[analyzer] Fix unreachable creating PathDiagnosticLocation with widen-loops=true
In the original design of the analyzer, it was assumed that a BlockEntrance
doesn't create a new binding on the Store, but this assumption isn't true when
'widen-loops' is set to true. Fix this by finding an appropriate location
BlockEntrace program points.
Patch by Henry Wong!
Differential Revision: https://reviews.llvm.org/D37187
llvm-svn: 319333
diff --git a/clang/test/Analysis/loop-widening-notes.cpp b/clang/test/Analysis/loop-widening-notes.cpp
new file mode 100644
index 0000000..56bde74
--- /dev/null
+++ b/clang/test/Analysis/loop-widening-notes.cpp
@@ -0,0 +1,72 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha -analyzer-max-loop 2 -analyzer-config widen-loops=true -analyzer-output=text -verify %s
+
+int *p_a;
+int bar();
+int flag_a;
+int test_for_bug_25609() {
+ if (p_a == 0) // expected-note {{Assuming 'p_a' is equal to null}}
+ // expected-note@-1 {{Taking true branch}}
+ bar();
+ for (int i = 0; // expected-note {{Loop condition is true. Entering loop body}}
+ // expected-note@-1 {{Loop condition is false. Execution continues on line 16}}
+ ++i, // expected-note {{Value assigned to 'p_a'}}
+ i < flag_a;
+ ++i) {}
+
+ *p_a = 25609; // no-crash expected-warning {{Dereference of null pointer (loaded from variable 'p_a')}}
+ // expected-note@-1 {{Dereference of null pointer (loaded from variable 'p_a')}}
+ return *p_a;
+}
+
+int flag_b;
+int while_analyzer_output() {
+ flag_b = 100;
+ int num = 10;
+ while (flag_b-- > 0) { // expected-note {{Loop condition is true. Entering loop body}}
+ // expected-note@-1 {{Value assigned to 'num'}}
+ // expected-note@-2 {{Loop condition is false. Execution continues on line 30}}
+ num = flag_b;
+ }
+ if (num < 0) // expected-note {{Assuming 'num' is >= 0}}
+ // expected-note@-1 {{Taking false branch}}
+ flag_b = 0;
+ else if (num >= 1) // expected-note {{Assuming 'num' is < 1}}
+ // expected-note@-1 {{Taking false branch}}
+ flag_b = 50;
+ else
+ flag_b = 100;
+ return flag_b / num; // no-crash expected-warning {{Division by zero}}
+ // expected-note@-1 {{Division by zero}}
+}
+
+int flag_c;
+int do_while_analyzer_output() {
+ int num = 10;
+ do { // expected-note {{Loop condition is true. Execution continues on line 47}}
+ // expected-note@-1 {{Loop condition is false. Exiting loop}}
+ num--;
+ } while (flag_c-- > 0); //expected-note {{Value assigned to 'num'}}
+ int local = 0;
+ if (num == 0) // expected-note {{Assuming 'num' is equal to 0}}
+ // expected-note@-1 {{Taking true branch}}
+ local = 10 / num; // no-crash expected-warning {{Division by zero}}
+ // expected-note@-1 {{Division by zero}}
+ return local;
+}
+
+int flag_d;
+int test_for_loop() {
+ int num = 10;
+ for (int i = 0; // expected-note {{Loop condition is true. Entering loop body}}
+ // expected-note@-1 {{Loop condition is false. Execution continues on line 67}}
+ new int(10), // expected-note {{Value assigned to 'num'}}
+ i < flag_d;
+ ++i) {
+ ++num;
+ }
+ if (num == 0) // expected-note {{Assuming 'num' is equal to 0}}
+ // expected-note@-1 {{Taking true branch}}
+ flag_d += 10;
+ return flag_d / num; // no-crash expected-warning {{Division by zero}}
+ // expected-note@-1 {{Division by zero}}
+}