uARM: Fix depreciate warning printing wrongly for other toolchains.

Author: rajkan01

tools/build_api.py

@@ -236,15 +236,19 @@ def find_valid_toolchain(target, toolchain):
         internal_tc_name = get_toolchain_name(target, toolchain_name)
         if toolchain == "ARM" and toolchain_name == "ARMC5" and index != 0:
             end_warnings.append(ARMC5_MIGRATION_WARNING)
+            if target.default_toolchain == "uARM":
+                end_warnings.append(UARM_DEFAULT_TOOLCHAIN_WARNING)
         if not TOOLCHAIN_CLASSES[internal_tc_name].check_executable():
             search_path = TOOLCHAIN_PATHS[internal_tc_name] or "No path set"
             last_error = (
                 "Could not find executable for {}.\n"
                 "Currently set search path: {}"
             ).format(toolchain_name, search_path)
         else:
-            if toolchain_name == "uARM" or target.default_toolchain == "uARM":
-                 end_warnings.append(UARM_TOOLCHAIN_WARNING)
+            if toolchain_name == "uARM":
+                end_warnings.append(UARM_TOOLCHAIN_WARNING)
+            elif toolchain_name == "ARMC6" and target.default_toolchain == "uARM":                
+                end_warnings.append(UARM_DEFAULT_TOOLCHAIN_WARNING)
             return toolchain_name, internal_tc_name, end_warnings
     else:
         if last_error:

tools/toolchains/arm.py

@@ -44,6 +44,13 @@
     "please visit https://os.mbed.com/docs/mbed-os/latest/reference/using-small-c-libraries.html"
 )
 
+UARM_DEFAULT_TOOLCHAIN_WARNING = (
+    "Warning: We noticed that this target default_toolchain overrides --toolchain option with uARM Toolchain. "
+    "We are deprecating the use of uARM Toolchain. "
+    "For more information on how to use the ARM toolchain with small C libraries, "
+    "please visit https://os.mbed.com/docs/mbed-os/latest/reference/using-small-c-libraries.html"
+)
+
 class ARM(mbedToolchain):
     LINKER_EXT = '.sct'
     LIBRARY_EXT = '.ar'