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author | Artem Dergachev <artem.dergachev@gmail.com> | 2015-12-10 09:28:06 +0000 |
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committer | Artem Dergachev <artem.dergachev@gmail.com> | 2015-12-10 09:28:06 +0000 |
commit | 37ffc1a156dbbce81e4af2811b689d586d556de0 (patch) | |
tree | 7c2b5ae3afc23a72ffd156848cdaba38cce12506 /docs/analyzer | |
parent | dfc7574e1ecf3d086577ca89ad94ef4d08ecc0cc (diff) |
[analyzer] Fix symbolic element index lifetime.
SymbolReaper was destroying the symbol too early when it was referenced only
from an index SVal of a live ElementRegion.
In order to test certain aspects of this patch, extend the debug.ExprInspection
checker to allow testing SymbolReaper in a direct manner.
Differential Revision: http://reviews.llvm.org/D12726
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@255236 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/analyzer')
-rw-r--r-- | docs/analyzer/DebugChecks.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/docs/analyzer/DebugChecks.rst b/docs/analyzer/DebugChecks.rst index 14d6ae4c4c..771e39fc43 100644 --- a/docs/analyzer/DebugChecks.rst +++ b/docs/analyzer/DebugChecks.rst @@ -138,6 +138,29 @@ ExprInspection checks clang_analyzer_warnIfReached(); // no-warning } +- void clang_analyzer_warnOnDeadSymbol(int); + + Subscribe for a delayed warning when the symbol that represents the value of + the argument is garbage-collected by the analyzer. + + When calling 'clang_analyzer_warnOnDeadSymbol(x)', if value of 'x' is a + symbol, then this symbol is marked by the ExprInspection checker. Then, + during each garbage collection run, the checker sees if the marked symbol is + being collected and issues the 'SYMBOL DEAD' warning if it does. + This way you know where exactly, up to the line of code, the symbol dies. + + It is unlikely that you call this function after the symbol is already dead, + because the very reference to it as the function argument prevents it from + dying. However, if the argument is not a symbol but a concrete value, + no warning would be issued. + + Example usage:: + + do { + int x = generate_some_integer(); + clang_analyzer_warnOnDeadSymbol(x); + } while(0); // expected-warning{{SYMBOL DEAD}} + Statistics ========== |