cmake,ccmake: Produce shorter output on no arguments (#14973)

Instead printing complete help cmake/ccmake now prints only Usage section and
extra information how to get more help or start your build.

Implementation Details:

  Usage help type was renamed to Help, and new Usage was introduces that prints
  only command line usage information without any extra details.

  Commands add some extra information when no arguments are passed.

Source/CursesDialog/ccmake.cxx

@@ -38,6 +38,18 @@ static const char * cmDocumentationUsage[][2] =
   {0,
    "  ccmake <path-to-source>\n"
    "  ccmake <path-to-existing-build>"},
+  {0,
+   "Specify a source directory to (re-)generate a build system for "
+   "it in the current working directory.  Specify an existing build "
+   "directory to re-generate its build system."},
+  {0,0}
+};
+
+//----------------------------------------------------------------------------
+static const char * cmDocumentationUsageNote[][2] =
+{
+  {0,
+   "Run 'ccmake --help' for more information."},
   {0,0}
 };
 
@@ -102,6 +114,10 @@ int main(int argc, char const* const* argv)
     doc.SetName("ccmake");
     doc.SetSection("Name",cmDocumentationName);
     doc.SetSection("Usage",cmDocumentationUsage);
+    if ( argc == 1 )
+      {
+      doc.AppendSection("Usage",cmDocumentationUsageNote);
+      }
     doc.SetSection("Generators",generators);
     doc.PrependSection("Options",cmDocumentationOptions);
     return doc.PrintRequestedDocumentation(std::cout)? 0:1;

Source/cmDocumentation.cxx

@@ -113,7 +113,9 @@ bool cmDocumentation::PrintDocumentation(Type ht, std::ostream& os)
   switch (ht)
     {
     case cmDocumentation::Usage:
-      return this->PrintDocumentationUsage(os);
+      return this->PrintUsage(os);
+    case cmDocumentation::Help:
+      return this->PrintHelp(os);
     case cmDocumentation::Full:
       return this->PrintHelpFull(os);
     case cmDocumentation::OneManual:
@@ -300,7 +302,7 @@ bool cmDocumentation::CheckOptions(int argc, const char* const* argv,
        (strcmp(argv[i], "-h") == 0) ||
        (strcmp(argv[i], "-H") == 0))
       {
-      help.HelpType = cmDocumentation::Usage;
+      help.HelpType = cmDocumentation::Help;
       GET_OPT_ARGUMENT(help.Argument);
       help.Argument = cmSystemTools::LowerCase(help.Argument);
       // special case for single command
@@ -841,7 +843,19 @@ bool cmDocumentation::PrintHelpListVariables(std::ostream& os)
 }
 
 //----------------------------------------------------------------------------
-bool cmDocumentation::PrintDocumentationUsage(std::ostream& os)
+bool cmDocumentation::PrintUsage(std::ostream& os)
+{
+  std::map<std::string,cmDocumentationSection*>::iterator si;
+  si = this->AllSections.find("Usage");
+  if(si != this->AllSections.end())
+    {
+    this->Formatter.PrintSection(os, *si->second);
+    }
+  return true;
+}
+
+//----------------------------------------------------------------------------
+bool cmDocumentation::PrintHelp(std::ostream& os)
 {
   std::map<std::string,cmDocumentationSection*>::iterator si;
   si = this->AllSections.find("Usage");

Source/cmDocumentation.h

@@ -102,6 +102,8 @@ private:
   bool PrintFiles(std::ostream& os, std::string const& pattern);
 
   bool PrintVersion(std::ostream& os);
+  bool PrintUsage(std::ostream& os);
+  bool PrintHelp(std::ostream& os);
   bool PrintHelpFull(std::ostream& os);
   bool PrintHelpOneManual(std::ostream& os);
   bool PrintHelpOneCommand(std::ostream& os);
@@ -115,7 +117,6 @@ private:
   bool PrintHelpListProperties(std::ostream& os);
   bool PrintHelpListVariables(std::ostream& os);
   bool PrintHelpListPolicies(std::ostream& os);
-  bool PrintDocumentationUsage(std::ostream& os);
   bool PrintOldCustomModules(std::ostream& os);
 
   const char* GetNameString() const;

Source/cmDocumentationFormatter.h

@@ -26,7 +26,7 @@ public:
   /** Types of help provided.  */
   enum Type
   {
-    None, Version, Usage, Full, ListManuals,
+    None, Version, Usage, Help, Full, ListManuals,
     ListCommands, ListModules, ListProperties, ListVariables, ListPolicies,
     OneManual, OneCommand, OneModule, OneProperty, OneVariable, OnePolicy,
     OldCustomModules

Source/cmakemain.cxx

@@ -42,6 +42,18 @@ static const char * cmDocumentationUsage[][2] =
   {0,
    "  cmake [options] <path-to-source>\n"
    "  cmake [options] <path-to-existing-build>"},
+  {0,
+   "Specify a source directory to (re-)generate a build system for "
+   "it in the current working directory.  Specify an existing build "
+   "directory to re-generate its build system."},
+  {0,0}
+};
+
+//----------------------------------------------------------------------------
+static const char * cmDocumentationUsageNote[][2] =
+{
+  {0,
+   "Run 'cmake --help' for more information."},
   {0,0}
 };
 
@@ -223,6 +235,10 @@ int do_cmake(int ac, char const* const* av)
     doc.SetName("cmake");
     doc.SetSection("Name",cmDocumentationName);
     doc.SetSection("Usage",cmDocumentationUsage);
+    if ( ac == 1 )
+      {
+      doc.AppendSection("Usage",cmDocumentationUsageNote);
+      }
     doc.AppendSection("Generators",generators);
     doc.PrependSection("Options",cmDocumentationOptions);