Commit Graph

18 Commits

Author SHA1 Message Date
Artem Dergachev 99b94f29ac [analyzer] LoopUnrolling: fix crash when a parameter is a loop counter.
When loop counter is a function parameter "isPossiblyEscaped" will not find
the variable declaration which lead to hitting "llvm_unreachable".
Parameters of reference type should be escaped like global variables;
otherwise treat them as unescaped.

Patch by Abbas Sabra!

Differential Revision: https://reviews.llvm.org/D80171
2020-05-22 16:14:48 +03:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Artem Dergachev 6b85f8e99b [analyzer] NFC: Move getStmt() and createEndOfPath() out of PathDiagnostic.
These static functions deal with ExplodedNodes which is something we don't want
the PathDiagnostic interface to know anything about, as it's planned to be
moved out of libStaticAnalyzerCore.

Differential Revision: https://reviews.llvm.org/D67382

llvm-svn: 371659
2019-09-11 20:54:21 +00:00
Artem Dergachev 4e53032d9b [CFG] NFC: Remove implicit conversion from CFGTerminator to Stmt *.
Turn it into a variant class instead. This conversion does indeed save some code
but there's a plan to add support for more kinds of terminators that aren't
necessarily based on statements, and with those in mind it becomes more and more
confusing to have CFGTerminators implicitly convertible to a Stmt *.

Differential Revision: https://reviews.llvm.org/D61814

llvm-svn: 361586
2019-05-24 01:34:22 +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
Henry Wong f717d4795a [analyzer] Unroll the loop when it has a unsigned counter.
Summary:
The original implementation in the `LoopUnrolling.cpp` didn't consider the case where the counter is unsigned. This case is only handled in `simpleCondition()`, but this is not enough, we also need to deal with the unsinged counter with the counter initialization.

Since `IntegerLiteral` is `signed`, there is a `ImplicitCastExpr<IntegralCast>` in `unsigned counter = IntergerLiteral`. This patch add the `ignoringParenImpCasts()` in the `IntegerLiteral` matcher.

Reviewers: szepet, a.sidorin, NoQ, george.karpenkov

Reviewed By: szepet, george.karpenkov

Subscribers: xazax.hun, rnkovacs, cfe-commits, MTC

Differential Revision: https://reviews.llvm.org/D45086

llvm-svn: 328919
2018-03-31 12:46:46 +00:00
Peter Szecsi 4c87d233b0 [analyzer] LoopUnrolling: update the matched assignment operators
Extended the matched assignment operators when checking for bound changes in a body of the loop by using the freshly added isAssignmentOperator matcher.
This covers all the (current) possible assignments, tests added as well.

Differential Revision: https://reviews.llvm.org/D38921

llvm-svn: 328619
2018-03-27 12:16:56 +00:00
Peter Szecsi 1496d188a0 [analyzer] LoopUnrolling: check the bitwidth of the used numbers (pr34943)
The loop unrolling feature aims to track the maximum possible steps a loop can
make. In order to implement this, it investigates the initial value of the 
counter variable and the bound number. (It has to be known.)
These numbers are used as llvm::APInts, however, it was not checked if their
bitwidths are the same which lead to some crashes.
This revision solves this problem by extending the "shorter" one (to the length
of the "longer" one).
For the detailed bug report, see: https://bugs.llvm.org/show_bug.cgi?id=34943

Differential Revision: https://reviews.llvm.org/D38922

llvm-svn: 316830
2017-10-28 12:19:08 +00:00
Peter Szecsi 0db84863d0 [StaticAnalyzer] LoopUnrolling: Keep track the maximum number of steps for each loop
This way the unrolling can be restricted for loops which will take at most a
given number of steps. It is defined as 128 in this patch and it seems to have
a good number for that purpose.

Differential Revision: https://reviews.llvm.org/D37181

llvm-svn: 311883
2017-08-28 10:50:28 +00:00
Peter Szecsi d0604acd8e [StaticAnalyzer] LoopUnrolling: Excluding loops which splits the state
Added check if the execution of the last step of the given unrolled loop has
generated more branches. If yes, than treat it as a normal (non-unrolled) loop
in the remaining part of the analysis.

Differential Revision: https://reviews.llvm.org/D36962

llvm-svn: 311881
2017-08-28 10:34:50 +00:00
Peter Szecsi d91554bc91 [StaticAnalyzer] LoopUnrolling fixes
1. The LoopUnrolling feature needs the LoopExit included in the CFG so added this
dependency via the config options
2. The LoopExit element can be encountered even if we haven't encountered the 
block of the corresponding LoopStmt. So the asserts were not right.
3. If we are caching out the Node then we get a nullptr from generateNode which
case was not handled.


Differential Revision: https://reviews.llvm.org/D37103

llvm-svn: 311880
2017-08-28 10:21:24 +00:00
Peter Szecsi 3c3e1b0b54 [StaticAnalyzer] LoopUnrolling: Track a LoopStack in order to completely unroll specific loops
The LoopExit CFG information provides the opportunity to not mark the loops but
having a stack which tracks if a loop is unrolled or not. So in case of
simulating a loop we just add it and the information if it meets the
requirements to be unrolled to the top of the stack.

Differential Revision: https://reviews.llvm.org/D35684

llvm-svn: 311346
2017-08-21 16:32:57 +00:00
Peter Szecsi 8de103f2f0 [StaticAnalyzer] LoopUnrolling: Exclude cases where the counter is escaped before the loop
Adding escape check for the counter variable of the loop.
It is achieved by jumping back on the ExplodedGraph to its declStmt.

Differential Revision: https://reviews.llvm.org/D35657

llvm-svn: 311234
2017-08-19 10:24:52 +00:00
Peter Szecsi d39a7ed1ac [StaticAnalyzer] LoopUnrolling - Attempt #2 to fix a crash in r309006.
llvm-svn: 309061
2017-07-25 23:49:16 +00:00
Peter Szecsi 4601ebaaf4 [StaticAnalyzer] LoopUnrolling - Attempt to fix a crash in r309006.
llvm-svn: 309036
2017-07-25 21:54:58 +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 251a611cd6 [StaticAnalyzer] Completely unrolling specific loops with known bound option
Missing files added to rL308558.

llvm-svn: 308561
2017-07-20 00:05:25 +00:00