[Sema] Don't skip function bodies with 'auto' without trailing return type

Summary:
Skipping them was clearly not intentional. It's impossible to
guarantee correctness if the bodies are skipped.
Also adds a test case for r327504, now that it does not produce
invalid errors that made the test fail.

Reviewers: aaron.ballman, sammccall, rsmith

Reviewed By: rsmith

Subscribers: rayglover-ibm, rwols, cfe-commits

Differential Revision: https://reviews.llvm.org/D44480

llvm-svn: 333538

1 files changed, 43 insertions, 0 deletions

diff --git a/clang/test/CodeCompletion/skip-auto-funcs.cpp b/clang/test/CodeCompletion/skip-auto-funcs.cpp
new file mode 100644
index 00000000000..b20f95bdf2e
--- /dev/null
+++ b/clang/test/CodeCompletion/skip-auto-funcs.cpp
@@ -0,0 +1,43 @@
+// We run clang in completion mode to force skipping of function bodies and
+// check if the function bodies were skipped by observing the warnings that
+// clang produces.
+// RUN: not %clang_cc1 -fsyntax-only -code-completion-at=%s:42:1 %s -o - 2>&1 | FileCheck %s
+template <class T>
+auto not_skipped() {
+  int x;
+  if (x = 10) {}
+  // Check that this function is not skipped.
+  // CHECK: 8:9: warning: using the result of an assignment as a condition without parentheses
+  return 1;
+}
+
+template <class T>
+auto lambda_not_skipped = []() {
+  int x;
+  if (x = 10) {}
+  // Check that this function is not skipped.
+  // CHECK: 17:9: warning: using the result of an assignment as a condition without parentheses
+  return 1;
+}
+
+template <class T>
+auto skipped() -> T {
+  int x;
+  if (x = 10) {}
+  // Check that this function is skipped.
+  // CHECK-NOT: 26:9: warning: using the result of an assignment as a condition without parentheses
+  return 1;
+};
+
+auto lambda_skipped = []() -> int {
+  int x;
+  if (x = 10) {}
+  // This could potentially be skipped, but it isn't at the moment.
+  // CHECK: 34:9: warning: using the result of an assignment as a condition without parentheses
+  return 1;
+};
+
+int test() {
+  int complete_in_this_function;
+  // CHECK: COMPLETION: complete_in_this_function
+}