[PATCH C++] Fix PR70182 -- missing "on" in mangling of unresolved operators

[Markus Trippelsdorf]

The ABI says:

<unresolved-name>
   ::= [gs] <base-unresolved-name>
   ::= sr <unresolved-type> <base-unresolved-name>
   ::= srN <unresolved-type> <unresolved-qualifier-level>+ E 
<base-unresolved-name>
   ::= [gs] sr <unresolved-qualifier-level>+ E <base-unresolved-name>

<base-unresolved-name>
   ::= <simple-id>
   ::= on <operator-name>
   ::= on <operator-name> <template-args>
   ::= dn <destructor-name

Currently gcc doesn't add "on" for operators. The fix is trivial, but
some tests from the testsuite need adjustments.

Tested on ppc64le. Ok for trunk?

Thanks.

libiberty:

        PR c++/70182
        * cp-demangle.c (d_unqualified_name): Handle "on" for
        operator names.
        * testsuite/demangle-expected: Add tests.

gcc/cp:

        PR c++/70182
        * mangle.c (write_template_args): Add "on" for operator names.

diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index ee75f4a25621..d28538e776b6 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -2813,6 +2813,8 @@ write_template_args (tree args)
 static void
 write_member_name (tree member)
 {
+  if (abi_version_at_least (11) && IDENTIFIER_OPNAME_P (member))
+    write_string ("on");
   if (identifier_p (member))
     write_unqualified_id (member);
   else if (DECL_P (member))
diff --git a/gcc/testsuite/g++.dg/abi/mangle13.C 
b/gcc/testsuite/g++.dg/abi/mangle13.C
index 716c4c36f410..c8822a34039c 100644
--- a/gcc/testsuite/g++.dg/abi/mangle13.C
+++ b/gcc/testsuite/g++.dg/abi/mangle13.C
@@ -1,4 +1,4 @@
-// { dg-options "-fabi-version=0" }
+// { dg-options "-fabi-version=10" }
 
 struct A {
   template <typename T> int f ();
diff --git a/gcc/testsuite/g++.dg/abi/mangle37.C 
b/gcc/testsuite/g++.dg/abi/mangle37.C
index 691566b384ba..4dd87e84c108 100644
--- a/gcc/testsuite/g++.dg/abi/mangle37.C
+++ b/gcc/testsuite/g++.dg/abi/mangle37.C
@@ -1,5 +1,6 @@
 // Testcase for mangling of expressions involving operator names.
 // { dg-do compile { target c++11 } }
+// { dg-options "-fabi-version=10" }
 // { dg-final { scan-assembler "_Z1fI1AEDTclonplfp_fp_EET_" } }
 // { dg-final { scan-assembler "_Z1gI1AEDTclonplIT_Efp_fp_EES1_" } }
 // { dg-final { scan-assembler "_Z1hI1AEDTcldtfp_miEET_" } }
diff --git a/gcc/testsuite/g++.dg/abi/pr70182.C 
b/gcc/testsuite/g++.dg/abi/pr70182.C
new file mode 100644
index 000000000000..d299362910c1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/pr70182.C
@@ -0,0 +1,28 @@
+// { dg-options "-fabi-version=0" }
+
+struct A {
+  template <typename T> int f ();
+  int operator+();
+  operator int ();
+  template <typename T> 
+  int operator-();
+};
+
+typedef int (A::*P)();
+
+template <P> struct S {};
+
+template <typename T> void g (S<&T::template f<int> >) {}
+template <typename T> void g (S<&T::operator+ >) {}
+template <typename T> void g (S<&T::operator int>) {}
+template <typename T> void g (S<&T::template operator- <double> >) {}
+
+template void g<A> (S<&A::f<int> >);
+template void g<A> (S<&A::operator+>);
+template void g<A> (S<&A::operator int>);
+template void g<A> (S<&A::operator-<double> >);
+
+// { dg-final { scan-assembler _Z1gI1AEv1SIXadsrT_1fIiEEE } }
+// { dg-final { scan-assembler _Z1gI1AEv1SIXadsrT_onplEE } }
+// { dg-final { scan-assembler _Z1gI1AEv1SIXadsrT_oncviEE } }
+// { dg-final { scan-assembler _Z1gI1AEv1SIXadsrT_onmiIdEEE } }
diff --git a/gcc/testsuite/g++.dg/dfp/mangle-1.C 
b/gcc/testsuite/g++.dg/dfp/mangle-1.C
index 455d3e4c0ef6..ee9644b27a53 100644
--- a/gcc/testsuite/g++.dg/dfp/mangle-1.C
+++ b/gcc/testsuite/g++.dg/dfp/mangle-1.C
@@ -1,4 +1,5 @@
 // { dg-do compile }
+// { dg-options "-fabi-version=10" }
 
 // Mangling of classes from std::decimal are special-cased.
 // Derived from g++.dg/abi/mangle13.C.
diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index d84929eca20d..f0dbf9381c6b 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -1594,6 +1594,8 @@ d_unqualified_name (struct d_info *di)
     ret = d_source_name (di);
   else if (IS_LOWER (peek))
     {
+      if (peek == 'o' && d_peek_next_char (di) == 'n')
+       d_advance (di, 2);
       ret = d_operator_name (di);
       if (ret != NULL && ret->type == DEMANGLE_COMPONENT_OPERATOR)
        {
diff --git a/libiberty/testsuite/demangle-expected 
b/libiberty/testsuite/demangle-expected
index 07e258fe58b3..c1cfa1545eca 100644
--- a/libiberty/testsuite/demangle-expected
+++ b/libiberty/testsuite/demangle-expected
@@ -4682,3 +4682,10 @@ _ZZ3foovE8localVar__9_
 
 _ZZ3foovE8localVar__12
 _ZZ3foovE8localVar__12
+
+# PR 70182
+_Z1gI1AEv1SIXadsrT_onplEE
+void g<A>(S<&A::operator+>)
+
+_Z1gI1AEv1SIXadsrT_plEE
+void g<A>(S<&A::operator+>)
-- 
Markus