cmGeneratorExpression: Re-write for multi-stage evaluation

The expressions may be parsed and then cached and evaluated multiple
times.  They are evaluated lazily so that literals such as ',' can be
treated as universal parameter separators, and can be processed from
results without appearing literally, and without interfering with the
parsing/evaluation of the entire expression.

1 files changed, 36 insertions, 0 deletions

diff --git a/Tests/RunCMake/GeneratorExpression/BadCONFIG-stderr.txt b/Tests/RunCMake/GeneratorExpression/BadCONFIG-stderr.txt
index 7c86b25..1cfbf40 100644
--- a/Tests/RunCMake/GeneratorExpression/BadCONFIG-stderr.txt
+++ b/Tests/RunCMake/GeneratorExpression/BadCONFIG-stderr.txt
@@ -1,8 +1,44 @@
 CMake Error at BadCONFIG.cmake:1 \(add_custom_target\):
   Error evaluating generator expression:
 
+    \$<CONFIG>
+
+  \$<CONFIG> expression requires exactly one parameter.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at BadCONFIG.cmake:1 \(add_custom_target\):
+  Error evaluating generator expression:
+
     \$<CONFIG:.>
 
   Expression syntax not recognized.
 Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at BadCONFIG.cmake:1 \(add_custom_target\):
+  Error evaluating generator expression:
+
+    \$<CONFIG:Foo,Bar>
+
+  \$<CONFIG> expression requires exactly one parameter.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at BadCONFIG.cmake:1 \(add_custom_target\):
+  Error evaluating generator expression:
+
+    \$<CONFIG:Foo-Bar>
+
+  Expression syntax not recognized.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at BadCONFIG.cmake:1 \(add_custom_target\):
+  Error evaluating generator expression:
+
+    \$<CONFIG:Foo-Nested>
+
+  Expression syntax not recognized.
+Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)$