> Date: Mon, 22 Jan 2024 14:33:59 -0500
> From: Marek Polacek <[email protected]>
> The problem seems to be more about conversion so
> g++.dg/conversion/reinterpret5.C
> or g++.dg/cpp0x/constexpr-reinterpret3.C seems more appropriate.
>
> > @@ -0,0 +1,49 @@
>
> Please add
>
> PR c++/113545
> > + unsigned const char c = swbar(reinterpret_cast<__UINTPTR_TYPE__>(&foo));
> > + xyzzy(c);
> > + unsigned const char d = ifbar(reinterpret_cast<__UINTPTR_TYPE__>(&foo));
>
> I suppose we should also test a C-style cast (which leads to a
> reinterpret_cast
> in this case).
>
> Maybe check we get an error when c/d are constexpr (that used to ICE).
Like this? Not sure about the value of that variant, but here goes.
I checked that these behave as expected (xfail as ICE properly) without the
previosly posted patch to cp/constexpr.cc and XPASS with it applied.
Ok to commit?
-- >8 --
Subject: [PATCH] c++: testcases for PR113545 (constexpr with switch and
passing non-constexpr parameter)
gcc/testsuite:
PR c++/113545
* g++.dg/cpp0x/constexpr-reinterpret3.C,
g++.dg/cpp0x/constexpr-reinterpret4.C: New tests.
---
.../g++.dg/cpp0x/constexpr-reinterpret3.C | 55 +++++++++++++++++++
.../g++.dg/cpp0x/constexpr-reinterpret4.C | 54 ++++++++++++++++++
2 files changed, 109 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret3.C
create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret4.C
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret3.C
b/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret3.C
new file mode 100644
index 000000000000..319cc5e8bee9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret3.C
@@ -0,0 +1,55 @@
+// PR c++/113545
+// { dg-do run { target c++11 } }
+// { dg-ice "PR112545 - constexpr function with switch called for
reinterpret_cast" }
+
+char foo;
+
+// This one caught a call to gcc_unreachable in
+// cp/constexpr.cc:label_matches, when passed a convert_expr from the
+// cast in the call.
+constexpr unsigned char swbar(__UINTPTR_TYPE__ baz)
+{
+ switch (baz)
+ {
+ case 13:
+ return 11;
+ case 14:
+ return 78;
+ case 2048:
+ return 13;
+ default:
+ return 42;
+ }
+}
+
+// For reference, the equivalent* if-statements.
+constexpr unsigned char ifbar(__UINTPTR_TYPE__ baz)
+{
+ if (baz == 13)
+ return 11;
+ else if (baz == 14)
+ return 78;
+ else if (baz == 2048)
+ return 13;
+ else
+ return 42;
+}
+
+__attribute__ ((__noipa__))
+void xyzzy(int x)
+{
+ if (x != 42)
+ __builtin_abort ();
+}
+
+int main()
+{
+ unsigned const char c = swbar(reinterpret_cast<__UINTPTR_TYPE__>(&foo));
+ xyzzy(c);
+ unsigned const char d = ifbar(reinterpret_cast<__UINTPTR_TYPE__>(&foo));
+ xyzzy(d);
+ unsigned const char e = swbar((__UINTPTR_TYPE__) &foo);
+ xyzzy(e);
+ unsigned const char f = ifbar((__UINTPTR_TYPE__) &foo);
+ xyzzy(f);
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret4.C
b/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret4.C
new file mode 100644
index 000000000000..4d0fdf2c0a78
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret4.C
@@ -0,0 +1,54 @@
+// PR c++/113545
+// { dg-do compile { target c++11 } }
+
+char foo;
+
+// This one caught a call to gcc_unreachable in
+// cp/constexpr.cc:label_matches, when passed a convert_expr from the
+// cast in the call.
+constexpr unsigned char swbar(__UINTPTR_TYPE__ baz)
+{
+ switch (baz)
+ {
+ case 13:
+ return 11;
+ case 14:
+ return 78;
+ case 2048:
+ return 13;
+ default:
+ return 42;
+ }
+}
+
+// For reference, the equivalent* if-statements.
+constexpr unsigned char ifbar(__UINTPTR_TYPE__ baz)
+{
+ if (baz == 13)
+ return 11;
+ else if (baz == 14)
+ return 78;
+ else if (baz == 2048)
+ return 13;
+ else
+ return 42;
+}
+
+__attribute__ ((__noipa__))
+void xyzzy(int x)
+{
+ if (x != 42)
+ __builtin_abort ();
+}
+
+int main()
+{
+ unsigned constexpr char c = swbar(reinterpret_cast<__UINTPTR_TYPE__>(&foo));
// { dg-error "conversion from pointer type" }
+ xyzzy(c);
+ unsigned constexpr char d = ifbar(reinterpret_cast<__UINTPTR_TYPE__>(&foo));
// { dg-error "conversion from pointer type" }
+ xyzzy(d);
+ unsigned constexpr char e = swbar((__UINTPTR_TYPE__) &foo); // { dg-error
"conversion from pointer type" }
+ xyzzy(e);
+ unsigned constexpr char f = ifbar((__UINTPTR_TYPE__) &foo); // { dg-error
"conversion from pointer type" }
+ xyzzy(f);
+}
--
2.30.2
