Merge pull request #2176 from 0xc0170/fix_#2171

Exporters - progen TARGETS lazy evaluated

tools/export/iar.py

@@ -35,16 +35,19 @@ class IAREmbeddedWorkbench(Exporter):
 
     MBED_CONFIG_HEADER_SUPPORTED = True
 
-    # backward compatibility with our scripts
+    @property
-    TARGETS = []
+    def TARGETS(self):
+        if not hasattr(self, "_targets_supported"):
+            self._targets_supported = []
             for target in TARGET_NAMES:
                 try:
                     if (ProGenDef('iar').is_supported(str(TARGET_MAP[target])) or
                         ProGenDef('iar').is_supported(TARGET_MAP[target].progen['target'])):
-                TARGETS.append(target)
+                        self._targets_supported.append(target)
                 except AttributeError:
                     # target is not supported yet
                     continue
+        return self._targets_supported
 
     def generate(self):
         """ Generates the project files """

tools/export/uvision4.py

@@ -36,16 +36,19 @@ class Uvision4(Exporter):
 
     MBED_CONFIG_HEADER_SUPPORTED = True
 
-    # backward compatibility with our scripts
+    @property
-    TARGETS = []
+    def TARGETS(self):
+        if not hasattr(self, "_targets_supported"):
+            self._targets_supported = []
             for target in TARGET_NAMES:
                 try:
                     if (ProGenDef('uvision').is_supported(str(TARGET_MAP[target])) or
                         ProGenDef('uvision').is_supported(TARGET_MAP[target].progen['target'])):
-                TARGETS.append(target)
+                        self._targets_supported.append(target)
                 except AttributeError:
                     # target is not supported yet
                     continue
+        return self._targets_supported
 
     def get_toolchain(self):
         return TARGET_MAP[self.target].default_toolchain

tools/export/uvision5.py

@@ -37,15 +37,22 @@ class Uvision5(Exporter):
     MBED_CONFIG_HEADER_SUPPORTED = True
 
     # backward compatibility with our scripts
-    TARGETS = []
+    def __init__(self):
+        self._targets = []
+
+    @property
+    def TARGETS(self):
+        if not hasattr(self, "_targets_supported"):
+            self._targets_supported = []
             for target in TARGET_NAMES:
                 try:
                     if (ProGenDef('uvision5').is_supported(str(TARGET_MAP[target])) or
                         ProGenDef('uvision5').is_supported(TARGET_MAP[target].progen['target'])):
-                TARGETS.append(target)
+                        self._targets_supported.append(target)
                 except AttributeError:
                     # target is not supported yet
                     continue
+        return self._targets_supported
 
     def get_toolchain(self):
         return TARGET_MAP[self.target].default_toolchain