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, 151 insertions, 0 deletions

diff --git a/Source/cmGeneratorExpressionEvaluationFile.cxx b/Source/cmGeneratorExpressionEvaluationFile.cxx
new file mode 100644
index 0000000..cab99ed
--- /dev/null
+++ b/Source/cmGeneratorExpressionEvaluationFile.cxx
@@ -0,0 +1,151 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2013 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.
+============================================================================*/
+
+#include "cmGeneratorExpressionEvaluationFile.h"
+
+#include "cmMakefile.h"
+
+#include <assert.h>
+
+//----------------------------------------------------------------------------
+cmGeneratorExpressionEvaluationFile::cmGeneratorExpressionEvaluationFile(
+        const std::string &input,
+        cmsys::auto_ptr<cmCompiledGeneratorExpression> outputFileExpr,
+        cmMakefile *makefile,
+        cmsys::auto_ptr<cmCompiledGeneratorExpression> condition,
+        bool inputIsContent)
+  : Input(input),
+    OutputFileExpr(outputFileExpr),
+    Makefile(makefile),
+    Condition(condition),
+    InputIsContent(inputIsContent)
+{
+}
+
+//----------------------------------------------------------------------------
+void cmGeneratorExpressionEvaluationFile::Generate(const char *config,
+              cmCompiledGeneratorExpression* inputExpression,
+              std::map<std::string, std::string> &outputFiles)
+{
+  std::string rawCondition = this->Condition->GetInput();
+  if (!rawCondition.empty())
+    {
+    std::string condResult = this->Condition->Evaluate(this->Makefile, config);
+    if (condResult == "0")
+      {
+      return;
+      }
+    if (condResult != "1")
+      {
+      cmOStringStream e;
+      e << "Evaluation file condition \"" << rawCondition << "\" did "
+          "not evaluate to valid content. Got \"" << condResult << "\".";
+      this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str().c_str());
+      return;
+      }
+    }
+
+  const std::string outputFileName
+                    = this->OutputFileExpr->Evaluate(this->Makefile, config);
+  const std::string outputContent
+                          = inputExpression->Evaluate(this->Makefile, config);
+
+  std::map<std::string, std::string>::iterator it
+                                          = outputFiles.find(outputFileName);
+
+  if(it != outputFiles.end())
+    {
+    if (it->second == outputContent)
+      {
+      return;
+      }
+    cmOStringStream e;
+    e << "Evaluation file to be written multiple times for different "
+         "configurations with different content:\n  " << outputFileName;
+    this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str().c_str());
+    return;
+    }
+
+  this->Files.push_back(outputFileName);
+  outputFiles[outputFileName] = outputContent;
+
+  std::ofstream fout(outputFileName.c_str());
+
+  if(!fout)
+    {
+    cmOStringStream e;
+    e << "Evaluation file \"" << outputFileName << "\" cannot be written.";
+    this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str().c_str());
+    return;
+    }
+
+  fout << outputContent;
+
+  fout.close();
+}
+
+//----------------------------------------------------------------------------
+void cmGeneratorExpressionEvaluationFile::Generate()
+{
+  std::string inputContent;
+  if (this->InputIsContent)
+    {
+    inputContent = this->Input;
+    }
+  else
+    {
+    std::ifstream fin(this->Input.c_str());
+    if(!fin)
+      {
+      cmOStringStream e;
+      e << "Evaluation file \"" << this->Input << "\" cannot be read.";
+      this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str().c_str());
+      return;
+      }
+
+    std::string line;
+    std::string sep;
+    while(cmSystemTools::GetLineFromStream(fin, line))
+      {
+      inputContent += sep + line;
+      sep = "\n";
+      }
+    inputContent += sep;
+    }
+
+  cmListFileBacktrace lfbt = this->OutputFileExpr->GetBacktrace();
+  cmGeneratorExpression contentGE(lfbt);
+  cmsys::auto_ptr<cmCompiledGeneratorExpression> inputExpression
+                                              = contentGE.Parse(inputContent);
+
+  std::map<std::string, std::string> outputFiles;
+
+  std::vector<std::string> allConfigs;
+  this->Makefile->GetConfigurations(allConfigs);
+
+  if (allConfigs.empty())
+    {
+    this->Generate(0, inputExpression.get(), outputFiles);
+    }
+  else
+    {
+    for(std::vector<std::string>::const_iterator li = allConfigs.begin();
+        li != allConfigs.end(); ++li)
+      {
+      this->Generate(li->c_str(), inputExpression.get(), outputFiles);
+      if(cmSystemTools::GetFatalErrorOccured())
+        {
+        return;
+        }
+      }
+    }
+}