1 files changed, 104 insertions, 0 deletions
diff --git a/test/Analysis/unreachable-code-path.c b/test/Analysis/unreachable-code-path.c
new file mode 100644
index 000000000000..071532739cbe
--- /dev/null
+++ b/test/Analysis/unreachable-code-path.c
@@ -0,0 +1,104 @@
+// RUN: %clang_cc1 -analyze -analyzer-experimental-checks -analyzer-check-objc-mem -analyzer-check-dead-stores -verify -analyzer-opt-analyze-nested-blocks %s
+
+extern void foo(int a);
+
+// The first few tests are non-path specific - we should be able to find them
+
+void test(unsigned a) {
+  switch (a) {
+    a += 5; // expected-warning{{never executed}}
+  case 2:
+    a *= 10;
+  case 3:
+    a %= 2;
+  }
+  foo(a);
+}
+
+void test2(unsigned a) {
+ help:
+  if (a > 0)
+    return;
+  if (a == 0)
+    return;
+  foo(a); // expected-warning{{never executed}}
+  goto help;
+}
+
+void test3(unsigned a) {
+  while(1);
+  if (a > 5) { // expected-warning{{never executed}}
+    return;
+  }
+}
+
+// These next tests are path-sensitive
+
+void test4() {
+  int a = 5;
+
+  while (a > 1)
+    a -= 2;
+
+  if (a > 1) {
+    a = a + 56; // expected-warning{{never executed}}
+  }
+
+  foo(a);
+}
+
+extern void bar(char c);
+
+void test5(const char *c) {
+  foo(c[0]);
+
+  if (!c) {
+    bar(1); // expected-warning{{never executed}}
+  }
+}
+
+// These next tests are false positives and should not generate warnings
+
+void test6(const char *c) {
+  if (c) return;
+  if (!c) return;
+  __builtin_unreachable(); // no-warning
+}
+
+// Compile-time constant false positives
+#define CONSTANT 0
+enum test_enum { Off, On };
+void test7() {
+  if (CONSTANT)
+    return; // no-warning
+
+  if (sizeof(int))
+    return; // no-warning
+
+  if (Off)
+    return; // no-warning
+}
+
+void test8() {
+  static unsigned a = 0;
+
+  if (a)
+    a = 123; // no-warning
+
+  a = 5;
+}
+
+// Check for bugs where multiple statements are reported
+void test9(unsigned a) {
+  switch (a) {
+    if (a) // expected-warning{{never executed}}
+      foo(a + 5); // no-warning
+    else // no-warning
+      foo(a); // no-warning
+    case 1:
+    case 2:
+      break;
+    default:
+      break;
+  }
+}