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| author | Artem Dergachev <artem.dergachev@gmail.com> | 2018-12-16 23:44:06 +0000 |
|---|---|---|
| committer | Artem Dergachev <artem.dergachev@gmail.com> | 2018-12-16 23:44:06 +0000 |
| commit | dda42164ecd754d87d70108fccacf4ee04c30bc1 (patch) | |
| tree | 4abdb3ad03ce42c9eb7b6646655b154638b732f3 /clang/docs | |
| parent | d0c9e43b1c6bd016044a0916fae5dbf04458450c (diff) | |
[analyzer] Fix some expressions staying live too long. Add a debug checker.
StaticAnalyzer uses the CFG-based RelaxedLiveVariables analysis in order to,
in particular, figure out values of which expressions are still needed.
When the expression becomes "dead", it is garbage-collected during
the dead binding scan.
Expressions that constitute branches/bodies of control flow statements,
eg. `E1' in `if (C1) E1;' but not `E2' in `if (C2) { E2; }', were kept alive
for too long. This caused false positives in MoveChecker because it relies
on cleaning up loop-local variables when they go out of scope, but some of those
live-for-too-long expressions were keeping a reference to those variables.
Fix liveness analysis to correctly mark these expressions as dead.
Add a debug checker, debug.DumpLiveStmts, in order to test expressions liveness.
Differential Revision: https://reviews.llvm.org/D55566
llvm-svn: 349320
Diffstat (limited to 'clang/docs')
| -rw-r--r-- | clang/docs/analyzer/DebugChecks.rst | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/clang/docs/analyzer/DebugChecks.rst b/clang/docs/analyzer/DebugChecks.rst index 7b192f65224f..bb2f37f33955 100644 --- a/clang/docs/analyzer/DebugChecks.rst +++ b/clang/docs/analyzer/DebugChecks.rst @@ -30,9 +30,12 @@ using a 'dot' format viewer (such as Graphviz on OS X) instead. - debug.DumpLiveVars: Show the results of live variable analysis for each top-level function being analyzed. +- debug.DumpLiveStmts: Show the results of live statement analysis for each + top-level function being analyzed. + - debug.ViewExplodedGraph: Show the Exploded Graphs generated for the analysis of different functions in the input translation unit. When there - are several functions analyzed, display one graph per function. Beware + are several functions analyzed, display one graph per function. Beware that these graphs may grow very large, even for small functions. Path Tracking |