Revise implementation of case-insensitive command names

Store both the as-written and lower-case command names and use
the latter to avoid case-insensitive string comparisons.

With this I obtain 2-6% speed increase (on Windows) for the configure
step with no significant changes in memory usage.  A case-insensitive
comparison is a lot slower than just calling `==` because the operator
will use things like memcmp, so prefer the latter.

The `cmSystemTools::LowerCase` function allocates a new string each time
it is called, so before this change we were allocating in:

* cmMakefile::Configure two times for each function
  (to look for `cmake_minimum_required` and `project`)
* cmMakefile::ExecuteCommand twice by function by calling
  cmState::GetCommand and copying the name

Now we are only allocating once by function instead of four.

1 files changed, 3 insertions, 4 deletions

diff --git a/Source/cmFunctionCommand.cxx b/Source/cmFunctionCommand.cxx
index 774df84..67c9e9a 100644
--- a/Source/cmFunctionCommand.cxx
+++ b/Source/cmFunctionCommand.cxx
@@ -9,7 +9,6 @@
 #include "cmMakefile.h"
 #include "cmPolicies.h"
 #include "cmState.h"
-#include "cmSystemTools.h"
 
 // define the class for function commands
 class cmFunctionHelperCommand : public cmCommand
@@ -128,9 +127,9 @@ bool cmFunctionFunctionBlocker::IsFunctionBlocked(
 {
   // record commands until we hit the ENDFUNCTION
   // at the ENDFUNCTION call we shift gears and start looking for invocations
-  if (!cmSystemTools::Strucmp(lff.Name.c_str(), "function")) {
+  if (lff.Name.Lower == "function") {
     this->Depth++;
-  } else if (!cmSystemTools::Strucmp(lff.Name.c_str(), "endfunction")) {
+  } else if (lff.Name.Lower == "endfunction") {
     // if this is the endfunction for this function then execute
     if (!this->Depth) {
       // create a new command and add it to cmake
@@ -157,7 +156,7 @@ bool cmFunctionFunctionBlocker::IsFunctionBlocked(
 bool cmFunctionFunctionBlocker::ShouldRemove(const cmListFileFunction& lff,
                                              cmMakefile& mf)
 {
-  if (!cmSystemTools::Strucmp(lff.Name.c_str(), "endfunction")) {
+  if (lff.Name.Lower == "endfunction") {
     std::vector<std::string> expandedArguments;
     mf.ExpandArguments(lff.Arguments, expandedArguments,
                        this->GetStartingContext().FilePath.c_str());