ENH: Define RULE_LAUNCH_* properties

This defines global, directory, and target properties
RULE_LAUNCH_COMPILE, RULE_LAUNCH_LINK, and RULE_LAUNCH_CUSTOM.  Their
values specify 'launcher' command lines which are prefixed to compile,
link, and custom build rules by Makefile generators.

Modules/CTestTargets.cmake

@@ -50,6 +50,7 @@ IF(NOT _CTEST_TARGETS_ADDED)
     ADD_CUSTOM_TARGET(${mode}
       ${CMAKE_CTEST_COMMAND} ${__conf_types} -D ${mode}
       )
+    SET_PROPERTY(TARGET ${mode} PROPERTY RULE_LAUNCH_CUSTOM "")
   ENDFOREACH(mode)
 
   # For Makefile generators add more granular targets.
@@ -63,6 +64,7 @@ IF(NOT _CTEST_TARGETS_ADDED)
         ADD_CUSTOM_TARGET(${mode}${testtype}
           ${CMAKE_CTEST_COMMAND} ${__conf_types} -D ${mode}${testtype}
           )
+        SET_PROPERTY(TARGET ${mode}${testtype} PROPERTY RULE_LAUNCH_CUSTOM "")
       ENDFOREACH(testtype)
     ENDFOREACH(mode)
   ENDIF("${CMAKE_GENERATOR}" MATCHES Make)

Source/cmLocalGenerator.cxx

@@ -1034,6 +1034,8 @@ cmLocalGenerator::ExpandRuleVariables(std::string& s,
 {
   std::vector<std::string> enabledLanguages;
   this->GlobalGenerator->GetEnabledLanguages(enabledLanguages);
+  this->InsertRuleLauncher(s, replaceValues.CMTarget,
+                           replaceValues.RuleLauncher);
   std::string::size_type start = s.find('<');
   // no variables to expand
   if(start == s.npos)
@@ -1075,6 +1077,32 @@ cmLocalGenerator::ExpandRuleVariables(std::string& s,
   s = expandedInput;
 }
 
+//----------------------------------------------------------------------------
+const char* cmLocalGenerator::GetRuleLauncher(cmTarget* target,
+                                              const char* prop)
+{
+  if(target)
+    {
+    return target->GetProperty(prop);
+    }
+  else
+    {
+    return this->Makefile->GetProperty(prop);
+    }
+}
+
+//----------------------------------------------------------------------------
+void cmLocalGenerator::InsertRuleLauncher(std::string& s, cmTarget* target,
+                                          const char* prop)
+{
+  if(const char* val = this->GetRuleLauncher(target, prop))
+    {
+    cmOStringStream wrapped;
+    wrapped << val << " " << s;
+    s = wrapped.str();
+    }
+}
+
 //----------------------------------------------------------------------------
 std::string
 cmLocalGenerator::ConvertToOutputForExistingCommon(const char* remote,

Source/cmLocalGenerator.h

@@ -203,6 +203,7 @@ public:
       {
         memset(this, 0,  sizeof(*this));
       }
+    cmTarget* CMTarget;
     const char* TargetPDB;
     const char* TargetVersionMajor;
     const char* TargetVersionMinor;
@@ -222,6 +223,7 @@ public:
     const char* LinkFlags;
     const char* LanguageCompileFlags;
     const char* Defines;
+    const char* RuleLauncher;
   };
 
   /** Set whether to treat conversions to SHELL as a link script shell.  */
@@ -318,6 +320,11 @@ protected:
   std::string ExpandRuleVariable(std::string const& variable,
                                  const RuleVariables& replaceValues);
 
+  const char* GetRuleLauncher(cmTarget* target, const char* prop);
+  void InsertRuleLauncher(std::string& s, cmTarget* target,
+                          const char* prop);
+
+  
   /** Convert a target to a utility target for unsupported 
    *  languages of a generator */
   void AddBuildTargetRule(const char* llang, cmTarget& target);

Source/cmLocalUnixMakefileGenerator3.cxx

@@ -974,7 +974,6 @@ cmLocalUnixMakefileGenerator3
                       cmLocalGenerator::RelativeRoot relative,
                       std::ostream* content)
 {
-  static_cast<void>(target); // Future use
   // Optionally create a command to display the custom command's
   // comment text.  This is used for pre-build, pre-link, and
   // post-build command comments.  Custom build step commands have
@@ -1043,7 +1042,9 @@ cmLocalUnixMakefileGenerator3
           cmd = scmd;
           }
         }
-      cmd = this->Convert(cmd.c_str(),NONE,SHELL);
+      std::string launcher =
+        this->MakeLauncher(cc, target, workingDir? NONE : START_OUTPUT);
+      cmd = launcher + this->Convert(cmd.c_str(),NONE,SHELL);
       for(unsigned int j=1; j < commandLine.size(); ++j)
         {
         cmd += " ";
@@ -1059,7 +1060,8 @@ cmLocalUnixMakefileGenerator3
         }
       if(content)
         {
-        *content << cmd;
+        // Rule content does not include the launcher.
+        *content << (cmd.c_str()+launcher.size());
         }
       if(this->BorlandMakeCurlyHack)
         {
@@ -1093,6 +1095,35 @@ cmLocalUnixMakefileGenerator3
   commands.insert(commands.end(), commands1.begin(), commands1.end());
 }
 
+//----------------------------------------------------------------------------
+std::string
+cmLocalUnixMakefileGenerator3::MakeLauncher(const cmCustomCommand& cc,
+                                            cmTarget* target,
+                                            RelativeRoot relative)
+{
+  // Short-circuit if there is no launcher.
+  const char* prop = "RULE_LAUNCH_CUSTOM";
+  const char* val = this->GetRuleLauncher(target, prop);
+  if(!(val && *val))
+    {
+    return "";
+    }
+
+  // Expand rules in the empty string.  It may insert the launcher and
+  // perform replacements.
+  RuleVariables vars;
+  vars.RuleLauncher = prop;
+  vars.CMTarget = target;
+
+  std::string launcher;
+  this->ExpandRuleVariables(launcher, vars);
+  if(!launcher.empty())
+    {
+    launcher += " ";
+    }
+  return launcher;
+}
+
 //----------------------------------------------------------------------------
 void
 cmLocalUnixMakefileGenerator3

Source/cmLocalUnixMakefileGenerator3.h

@@ -347,6 +347,9 @@ protected:
   void CheckMultipleOutputs(bool verbose);
 
 private:
+  std::string MakeLauncher(const cmCustomCommand& cc, cmTarget* target,
+                           RelativeRoot relative);
+
   friend class cmMakefileTargetGenerator;
   friend class cmMakefileExecutableTargetGenerator;
   friend class cmMakefileLibraryTargetGenerator;

Source/cmMakefile.cxx

@@ -3564,6 +3564,25 @@ void cmMakefile::DefineProperties(cmake *cm)
      "This read-only property specifies the list of directories given "
      "so far to the link_directories command.  "
      "It is intended for debugging purposes.", false);
+
+  cm->DefineProperty
+    ("RULE_LAUNCH_COMPILE", cmProperty::DIRECTORY,
+     "Specify a launcher for compile rules.",
+     "See the global property of the same name for details.  "
+     "This overrides the global property for a directory.",
+     true);
+  cm->DefineProperty
+    ("RULE_LAUNCH_LINK", cmProperty::DIRECTORY,
+     "Specify a launcher for link rules.",
+     "See the global property of the same name for details.  "
+     "This overrides the global property for a directory.",
+     true);
+  cm->DefineProperty
+    ("RULE_LAUNCH_CUSTOM", cmProperty::DIRECTORY,
+     "Specify a launcher for custom rules.",
+     "See the global property of the same name for details.  "
+     "This overrides the global property for a directory.",
+     true);
 }
 
 //----------------------------------------------------------------------------

Source/cmMakefileExecutableTargetGenerator.cxx

@@ -360,6 +360,8 @@ void cmMakefileExecutableTargetGenerator::WriteExecutableRule(bool relink)
                           buildObjs, depends);
 
   cmLocalGenerator::RuleVariables vars;
+  vars.RuleLauncher = "RULE_LAUNCH_LINK";
+  vars.CMTarget = this->Target;
   vars.Language = linkLanguage;
   vars.Objects = buildObjs.c_str();
   vars.Target = targetOutPathReal.c_str();

Source/cmMakefileLibraryTargetGenerator.cxx

@@ -713,6 +713,8 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules
   vars.TargetVersionMajor = targetVersionMajor.c_str();
   vars.TargetVersionMinor = targetVersionMinor.c_str();
 
+  vars.RuleLauncher = "RULE_LAUNCH_LINK";
+  vars.CMTarget = this->Target;
   vars.Language = linkLanguage;
   vars.Objects = buildObjs.c_str();
   std::string objdir = cmake::GetCMakeFilesDirectoryPostSlash();

Source/cmMakefileTargetGenerator.cxx

@@ -619,6 +619,8 @@ cmMakefileTargetGenerator
                   cmLocalGenerator::SHELL);
   }
   cmLocalGenerator::RuleVariables vars;
+  vars.RuleLauncher = "RULE_LAUNCH_COMPILE";
+  vars.CMTarget = this->Target;
   vars.Language = lang;
   vars.TargetPDB = targetOutPathPDB.c_str();
   vars.Source = sourceFile.c_str();

Source/cmTarget.cxx

@@ -522,6 +522,25 @@ void cmTarget::DefineProperties(cmake *cm)
      "On non-Apple platforms these files may be installed using the "
      "RESOURCE option to the install(TARGETS) command.");
 
+  cm->DefineProperty
+    ("RULE_LAUNCH_COMPILE", cmProperty::TARGET,
+     "Specify a launcher for compile rules.",
+     "See the global property of the same name for details.  "
+     "This overrides the global and directory property for a target.",
+     true);
+  cm->DefineProperty
+    ("RULE_LAUNCH_LINK", cmProperty::TARGET,
+     "Specify a launcher for link rules.",
+     "See the global property of the same name for details.  "
+     "This overrides the global and directory property for a target.",
+     true);
+  cm->DefineProperty
+    ("RULE_LAUNCH_CUSTOM", cmProperty::TARGET,
+     "Specify a launcher for custom rules.",
+     "See the global property of the same name for details.  "
+     "This overrides the global and directory property for a target.",
+     true);
+
   cm->DefineProperty
     ("SKIP_BUILD_RPATH", cmProperty::TARGET,
      "Should rpaths be used for the build tree.",

Source/cmake.cxx

@@ -3444,6 +3444,31 @@ void cmake::DefineProperties(cmake *cm)
      "enabled languages",
      "Set to list of currently enabled lanauges.");
 
+  cm->DefineProperty
+    ("RULE_LAUNCH_COMPILE", cmProperty::GLOBAL,
+     "Specify a launcher for compile rules.",
+     "Makefile generators prefix compiler commands with the given "
+     "launcher command line.  "
+     "This is intended to allow launchers to intercept build problems "
+     "with high granularity.  "
+     "Non-Makefile generators currently ignore this property.");
+  cm->DefineProperty
+    ("RULE_LAUNCH_LINK", cmProperty::GLOBAL,
+     "Specify a launcher for link rules.",
+     "Makefile generators prefix link and archive commands with the given "
+     "launcher command line.  "
+     "This is intended to allow launchers to intercept build problems "
+     "with high granularity.  "
+     "Non-Makefile generators currently ignore this property.");
+  cm->DefineProperty
+    ("RULE_LAUNCH_CUSTOM", cmProperty::GLOBAL,
+     "Specify a launcher for custom rules.",
+     "Makefile generators prefix custom commands with the given "
+     "launcher command line.  "
+     "This is intended to allow launchers to intercept build problems "
+     "with high granularity.  "
+     "Non-Makefile generators currently ignore this property.");
+
   // ================================================================
   // define variables as well
   // ================================================================