-Rename -Wargument-larger-than -> -Wlarge-by-value-copy

-Improve the diagnostic message
-Add some comments

Suggestions by Chris.

llvm-svn: 119594

1 files changed, 42 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/warn-large-by-value-copy.cpp b/clang/test/SemaCXX/warn-large-by-value-copy.cpp
new file mode 100644
index 00000000000..39dbd7697d2
--- /dev/null
+++ b/clang/test/SemaCXX/warn-large-by-value-copy.cpp
@@ -0,0 +1,42 @@
+// RUN: %clang_cc1 -verify -fsyntax-only -Wlarge-by-value-copy=100 %s
+
+// rdar://8548050
+namespace rdar8548050 {
+
+struct S100 {
+    char x[100];
+};
+
+struct S101 {
+    char x[101];
+};
+
+S100 f100(S100 s) { return s; }
+
+S101 f101(S101 s) { return s; } // expected-warning {{return value of 'f101' is a large (101 bytes) pass-by-value object}} \
+                                // expected-warning {{'s' is a large (101 bytes) pass-by-value argument}}
+
+typedef int Arr[200];
+void farr(Arr a) { }
+
+struct NonPOD {
+  char x[200];
+  virtual void m();
+};
+
+NonPOD fNonPOD(NonPOD s) { return s; }
+
+template <unsigned size>
+struct TS {
+    char x[size];
+};
+
+template <unsigned size>
+void tf(TS<size> ts) {} // expected-warning {{ts' is a large (300 bytes) pass-by-value argument}}
+
+void g() {
+    TS<300> ts;
+    tf<300>(ts); // expected-note {{instantiation}}
+}
+
+}