Hi,
This patch fixes a missed warning opportunity when casting from a D
class to a C++ class, and adds tests covering warnings within the code
generator.
Before, the warning was only issued when casting in the other direction.
Now a warning is printed for both directions.
Bootstrapped and regression tested on x86_64-linux-gnu/-m32/-x32.
Committed to mainline.
Regards
Iain.
---
gcc/d/ChangeLog:
* d-convert.cc (convert_expr): Warn when casting from a D class to a
C++ class.
gcc/testsuite/ChangeLog:
* gdc.dg/Waddress.d: New test.
* gdc.dg/Wcastresult1.d: New test.
* gdc.dg/Wcastresult2.d: New test.
---
gcc/d/d-convert.cc | 4 ++--
gcc/testsuite/gdc.dg/Waddress.d | 12 ++++++++++++
gcc/testsuite/gdc.dg/Wcastresult1.d | 18 ++++++++++++++++++
gcc/testsuite/gdc.dg/Wcastresult2.d | 12 ++++++++++++
4 files changed, 44 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gdc.dg/Waddress.d
create mode 100644 gcc/testsuite/gdc.dg/Wcastresult1.d
create mode 100644 gcc/testsuite/gdc.dg/Wcastresult2.d
diff --git a/gcc/d/d-convert.cc b/gcc/d/d-convert.cc
index 5e3e855b2cb..40e84f05347 100644
--- a/gcc/d/d-convert.cc
+++ b/gcc/d/d-convert.cc
@@ -430,10 +430,10 @@ convert_expr (tree exp, Type *etype, Type *totype)
/* d_convert will make a no-op cast. */
break;
}
- else if (cdfrom->isCPPclass ())
+ else if (cdfrom->isCPPclass () || cdto->isCPPclass ())
{
/* Downcasting in C++ is a no-op. */
- if (cdto->isCPPclass ())
+ if (cdfrom->isCPPclass () && cdto->isCPPclass ())
break;
/* Casting from a C++ interface to a class/non-C++ interface
diff --git a/gcc/testsuite/gdc.dg/Waddress.d b/gcc/testsuite/gdc.dg/Waddress.d
new file mode 100644
index 00000000000..74d7de80775
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/Waddress.d
@@ -0,0 +1,12 @@
+// { dg-do compile }
+// { dg-options "-Waddress" }
+
+void* ptr;
+
+int test()
+{
+ if (&ptr) // { dg-warning "the address of 'ptr' will always evaluate as
'true'" }
+ return 1;
+
+ return 0;
+}
diff --git a/gcc/testsuite/gdc.dg/Wcastresult1.d
b/gcc/testsuite/gdc.dg/Wcastresult1.d
new file mode 100644
index 00000000000..759b338acdc
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/Wcastresult1.d
@@ -0,0 +1,18 @@
+// { dg-do compile }
+// { dg-options "-Wcast-result" }
+
+extern(C++) class CPPClass
+{
+ int a;
+}
+
+extern(D) class DClass
+{
+ int a;
+}
+
+void test()
+{
+ auto cpptod = cast(DClass)new CPPClass; // { dg-warning "cast to
'Wcastresult1.DClass' will produce null result" }
+ auto dtocpp = cast(CPPClass)new DClass; // { dg-warning "cast to
'Wcastresult1.CPPClass' will produce null result" }
+}
diff --git a/gcc/testsuite/gdc.dg/Wcastresult2.d
b/gcc/testsuite/gdc.dg/Wcastresult2.d
new file mode 100644
index 00000000000..56d2dd20e82
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/Wcastresult2.d
@@ -0,0 +1,12 @@
+// { dg-do compile }
+// { dg-options "-Wcast-result" }
+
+void test()
+{
+ auto imvalue = 1.23i;
+ auto revalue = 1.23;
+
+ auto imtore = cast(double)imvalue; // { dg-warning "cast from 'idouble' to
'double' will produce zero result" }
+ auto retoim = cast(idouble)revalue; // { dg-warning "cast from 'double' to
'idouble' will produce zero result" }
+ return;
+}
--
2.25.1
