Commit Graph

36 Commits

Author SHA1 Message Date
Ted Kremenek f2819198d2 Refine IdempotentOperationChecker::PathWasCompletelyAnalyzed() to also check
BlockEdges, BlockEntrances, and BlockExits for the target block value.

llvm-svn: 118984
2010-11-13 05:12:26 +00:00
Ted Kremenek cf9dbe9c20 Teach IdempotentOperations::PathWasCompletelyAnalyzed to also consider items remaining in the
worklist that could have impacted the evaluation of a block.

Fixes <rdar://problem/8663596>.

llvm-svn: 118983
2010-11-13 05:04:52 +00:00
Ted Kremenek 310c5a8e31 Don't flag idempotent '+' or '-' warnings for pointer arithmetic (typically false positives).
Fixes <rdar://problem/8601243>.

llvm-svn: 117635
2010-10-29 01:06:54 +00:00
Tom Care 0bd3431a5e Revert r114244 since it breaks a test in Analysis.
llvm-svn: 114246
2010-09-18 00:17:17 +00:00
Tom Care 0f99e64305 IdempotentOperationChecker no longer reports errors that are post-dominated by a sink. This fixes some false positives that were flagged because a path was incomplete (usually in a loop).
llvm-svn: 114244
2010-09-18 00:06:34 +00:00
Ted Kremenek 5f256da834 Rename GRState::getSVal() -> getRawSVal() and getSimplifiedSVal() -> getSVal().
The end result is now we eagarly constant-fold symbols in the analyzer that are perfectly constrained
to be a constant value.  This allows us to recover some path-sensitivity in some cases by lowering
the required level of reasoning power needed to evaluate some expressions.

The net win from this change is that the false positive in PR 8015 is fixed, and we also
find more idempotent operations bugs.

We do, however, regress with the BugReporterVisitors, which need to be modified to understand
this constant folding (and look past it).  This causes some diagnostic regressions in plist-output.m
which will get addressed in a future patch.  plist-output.m is now marked XFAIL, while
plist-output-alternate.m now tests that the plist output is working, but with the suboptimal
diagnostics.  This second test file will eventually be removed.

llvm-svn: 113477
2010-09-09 07:13:00 +00:00
Tom Care 68df12f0c4 Simplified reachability checking in IdempotentOperationChecker and added a helper function for path display.
- Created private class CFGReachabilityAnalysis, which provides cached reachability lookups in the CFG
- Simplified PathWasCompletelyAnalyzed to use the new reachability class
- Added getLastRelevantNodes function for future use with path displaying in BugReporter

llvm-svn: 113465
2010-09-09 02:04:52 +00:00
Tom Care bc9eaef24c Re-enabled truncation/extension checking in IdempotentOperationChecker and added a test case.
llvm-svn: 113269
2010-09-07 20:27:56 +00:00
Chris Lattner 3dd48bd169 "I see dead code". IdempotentOperationChecker::isTruncationExtensionAssignment
should probably be removed if it has no purpose, but I just #if'd it out
in case it's usefulIdempotentOperationChecker::isTruncationExtensionAssignment
should probably be removed if it has no purpose, but I just #if'd it out
in case it's useful

llvm-svn: 112949
2010-09-03 04:34:38 +00:00
Tom Care 796ed50433 Reapply 112850 and 112839 with a constructor for the BinaryOperatorData struct. Clang would zero out the enum and pointer in the struct in some conditions, but GCC would never zero out the values.
llvm-svn: 112909
2010-09-02 23:30:22 +00:00
Tom Care 9fbfeea05b Reverting 112850 and 112839 due to test failures on some systems
llvm-svn: 112857
2010-09-02 20:58:38 +00:00
Tom Care a25b273a5b Fixed broken build with GCC
llvm-svn: 112850
2010-09-02 19:00:08 +00:00
Tom Care 1ce2faca05 Improved error reporting in IdempotentOperationChecker
- SourceRange highlighting is only given for the relevant side of the operator (assignments give both)
- Added PostVisitBinaryOperator hook to retrieve the ExplodedNode for an operator
- Added a BugReporterVisitor to display the last store to every VarDecl in a Stmt
- Changed bug reporting to use the new BugReporterVisitor

llvm-svn: 112839
2010-09-02 17:49:20 +00:00
Tom Care 9026d4b488 Adjusted the semantics of assign checking in IdempotentOperationChecker
- Fixed a regression where assigning '0' would be reported
- Changed the way self assignments are filtered to allow constant testing
- Added a test case for assign ops
- Fixed one test case where a function pointer was not considered constant
- Fixed test cases relating to 0 assignment

llvm-svn: 112501
2010-08-30 19:25:43 +00:00
Tom Care 71cc9d886a Added checking of (x == x) and (x != x) to IdempotentOperationChecker and updated test cases flagged by it.
llvm-svn: 112313
2010-08-27 22:50:47 +00:00
Tom Care c29c91aaaa Fix bug in IdempotentOperationChecker where an assumption would not get updated properly.
llvm-svn: 112309
2010-08-27 22:35:28 +00:00
John McCall e302792b61 GCC didn't care for my attempt at API compatibility, so brute-force everything
to the new constants.

llvm-svn: 112047
2010-08-25 11:45:40 +00:00
Tom Care a460311710 Improvements to IdempotentOperationChecker and its use of PseudoConstantAnalysis
- Added wasReferenced function to PseudoConstantAnalysis to determine if a variable was ever referenced in a function (outside of a self-assignment)
- BlockDeclRefExpr referenced variables are now explicitly added to the non-constant list
- Remove unnecessary ignore of implicit casts
- Generalized parameter self-assign detection to detect deliberate self-assigns of variables to avoid unused variable warnings
- Updated test cases with deliberate self-assignments
- Fixed bug with C++ references and pseudoconstants
- Added test case for C++ references and pseudoconstants

llvm-svn: 111965
2010-08-24 21:09:07 +00:00
Tom Care e332c3b762 Several small changes to PseudoConstantAnalysis and the way IdempotentOperationChecker uses it.
- Psuedo -> Pseudo (doh...)
- C++ reference support
- Added pseudoconstant test case for __block vars
- Separated out static local checking from pseudoconstant analysis and generalized to non-local checking
- Added missing test cases for storage false positives

llvm-svn: 111832
2010-08-23 19:51:57 +00:00
Tom Care b9933f365e Added psuedo-constant analysis and integrated it into the false positive reduction stage in IdempotentOperationChecker.
- Renamed IdempotentOperationChecker::isConstant to isConstantOrPseudoConstant to better reflect the function
- Changed IdempotentOperationChecker::PreVisitBinaryOperator to only run 'CanVary' once on undefined assumptions
- Created new PsuedoConstantAnalysis class and added it to AnalysisContext
- Changed IdempotentOperationChecker to exploit the new analysis
- Updated tests with psuedo-constants
- Added check to IdempotentOperationChecker to see if a Decl is const qualified

llvm-svn: 111426
2010-08-18 21:17:24 +00:00
Tom Care c129cc18f0 Added basic psuedoconstant checking in IdempotentOperationChecker and fixed some test cases.
llvm-svn: 111190
2010-08-16 21:43:52 +00:00
Eli Friedman a2622dd266 Zap unused UnaryOperator::OffsetOf.
llvm-svn: 110996
2010-08-13 01:36:11 +00:00
Tom Care f8a9863df9 Improved IdempotentOperationChecker false positives and false negatives.
- Unfinished analysis may still report valid warnings if the path was completely analyzed
- New 'CanVary' heuristic to recursively determine if a subexpression has a varying element
- Updated test cases, including one known bug
- Exposed GRCoreEngine through GRExprEngine

llvm-svn: 110970
2010-08-12 22:45:47 +00:00
Tom Care 925501c548 Removed IdempotentOperationChecker from default analysis and returned back to a flag (-analyzer-check-idempotent-operations)
- Added IdempotentOperationChecker to experimental analyses for testing purposes
- Updated test cases to explictly call the checker

llvm-svn: 110482
2010-08-06 22:23:07 +00:00
Tom Care 44081fbc6c Changed GRExprEngine to pass down a reference to itself when checkers are doing postanalysis. This allows the checker to gather information about the state of the engine when it has finished.
- Exposed the worklist and BlockAborted flag in GRCoreEngine
- Changed postanalysis checkers to use the new infrastructure

llvm-svn: 110095
2010-08-03 01:55:07 +00:00
Ted Kremenek 8a4a2b14e8 'Assumption &A' gets default initialized to 'Possible' if it doesn't exist; no need to two
lookups in the hashtable.

llvm-svn: 110059
2010-08-02 20:33:02 +00:00
Tom Care 18f67e669f Uncomment unfinished work bailout in IdempotentOperationsChecker.
llvm-svn: 109893
2010-07-30 21:14:15 +00:00
Tom Care 76bdd685c2 Extracted out some useful common functions in IdempotentOperationChecker to their own CheckerHelpers file.
llvm-svn: 109560
2010-07-27 23:26:07 +00:00
Ted Kremenek 83b598c14f Finesse 'idempotent operations' analyzer issues to include the opcode of the binary operator for clearer error reporting. Also remove the 'Idempotent operation' prefix in messages; it's redundant since the bug type is the same.
llvm-svn: 109527
2010-07-27 18:49:08 +00:00
Ted Kremenek e5cc6a858a Put 'Idempotent operations' static analyzer issues in the 'Dead code' category.
llvm-svn: 109517
2010-07-27 17:52:52 +00:00
Ted Kremenek 8b9fd890e3 Fix APFloat assertion failure in IdempotentOperationChecker resulting in having
an APFloat with different "float semantics" than the compared float literal.

llvm-svn: 108590
2010-07-17 00:40:32 +00:00
Tom Care 826e6b4023 Improved false positive rate for the idempotent operations checker and moved it into the default path-sensitive analysis options.
- Added checks for static local variables, self assigned parameters, and truncating/extending self assignments
- Removed command line option (now default with --analyze)
- Updated test cases to pass with idempotent operation warnings

llvm-svn: 108550
2010-07-16 20:41:41 +00:00
Tom Care ca1f871ff8 Change explicit handling of impossible condition to call llvm_unreachable in IdempotentOperationChecker::PreVisitBinaryOperator.
llvm-svn: 107748
2010-07-07 01:27:17 +00:00
Chandler Carruth 509a9ce9da Silence an annoying GCC warning about use of an uninitialized variable. Even
making the other switch case unreachable, or sinking the 'continue' into it
doesn't silence this.

llvm-svn: 107745
2010-07-07 00:36:56 +00:00
Chandler Carruth dce439d11d Use 'llvm_unreachable' to mark impossible code paths so that GCC doesn't
consider them for warnings.

llvm-svn: 107741
2010-07-07 00:07:37 +00:00
Tom Care 3ff08a8e76 Added a path-sensitive idempotent operation checker (-analyzer-idempotent-operation). Finds idempotent and/or tautological operations in a path sensitive context, flagging operations that have no effect or a predictable effect.
Example:
{
int a = 1;
int b = 5;
int c = b / a; // a is 1 on all paths
}

- New IdempotentOperationChecker class
- Moved recursive Stmt functions in r107675 to IdempotentOperationChecker
- Minor refactoring of SVal to allow checking for any integer
- Added command line option for check
- Added basic test cases

llvm-svn: 107706
2010-07-06 21:43:29 +00:00