Summary: Uses [[clang::fallthrough]] attribute in a template function, and -Wimplicit-fallthrough to check the attribute presence in an instantiation.
Reviewers: rsmith
Reviewed By: rsmith
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D55
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165068
91177308-0d34-0410-b5e6-
96231b3b80d8
--- /dev/null
+// To be used with cxx11-statement-attributes.cpp.
+template<const int N>
+int f(int n) {
+ switch (n * N) {
+ case 0:
+ n += 15;
+ [[clang::fallthrough]]; // This shouldn't generate a warning.
+ case 1:
+ n += 20;
+ [[clang::fallthrough]]; // This should generate a warning: "fallthrough annotation does not directly precede switch label".
+ break;
+ }
+ return n;
+}
--- /dev/null
+// Sanity check.
+// RUN: %clang_cc1 -include %S/Inputs/cxx11-statement-attributes.h -std=c++11 -Wimplicit-fallthrough -fsyntax-only %s -o - -verify
+// Run the same tests, this time with the attributes loaded from the PCH file.
+// RUN: %clang_cc1 -x c++-header -emit-pch -std=c++11 -o %t %S/Inputs/cxx11-statement-attributes.h
+// RUN: %clang_cc1 -include-pch %t -std=c++11 -Wimplicit-fallthrough -fsyntax-only %s -o - -verify
+
+// Warning from Inputs/cxx11-statement-attributes.h:
+// expected-warning@10 {{fallthrough annotation does not directly precede switch label}}
+
+void g(int n) {
+ f<1>(n); // expected-note {{in instantiation of function template specialization 'f<1>' requested here}}
+}