Teach --help-* options to load documentation from .rst files

Install the Help directory next to Modules to make it available in CMake
distributions.  Use cmRST to read Help .rst documents and print them as
help output.

Add options

 --help-manual-list
 --help-manual

to list available manuals or print one of them.  Implement the options

 --help-commands
 --help-modules
 --help-policies
 --help-properties
 --help-variables

by mapping to the corresponding manual page.  Implement the options

 --help-command-list
 --help-module-list
 --help-policy-list
 --help-property-list
 --help-variable-list

by globbing the available Help .rst documents of the corresponding type
and reading their titles.  Implement the options

 --help-command
 --help-module
 --help-policy
 --help-property
 --help-variable

by globbing the matching Help .rst document(s) and printing them.

6 files changed, 309 insertions, 37 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 620b5d8..25cd576 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -582,7 +582,7 @@ install(FILES Copyright.txt DESTINATION ${CMAKE_DOC_DIR})
 
 # Install script directories.
 install(
-  DIRECTORY Modules Templates
+  DIRECTORY Help Modules Templates
   DESTINATION ${CMAKE_DATA_DIR}
   FILE_PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
   DIRECTORY_PERMISSIONS OWNER_READ OWNER_EXECUTE OWNER_WRITE
diff --git a/Source/cmDocumentation.cxx b/Source/cmDocumentation.cxx
index f8f215f..3c51e7a 100644
--- a/Source/cmDocumentation.cxx
+++ b/Source/cmDocumentation.cxx
@@ -13,9 +13,13 @@
 
 #include "cmSystemTools.h"
 #include "cmVersion.h"
+#include "cmRST.h"
+
 #include <cmsys/Directory.hxx>
 #include <cmsys/Glob.hxx>
 
+#include <ctype.h>
+
 #include <algorithm>
 
 //----------------------------------------------------------------------------
@@ -101,22 +105,30 @@ bool cmDocumentation::PrintDocumentation(Type ht, std::ostream& os)
     {
     case cmDocumentation::Usage:
       return this->PrintDocumentationUsage(os);
-    case cmDocumentation::Single:
-    case cmDocumentation::SingleModule:
-    case cmDocumentation::SinglePolicy:
-    case cmDocumentation::SingleProperty:
-    case cmDocumentation::SingleVariable:
-    case cmDocumentation::List:
-    case cmDocumentation::ModuleList:
-    case cmDocumentation::PropertyList:
-    case cmDocumentation::VariableList:
-    case cmDocumentation::PolicyList:
-    case cmDocumentation::Modules:
-    case cmDocumentation::Policies:
-    case cmDocumentation::Properties:
-    case cmDocumentation::Variables:
-    case cmDocumentation::Commands:
-      return false;
+    case cmDocumentation::OneManual:
+      return this->PrintHelpOneManual(os);
+    case cmDocumentation::OneCommand:
+      return this->PrintHelpOneCommand(os);
+    case cmDocumentation::OneModule:
+      return this->PrintHelpOneModule(os);
+    case cmDocumentation::OnePolicy:
+      return this->PrintHelpOnePolicy(os);
+    case cmDocumentation::OneProperty:
+      return this->PrintHelpOneProperty(os);
+    case cmDocumentation::OneVariable:
+      return this->PrintHelpOneVariable(os);
+    case cmDocumentation::ListManuals:
+      return this->PrintHelpListManuals(os);
+    case cmDocumentation::ListCommands:
+      return this->PrintHelpListCommands(os);
+    case cmDocumentation::ListModules:
+      return this->PrintHelpListModules(os);
+    case cmDocumentation::ListProperties:
+      return this->PrintHelpListProperties(os);
+    case cmDocumentation::ListVariables:
+      return this->PrintHelpListVariables(os);
+    case cmDocumentation::ListPolicies:
+      return this->PrintHelpListPolicies(os);
     case cmDocumentation::Version:
       return this->PrintVersion(os);
     default: return false;
@@ -126,6 +138,7 @@ bool cmDocumentation::PrintDocumentation(Type ht, std::ostream& os)
 //----------------------------------------------------------------------------
 bool cmDocumentation::PrintRequestedDocumentation(std::ostream& os)
 {
+  int count = 0;
   bool result = true;
 
   // Loop over requested documentation types.
@@ -152,6 +165,10 @@ bool cmDocumentation::PrintRequestedDocumentation(std::ostream& os)
         result = false;
         }
       }
+    else if(++count > 1)
+      {
+      os << "\n\n";
+      }
 
     // Print this documentation type to the stream.
     if(!this->PrintDocumentation(i->HelpType, *s) || !*s)
@@ -287,33 +304,37 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
       // special case for single command
       if (!help.Argument.empty())
         {
-        help.HelpType = cmDocumentation::Single;
+        help.HelpType = cmDocumentation::OneCommand;
         }
       }
     else if(strcmp(argv[i], "--help-properties") == 0)
       {
-      help.HelpType = cmDocumentation::Properties;
+      help.HelpType = cmDocumentation::OneManual;
+      help.Argument = "cmake-properties.7";
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
                                                 &help.ManSection);
       }
     else if(strcmp(argv[i], "--help-policies") == 0)
       {
-      help.HelpType = cmDocumentation::Policies;
+      help.HelpType = cmDocumentation::OneManual;
+      help.Argument = "cmake-policies.7";
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
                                                 &help.ManSection);
       }
     else if(strcmp(argv[i], "--help-variables") == 0)
       {
-      help.HelpType = cmDocumentation::Variables;
+      help.HelpType = cmDocumentation::OneManual;
+      help.Argument = "cmake-variables.7";
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
                                                 &help.ManSection);
       }
     else if(strcmp(argv[i], "--help-modules") == 0)
       {
-      help.HelpType = cmDocumentation::Modules;
+      help.HelpType = cmDocumentation::OneManual;
+      help.Argument = "cmake-modules.7";
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
                                                 &help.ManSection);
@@ -327,7 +348,8 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
       }
     else if(strcmp(argv[i], "--help-commands") == 0)
       {
-      help.HelpType = cmDocumentation::Commands;
+      help.HelpType = cmDocumentation::OneManual;
+      help.Argument = "cmake-commands.7";
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
                                                 &help.ManSection);
@@ -359,7 +381,7 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
       }
     else if(strcmp(argv[i], "--help-command") == 0)
       {
-      help.HelpType = cmDocumentation::Single;
+      help.HelpType = cmDocumentation::OneCommand;
       GET_OPT_ARGUMENT(help.Argument);
       GET_OPT_ARGUMENT(help.Filename);
       help.Argument = cmSystemTools::LowerCase(help.Argument);
@@ -368,7 +390,7 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
       }
     else if(strcmp(argv[i], "--help-module") == 0)
       {
-      help.HelpType = cmDocumentation::SingleModule;
+      help.HelpType = cmDocumentation::OneModule;
       GET_OPT_ARGUMENT(help.Argument);
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
@@ -376,7 +398,7 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
       }
     else if(strcmp(argv[i], "--help-property") == 0)
       {
-      help.HelpType = cmDocumentation::SingleProperty;
+      help.HelpType = cmDocumentation::OneProperty;
       GET_OPT_ARGUMENT(help.Argument);
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
@@ -384,7 +406,7 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
       }
     else if(strcmp(argv[i], "--help-policy") == 0)
       {
-      help.HelpType = cmDocumentation::SinglePolicy;
+      help.HelpType = cmDocumentation::OnePolicy;
       GET_OPT_ARGUMENT(help.Argument);
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
@@ -392,42 +414,54 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
       }
     else if(strcmp(argv[i], "--help-variable") == 0)
       {
-      help.HelpType = cmDocumentation::SingleVariable;
+      help.HelpType = cmDocumentation::OneVariable;
       GET_OPT_ARGUMENT(help.Argument);
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = this->GetFormFromFilename(help.Filename,
                                                 &help.ManSection);
       }
+    else if(strcmp(argv[i], "--help-manual") == 0)
+      {
+      help.HelpType = cmDocumentation::OneManual;
+      GET_OPT_ARGUMENT(help.Argument);
+      GET_OPT_ARGUMENT(help.Filename);
+      this->WarnFormFromFilename(help);
+      }
     else if(strcmp(argv[i], "--help-command-list") == 0)
       {
-      help.HelpType = cmDocumentation::List;
+      help.HelpType = cmDocumentation::ListCommands;
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = cmDocumentation::TextForm;
       }
     else if(strcmp(argv[i], "--help-module-list") == 0)
       {
-      help.HelpType = cmDocumentation::ModuleList;
+      help.HelpType = cmDocumentation::ListModules;
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = cmDocumentation::TextForm;
       }
     else if(strcmp(argv[i], "--help-property-list") == 0)
       {
-      help.HelpType = cmDocumentation::PropertyList;
+      help.HelpType = cmDocumentation::ListProperties;
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = cmDocumentation::TextForm;
       }
     else if(strcmp(argv[i], "--help-variable-list") == 0)
       {
-      help.HelpType = cmDocumentation::VariableList;
+      help.HelpType = cmDocumentation::ListVariables;
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = cmDocumentation::TextForm;
       }
     else if(strcmp(argv[i], "--help-policy-list") == 0)
       {
-      help.HelpType = cmDocumentation::PolicyList;
+      help.HelpType = cmDocumentation::ListPolicies;
       GET_OPT_ARGUMENT(help.Filename);
       help.HelpForm = cmDocumentation::TextForm;
       }
+    else if(strcmp(argv[i], "--help-manual-list") == 0)
+      {
+      help.HelpType = cmDocumentation::ListManuals;
+      GET_OPT_ARGUMENT(help.Filename);
+      }
     else if(strcmp(argv[i], "--copyright") == 0)
       {
       GET_OPT_ARGUMENT(help.Filename);
@@ -617,6 +651,217 @@ void cmDocumentation::PrependSection(const char *name,
 }
 
 //----------------------------------------------------------------------------
+void cmDocumentation::GlobHelp(std::vector<std::string>& files,
+                               std::string const& pattern)
+{
+  cmsys::Glob gl;
+  std::string findExpr = this->CMakeRoot + "/Help/" + pattern + ".rst";
+  if(gl.FindFiles(findExpr))
+    {
+    files = gl.GetFiles();
+    }
+}
+
+//----------------------------------------------------------------------------
+void cmDocumentation::PrintNames(std::ostream& os,
+                                 std::string const& pattern)
+{
+  std::vector<std::string> files;
+  this->GlobHelp(files, pattern);
+  std::vector<std::string> names;
+  for (std::vector<std::string>::const_iterator i = files.begin();
+       i != files.end(); ++i)
+    {
+    std::string line;
+    std::ifstream fin(i->c_str());
+    while(fin && cmSystemTools::GetLineFromStream(fin, line))
+      {
+      if(!line.empty() && (isalnum(line[0]) || line[0] == '<'))
+        {
+        names.push_back(line);
+        break;
+        }
+      }
+    }
+  std::sort(names.begin(), names.end());
+  for (std::vector<std::string>::iterator i = names.begin();
+       i != names.end(); ++i)
+    {
+    os << *i << "\n";
+    }
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintFiles(std::ostream& os,
+                                 std::string const& pattern)
+{
+  bool found = false;
+  std::vector<std::string> files;
+  this->GlobHelp(files, pattern);
+  std::sort(files.begin(), files.end());
+  cmRST r(os, this->CMakeRoot + "/Help");
+  for (std::vector<std::string>::const_iterator i = files.begin();
+       i != files.end(); ++i)
+    {
+    found = r.ProcessFile(i->c_str()) || found;
+    }
+  return found;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpOneManual(std::ostream& os)
+{
+  std::string mname = this->CurrentArgument;
+  std::string::size_type mlen = mname.length();
+  if(mlen > 3 && mname[mlen-3] == '(' &&
+                 mname[mlen-1] == ')')
+    {
+    mname = mname.substr(0, mlen-3) + "." + mname[mlen-2];
+    }
+  if(this->PrintFiles(os, "manual/" + mname) ||
+     this->PrintFiles(os, "manual/" + mname + ".[0-9]"))
+    {
+    return true;
+    }
+  // Argument was not a manual.  Complain.
+  os << "Argument \"" << this->CurrentArgument.c_str()
+     << "\" to --help-manual is not an available manual.  "
+     << "Use --help-manual-list to see all available manuals.\n";
+  return false;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpListManuals(std::ostream& os)
+{
+  this->PrintNames(os, "manual/*");
+  return true;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpOneCommand(std::ostream& os)
+{
+  std::string cname = cmSystemTools::LowerCase(this->CurrentArgument);
+  if(this->PrintFiles(os, "command/" + cname))
+    {
+    return true;
+    }
+  // Argument was not a command.  Complain.
+  os << "Argument \"" << this->CurrentArgument.c_str()
+     << "\" to --help-command is not a CMake command.  "
+     << "Use --help-command-list to see all commands.\n";
+  return false;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpListCommands(std::ostream& os)
+{
+  this->PrintNames(os, "command/*");
+  return true;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpOneModule(std::ostream& os)
+{
+  std::string mname = this->CurrentArgument;
+  if(this->PrintFiles(os, "module/" + mname))
+    {
+    return true;
+    }
+  // Argument was not a module.  Complain.
+  os << "Argument \"" << this->CurrentArgument.c_str()
+     << "\" to --help-module is not a CMake module.\n";
+  return false;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpListModules(std::ostream& os)
+{
+  std::vector<std::string> files;
+  this->GlobHelp(files, "module/*");
+  std::vector<std::string> modules;
+  for (std::vector<std::string>::iterator fi = files.begin();
+       fi != files.end(); ++fi)
+    {
+    std::string module = cmSystemTools::GetFilenameName(*fi);
+    modules.push_back(module.substr(0, module.size()-4));
+    }
+  std::sort(modules.begin(), modules.end());
+  for (std::vector<std::string>::iterator i = modules.begin();
+       i != modules.end(); ++i)
+    {
+    os << *i << "\n";
+    }
+  return true;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpOneProperty(std::ostream& os)
+{
+  std::string pname = cmSystemTools::HelpFileName(this->CurrentArgument);
+  if(this->PrintFiles(os, "prop_*/" + pname))
+    {
+    return true;
+    }
+  // Argument was not a property.  Complain.
+  os << "Argument \"" << this->CurrentArgument.c_str()
+     << "\" to --help-property is not a CMake property.  "
+     << "Use --help-property-list to see all properties.\n";
+  return false;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpListProperties(std::ostream& os)
+{
+  this->PrintNames(os, "prop_*/*");
+  return true;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpOnePolicy(std::ostream& os)
+{
+  std::string pname = this->CurrentArgument;
+  std::vector<std::string> files;
+  if(this->PrintFiles(os, "policy/" + pname))
+    {
+    return true;
+    }
+
+  // Argument was not a policy.  Complain.
+  os << "Argument \"" << this->CurrentArgument.c_str()
+     << "\" to --help-policy is not a CMake policy.\n";
+  return false;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpListPolicies(std::ostream& os)
+{
+  this->PrintNames(os, "policy/*");
+  return true;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpOneVariable(std::ostream& os)
+{
+  std::string vname = cmSystemTools::HelpFileName(this->CurrentArgument);
+  if(this->PrintFiles(os, "variable/" + vname))
+    {
+    return true;
+    }
+  // Argument was not a variable.  Complain.
+  os << "Argument \"" << this->CurrentArgument.c_str()
+     << "\" to --help-variable is not a defined variable.  "
+     << "Use --help-variable-list to see all defined variables.\n";
+  return false;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelpListVariables(std::ostream& os)
+{
+  this->PrintNames(os, "variable/*");
+  return true;
+}
+
+//----------------------------------------------------------------------------
 bool cmDocumentation::PrintDocumentationUsage(std::ostream& os)
 {
   this->ClearSections();
diff --git a/Source/cmDocumentation.h b/Source/cmDocumentation.h
index fac3748..31c7602 100644
--- a/Source/cmDocumentation.h
+++ b/Source/cmDocumentation.h
@@ -131,7 +131,23 @@ public:
 private:
   void SetForm(Form f, int manSection);
 
+  void GlobHelp(std::vector<std::string>& files, std::string const& pattern);
+  void PrintNames(std::ostream& os, std::string const& pattern);
+  bool PrintFiles(std::ostream& os, std::string const& pattern);
+
   bool PrintVersion(std::ostream& os);
+  bool PrintHelpOneManual(std::ostream& os);
+  bool PrintHelpOneCommand(std::ostream& os);
+  bool PrintHelpOneModule(std::ostream& os);
+  bool PrintHelpOnePolicy(std::ostream& os);
+  bool PrintHelpOneProperty(std::ostream& os);
+  bool PrintHelpOneVariable(std::ostream& os);
+  bool PrintHelpListManuals(std::ostream& os);
+  bool PrintHelpListCommands(std::ostream& os);
+  bool PrintHelpListModules(std::ostream& os);
+  bool PrintHelpListProperties(std::ostream& os);
+  bool PrintHelpListVariables(std::ostream& os);
+  bool PrintHelpListPolicies(std::ostream& os);
   bool PrintDocumentationUsage(std::ostream& os);
 
   const char* GetNameString() const;
diff --git a/Source/cmDocumentationFormatter.h b/Source/cmDocumentationFormatter.h
index 534a4de..0bce50c 100644
--- a/Source/cmDocumentationFormatter.h
+++ b/Source/cmDocumentationFormatter.h
@@ -25,10 +25,11 @@ class cmDocumentationEnums
 public:
   /** Types of help provided.  */
   enum Type
-  { None, Usage, Single, SingleModule, SingleProperty, SingleVariable,
-    List, ModuleList, PropertyList, VariableList, PolicyList,
-    Properties, Variables, Modules, Commands,
-    Copyright, Version, Policies, SinglePolicy };
+  {
+    None, Version, Usage, ListManuals,
+    ListCommands, ListModules, ListProperties, ListVariables, ListPolicies,
+    OneManual, OneCommand, OneModule, OneProperty, OneVariable, OnePolicy
+  };
 
   /** Forms of documentation output.  */
   enum Form { TextForm, HTMLForm, RSTForm, ManForm, UsageForm, DocbookForm };
diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx
index 9ec4938..cbd4632 100644
--- a/Source/cmSystemTools.cxx
+++ b/Source/cmSystemTools.cxx
@@ -200,6 +200,13 @@ std::string cmSystemTools::EscapeQuotes(const char* str)
   return result;
 }
 
+std::string cmSystemTools::HelpFileName(std::string name)
+{
+  cmSystemTools::ReplaceString(name, "<", "");
+  cmSystemTools::ReplaceString(name, ">", "");
+  return name;
+}
+
 std::string cmSystemTools::TrimWhitespace(const std::string& s)
 {
   std::string::const_iterator start = s.begin();
diff --git a/Source/cmSystemTools.h b/Source/cmSystemTools.h
index 9d7dae9..cbc1140 100644
--- a/Source/cmSystemTools.h
+++ b/Source/cmSystemTools.h
@@ -49,6 +49,9 @@ public:
   ///! Escape quotes in a string.
   static std::string EscapeQuotes(const char* str);
 
+  /** Map help document name to file name.  */
+  static std::string HelpFileName(std::string);
+
   /**
    * Returns a string that has whitespace removed from the start and the end.
    */