From 26e98c34dc2a1414f79b6a12de3c4ca060af7578 Mon Sep 17 00:00:00 2001
From: Stephen Kelly <steveire@gmail.com>
Date: Tue, 22 Jul 2014 15:07:39 +0200
Subject: [PATCH] file(GENERATE): Re-run cmake when appropriate.

Re-run if the input file changes or if the output file is removed.

This only works with the Makefile generators currently.  The limitation
of the Ninja generator is tracked as issue #15256.  The IDE
generators will need larger refactoring as they currently rely on
being able to determine the depends and output files at the start of
generate-time, which is too early for the file(GENERATE) case.
---
 .../cmGeneratorExpressionEvaluationFile.cxx   |  2 ++
 .../File_Generate/ReRunCMake-result.txt       |  1 +
 .../File_Generate/ReRunCMake-stderr.txt       |  1 +
 Tests/RunCMake/File_Generate/ReRunCMake.cmake |  5 +++
 .../RunCMake/File_Generate/RunCMakeTest.cmake | 31 +++++++++++++++++++
 5 files changed, 40 insertions(+)
 create mode 100644 Tests/RunCMake/File_Generate/ReRunCMake-result.txt
 create mode 100644 Tests/RunCMake/File_Generate/ReRunCMake-stderr.txt
 create mode 100644 Tests/RunCMake/File_Generate/ReRunCMake.cmake

diff --git a/Source/cmGeneratorExpressionEvaluationFile.cxx b/Source/cmGeneratorExpressionEvaluationFile.cxx
index 1a101ddf6..03d0bc63d 100644
--- a/Source/cmGeneratorExpressionEvaluationFile.cxx
+++ b/Source/cmGeneratorExpressionEvaluationFile.cxx
@@ -80,6 +80,7 @@ void cmGeneratorExpressionEvaluationFile::Generate(const std::string& config,
     return;
     }
 
+  this->Makefile->AddCMakeOutputFile(outputFileName.c_str());
   this->Files.push_back(outputFileName);
   outputFiles[outputFileName] = outputContent;
 
@@ -117,6 +118,7 @@ void cmGeneratorExpressionEvaluationFile::Generate()
     }
   else
     {
+    this->Makefile->AddCMakeDependFile(this->Input.c_str());
     cmSystemTools::GetPermissions(this->Input.c_str(), perm);
     cmsys::ifstream fin(this->Input.c_str());
     if(!fin)
diff --git a/Tests/RunCMake/File_Generate/ReRunCMake-result.txt b/Tests/RunCMake/File_Generate/ReRunCMake-result.txt
new file mode 100644
index 000000000..573541ac9
--- /dev/null
+++ b/Tests/RunCMake/File_Generate/ReRunCMake-result.txt
@@ -0,0 +1 @@
+0
diff --git a/Tests/RunCMake/File_Generate/ReRunCMake-stderr.txt b/Tests/RunCMake/File_Generate/ReRunCMake-stderr.txt
new file mode 100644
index 000000000..10f32932e
--- /dev/null
+++ b/Tests/RunCMake/File_Generate/ReRunCMake-stderr.txt
@@ -0,0 +1 @@
+^$
diff --git a/Tests/RunCMake/File_Generate/ReRunCMake.cmake b/Tests/RunCMake/File_Generate/ReRunCMake.cmake
new file mode 100644
index 000000000..109d60e6f
--- /dev/null
+++ b/Tests/RunCMake/File_Generate/ReRunCMake.cmake
@@ -0,0 +1,5 @@
+
+file(GENERATE
+  OUTPUT output_file.txt
+  INPUT "${CMAKE_CURRENT_BINARY_DIR}/input_file.txt"
+)
diff --git a/Tests/RunCMake/File_Generate/RunCMakeTest.cmake b/Tests/RunCMake/File_Generate/RunCMakeTest.cmake
index 7db77d447..97f93d5af 100644
--- a/Tests/RunCMake/File_Generate/RunCMakeTest.cmake
+++ b/Tests/RunCMake/File_Generate/RunCMakeTest.cmake
@@ -61,3 +61,34 @@ if (UNIX AND EXISTS /bin/sh)
     message(SEND_ERROR "Generated script did not execute correctly:\n${script_output}\n====\n${script_error}")
   endif()
 endif()
+
+if (RunCMake_GENERATOR MATCHES Makefiles)
+  file(MAKE_DIRECTORY "${RunCMake_BINARY_DIR}/ReRunCMake-build/")
+  file(WRITE "${RunCMake_BINARY_DIR}/ReRunCMake-build/input_file.txt" "InitialContent\n")
+
+  set(RunCMake_TEST_NO_CLEAN ON)
+  run_cmake(ReRunCMake)
+  unset(RunCMake_TEST_NO_CLEAN)
+  file(TIMESTAMP "${RunCMake_BINARY_DIR}/ReRunCMake-build/output_file.txt" timestamp ${timeformat})
+  if(NOT timestamp)
+    message(SEND_ERROR "Could not get timestamp for \"${RunCMake_BINARY_DIR}/ReRunCMake-build/output_file.txt\"")
+  endif()
+
+  execute_process(COMMAND ${CMAKE_COMMAND} -E sleep 1)
+
+  file(WRITE "${RunCMake_BINARY_DIR}/ReRunCMake-build/input_file.txt" "ChangedContent\n")
+  execute_process(COMMAND ${CMAKE_COMMAND} --build "${RunCMake_BINARY_DIR}/ReRunCMake-build/")
+  file(READ "${RunCMake_BINARY_DIR}/ReRunCMake-build/output_file.txt" out_content)
+
+  if(NOT out_content STREQUAL "ChangedContent\n")
+    message(SEND_ERROR "File did not change: \"${RunCMake_BINARY_DIR}/ReRunCMake-build/output_file.txt\"")
+  endif()
+
+
+  file(REMOVE "${RunCMake_BINARY_DIR}/ReRunCMake-build/output_file.txt")
+  execute_process(COMMAND ${CMAKE_COMMAND} --build "${RunCMake_BINARY_DIR}/ReRunCMake-build/")
+
+  if (NOT EXISTS "${RunCMake_BINARY_DIR}/ReRunCMake-build/output_file.txt")
+    message(SEND_ERROR "File did not re-generate: \"${RunCMake_BINARY_DIR}/ReRunCMake-build/output_file.txt\"")
+  endif()
+endif()