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, 118 insertions, 0 deletions

diff --git a/Source/cmGeneratorExpressionEvaluator.h b/Source/cmGeneratorExpressionEvaluator.h
new file mode 100644
index 0000000..5163ca0
--- /dev/null
+++ b/Source/cmGeneratorExpressionEvaluator.h
@@ -0,0 +1,118 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2012 Stephen Kelly <steveire@gmail.com>
+
+  Distributed under the OSI-approved BSD License (the "License");
+  see accompanying file Copyright.txt for details.
+
+  This software is distributed WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the License for more information.
+============================================================================*/
+#ifndef cmGeneratorExpressionEvaluator_h
+#define cmGeneratorExpressionEvaluator_h
+
+#include <vector>
+#include <string>
+
+//----------------------------------------------------------------------------
+struct cmGeneratorExpressionContext
+{
+  cmListFileBacktrace Backtrace;
+  std::set<cmTarget*> Targets;
+  cmMakefile *Makefile;
+  const char *Config;
+  cmTarget *Target;
+  bool Quiet;
+  bool HadError;
+};
+
+//----------------------------------------------------------------------------
+struct cmGeneratorExpressionEvaluator
+{
+  cmGeneratorExpressionEvaluator() {}
+  virtual ~cmGeneratorExpressionEvaluator() {}
+
+  enum Type
+  {
+    Text,
+    Generator
+  };
+
+  virtual Type GetType() const = 0;
+
+  virtual std::string Evaluate(cmGeneratorExpressionContext *context
+                              ) const = 0;
+
+private:
+  cmGeneratorExpressionEvaluator(const cmGeneratorExpressionEvaluator &);
+  void operator=(const cmGeneratorExpressionEvaluator &);
+};
+
+struct TextContent : public cmGeneratorExpressionEvaluator
+{
+  TextContent(const char *start, unsigned int length)
+    : Content(start), Length(length)
+  {
+
+  }
+
+  std::string Evaluate(cmGeneratorExpressionContext *) const
+  {
+    return std::string(this->Content, this->Length);
+  }
+
+  Type GetType() const
+  {
+    return cmGeneratorExpressionEvaluator::Text;
+  }
+
+  void Extend(unsigned int length)
+  {
+    this->Length += length;
+  }
+
+  unsigned int GetLength()
+  {
+    return this->Length;
+  }
+
+private:
+  const char *Content;
+  unsigned int Length;
+};
+
+//----------------------------------------------------------------------------
+struct GeneratorExpressionContent : public cmGeneratorExpressionEvaluator
+{
+  GeneratorExpressionContent(const char *startContent, unsigned int length);
+  void SetIdentifier(std::vector<cmGeneratorExpressionEvaluator*> identifier)
+  {
+    this->IdentifierChildren = identifier;
+  }
+
+  void SetParameters(
+        std::vector<std::vector<cmGeneratorExpressionEvaluator*> > parameters)
+  {
+    this->ParamChildren = parameters;
+  }
+
+  Type GetType() const
+  {
+    return cmGeneratorExpressionEvaluator::Generator;
+  }
+
+  std::string Evaluate(cmGeneratorExpressionContext *context) const;
+
+  std::string GetOriginalExpression() const;
+
+  ~GeneratorExpressionContent();
+
+private:
+  std::vector<cmGeneratorExpressionEvaluator*> IdentifierChildren;
+  std::vector<std::vector<cmGeneratorExpressionEvaluator*> > ParamChildren;
+  const char *StartContent;
+  unsigned int ContentLength;
+};
+
+#endif