cmGeneratorExpression: Port users to two-stage processing

Removing the Process() API and removing the parameters from the
constructor will allow cmGeneratorExpressions to be cached and evaluated
with multiple configs for example, such as when evaluating target
properties.  This requires the creation of a new compiled representation
of cmGeneratorExpression.  The cmListFileBacktrace remains in the
constructor so that we can record where a particular generator
expression appeared in the CMakeLists file.

1 files changed, 39 insertions, 26 deletions

diff --git a/Source/cmGeneratorExpression.cxx b/Source/cmGeneratorExpression.cxx
index 198b43a..0885616 100644
--- a/Source/cmGeneratorExpression.cxx
+++ b/Source/cmGeneratorExpression.cxx
@@ -22,48 +22,50 @@
 
 //----------------------------------------------------------------------------
 cmGeneratorExpression::cmGeneratorExpression(
-  cmMakefile* mf, const char* config,
-  cmListFileBacktrace const& backtrace, bool quiet):
-  Makefile(mf), Config(config), Backtrace(backtrace), Quiet(quiet),
-  NeedsParsing(true)
+  cmListFileBacktrace const& backtrace):
+  Backtrace(backtrace), CompiledExpression(0)
 {
 }
 
 //----------------------------------------------------------------------------
-const char* cmGeneratorExpression::Process(std::string const& input)
+const cmCompiledGeneratorExpression &
+cmGeneratorExpression::Parse(std::string const& input)
 {
-  return this->Process(input.c_str());
+  return this->Parse(input.c_str());
 }
 
 //----------------------------------------------------------------------------
-const char* cmGeneratorExpression::Process(const char* input)
+const cmCompiledGeneratorExpression &
+cmGeneratorExpression::Parse(const char* input)
 {
-  this->Parse(input);
-  return this->Evaluate(this->Makefile, this->Config, this->Quiet);
-}
-
-//----------------------------------------------------------------------------
-void cmGeneratorExpression::Parse(const char* input)
-{
-  this->Evaluators.clear();
-
-  this->Input = input;
   cmGeneratorExpressionLexer l;
-  std::vector<cmGeneratorExpressionToken> tokens = l.Tokenize(this->Input);
-  this->NeedsParsing = l.GetSawGeneratorExpression();
+  std::vector<cmGeneratorExpressionToken> tokens = l.Tokenize(input);
+  bool needsParsing = l.GetSawGeneratorExpression();
+  std::vector<cmGeneratorExpressionEvaluator*> evaluators;
 
-  if (!this->NeedsParsing)
+  if (needsParsing)
     {
-    return;
+    cmGeneratorExpressionParser p(tokens);
+    p.Parse(evaluators);
     }
 
-  cmGeneratorExpressionParser p(tokens);
-  p.Parse(this->Evaluators);
+  delete this->CompiledExpression;
+  this->CompiledExpression = new cmCompiledGeneratorExpression(
+                                      this->Backtrace,
+                                      evaluators,
+                                      input,
+                                      needsParsing);
+  return *this->CompiledExpression;
+}
+
+cmGeneratorExpression::~cmGeneratorExpression()
+{
+  delete this->CompiledExpression;
 }
 
 //----------------------------------------------------------------------------
-const char *cmGeneratorExpression::Evaluate(
-  cmMakefile* mf, const char* config, bool quiet)
+const char *cmCompiledGeneratorExpression::Evaluate(
+  cmMakefile* mf, const char* config, bool quiet) const
 {
   if (!this->NeedsParsing)
     {
@@ -99,8 +101,19 @@ const char *cmGeneratorExpression::Evaluate(
   return this->Output.c_str();
 }
 
+cmCompiledGeneratorExpression::cmCompiledGeneratorExpression(
+              cmListFileBacktrace const& backtrace,
+              const std::vector<cmGeneratorExpressionEvaluator*> &evaluators,
+              const char *input, bool needsParsing)
+  : Backtrace(backtrace), Evaluators(evaluators), Input(input),
+    NeedsParsing(needsParsing)
+{
+
+}
+
+
 //----------------------------------------------------------------------------
-cmGeneratorExpression::~cmGeneratorExpression()
+cmCompiledGeneratorExpression::~cmCompiledGeneratorExpression()
 {
   std::vector<cmGeneratorExpressionEvaluator*>::const_iterator it
                                                   = this->Evaluators.begin();