Add the JOIN generator expression.

This generator expression joins a list with a separator. The separator
may contain arbitrary content, such as commas, which is ordinarily a
delimiter in the generator expression syntax.

2 files changed, 32 insertions, 0 deletions

diff --git a/Source/cmDocumentGeneratorExpressions.h b/Source/cmDocumentGeneratorExpressions.h
index 6cc3f25..ac52db0 100644
--- a/Source/cmDocumentGeneratorExpressions.h
+++ b/Source/cmDocumentGeneratorExpressions.h
@@ -28,6 +28,8 @@
   "strings which contain a ',' for example.\n"                          \
   "  $<SEMICOLON>              = A literal ';'. Used to prevent "       \
   "list expansion on an argument with ';'.\n"                           \
+  "  $<JOIN:list,...>          = joins the list with the content of "   \
+  "\"...\"\n"                                                           \
   "  $<TARGET_NAME:...>        = Marks ... as being the name of a "     \
   "target.  This is required if exporting targets to multiple "         \
   "dependent export sets.  The '...' must be a literal name of a "      \
diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index efb8117..6092aa2 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -307,6 +307,34 @@ static const struct ConfigurationTestNode : public cmGeneratorExpressionNode
 } configurationTestNode;
 
 
+static const struct JoinNode : public cmGeneratorExpressionNode
+{
+  JoinNode() {}
+
+  virtual int NumExpectedParameters() const { return 2; }
+
+  virtual bool AcceptsArbitraryContentParameter() const { return true; }
+
+  std::string Evaluate(const std::vector<std::string> &parameters,
+                       cmGeneratorExpressionContext *,
+                       const GeneratorExpressionContent *,
+                       cmGeneratorExpressionDAGChecker *) const
+  {
+    std::string result;
+
+    std::vector<std::string> list;
+    cmSystemTools::ExpandListArgument(parameters.front(), list);
+    std::string sep;
+    for(std::vector<std::string>::const_iterator li = list.begin();
+      li != list.end(); ++li)
+      {
+      result += sep + *li;
+      sep = parameters[1];
+      }
+    return result;
+  }
+} joinNode;
+
 //----------------------------------------------------------------------------
 static const char* targetPropertyTransitiveWhitelist[] = {
     "INTERFACE_INCLUDE_DIRECTORIES"
@@ -973,6 +1001,8 @@ cmGeneratorExpressionNode* GetNode(const std::string &identifier)
     return &installInterfaceNode;
   else if (identifier == "INSTALL_PREFIX")
     return &installPrefixNode;
+  else if (identifier == "JOIN")
+    return &joinNode;
   return 0;
 
 }