[Static Analyzer] Warn when inner and outer conditions are identical. The inner condition is always true.

Reviewed in http://reviews.llvm.org/D10892.

llvm-svn: 244435

1 files changed, 32 insertions, 0 deletions

diff --git a/clang/test/Analysis/identical-expressions.cpp b/clang/test/Analysis/identical-expressions.cpp
index 46dd56289c4..138cd7ce988 100644
--- a/clang/test/Analysis/identical-expressions.cpp
+++ b/clang/test/Analysis/identical-expressions.cpp
@@ -1530,3 +1530,35 @@ void test_nowarn_long() {
     c = 0LL;
   }
 }
+
+// Identical inner conditions
+
+void test_warn_inner_if_1(int x) {
+  if (x == 1) {
+    if (x == 1) // expected-warning {{conditions of the inner and outer statements are identical}}
+      ;
+  }
+
+  // FIXME: Should warn here. The warning is currently not emitted because there
+  // is code between the conditions.
+  if (x == 1) {
+    int y = x;
+    if (x == 1)
+      ;
+  }
+}
+
+void test_nowarn_inner_if_1(int x) {
+  // Don't warn when condition has side effects.
+  if (x++ == 1) {
+    if (x++ == 1)
+      ;
+  }
+
+  // Don't warn when x is changed before inner condition.
+  if (x < 10) {
+    x++;
+    if (x < 10)
+      ;
+  }
+}