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path: root/lib/Analysis/UninitializedValues.cpp
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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
2011-04-13Teach -Wuninitialized about C++'s typeid expression, including both theChandler Carruth
evaluated and unevaluated contexts. Add some testing of sizeof and typeid. Both of the typeid tests added here were triggering warnings previously. Now the one false positive is suppressed without suppressing the warning on actually buggy code. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129431 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07Teach -Wuninitialized to not warn about variables declared in C++ catch ↵Ted Kremenek
statements. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129102 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-05Commit a bit of a hack to fully handle the situation where variables areChandler Carruth
marked explicitly as uninitialized through direct self initialization: int x = x; With r128894 we prevented warnings about this code, and this patch teaches the analysis engine to continue analyzing subsequent uses of 'x'. This should wrap up PR9624. There is still an open question of whether we should suppress the maybe-uninitialized warnings resulting from variables initialized in this fashion. The definitely-uninitialized uses should always be warned. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128932 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-04Fix PR 9626 (duplicated self-init warnings under -Wuninitialized) with ↵Ted Kremenek
numerous CFG and UninitializedValues analysis changes: 1) Change the CFG to include the DeclStmt for conditional variables, instead of using the condition itself as a faux DeclStmt. 2) Update ExprEngine (the static analyzer) to understand (1), so not to regress. 3) Update UninitializedValues.cpp to initialize all tracked variables to Uninitialized at the start of the function/method. 4) Only use the SelfReferenceChecker (SemaDecl.cpp) on global variables, leaving the dataflow analysis to handle other cases. The combination of (1) and (3) allows the dataflow-based -Wuninitialized to find self-init problems when the initializer contained control-flow. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128858 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-04-Wuninitialized: don't warn about uninitialized variables in unreachable code.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128840 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31-Wuninitialized should not warn about variables captured by blocks as byref.Ted Kremenek
Note this can potentially be enhanced to detect if the __block variable is actually written by the block, or only when the block "escapes" or is actually used, but that requires more analysis than it is probably worth for this simple check. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128681 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-29Add workaround for Sema issue found in <rdar://problem/9188004>, which leads ↵Ted Kremenek
to an assertion failure in the uninitialized variables analysis. The problem is that Sema isn't properly registering a variable in a DeclContext (which -Wuninitialized relies on), but my expertise on the template instantiation logic isn't good enough to fix this problem for real. This patch worksaround the problem in -Wuninitialized, but we should fix it for real later. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128443 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-26Make helpers static.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128339 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-17Extend -Wuninitialized to support vector types.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127794 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15Appease GCC. I'm surprised Clang accepted this.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127672 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15Split warnings from -Wuninitialized-experimental into "must-be-initialized" ↵Ted Kremenek
and "may-be-initialized" warnings, each controlled by different flags. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127669 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15Split warnings from -Wuninitialized-experimental into "must-be-initialized" ↵Ted Kremenek
and "may-be-initialized" warnings, each controlled by different flags. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127666 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15UninitializedValues: introduce ValueVector:reference class to forward to ↵Ted Kremenek
llvm::BitVector. No real functionality change, but this is a stepping stone to moving to tri-state logic. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127665 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15UninitializedValues: wrap BitVector references in a new class ValueVector. ↵Ted Kremenek
No functionality change. This defines the minimum interface that ValueVector needs to support when we no longer base it strictly on a direct interpretation of BitVector. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127664 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15Substitue term "BitVector" with "ValueVector" to prep for further revisions. ↵Ted Kremenek
No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127663 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15Rename UninitializedValuesV2 to UninitializedValues.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127657 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15Remove old UninitializedValues analysis.Ted Kremenek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127656 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-17Change the representation of GNU ?: expressions to use a different expressionJohn McCall
class and to bind the shared value using OpaqueValueExpr. This fixes an unnoticed problem with deserialization of these expressions where the deserialized form would lose the vital pointer-equality trait; or rather, it fixes it because this patch also does the right thing for deserializing OVEs. Change OVEs to not be a "temporary object" in the sense that copy elision is permitted. This new representation is not totally unawkward to work with, but I think that's really part and parcel with the semantics we're modelling here. In particular, it's much easier to fix things like the copy elision bug and to make the CFG look right. I've tried to update the analyzer to deal with this in at least some obvious cases, and I think we get a much better CFG out, but the printing of OpaqueValueExprs probably needs some work. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125744 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13Give some convenient idiomatic accessors to Stmt::child_range andJohn McCall
Stmt::const_child_range, then make a bunch of places use them instead of the individual iterator accessors. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125450 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-11Don't report dead stores on unreachable code paths. Fixes ↵Ted Kremenek
<rdar://problem/8405222>. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125415 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-15Death to blocks, or at least the word "block" in one particular obnoxiouslyJohn McCall
ambiguous context. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116567 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-25GCC didn't care for my attempt at API compatibility, so brute-force everythingJohn McCall
to the new constants. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112047 91177308-0d34-0410-b5e6-96231b3b80d8