Szelethus created this revision.
Szelethus added reviewers: NoQ, xazax.hun, baloghadamsoftware, dcoughlin,
rnkovacs, Charusso.
Szelethus added a project: clang.
Herald added subscribers: cfe-commits, gamesh411, dkrupp, donat.nagy,
mikhail.ramalho, a.sidorin, szepet, whisperity.
As discussed on the mailing list, notes originating from the tracking of
foreach loop conditions are always meaningless.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D66131
Files:
clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
clang/test/Analysis/track-control-dependency-conditions.cpp
Index: clang/test/Analysis/track-control-dependency-conditions.cpp
===================================================================
--- clang/test/Analysis/track-control-dependency-conditions.cpp
+++ clang/test/Analysis/track-control-dependency-conditions.cpp
@@ -407,6 +407,40 @@
}
} // end of namespace condition_written_in_nested_stackframe_before_assignment
+namespace dont_explain_foreach_loops {
+
+struct Iterator {
+ int *pos;
+ bool operator!=(Iterator other) const {
+ return pos && other.pos && pos != other.pos;
+ }
+ int operator*();
+ Iterator operator++();
+};
+
+struct Container {
+ Iterator begin();
+ Iterator end();
+};
+
+void f(Container Cont) {
+ int flag = 0;
+ int *x = 0; // expected-note{{'x' initialized to a null pointer value}}
+ for (int i : Cont)
+ if (i) // expected-note {{Assuming 'i' is not equal to 0}}
+ // expected-note@-1{{Taking true branch}}
+ // debug-note@-2{{Tracking condition 'i'}}
+ flag = i;
+
+ if (flag) // expected-note{{'flag' is not equal to 0}}
+ // expected-note@-1{{Taking true branch}}
+ // debug-note@-2{{Tracking condition 'flag'}}
+ *x = 5; // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
+}
+
+} // end of namespace dont_explain_foreach_loops
+
namespace collapse_point_not_in_condition_bool {
[[noreturn]] void halt();
Index: clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -1830,6 +1830,11 @@
return nullptr;
if (ControlDeps.isControlDependent(OriginB, NB)) {
+ // We don't really want to explain for range loops. Evidence suggests that
+ // the only thing that leads to is the addition of calls to operator!=.
+ if (isa<CXXForRangeStmt>(NB->getTerminator()))
+ return nullptr;
+
if (const Expr *Condition = NB->getLastCondition()) {
// Keeping track of the already tracked conditions on a visitor level
// isn't sufficient, because a new visitor is created for each tracked
Index: clang/test/Analysis/track-control-dependency-conditions.cpp
===================================================================
--- clang/test/Analysis/track-control-dependency-conditions.cpp
+++ clang/test/Analysis/track-control-dependency-conditions.cpp
@@ -407,6 +407,40 @@
}
} // end of namespace condition_written_in_nested_stackframe_before_assignment
+namespace dont_explain_foreach_loops {
+
+struct Iterator {
+ int *pos;
+ bool operator!=(Iterator other) const {
+ return pos && other.pos && pos != other.pos;
+ }
+ int operator*();
+ Iterator operator++();
+};
+
+struct Container {
+ Iterator begin();
+ Iterator end();
+};
+
+void f(Container Cont) {
+ int flag = 0;
+ int *x = 0; // expected-note{{'x' initialized to a null pointer value}}
+ for (int i : Cont)
+ if (i) // expected-note {{Assuming 'i' is not equal to 0}}
+ // expected-note@-1{{Taking true branch}}
+ // debug-note@-2{{Tracking condition 'i'}}
+ flag = i;
+
+ if (flag) // expected-note{{'flag' is not equal to 0}}
+ // expected-note@-1{{Taking true branch}}
+ // debug-note@-2{{Tracking condition 'flag'}}
+ *x = 5; // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
+}
+
+} // end of namespace dont_explain_foreach_loops
+
namespace collapse_point_not_in_condition_bool {
[[noreturn]] void halt();
Index: clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -1830,6 +1830,11 @@
return nullptr;
if (ControlDeps.isControlDependent(OriginB, NB)) {
+ // We don't really want to explain for range loops. Evidence suggests that
+ // the only thing that leads to is the addition of calls to operator!=.
+ if (isa<CXXForRangeStmt>(NB->getTerminator()))
+ return nullptr;
+
if (const Expr *Condition = NB->getLastCondition()) {
// Keeping track of the already tracked conditions on a visitor level
// isn't sufficient, because a new visitor is created for each tracked
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