[clang-tidy] Check for dynamically initialized statics in headers.

Finds instances where variables with static storage are initialized dynamically in header files.

Reviewed By: aaron.ballman, alexfh

Patch by Charles Zhang!

Differential Revision: https://reviews.llvm.org/D62829

llvm-svn: 369568

1 files changed, 44 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/bugprone-dynamic-static-initializers.hpp b/clang-tools-extra/test/clang-tidy/bugprone-dynamic-static-initializers.hpp
new file mode 100644
index 00000000000..647b2e57165
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/bugprone-dynamic-static-initializers.hpp
@@ -0,0 +1,44 @@
+// RUN: %check_clang_tidy %s bugprone-dynamic-static-initializers %t -- -- -fno-threadsafe-statics
+
+int fact(int n) {
+  return (n == 0) ? 1 : n * fact(n - 1);
+}
+
+int static_thing = fact(5);
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: static variable 'static_thing' may be dynamically initialized in this header file [bugprone-dynamic-static-initializers]
+
+int sample() {
+    int x;
+    return x;
+}
+
+int dynamic_thing = sample();
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: static variable 'dynamic_thing' may be dynamically initialized in this header file [bugprone-dynamic-static-initializers]
+
+int not_so_bad = 12 + 4942; // no warning
+
+extern int bar();
+
+int foo() {
+  static int k = bar();
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: static variable 'k' may be dynamically initialized in this header file [bugprone-dynamic-static-initializers]
+  return k;
+}
+
+int bar2() {
+  return 7;
+}
+
+int foo2() {
+  // This may work fine when optimization is enabled because bar() can
+  // be turned into a constant 7.  But without optimization, it can
+  // cause problems. Therefore, we must err on the side of conservatism.
+  static int x = bar2();
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: static variable 'x' may be dynamically initialized in this header file [bugprone-dynamic-static-initializers]
+  return x;
+}
+
+int foo3() {
+  static int p = 7 + 83; // no warning
+  return p;
+}