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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107706 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index c19879f..2520341 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -112,6 +112,8 @@
Res.push_back("-analyzer-experimental-checks");
if (Opts.EnableExperimentalInternalChecks)
Res.push_back("-analyzer-experimental-internal-checks");
+ if (Opts.EnableIdempotentOperationChecker)
+ Res.push_back("-analyzer-idempotent-operation");
}
static void CodeGenOptsToArgs(const CodeGenOptions &Opts,
@@ -788,6 +790,8 @@
Opts.EnableExperimentalChecks = Args.hasArg(OPT_analyzer_experimental_checks);
Opts.EnableExperimentalInternalChecks =
Args.hasArg(OPT_analyzer_experimental_internal_checks);
+ Opts.EnableIdempotentOperationChecker =
+ Args.hasArg(OPT_analyzer_idempotent_operation);
Opts.TrimGraph = Args.hasArg(OPT_trim_egraph);
Opts.MaxNodes = Args.getLastArgIntValue(OPT_analyzer_max_nodes, 150000,Diags);
Opts.MaxLoop = Args.getLastArgIntValue(OPT_analyzer_max_loop, 3, Diags);