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2013-02-23Remove the CFGElement "Invalid" state.David Blaikie
Use Optional<CFG*> where invalid states were needed previously. In the one case where that's not possible (beginAutomaticObjDtorsInsert) just use a dummy CFGAutomaticObjDtor. Thanks for the help from Jordan Rose & discussion/feedback from Ted Kremenek and Doug Gregor. Post commit code review feedback on r175796 by Ted Kremenek. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175938 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-21Replace CFGElement llvm::cast support to be well-defined.David Blaikie
See r175462 for another example/more details. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175796 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-21Use None rather than Optional<T>() where possible.David Blaikie
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175705 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-20Include llvm::Optional in clang/Basic/LLVM.hDavid Blaikie
Post-commit CR feedback from Jordan Rose regarding r175594. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175679 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-19-Wuninitialized: warn about uninitialized values resulting from ?: that ↵Ted Kremenek
evaluate to lvalues (in C++). git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172875 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-12Remove useless 'llvm::' qualifier from names like StringRef and others that areDmitri Gribenko
brought into 'clang' namespace by clang/Basic/LLVM.h git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172323 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-11Test commit.Enea Zaffanella
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172195 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-01Pull the Attr iteration parts out of Attr.h, so including DeclBase.h doesn't ↵Benjamin Kramer
pull in all the generated Attr code. Required to pull some functions out of line, but this shouldn't have a perf impact. No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169092 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-17Further reduce "-fsyntax-only -Wuninitialized" time on sqlite3.c by another ↵Ted Kremenek
2.5% using intelligent pruning of blocks during the final reporting pass. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@168257 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-17Switch -Wuninitialized to use a reverse-post order traversal asTed Kremenek
an initial baseline for enqueued blocks, but use a simple DFS stack for propagating changes quickly up back edges. This provides a 3.5% reduction in -fsyntax-only time on sqlite3.c. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@168241 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-28Avoid malloc thrashing in the uninitialized value analysis.Benjamin Kramer
- The size of the packed vector is often small, save mallocs using SmallBitVector. - Copying SmallBitVectors is also cheap, remove a level of indirection. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164827 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13Teach -Wuninitialized to recognize common "noreturn" idioms inTed Kremenek
Objective-C related to NSException. Fixes <rdar://problem/12287498> I debated whether or not this logic should be sunk into the CFG itself. It's not clear if we should, as different analyses may wish to have different policies. We can re-evaluate this in the future. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163760 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-12Teach -Wuninitialized to recognize __attribute__((analyzer_noreturn))Ted Kremenek
for halting the propagation of uninitialized value tracking along a path. Unlike __attribute__((noreturn)), this attribute (which is used by clients of the static analyzer) can be used to annotate functions that essentially never return, but in rare cares may be allowed to return for (special) debugging purposes. This attribute has been shown in reducing false positives in the static analyzer by pruning false postives, and is equally applicable here. Handling this attribute in the CFG itself is another option, but this is not something all clients (e.g., possibly -Wunreachable-code) would want to see. Addresses <rdar://problem/12281583>. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163681 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-19Simplify UninitializedValues.cpp by removing logic to handle the previous ↵Ted Kremenek
(imprecise) representation of '&&' and '||' in the CFG. This is no longer needed, and greatly simplifies the code. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160494 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-17Uninitialized variables: two little changes:Richard Smith
* Treat compound assignment as a use, at Jordy's request. * Always add compound assignments into the CFG, so we can correctly diagnose the use in 'return x += 1;' git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160334 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-17-Wuninitialized: Split the classification of DeclRefExprs as initialization orRichard Smith
use out of TransferFunctions, and compute it in advance rather than on-the-fly. This allows us to handle compound assignments with DeclRefExprs on the RHS correctly, and also makes it trivial to treat const& function parameters as not initializing the argument. The patch also makes both of those changes. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160330 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-13PR13360: When deciding the earliest point which inevitably leads to anRichard Smith
uninitialized variable use, walk back over branches where we've reached all the non-null successors, not just cases where we've reached all successors. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160206 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02-Wuninitialized: assume that an __attribute__((returns_twice)) function mightRichard Smith
initialize any variable. This is extremely conservative, but is sufficient for now. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159620 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-16-Wuninitialized bugfix: when entering the scope of a variable with noRichard Smith
initializer, it is uninitialized, even if we may be coming from somewhere where it was initialized. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158611 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-06Revert Decl's iterators back to pointer value_type rather than reference ↵David Blaikie
value_type In addition, I've made the pointer and reference typedef 'void' rather than T* just so they can't get misused. I would've omitted them entirely but std::distance likes them to be there even if it doesn't use them. This rolls back r155808 and r155869. Review by Doug Gregor incorporating feedback from Chandler Carruth. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158104 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-25Split a chunk of -Wconditional-uninitialized warnings out into a separate flag,Richard Smith
-Wsometimes-uninitialized. This detects cases where an explicitly-written branch inevitably leads to an uninitialized variable use (so either the branch is dead code or there is an uninitialized use bug). This chunk of warnings tentatively lives within -Wuninitialized, in order to give it more visibility to existing Clang users. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@157458 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-24Some cleanups around the uninitialized variables warning, and a FIXME. No ↵Richard Smith
functional change. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@157440 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-30Remove the ref/value inconsistency in filter_decl_iterator.David Blaikie
filter_decl_iterator had a weird mismatch where both op* and op-> returned T* making it difficult to generalize this filtering behavior into a reusable library of any kind. This change errs on the side of value, making op-> return T* and op* return T&. (reviewed by Richard Smith) git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@155808 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-30PR11926 + duplicates: Fix crash in -Wuninitialized when using a compiler likeRichard Smith
g++4.7, which reuses stack space allocated for temporaries. CFGElement::getAs returns a suitably-cast version of 'this'. Patch by Markus Trippelsdorf! No test: this code has the same observable behavior as the old code when built with most compilers, and the tests were already failing when built with a compiler for which this produced a broken binary. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@155803 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-01Move llvm/ADT/SaveAndRestore.h -> llvm/Support/SaveAndRestore.h.Argyrios Kyrtzidis
Needs llvm update. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151829 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-27Move "clang/Analysis/Support/SaveAndRestore.h" to "llvm/ADT/SaveAndRestore.h"Argyrios Kyrtzidis
to make it more widely available. Depends on llvm commit r151564 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151566 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-24Rename AnalysisContext to AnalysisDeclContext. Not only is this name more ↵Ted Kremenek
accurate, but it frees up the name AnalysisContext for other uses. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142782 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-13Tweak -Wuninitialized's handling of 'int x = x' to report that as the root ↵Ted Kremenek
cause of an uninitialized variable IFF there are other uses of that uninitialized variable. Fixes <rdar://problem/9259237>. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141881 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-07Fix infinite loop in -Wuninitialized reported in PR 11069.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141345 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-02-Wuninitialized: fix insidious bug resulting from interplay of blocks and ↵Ted Kremenek
dead code. Fixes <rdar://problem/10060250>. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139027 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-23Constify the result of CFGStmt::getStmt().Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138408 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-20Remove dead code.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138183 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-17Fix else style. No functionality change intended.Chad Rosier
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@137896 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-12Cleanup various declarations of 'Stmt*' to be 'Stmt *', etc. in libAnalyzer ↵Ted Kremenek
and libStaticAnalyzer[*]. It was highly inconsistent, and very ugly to look at. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@137537 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-08Fix another -Wuninitialized assertion failure (this one involving bit casts) ↵Ted Kremenek
resulting from the recent -Wuninitialized changes. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@137068 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-04Fix assertion failure in -Wuninitialized involving no-op casts. Fixes PR 10577.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136939 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-23remove unneeded llvm:: namespace qualifiers on some core types now that ↵Chris Lattner
LLVM.h imports them into the clang namespace. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135852 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-22Move duplicate uninitialized warning suppression into theChandler Carruth
AnalysisBasedWarnings Sema layer and out of the Analysis library itself. This returns the uninitialized values analysis to a more pure form, allowing its original logic to correctly detect some categories of definitely uninitialized values. Fixes PR10358 (again). Thanks to Ted for reviewing and updating this patch after his rewrite of several portions of this analysis. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135748 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-20Fix -Wuninitialized regression involving functions invalidating parameters ↵Ted Kremenek
passed by reference. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135610 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-19Fix false negative in -Wuninitialized involving a () wrapping an ↵Ted Kremenek
lvalue-to-rvalue conversion in a DeclStmt. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135525 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-19Fix assertion failure in UninitializedValues.cpp where an lvalue to rvalue ↵Ted Kremenek
conversion is wrapped in a parenthesis. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135519 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-19Reduce -Wuninitialized time by 22% (on sqlite) by removing the recursive AST ↵Ted Kremenek
crawl. This is accomplished by forcing the needed expressions for -Wuninitialized to always be CFGElements in the CFG. This allows us to remove a fair amount of the code for -Wuninitialized. Some fallout: - AnalysisBasedWarnings.cpp now specifically toggles the CFGBuilder to create a CFG that is suitable for -Wuninitialized. This is a layering violation, since the logic for -Wuninitialized is in libAnalysis. This can be fixed with the proper refactoring. - Some of the source locations for -Wunreachable-code warnings have shifted. While not ideal, this is okay because that analysis already needs some serious reworking. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135480 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-16Revert r135217, which wasn't the correct fix for PR10358. With thisChandler Carruth
patch, we actually move the state-machine for the value set backwards one step. This can pretty easily lead to infinite loops where we continually try to propagate a bit, succeed for one iteration, but then back up because we find an uninitialized use. A reduced test case from PR10379 is included. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135359 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-14Fix false negative reported in PR 10358 by using 'Unknown' in ↵Ted Kremenek
-Wuninitialized to avoid cascading warnings. Patch by Kaelyn Uhrain. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135217 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-08Make the worklist in the uninitialized values checker actually a queue.Chandler Carruth
Previously, despite the names 'enqueue' and 'dequeue', it behaved as a stack and visited blocks in a LIFO fashion. This interacts badly with extremely broad CFGs *inside* of a loop (such as a large switch inside a state machine) where every block updates a different variable. When encountering such a CFG, the checker visited blocks in essentially a "depth first" order due to the stack-like behavior of the work list. Combined with each block updating a different variable, the saturation logic of the checker caused it to re-traverse blocks [1,N-1] of the broad CFG inside the loop after traversing block N. These re-traversals were to propagate the variable values derived from block N. Assuming approximately the same number of variables as inner blocks exist, the end result is O(N^2) updates. By making this a queue, we also make the traversal essentially "breadth-first" across each of the N inner blocks of the loop. Then all of this state is propagated around to all N inner blocks of the loop. The result is O(N) updates. The truth is in the numbers: Before, gcc.c: 96409 block visits (max: 61546, avg: 591) After, gcc.c: 69958 block visits (max: 33090, avg: 429) Before, PR10183: 2540494 block vists (max: 2536495, avg: 37360) After, PR10183: 137803 block visits (max: 134406, avg: 2026) The nearly 20x reduction in work for PR10183 corresponds to a roughly 100x speedup in compile time. I've tested it on all the code I can get my hands on, and I've seen no slowdowns due to this change. Where I've collected stats, the ammount of work done is on average less. I'll also commit shortly some synthetic test cases useful in analyzing the performance of CFG-based warnings. Submitting this based on Doug's feedback that post-commit review should be good. Ted, please review! Hopefully this helps compile times until then. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134697 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-06Build up statistics about the work done for analysis based warnings.Chandler Carruth
Special detail is added for uninitialized variable analysis as this has serious performance problems than need to be tracked. Computing some of this data is expensive, for example walking the CFG to determine its size. To avoid doing that unless the stats data is going to be used, we thread a bit into the Sema object to track whether detailed stats should be collected or not. This bit is used to avoid computations whereever the computations are likely to be more expensive than checking the state of the flag. Thus, counters are in some cases unconditionally updated, but the more expensive (and less frequent) aggregation steps are skipped. With this patch, we're able to see that for 'gcc.c': *** Analysis Based Warnings Stats: 232 functions analyzed (0 w/o CFGs). 7151 CFG blocks built. 30 average CFG blocks per function. 1167 max CFG blocks per function. 163 functions analyzed for uninitialiazed variables 640 variables analyzed. 3 average variables per function. 94 max variables per function. 96409 block visits. 591 average block visits per function. 61546 max block visits per function. And for the reduced testcase in PR10183: *** Analysis Based Warnings Stats: 98 functions analyzed (0 w/o CFGs). 8526 CFG blocks built. 87 average CFG blocks per function. 7277 max CFG blocks per function. 68 functions analyzed for uninitialiazed variables 1359 variables analyzed. 19 average variables per function. 1196 max variables per function. 2540494 block visits. 37360 average block visits per function. 2536495 max block visits per function. That last number is the somewhat scary one that indicates the problem in PR10183. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134494 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-31Utilize PackedVector, introduced with llvm commit r132325.Argyrios Kyrtzidis
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@132326 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-10Fix crash in -Wuninitialized when using switch statments whose condition is ↵Ted Kremenek
a logical operation. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131158 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-28Silence more -Wnon-pod-memset given its current implementation. I may beChandler Carruth
able to revert these based on a patch I'm working on, but no reason for people to be spammed with warnings in the interim. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130394 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-14When we transform a C++ exception declaration (e.g., for templateDouglas Gregor
instantiation), be sure to add the transformed declaration into the current DeclContext. Also, remove the -Wuninitialized hack that works around this bug. Fixes <rdar://problem/9200676>. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129544 91177308-0d34-0410-b5e6-96231b3b80d8