EVIS: Reimplement using custom parsing code

Introduce a new implementation of ExpandVariablesInString and select
between the old and new implementations based on policy CMP0053.
Instead of cmCommandArgumentParserHelper, use a custom parser with our
own stack.  This is much faster and works well for our simple grammar.

The new behavior of CMP0053 should expand @VAR@ syntax only in certain
contexts.  All existing EVIS callers use "replaceAt == true" so
hard-code our call to the old implementation.  Update the signature to
default to "replaceAt == false" and pass "replaceAt == true" explicitly
in the call sites for configure_file and string(CONFIGURE).

Testing the configure (no generate) step with ParaView shows ~20%
performance improvement.

In terms of complete configure/generate steps, further testing with
ParaView shows a 20% performance improvement over 2.8.12.2 with Unix
Makefiles and minimal with Ninja. Ninja is less because it generate step
is the expensive part (future work will address this) by a long shot and
these changes help the configure step for the most part.

1 files changed, 24 insertions, 1 deletions

diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index ac00771..2bfd19b 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -679,7 +679,7 @@ public:
                                       const char* filename = 0,
                                       long line = -1,
                                       bool removeEmpty = false,
-                                      bool replaceAt = true) const;
+                                      bool replaceAt = false) const;
 
   /**
    * Remove any remaining variables in the string. Anything with ${var} or
@@ -994,6 +994,7 @@ private:
   mutable cmsys::RegularExpression cmDefineRegex;
   mutable cmsys::RegularExpression cmDefine01Regex;
   mutable cmsys::RegularExpression cmAtVarRegex;
+  mutable cmsys::RegularExpression cmNamedCurly;
 
   cmPropertyMap Properties;
 
@@ -1050,6 +1051,28 @@ private:
   // Enforce rules about CMakeLists.txt files.
   void EnforceDirectoryLevelRules() const;
 
+  // CMP0053 == old
+  cmake::MessageType ExpandVariablesInStringOld(
+                                  std::string& errorstr,
+                                  std::string& source,
+                                  bool escapeQuotes,
+                                  bool noEscapes,
+                                  bool atOnly,
+                                  const char* filename,
+                                  long line,
+                                  bool removeEmpty,
+                                  bool replaceAt) const;
+  // CMP0053 == new
+  cmake::MessageType ExpandVariablesInStringNew(
+                                  std::string& errorstr,
+                                  std::string& source,
+                                  bool escapeQuotes,
+                                  bool noEscapes,
+                                  bool atOnly,
+                                  const char* filename,
+                                  long line,
+                                  bool removeEmpty,
+                                  bool replaceAt) const;
   bool GeneratingBuildSystem;
   /**
    * Old version of GetSourceFileWithOutput(const std::string&) kept for