New o3tl::try/doGet to obtain value from Any

...in an attempt to reduce usage of type-unsafe

void const * css::uno::Any::getValue()

These new functions are often more convenient to use than the existing ">>=" and
Any::get<T>.  Note how they are careful to provide a pointer directly into the
given Any, instead of creating temporaries.

As an example, replaced most calls of getValue across xmloff:

* Cases that first check for a specific type (via getValueType etc.) and then
call getValue can instead call tryGet.  (But beware that tryGet supports some
conversions, which a check for a specific type may have missed---either
intentionally or by accident.  Also beware the somewhat common idiom of
checking for TypeClass_ENUM and then using getValue to obtain a sal_Int32;
this cannot be replaced with a call to tryGet.)

* Cases that seem confident that the Any is of the correct type when calling
getValue (but apparently are confident due to some higher-layer protocol, as
the surrounding code does not do any checking via getValueType or similar) can
instead call doGet.  It throws an exception if it turns out the confidence
wasn't warranted.  (Many of the existing calls that directly dereferenced the
return value of getValue as sal_Bool look suspicious, in that the author might
have thought the given code would also cover a VOID Any---which technically it
even would have happened to do.  If any RuntimeExceptions thrown from these
doGet calls start to crop up, these changes need to be revisited.  Some may
even be rewritten as uses of ">>=".  But at least "make check" did not show
any such problems.  Also note that casting the value obtained from getValue to
any css::uno::Reference<X> with X being anything but the base
css::uno::XInterface was always prone to producing a bad pointer, in case the
interface actually stored in the Any derived from X via multiple inheritance.)

* Should there ever be cases where an Any is known to be of the requested type,
some additional forceGet could be introduced (which would assert instead of
throwing an exception).

Change-Id: I2d8739e86314eff73abfcafe01d806f5bc5c34db

1 files changed, 6 insertions, 3 deletions

diff --git a/xmloff/source/style/styleexp.cxx b/xmloff/source/style/styleexp.cxx
index f96e1c78f188..d87979d57cba 100644
--- a/xmloff/source/style/styleexp.cxx
+++ b/xmloff/source/style/styleexp.cxx
@@ -17,6 +17,9 @@
  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  */
 
+#include <sal/config.h>
+
+#include <o3tl/any.hxx>
 #include <tools/debug.hxx>
 #include <xmloff/nmspmap.hxx>
 #include <xmloff/xmlnmspe.hxx>
@@ -96,7 +99,7 @@ bool XMLStyleExport::exportStyle(
     if( xPropSetInfo->hasPropertyByName( sIsPhysical ) )
     {
         aAny = xPropSet->getPropertyValue( sIsPhysical );
-        if( !*static_cast<sal_Bool const *>(aAny.getValue()) )
+        if( !*o3tl::doGet<bool>(aAny) )
             return false;
     }
 
@@ -164,7 +167,7 @@ bool XMLStyleExport::exportStyle(
     if( xPropSetInfo->hasPropertyByName( sIsAutoUpdate ) )
     {
         aAny = xPropSet->getPropertyValue( sIsAutoUpdate );
-        if( *static_cast<sal_Bool const *>(aAny.getValue()) )
+        if( *o3tl::doGet<bool>(aAny) )
             GetExport().AddAttribute( XML_NAMESPACE_STYLE, XML_AUTO_UPDATE,
                                       XML_TRUE );
     }
@@ -474,7 +477,7 @@ void XMLStyleExport::exportStyleFamily(
             if (xPropSetInfo->hasPropertyByName( sIsPhysical ))
             {
                 Any aAny( xPropSet->getPropertyValue( sIsPhysical ) );
-                if (!*static_cast<sal_Bool const *>(aAny.getValue()))
+                if (!*o3tl::doGet<bool>(aAny))
                     continue;
             }