Fix soname in cross-compiled targets with Mac host (#11547)

The soname generation code was compile-time selected instead of runtime
selected.  The result is that a Mac-compiled cmake used to cross-compile
Mac -> Unix generates an soname of the form libfoo.x.y.so instead of
libfoo.so.x.y as expected.  Instead do a runtime check based on the
target platform.

Inspired-By: George Staikos <staikos@kde.org>

1 files changed, 24 insertions, 15 deletions

diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index ca61b1f..a226c40 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -3196,6 +3196,7 @@ void cmTarget::GetLibraryNames(std::string& name,
     // the library version as the soversion.
     soversion = version;
     }
+  bool isApple = this->Makefile->IsOn("APPLE");
 
   // Get the components of the library name.
   std::string prefix;
@@ -3207,26 +3208,33 @@ void cmTarget::GetLibraryNames(std::string& name,
   name = prefix+base+suffix;
 
   // The library's soname.
-#if defined(__APPLE__)
-  soName = prefix+base;
-#else
-  soName = name;
-#endif
+  if(isApple)
+    {
+    soName = prefix+base;
+    }
+  else
+    {
+    soName = name;
+    }
   if(soversion)
     {
     soName += ".";
     soName += soversion;
     }
-#if defined(__APPLE__)
-  soName += suffix;
-#endif
+  if(isApple)
+    {
+    soName += suffix;
+    }
 
   // The library's real name on disk.
-#if defined(__APPLE__)
-  realName = prefix+base;
-#else
+  if(isApple)
+    {
+    realName = prefix+base;
+    }
+  else
+    {
   realName = name;
-#endif
+    }
   if(version)
     {
     realName += ".";
@@ -3237,9 +3245,10 @@ void cmTarget::GetLibraryNames(std::string& name,
     realName += ".";
     realName += soversion;
     }
-#if defined(__APPLE__)
-  realName += suffix;
-#endif
+  if(isApple)
+    {
+    realName += suffix;
+    }
 
   // The import library name.
   if(this->GetType() == cmTarget::SHARED_LIBRARY ||