Introduce ScopedSafeLocale class, use it in a few places

Signed-off-by: falkTX <falktx@falktx.com>

distrho/extra/ScopedSafeLocale.hpp

@@ -0,0 +1,136 @@
+/*
+ * DISTRHO Plugin Framework (DPF)
+ * Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef DISTRHO_SCOPED_SAFE_LOCALE_HPP_INCLUDED
+#define DISTRHO_SCOPED_SAFE_LOCALE_HPP_INCLUDED
+
+#include "../DistrhoUtils.hpp"
+
+#include <clocale>
+
+#if ! (defined(DISTRHO_OS_HAIKU) || defined(DISTRHO_OS_MAC) || defined(DISTRHO_OS_WINDOWS))
+# define DISTRHO_USE_NEWLOCALE
+#endif
+
+#if defined(DISTRHO_OS_WINDOWS) && __MINGW64_VERSION_MAJOR >= 5
+# define DISTRHO_USE_CONFIGTHREADLOCALE
+#endif
+
+START_NAMESPACE_DISTRHO
+
+// -----------------------------------------------------------------------
+// ScopedSafeLocale class definition
+
+/**
+   ScopedSafeLocale is a handy class for setting current locale to C on constructor, and revert back on destructor.
+   It tries to be thread-safe, but it is not always possible.
+
+   Put it inside a scope of code where string conversions happen to ensure they are consistent across many systems.
+   For example:
+
+   ```
+      // stack buffer to put converted float value in
+      char strbuf[0xff];
+
+      {
+          // safe locale operations during this scope
+          const ScopedSafeLocale sl;
+          snprintf(strbuf, 0xff, "%f", value);
+      }
+
+      // do something with `strbuf` now, locale is reverted and left just as it was before
+   ```
+ */
+class ScopedSafeLocale {
+public:
+    /*
+     * Constructor.
+     * Current system locale will saved, while "C" is set as the next one to use.
+     */
+    inline ScopedSafeLocale() noexcept;
+
+    /*
+     * Destructor.
+     * System locale will revert back to the one saved during constructor.
+     */
+    inline ~ScopedSafeLocale() noexcept;
+
+private:
+#ifdef DISTRHO_USE_NEWLOCALE
+    locale_t newloc, oldloc;
+#else
+# ifdef DISTRHO_USE_CONFIGTHREADLOCALE
+    const int oldthreadloc;
+# endif
+    char* const oldloc;
+#endif
+
+    DISTRHO_DECLARE_NON_COPYABLE(ScopedSafeLocale)
+    DISTRHO_PREVENT_HEAP_ALLOCATION
+};
+
+// -----------------------------------------------------------------------
+// ScopedSafeLocale class implementation
+
+#ifdef DISTRHO_USE_NEWLOCALE
+static constexpr const locale_t kNullLocale = (locale_t)nullptr;
+#endif
+
+inline ScopedSafeLocale::ScopedSafeLocale() noexcept
+#ifdef DISTRHO_USE_NEWLOCALE
+    : newloc(::newlocale(LC_NUMERIC_MASK, "C", kNullLocale)),
+      oldloc(newloc != kNullLocale ? ::uselocale(newloc) : kNullLocale) {}
+#else
+# ifdef DISTRHO_USE_CONFIGTHREADLOCALE
+    : oldthreadloc(_configthreadlocale(_ENABLE_PER_THREAD_LOCALE)),
+# else
+    :
+# endif
+      oldloc(strdup(::setlocale(LC_NUMERIC, nullptr)))
+{
+    ::setlocale(LC_NUMERIC, "C");
+}
+#endif
+
+inline ScopedSafeLocale::~ScopedSafeLocale() noexcept
+{
+#ifdef DISTRHO_USE_NEWLOCALE
+    if (oldloc != kNullLocale)
+        ::uselocale(oldloc);
+    if (newloc != kNullLocale)
+        ::freelocale(newloc);
+#else // DISTRHO_USE_NEWLOCALE
+    if (oldloc != nullptr)
+    {
+        ::setlocale(LC_NUMERIC, oldloc);
+        std::free(oldloc);
+    }
+
+# ifdef DISTRHO_USE_CONFIGTHREADLOCALE
+    if (oldthreadloc != -1)
+        _configthreadlocale(oldthreadloc);
+# endif
+#endif // DISTRHO_USE_NEWLOCALE
+}
+
+// -----------------------------------------------------------------------
+
+#undef DISTRHO_USE_CONFIGTHREADLOCALE
+#undef DISTRHO_USE_NEWLOCALE
+
+END_NAMESPACE_DISTRHO
+
+#endif // DISTRHO_SCOPED_SAFE_LOCALE_HPP_INCLUDED

distrho/extra/String.hpp

@@ -1,6 +1,6 @@
 /*
  * DISTRHO Plugin Framework (DPF)
- * Copyright (C) 2012-2016 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
  *
  * Permission to use, copy, modify, and/or distribute this software for any purpose with
  * or without fee is hereby granted, provided that the above copyright notice and this
@@ -18,6 +18,7 @@
 #define DISTRHO_STRING_HPP_INCLUDED
 
 #include "../DistrhoUtils.hpp"
+#include "../extra/ScopedSafeLocale.hpp"
 
 #include <algorithm>
 
@@ -187,8 +188,7 @@ public:
         char strBuf[0xff+1];
 
         {
-            // TODO
-            // const ScopedLocale csl;
+            const ScopedSafeLocale ssl;
             std::snprintf(strBuf, 0xff, "%.12g", static_cast<double>(value));
         }
 
@@ -208,8 +208,7 @@ public:
         char strBuf[0xff+1];
 
         {
-            // TODO
-            // const ScopedLocale csl;
+            const ScopedSafeLocale ssl;
             std::snprintf(strBuf, 0xff, "%.24g", value);
         }
 

distrho/src/DistrhoPluginVST.cpp

@@ -1,6 +1,6 @@
 /*
  * DISTRHO Plugin Framework (DPF)
- * Copyright (C) 2012-2020 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
  *
  * Permission to use, copy, modify, and/or distribute this software for any purpose with
  * or without fee is hereby granted, provided that the above copyright notice and this
@@ -15,6 +15,7 @@
  */
 
 #include "DistrhoPluginInternal.hpp"
+#include "../extra/ScopedSafeLocale.hpp"
 
 #if DISTRHO_PLUGIN_HAS_UI && ! DISTRHO_PLUGIN_HAS_EMBED_UI
 # undef DISTRHO_PLUGIN_HAS_UI
@@ -104,32 +105,6 @@ void snprintf_iparam(char* const dst, const int32_t value, const size_t size)
 
 // -----------------------------------------------------------------------
 
-class ScopedSafeLocale {
-public:
-    ScopedSafeLocale() noexcept
-        : locale(::strdup(::setlocale(LC_NUMERIC, nullptr)))
-    {
-        ::setlocale(LC_NUMERIC, "C");
-    }
-
-    ~ScopedSafeLocale() noexcept
-    {
-        if (locale != nullptr)
-        {
-            ::setlocale(LC_NUMERIC, locale);
-            std::free(locale);
-        }
-    }
-
-private:
-    char* const locale;
-
-    DISTRHO_DECLARE_NON_COPY_CLASS(ScopedSafeLocale)
-    DISTRHO_PREVENT_HEAP_ALLOCATION
-};
-
-// -----------------------------------------------------------------------
-
 struct ParameterCheckHelper
 {
     bool* parameterChecks;
@@ -778,9 +753,6 @@ public:
                     // add another separator
                     chunkStr += "\xff";
 
-                    // temporarily set locale to "C" while converting floats
-                    const ScopedSafeLocale ssl;
-
                     for (uint32_t i=0; i<paramCount; ++i)
                     {
                         if (fPlugin.isParameterOutputOrTrigger(i))