Commit v3.4.0-rc1~494^2~4 (cmMakefile: Add API for elseif to create
backtrace., 2015-05-29) removed the use of cmMakefileCall to push/pop
execution context in favor of a new way to create backtraces.
However, a call to cmMakefile::GetExecutionContext is still invoked to
issue a contextual CMP0054 warning through cmConditionEvaluator. As
the elseif is not part of the call stack, this resulted in trying to
access an empty vector.
Avoid the attempt at getting execution context when evaluating elseif by
constructing a context and backtrace on behalf of the cmConditionEvaluator
in all cases.
if(TEST TestNameThatExists) will return true if a test with the name
TestNameThatExists has been added with add_test. The syntax is similar
to if(TARGET TargetName). Since use of "TEST" as an argument to if()
could previously be interpreted as a non-keyword argument, add policy
CMP0064 to treat it as a keyword as NEW behavior.
Stephen Kelly
Matt McCormick
Nils Gladitz