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.

5 files changed, 52 insertions, 5 deletions

diff --git a/Source/CursesDialog/ccmake.cxx b/Source/CursesDialog/ccmake.cxx
index a9d4d98..516e44d 100644
--- a/Source/CursesDialog/ccmake.cxx
+++ b/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;
diff --git a/Source/cmDocumentation.cxx b/Source/cmDocumentation.cxx
index 8d035af..3ff1017 100644
--- a/Source/cmDocumentation.cxx
+++ b/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");
diff --git a/Source/cmDocumentation.h b/Source/cmDocumentation.h
index c98e48e..b72b5fe 100644
--- a/Source/cmDocumentation.h
+++ b/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;
diff --git a/Source/cmDocumentationFormatter.h b/Source/cmDocumentationFormatter.h
index 61766b9..59513cc 100644
--- a/Source/cmDocumentationFormatter.h
+++ b/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
diff --git a/Source/cmakemain.cxx b/Source/cmakemain.cxx
index 9f9f6bb..085f263 100644
--- a/Source/cmakemain.cxx
+++ b/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);