Check for bool-like conversion in conditional expressions.

Add a check for bool-like conversions for the condition expression of
conditional operators.  This is similiar to the checking of condition
expressions of if statements, for-loops, while-loops, and do-while loops.
Specificially, this is to fix the problem of assert("message") not triggering
-Wstring-conversion when the assert macro uses a conditional operator.

llvm-svn: 237856
diff --git a/clang/test/Sema/warn-string-conversion.c b/clang/test/Sema/warn-string-conversion.c
index 708dd54..28dfc1b 100644
--- a/clang/test/Sema/warn-string-conversion.c
+++ b/clang/test/Sema/warn-string-conversion.c
@@ -1,12 +1,28 @@
 // RUN: %clang_cc1 -verify -fsyntax-only -Wstring-conversion %s
 
-#define assert(EXPR) (void)(EXPR);
+void do_nothing();
+void assert_error();
+
+#define assert1(expr) \
+  if (expr)           \
+    do_nothing();     \
+  else                \
+  assert_error()
+
+#define assert2(expr) \
+  ((expr) ? do_nothing() : assert_error())
 
 // Expection for common assert form.
 void test1() {
-  assert(0 && "foo");
-  assert("foo" && 0);
-  assert(0 || "foo"); // expected-warning {{string literal}}
+  assert1(0 && "foo");
+  assert1("foo" && 0);
+  assert1(0 || "foo"); // expected-warning {{string literal}}
+  assert1("foo"); // expected-warning {{string literal}}
+
+  assert2(0 && "foo");
+  assert2("foo" && 0);
+  assert2(0 || "foo"); // expected-warning {{string literal}}
+  assert2("foo"); // expected-warning {{string literal}}
 }
 
 void test2() {
@@ -14,4 +30,5 @@
   while ("hello") {}     // expected-warning {{string literal}}
   for (;"howdy";) {}     // expected-warning {{string literal}}
   do { } while ("hey");  // expected-warning {{string literal}}
+  int x = "hey" ? 1 : 2; // expected-warning {{string literal}}
 }