[analyzer] Relax the assert used when traversing the node graph.

The assertion gets exposed when changing the exploration order.
This is a quick hacky fix, but the intention is that if the nodes do
merge, it should not matter which predecessor should be traverse.
A proper fix would be not to traverse predecessors at all, as all
information relevant for any decision should be avilable locally.

rdar://37540480

Differential Revision: https://reviews.llvm.org/D42773

llvm-svn: 325977
This commit is contained in:
George Karpenkov 2018-02-23 23:26:57 +00:00
parent e15451a9c0
commit 60c206e0bd
2 changed files with 22 additions and 1 deletions

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@ -760,7 +760,11 @@ void ExprEngine::VisitGuardedExpr(const Expr *Ex,
for (const ExplodedNode *N = Pred ; N ; N = *N->pred_begin()) {
ProgramPoint PP = N->getLocation();
if (PP.getAs<PreStmtPurgeDeadSymbols>() || PP.getAs<BlockEntrance>()) {
assert(N->pred_size() == 1);
// If the state N has multiple predecessors P, it means that successors
// of P are all equivalent.
// In turn, that means that all nodes at P are equivalent in terms
// of observable behavior at N, and we can follow any of them.
// FIXME: a more robust solution which does not walk up the tree.
continue;
}
SrcBlock = PP.castAs<BlockEdge>().getSrc();

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@ -0,0 +1,17 @@
// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify -analyzer-config exploration_strategy=unexplored_first %s
// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify -analyzer-config exploration_strategy=dfs %s
extern void clang_analyzer_eval(int);
typedef struct { char a; } b;
int c(b* input) {
int x = (input->a ?: input) ? 1 : 0; // expected-warning{{pointer/integer type mismatch}}
if (input->a) {
// FIXME: The value should actually be "TRUE",
// but is incorrect due to a bug.
clang_analyzer_eval(x); // expected-warning{{FALSE}}
} else {
clang_analyzer_eval(x); // expected-warning{{TRUE}}
}
return x;
}