cmake_parse_arguments: consider duplicate keyword as warning

The behaviour of double specified keywords is rather undefined or at
least not clearly documented. This change introduces a strict check and
emits a warning in case a keyword has been specified more than once.

2 files changed, 43 insertions, 3 deletions

diff --git a/Tests/RunCMake/cmake_parse_arguments/Errors-stderr.txt b/Tests/RunCMake/cmake_parse_arguments/Errors-stderr.txt
index 5394eaf..f2ba9b8 100644
--- a/Tests/RunCMake/cmake_parse_arguments/Errors-stderr.txt
+++ b/Tests/RunCMake/cmake_parse_arguments/Errors-stderr.txt
@@ -1,14 +1,44 @@
-CMake Error at Errors\.cmake:1 \(cmake_parse_arguments\):
+CMake Error at Errors\.cmake:2 \(cmake_parse_arguments\):
   cmake_parse_arguments must be called with at least 4 arguments\.
 Call Stack \(most recent call first\):
   CMakeLists\.txt:3 \(include\)
 +
-CMake Error at Errors\.cmake:2 \(cmake_parse_arguments\):
+CMake Error at Errors\.cmake:3 \(cmake_parse_arguments\):
   cmake_parse_arguments must be called with at least 4 arguments\.
 Call Stack \(most recent call first\):
   CMakeLists\.txt:3 \(include\)
 +
-CMake Error at Errors\.cmake:3 \(cmake_parse_arguments\):
+CMake Error at Errors\.cmake:4 \(cmake_parse_arguments\):
   cmake_parse_arguments must be called with at least 4 arguments\.
 Call Stack \(most recent call first\):
   CMakeLists\.txt:3 \(include\)
++
+CMake Warning at Errors\.cmake:8 \(cmake_parse_arguments\):
+  keyword defined more than once: OPT
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:3 \(include\)
++
+CMake Warning at Errors\.cmake:9 \(cmake_parse_arguments\):
+  keyword defined more than once: OPT
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:3 \(include\)
++
+CMake Warning at Errors\.cmake:10 \(cmake_parse_arguments\):
+  keyword defined more than once: OPT
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:3 \(include\)
++
+CMake Warning at Errors\.cmake:12 \(cmake_parse_arguments\):
+  keyword defined more than once: OPT
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:3 \(include\)
++
+CMake Warning at Errors\.cmake:13 \(cmake_parse_arguments\):
+  keyword defined more than once: OPT
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:3 \(include\)
++
+CMake Warning at Errors\.cmake:14 \(cmake_parse_arguments\):
+  keyword defined more than once: OPT
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:3 \(include\)
diff --git a/Tests/RunCMake/cmake_parse_arguments/Errors.cmake b/Tests/RunCMake/cmake_parse_arguments/Errors.cmake
index 98e22e9..6a38081 100644
--- a/Tests/RunCMake/cmake_parse_arguments/Errors.cmake
+++ b/Tests/RunCMake/cmake_parse_arguments/Errors.cmake
@@ -1,4 +1,14 @@
+# wrong argument count
 cmake_parse_arguments()
 cmake_parse_arguments(prefix OPT)
 cmake_parse_arguments(prefix OPT SINGLE)
 cmake_parse_arguments(prefix OPT SINGLE MULTI) # not an error
+
+# duplicate keywords
+cmake_parse_arguments(prefix "OPT;OPT" "" "")
+cmake_parse_arguments(prefix "" "OPT;OPT" "")
+cmake_parse_arguments(prefix "" "" "OPT;OPT")
+
+cmake_parse_arguments(prefix "OPT" "OPT" "")
+cmake_parse_arguments(prefix "" "OPT" "OPT")
+cmake_parse_arguments(prefix "OPT" "" "OPT")