file: Add GENERATE command to produce files at generate time

The idea is to write to a temp file which contains generator
expressions, and at generate time, evaluate the generator expressions,
and write the result to a file.

Because executables on Windows are limited in the length of command line
it is possible to use, it is common to write command line arguments to a
file instead and specify the file as a source of arguments.

This new FILE(GENERATE) subcommand allows the use of generator
expressions to create such files so that they can be used with
add_custom_command for example.

1 files changed, 51 insertions, 0 deletions

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index df14331..f6cdeba 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -26,6 +26,7 @@
 #include "cmGeneratedFileStream.h"
 #include "cmGeneratorTarget.h"
 #include "cmGeneratorExpression.h"
+#include "cmGeneratorExpressionEvaluationFile.h"
 
 #include <cmsys/Directory.hxx>
 
@@ -69,6 +70,13 @@ cmGlobalGenerator::~cmGlobalGenerator()
     {
     delete this->LocalGenerators[i];
     }
+  for(std::vector<cmGeneratorExpressionEvaluationFile*>::const_iterator
+      li = this->EvaluationFiles.begin();
+      li != this->EvaluationFiles.end();
+      ++li)
+    {
+    delete *li;
+    }
   this->LocalGenerators.clear();
 
   if (this->ExtraGenerator)
@@ -981,6 +989,8 @@ void cmGlobalGenerator::Generate()
   // Create per-target generator information.
   this->CreateGeneratorTargets();
 
+  this->ProcessEvaluationFiles();
+
   // Compute the inter-target dependencies.
   if(!this->ComputeTargetDepends())
     {
@@ -2558,3 +2568,44 @@ std::string cmGlobalGenerator::EscapeJSON(const std::string& s) {
   }
   return result;
 }
+
+//----------------------------------------------------------------------------
+void cmGlobalGenerator::AddEvaluationFile(const std::string &inputFile,
+                    cmsys::auto_ptr<cmCompiledGeneratorExpression> outputExpr,
+                    cmMakefile *makefile,
+                    cmsys::auto_ptr<cmCompiledGeneratorExpression> condition,
+                    bool inputIsContent)
+{
+  this->EvaluationFiles.push_back(
+              new cmGeneratorExpressionEvaluationFile(inputFile, outputExpr,
+                                                      makefile, condition,
+                                                      inputIsContent));
+}
+
+//----------------------------------------------------------------------------
+void cmGlobalGenerator::ProcessEvaluationFiles()
+{
+  std::set<std::string> generatedFiles;
+  for(std::vector<cmGeneratorExpressionEvaluationFile*>::const_iterator
+      li = this->EvaluationFiles.begin();
+      li != this->EvaluationFiles.end();
+      ++li)
+    {
+    (*li)->Generate();
+    if (cmSystemTools::GetFatalErrorOccured())
+      {
+      return;
+      }
+    std::vector<std::string> files = (*li)->GetFiles();
+    for(std::vector<std::string>::const_iterator fi = files.begin();
+        fi != files.end(); ++fi)
+      {
+      if (!generatedFiles.insert(*fi).second)
+        {
+        cmSystemTools::Error("File to be generated by multiple different "
+          "commands: ", fi->c_str());
+        return;
+        }
+      }
+    }
+}