PR c++/90393 - ICE with thow in ?:

My previous patch for 64372 was incomplete: it only stopped making the
non-throw argument into an rvalue, lvalue_kind still considered the ?:
expression to be an rvalue, leaving us worse than before.

	PR c++/64372, DR 1560 - Gratuitous lvalue-to-rvalue conversion in ?:
	* tree.c (lvalue_kind): Handle throw in one arm.
	* typeck.c (rationalize_conditional_expr): Likewise.
	(cp_build_modify_expr): Likewise.

From-SVN: r274550

5 files changed, 45 insertions, 6 deletions

diff --git a/gcc/testsuite/g++.dg/abi/mangle53.C b/gcc/testsuite/g++.dg/abi/mangle53.C
index 13f9e71..727fd75 100644
--- a/gcc/testsuite/g++.dg/abi/mangle53.C
+++ b/gcc/testsuite/g++.dg/abi/mangle53.C
@@ -1,10 +1,11 @@
 // { dg-do compile { target c++11 } }
 
 bool b;
+int i;
 // { dg-final { scan-assembler "_Z1fIiEDTquL_Z1bEfp_twLi42EET_" } }
-template <class T> auto f (T t) -> decltype(b?t:throw 42) { return 0; }
+template <class T> auto f (T t) -> decltype(b?t:throw 42) { return i; }
 // { dg-final { scan-assembler "_Z2f2IiEDTquL_Z1bEfp_trET_" } }
-template <class T> auto f2 (T t) -> decltype(b?t:throw) { return 0; }
+template <class T> auto f2 (T t) -> decltype(b?t:throw) { return i; }
 
 int main()
 {
diff --git a/gcc/testsuite/g++.dg/expr/cond15.C b/gcc/testsuite/g++.dg/expr/cond15.C
new file mode 100644
index 0000000..4a9d057
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/cond15.C
@@ -0,0 +1,13 @@
+// PR c++/90393
+
+struct S {
+  S();
+  S(const S&) {}
+};
+
+S f() {
+  const S m;
+  return true ? m : throw 0;
+}
+
+int main() {}
diff --git a/gcc/testsuite/g++.dg/expr/cond16.C b/gcc/testsuite/g++.dg/expr/cond16.C
new file mode 100644
index 0000000..796828b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/cond16.C
@@ -0,0 +1,25 @@
+// PR c++/90393
+// { dg-do run }
+
+int c, d;
+
+struct string {
+  string(const char *p): s(p) { ++c; }
+  ~string() { ++d; }
+  string(const string& str): s(str.s) { ++c; }
+  const char* s;
+  bool empty() const { return !s; }
+};
+    
+string foo()
+{
+  string s("foo");
+  return s.empty() ? throw "empty" : s;
+}
+
+int main()
+{
+  foo();
+  if (c != d)
+    __builtin_abort();
+}
diff --git a/gcc/testsuite/g++.old-deja/g++.eh/cond1.C b/gcc/testsuite/g++.old-deja/g++.eh/cond1.C
index 1b2de1d..fe6d429 100644
--- a/gcc/testsuite/g++.old-deja/g++.eh/cond1.C
+++ b/gcc/testsuite/g++.old-deja/g++.eh/cond1.C
@@ -22,8 +22,8 @@ void fn(int i)
   (i ? throw X() : throw X());  // ok, void
   
   (i ? i : j) = 1; // ok, int &
-  (i ? throw X() : j) = 1; // { dg-error "" } non-lvalue
-  (i ? j : throw X()) = 1; // { dg-error "" } non-lvalue
+  (i ? throw X() : j) = 1; // ok, int &
+  (i ? j : throw X()) = 1; // ok, int &
   (i ? throw X() : throw X()) = 1;  // { dg-error "" } void
   
   (i ? (void)1 : i++); // { dg-error "" } ANSI forbids
diff --git a/gcc/testsuite/g++.old-deja/g++.other/cond5.C b/gcc/testsuite/g++.old-deja/g++.other/cond5.C
index f4d16e9..0d2baf9 100644
--- a/gcc/testsuite/g++.old-deja/g++.other/cond5.C
+++ b/gcc/testsuite/g++.old-deja/g++.other/cond5.C
@@ -35,8 +35,8 @@ void fn(int i)
   (i ? throw X() : throw X());  // ok, void
   
   (i ? i : j) = 1; // ok, int &
-  (i ? throw X() : j) = 1;    // { dg-error "lvalue" }
-  (i ? j : throw X()) = 1;    // { dg-error "lvalue" }
+  (i ? throw X() : j) = 1; // ok, int &
+  (i ? j : throw X()) = 1; // ok, int &
   (i ? throw X() : throw X()) = 1;  // { dg-error "lvalue" }
   
   (i ? (void)1 : i++);        // { dg-error "throw-expression" }