From 243f500e46153904e9860a9a1f8145583aface02 Mon Sep 17 00:00:00 2001
From: Ivan Maidanski <ivmai@mail.ru>
Date: Thu, 15 Sep 2016 01:03:15 +0300
Subject: [PATCH] Eliminate 'constructor with 1 argument is not explicit'
 cppcheck warning (Cherry-pick commits 569fd66 and 7811301 from 'master'
 branch.)

Note that -D CPPCHECK should be passed to cppcheck to activate
this workaround.

* include/gc_allocator.h (GC_ATTR_EXPLICIT): New macro (defined to
"explicit" keyword if at least C++11 or CPPCHECK, otherwise to empty).
* include/gc_allocator.h (gc_allocator::gc_allocator,
gc_allocator_ignore_off_page::gc_allocator_ignore_off_page,
traceable_allocator::traceable_allocator): Use GC_ATTR_EXPLICIT.
* tests/test_cpp.cc (A::A, B::B, C::C, D::D): Likewise.
* tests/test_cpp.cc (GC_ATTR_EXPLICIT): Define macro in the same way as
in include/gc_allocator.h
---
 include/gc_allocator.h | 17 +++++++++++++----
 tests/test_cpp.cc      | 16 ++++++++++++----
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/include/gc_allocator.h b/include/gc_allocator.h
index 367cfe24..3ea80a07 100644
--- a/include/gc_allocator.h
+++ b/include/gc_allocator.h
@@ -50,6 +50,14 @@
 #  define GC_ATTR_UNUSED
 #endif
 
+#ifndef GC_ATTR_EXPLICIT
+# if (__cplusplus >= 201103L) || defined(CPPCHECK)
+#   define GC_ATTR_EXPLICIT explicit
+# else
+#   define GC_ATTR_EXPLICIT /* empty */
+# endif
+#endif
+
 /* First some helpers to allow us to dispatch on whether or not a type
  * is known to be pointer-free.
  * These are private, except that the client may invoke the
@@ -116,7 +124,8 @@ public:
     gc_allocator(const gc_allocator&) throw() {}
 # if !(GC_NO_MEMBER_TEMPLATES || 0 < _MSC_VER && _MSC_VER <= 1200)
   // MSVC++ 6.0 do not support member templates
-  template <class GC_Tp1> gc_allocator(const gc_allocator<GC_Tp1>&) throw() {}
+  template <class GC_Tp1> GC_ATTR_EXPLICIT
+    gc_allocator(const gc_allocator<GC_Tp1>&) throw() {}
 # endif
   ~gc_allocator() throw() {}
 
@@ -191,7 +200,7 @@ public:
     gc_allocator_ignore_off_page(const gc_allocator_ignore_off_page&) throw() {}
 # if !(GC_NO_MEMBER_TEMPLATES || 0 < _MSC_VER && _MSC_VER <= 1200)
   // MSVC++ 6.0 do not support member templates
-  template <class GC_Tp1>
+  template <class GC_Tp1> GC_ATTR_EXPLICIT
     gc_allocator_ignore_off_page(const gc_allocator_ignore_off_page<GC_Tp1>&)
         throw() {}
 # endif
@@ -271,8 +280,8 @@ public:
     traceable_allocator(const traceable_allocator&) throw() {}
 # if !(GC_NO_MEMBER_TEMPLATES || 0 < _MSC_VER && _MSC_VER <= 1200)
   // MSVC++ 6.0 do not support member templates
-  template <class GC_Tp1> traceable_allocator
-          (const traceable_allocator<GC_Tp1>&) throw() {}
+  template <class GC_Tp1> GC_ATTR_EXPLICIT
+    traceable_allocator(const traceable_allocator<GC_Tp1>&) throw() {}
 # endif
   ~traceable_allocator() throw() {}
 
diff --git a/tests/test_cpp.cc b/tests/test_cpp.cc
index ca45dc11..024efae4 100644
--- a/tests/test_cpp.cc
+++ b/tests/test_cpp.cc
@@ -76,10 +76,18 @@ extern "C" {
 # define ATTR_UNUSED /* empty */
 #endif
 
+#ifndef GC_ATTR_EXPLICIT
+# if (__cplusplus >= 201103L) || defined(CPPCHECK)
+#   define GC_ATTR_EXPLICIT explicit
+# else
+#   define GC_ATTR_EXPLICIT /* empty */
+# endif
+#endif
+
 class A {public:
     /* An uncollectible class. */
 
-    A( int iArg ): i( iArg ) {}
+    GC_ATTR_EXPLICIT A( int iArg ): i( iArg ) {}
     void Test( int iArg ) {
         my_assert( i == iArg );}
     int i;};
@@ -88,7 +96,7 @@ class A {public:
 class B: public GC_NS_QUALIFY(gc), public A { public:
     /* A collectible class. */
 
-    B( int j ): A( j ) {}
+    GC_ATTR_EXPLICIT B( int j ): A( j ) {}
     ~B() {
         my_assert( deleting );}
     static void Deleting( int on ) {
@@ -101,7 +109,7 @@ int B::deleting = 0;
 class C: public GC_NS_QUALIFY(gc_cleanup), public A { public:
     /* A collectible class with cleanup and virtual multiple inheritance. */
 
-    C( int levelArg ): A( levelArg ), level( levelArg ) {
+    GC_ATTR_EXPLICIT C( int levelArg ): A( levelArg ), level( levelArg ) {
         nAllocated++;
         if (level > 0) {
             left = new C( level - 1 );
@@ -133,7 +141,7 @@ class D: public GC_NS_QUALIFY(gc) { public:
     /* A collectible class with a static member function to be used as
     an explicit clean-up function supplied to ::new. */
 
-    D( int iArg ): i( iArg ) {
+    GC_ATTR_EXPLICIT D( int iArg ): i( iArg ) {
         nAllocated++;}
     static void CleanUp( void* obj, void* data ) {
         D* self = static_cast<D*>(obj);
-- 
2.40.0