsi, Zoltan Gera, Daniel Krupp, Kareem Khazem.

Differential Revision: https://reviews.llvm.org/D30691

llvm-svn: 326323
2018-02-28 13:23:10 +00:00
George Karpenkov 06b7bd61f4 [analyzer] Switch the default exploration strategy to priority queue based on coverage
After the investigation it seems safe to flip the switch.

Differential Revision: https://reviews.llvm.org/D43782

llvm-svn: 326157
2018-02-27 01:31:56 +00:00
George Karpenkov 6dcbc1dbb3 [analyzer] Exploration strategy prioritizing unexplored nodes first
See D42775 for discussion.  Turns out, just exploring nodes which
weren't explored first is not quite enough, as e.g. the first quick
traversal resulting in a report can mark everything as "visited", and
then subsequent traversals of the same region will get all the pitfalls
of DFS.
Priority queue-based approach in comparison shows much greater
increase in coverage and even performance, without sacrificing memory.

Differential Revision: https://reviews.llvm.org/D43354

llvm-svn: 326136
2018-02-26 22:14:18 +00:00
Artem Dergachev 661ab34a31 [analyzer] Compute the correct this-region for temporary destructors.
Inline them if possible - a separate flag is added to control this.
The whole thing is under the cfg-temporary-dtors flag, off by default so far.

Temporary destructors are called at the end of full-expression. If the
temporary is lifetime-extended, automatic destructors kick in instead,
which are not addressed in this patch, and normally already work well
modulo the overally broken support for lifetime extension.

The patch operates by attaching the this-region to the CXXBindTemporaryExpr in
the program state, and then recalling it during destruction that was triggered
by that CXXBindTemporaryExpr. It has become possible because
CXXBindTemporaryExpr is part of the construction context since r325210.

Differential revision: https://reviews.llvm.org/D43104

llvm-svn: 325282
2018-02-15 19:17:44 +00:00
George Karpenkov 1235a63df5 [analyzer] Exploration strategy prioritizing unexplored coverage first
See reviews.llvm.org/M1 for evaluation, and
lists.llvm.org/pipermail/cfe-dev/2018-January/056718.html for
discussion.

Differential Revision: https://reviews.llvm.org/D42775

llvm-svn: 324956
2018-02-12 22:39:57 +00:00
George Karpenkov 5a755b333d [analyzer] Serialize statistics to plist when serialize-stats=true is set
Differential Revision: https://reviews.llvm.org/D43131

llvm-svn: 324793
2018-02-10 01:49:20 +00:00
Artem Dergachev 41ffb30716 [CFG] Add extra context to C++ constructor statement elements.
This patch adds a new CFGStmt sub-class, CFGConstructor, which replaces
the regular CFGStmt with CXXConstructExpr in it whenever the CFG has additional
information to provide regarding what sort of object is being constructed.

It is useful for figuring out what memory is initialized in client of the
CFG such as the Static Analyzer, which do not operate by recursive AST
traversal, but instead rely on the CFG to provide all the information when they
need it. Otherwise, the statement that triggers the construction and defines
what memory is being initialized would normally occur after the
construct-expression, and the client would need to peek to the next CFG element
or use statement parent map to understand the necessary facts about
the construct-expression.

As a proof of concept, CFGConstructors are added for new-expressions
and the respective test cases are provided to demonstrate how it works.

For now, the only additional data contained in the CFGConstructor element is
the "trigger statement", such as new-expression, which is the parent of the
constructor. It will be significantly expanded in later commits. The additional
data is organized as an auxiliary structure - the "construction context",
which is allocated separately from the CFGElement.

Differential Revision: https://reviews.llvm.org/D42672

llvm-svn: 324668
2018-02-08 22:58:15 +00:00
George Karpenkov 711091c3c8 Remove the change which accidentally crept in into the cherry-pick
llvm-svn: 324050
2018-02-02 02:14:33 +00:00
George Karpenkov 34090db516 [analyzer] Expose exploration strategy through analyzer options.
Differential Revision: https://reviews.llvm.org/D42774

llvm-svn: 324049
2018-02-02 02:01:55 +00:00
Artem Dergachev a396df3472 [analyzer] Enable c++-allocator-inlining by default.
This allows the analyzer to analyze ("inline") custom operator new() calls and,
even more importantly, inline constructors of objects that were allocated
by any operator new() - not necessarily a custom one.

All changes in the tests in the current commit are intended improvements,
even if they didn't carry any explicit FIXME flag.

It is possible to restore the old behavior via

  -analyzer-config c++-allocator-inlining=false

(this flag is supported by scan-build as well, and it can be into a clang
--analyze invocation via -Xclang .. -Xclang ..). There is no intention to
remove the old behavior for now.

Differential Revision: https://reviews.llvm.org/D42219
rdar://problem/12180598

llvm-svn: 323373
2018-01-24 20:59:40 +00:00
Peter Szecsi 999a25ff72 [CFG] Add LoopExit information to CFG
This patch introduces a new CFG element CFGLoopExit that indicate when a loop
ends. It does not deal with returnStmts yet (left it as a TODO).
It hidden behind a new analyzer-config flag called cfg-loopexit (false by
default).
Test cases added.

The main purpose of this patch right know is to make loop unrolling and loop
widening easier and more efficient. However, this information can be useful for
future improvements in the StaticAnalyzer core too.

Differential Revision: https://reviews.llvm.org/D35668

llvm-svn: 311235
2017-08-19 11:19:16 +00:00
Peter Szecsi 657ac14816 [StaticAnalyzer] Completely unrolling specific loops with known bound option
This feature allows the analyzer to consider loops to completely unroll.
New requirements/rules (for unrolling) can be added easily via ASTMatchers.

Right now it is hidden behind a flag, the aim is to find the correct heuristic
and create a solution which results higher coverage % and more precise
analysis, thus can be enabled by default.

Right now the blocks which belong to an unrolled loop are marked by the
LoopVisitor which adds them to the ProgramState.
Then whenever we encounter a CFGBlock in the processCFGBlockEntrance which is
marked then we skip its investigating. That means, it won't be considered to
be visited more than the maximal bound for visiting since it won't be checked.

llvm-svn: 309006
2017-07-25 19:23:23 +00:00
Peter Szecsi 58a8b6b4af Revert "[StaticAnalyzer] Completely unrolling specific loops with known bound option"
Revert r308561 and r308558.

Clang-ppc64be-linux seems to crash while running the test cases.

llvm-svn: 308592
2017-07-20 07:35:11 +00:00
Peter Szecsi cb387b11df This feature allows the analyzer to consider loops to completely unroll. New
requirements/rules (for unrolling) can be added easily via ASTMatchers.

The current implementation is hidden behind a flag.

Right now the blocks which belong to an unrolled loop are marked by the 
LoopVisitor which adds them to the ProgramState. Then whenever we encounter a
CFGBlock in the processCFGBlockEntrance which is marked then we skip its
investigating. That means, it won't be considered to be visited more than the
maximal bound for visiting since it won't be checked.

Differential Revision: https://reviews.llvm.org/D34260

llvm-svn: 308558
2017-07-19 23:50:00 +00:00
Matthias Gehre 351c218d15 CFG: Add CFGElement for automatic variables that leave the scope
Summary:
This mimics the implementation for the implicit destructors. The
generation of this scope leaving elements is hidden behind
a flag to the CFGBuilder, thus it should not affect existing code.

Currently, I'm missing a test (it's implicitly tested by the clang-tidy
lifetime checker that I'm proposing).
I though about a test using debug.DumpCFG, but then I would
have to add an option to StaticAnalyzer/Core/AnalyzerOptions
to enable the scope leaving CFGElement,
which would only be useful to that particular test.

Any other ideas how I could make a test for this feature?

Reviewers: krememek, jordan_rose

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D15031

llvm-svn: 307759
2017-07-12 07:04:19 +00:00
Artem Dergachev 4a084cfde7 [analyzer] Bump a few default performance thresholds.
This makes the analyzer around 10% slower by default,
allowing it to find deeper bugs.

Default values for the following -analyzer-config change:
max-nodes: 150000 -> 225000;
max-inlinable-size: 50 -> 100.

rdar://problem/32539666
Differential Revision: https://reviews.llvm.org/D34277

llvm-svn: 305900
2017-06-21 11:29:35 +00:00
Anna Zaks ae4772140f [analyzer] Turn suppress-c++-stdlib on by default
We have several reports of false positives coming from libc++. For example,
there are reports of false positives in std::regex, std::wcout, and also
a bunch of issues are reported in https://reviews.llvm.org/D30593. In many
cases, the analyzer trips over the complex libc++ code invariants. Let's turn
off the reports coming from these headers until we can re-evalate the support.

We can turn this back on once we individually suppress all known false
positives and perform deeper evaluation on large codebases that use libc++.
We'd also need to commit to doing these evaluations regularly as libc++
headers change.

Differential Revision: https://reviews.llvm.org/D30798

llvm-svn: 297429
2017-03-10 00:33:19 +00:00