Calls to `IsKeyword("...")` cause runtime construction of std::string.
Avoid possible repeated allocation by pre-allocating keyword strings
during initialization.
In commit v3.4.0-rc2~1^2 (cmIfCommand: Issue CMP0054 warning with
appropriate context, 2015-10-20) we added construction of a
cmListFileContext with conversion of the calling file path. This code
path runs on every condition (e.g. `if()`) and so the path conversion
has a noticeable performance cost. Fortunately the only use of this
context is for insertion into cmMakefile::CMP0054ReportedIds so we do
not need to convert the path. Simply drop the conversion.
While evaluating `if(MATCHES)` we get a `const char*` pointer to the
string to be matched. On code like
if(CMAKE_MATCH_COUNT MATCHES "Y")
the string to be matched may be owned by our own result variables.
We must move the value to our own buffer before clearing them.
Otherwise we risk reading freed storage.
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.
With PushScope and PopScope, keeping track of another bit of data for
each scope isn't easy. Instead, store it as another CMake variable so it
gets implicitly tracked along with everything else.
This works in a revert of commit
7d674b5f0b.
This reverts commit v3.1.0-rc1~557^2~2 (ClearMatches: Only clear matches
which were actually set, 2014-03-12). The optimization did not track
the match count in the same scope as the variables, allowing possible
inconsistency.
Resolve conflicts in Source/cmIfCommand.cxx, Source/cmMakefile.cxx,
and Source/cmMakefile.h by moving the changes to the new location
of the code involved.