1 files changed, 74 insertions, 5 deletions

diff --git a/Source/cmMakefileTargetGenerator.cxx b/Source/cmMakefileTargetGenerator.cxx
index c7a7110..641cd23 100644
--- a/Source/cmMakefileTargetGenerator.cxx
+++ b/Source/cmMakefileTargetGenerator.cxx
@@ -769,8 +769,8 @@ cmMakefileTargetGenerator
     }
 
   // Write the rule.
-  this->LocalGenerator->WriteMakeRule(*this->BuildFileStream, 0,
-                                      outputs, depends, commands, false);
+  this->WriteMakeRule(*this->BuildFileStream, 0, outputs,
+                      depends, commands, false);
 
   bool do_preprocess_rules = lang_has_preprocessor &&
     this->LocalGenerator->GetCreatePreprocessedSourceRules();
@@ -991,6 +991,57 @@ void cmMakefileTargetGenerator::WriteTargetCleanRules()
                                       depends, commands, true);
 }
 
+//----------------------------------------------------------------------------
+void cmMakefileTargetGenerator::WriteMakeRule(
+  std::ostream& os,
+  const char* comment,
+  const std::vector<std::string>& outputs,
+  const std::vector<std::string>& depends,
+  const std::vector<std::string>& commands,
+  bool symbolic,
+  bool in_help)
+{
+  if (outputs.size() == 0)
+    {
+    return;
+    }
+
+  // We always attach the actual commands to the first output.
+  this->LocalGenerator->WriteMakeRule(os, comment, outputs[0], depends,
+                                      commands, symbolic, in_help);
+
+  // For single outputs, we are done.
+  if (outputs.size() == 1)
+    {
+    return;
+    }
+
+  // For multiple outputs, make the extra ones depend on the first one.
+  std::vector<std::string> const output_depends(1, outputs[0]);
+  for (std::vector<std::string>::const_iterator o = outputs.begin()+1;
+       o != outputs.end(); ++o)
+    {
+    // Touch the extra output so "make" knows that it was updated,
+    // but only if the output was acually created.
+    std::string const out = this->Convert(*o, cmLocalGenerator::HOME_OUTPUT,
+                                          cmLocalGenerator::SHELL);
+    std::vector<std::string> output_commands;
+    if (!symbolic)
+      {
+      output_commands.push_back("@$(CMAKE_COMMAND) -E touch_nocreate " + out);
+      }
+    this->LocalGenerator->WriteMakeRule(os, 0, *o, output_depends,
+                                        output_commands, symbolic, in_help);
+
+    if (!symbolic)
+      {
+      // At build time, remove the first output if this one does not exist
+      // so that "make" will rerun the real commands that create this one.
+      MultipleOutputPairsType::value_type p(*o, outputs[0]);
+      this->MultipleOutputPairs.insert(p);
+      }
+    }
+}
 
 //----------------------------------------------------------------------------
 void cmMakefileTargetGenerator::WriteTargetDependRules()
@@ -1011,6 +1062,25 @@ void cmMakefileTargetGenerator::WriteTargetDependRules()
   this->LocalGenerator->
     WriteDependLanguageInfo(*this->InfoFileStream,*this->Target);
 
+  // Store multiple output pairs in the depend info file.
+  if(!this->MultipleOutputPairs.empty())
+    {
+    *this->InfoFileStream
+      << "\n"
+      << "# Pairs of files generated by the same build rule.\n"
+      << "set(CMAKE_MULTIPLE_OUTPUT_PAIRS\n";
+    for(MultipleOutputPairsType::const_iterator pi =
+          this->MultipleOutputPairs.begin();
+        pi != this->MultipleOutputPairs.end(); ++pi)
+      {
+      *this->InfoFileStream
+        << "  " << this->LocalGenerator->EscapeForCMake(pi->first)
+        << " "  << this->LocalGenerator->EscapeForCMake(pi->second)
+        << "\n";
+      }
+    *this->InfoFileStream << "  )\n\n";
+    }
+
   // Store list of targets linked directly or transitively.
   {
   *this->InfoFileStream
@@ -1206,9 +1276,8 @@ void cmMakefileTargetGenerator
       symbolic = sf->GetPropertyAsBool("SYMBOLIC");
       }
     }
-  this->LocalGenerator->WriteMakeRule(*this->BuildFileStream, 0,
-                                      outputs, depends, commands,
-                                      symbolic);
+  this->WriteMakeRule(*this->BuildFileStream, 0, outputs,
+                      depends, commands, symbolic);
 
   // If the rule has changed make sure the output is rebuilt.
   if(!symbolic)