cmArgumentParser: Model maybe-empty and non-empty lists with wrapper types

Previously bindings to `std::vector<std::string>` required at least one
value.  Some clients have been filtering `keywordsMissingValue` to
support keywords followed by empty lists.  Instead, require clients to
specify whether a keyword's list can be empty as part of the binding
type.

1 files changed, 28 insertions, 44 deletions

diff --git a/Source/cmFileCommand.cxx b/Source/cmFileCommand.cxx
index 45ec343..22ab5f7 100644
--- a/Source/cmFileCommand.cxx
+++ b/Source/cmFileCommand.cxx
@@ -30,6 +30,7 @@
 
 #include "cmAlgorithms.h"
 #include "cmArgumentParser.h"
+#include "cmArgumentParserTypes.h"
 #include "cmCMakePath.h"
 #include "cmCryptoHash.h"
 #include "cmELF.h"
@@ -2505,7 +2506,7 @@ bool HandleGenerateCommand(std::vector<std::string> const& args,
     cm::optional<std::string> NewLineStyle;
     bool NoSourcePermissions = false;
     bool UseSourcePermissions = false;
-    std::vector<std::string> FilePermissions;
+    ArgumentParser::NonEmpty<std::vector<std::string>> FilePermissions;
   };
 
   static auto const parser =
@@ -3052,17 +3053,18 @@ bool HandleGetRuntimeDependenciesCommand(std::vector<std::string> const& args,
     std::string ConflictingDependenciesPrefix;
     std::string RPathPrefix;
     std::string BundleExecutable;
-    std::vector<std::string> Executables;
-    std::vector<std::string> Libraries;
-    std::vector<std::string> Directories;
-    std::vector<std::string> Modules;
-    std::vector<std::string> PreIncludeRegexes;
-    std::vector<std::string> PreExcludeRegexes;
-    std::vector<std::string> PostIncludeRegexes;
-    std::vector<std::string> PostExcludeRegexes;
-    std::vector<std::string> PostIncludeFiles;
-    std::vector<std::string> PostExcludeFiles;
-    std::vector<std::string> PostExcludeFilesStrict;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> Executables;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> Libraries;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> Directories;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> Modules;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> PreIncludeRegexes;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> PreExcludeRegexes;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> PostIncludeRegexes;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> PostExcludeRegexes;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> PostIncludeFiles;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> PostExcludeFiles;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>>
+      PostExcludeFilesStrict;
   };
 
   static auto const parser =
@@ -3098,25 +3100,10 @@ bool HandleGetRuntimeDependenciesCommand(std::vector<std::string> const& args,
     return false;
   }
 
-  // Arguments that are allowed to be empty lists.  Keep entries sorted!
-  static const std::vector<cm::string_view> LIST_ARGS = {
-    "DIRECTORIES"_s,
-    "EXECUTABLES"_s,
-    "LIBRARIES"_s,
-    "MODULES"_s,
-    "POST_EXCLUDE_FILES"_s,
-    "POST_EXCLUDE_FILES_STRICT"_s,
-    "POST_EXCLUDE_REGEXES"_s,
-    "POST_INCLUDE_FILES"_s,
-    "POST_INCLUDE_REGEXES"_s,
-    "PRE_EXCLUDE_REGEXES"_s,
-    "PRE_INCLUDE_REGEXES"_s,
-  };
-  auto kwbegin = keywordsMissingValues.cbegin();
-  auto kwend = cmRemoveMatching(keywordsMissingValues, LIST_ARGS);
-  if (kwend != kwbegin) {
-    status.SetError(cmStrCat("Keywords missing values:\n  ",
-                             cmJoin(cmMakeRange(kwbegin, kwend), "\n  ")));
+  if (!keywordsMissingValues.empty()) {
+    status.SetError(
+      cmStrCat("Keywords missing values:\n  ",
+               cmJoin(cmMakeRange(keywordsMissingValues), "\n  ")));
     cmSystemTools::SetFatalErrorOccurred();
     return false;
   }
@@ -3362,7 +3349,8 @@ bool HandleArchiveCreateCommand(std::vector<std::string> const& args,
     std::string CompressionLevel;
     std::string MTime;
     bool Verbose = false;
-    std::vector<std::string> Paths;
+    // "PATHS" requires at least one value, but use a custom check below.
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> Paths;
   };
 
   static auto const parser =
@@ -3393,7 +3381,6 @@ bool HandleArchiveCreateCommand(std::vector<std::string> const& args,
                // value, but it has long been accidentally accepted without
                // one and treated as if an empty value were given.
                // Fixing this would require a policy.
-    "PATHS"_s, // "PATHS" is here only so we can issue a custom error below.
   };
   auto kwbegin = keywordsMissingValues.cbegin();
   auto kwend = cmRemoveMatching(keywordsMissingValues, LIST_ARGS);
@@ -3496,7 +3483,7 @@ bool HandleArchiveExtractCommand(std::vector<std::string> const& args,
     bool Verbose = false;
     bool ListOnly = false;
     std::string Destination;
-    std::vector<std::string> Patterns;
+    ArgumentParser::MaybeEmpty<std::vector<std::string>> Patterns;
     bool Touch = false;
   };
 
@@ -3520,13 +3507,10 @@ bool HandleArchiveExtractCommand(std::vector<std::string> const& args,
     return false;
   }
 
-  // Arguments that are allowed to be empty lists.  Keep entries sorted!
-  static const std::vector<cm::string_view> LIST_ARGS = { "PATTERNS"_s };
-  auto kwbegin = keywordsMissingValues.cbegin();
-  auto kwend = cmRemoveMatching(keywordsMissingValues, LIST_ARGS);
-  if (kwend != kwbegin) {
-    status.SetError(cmStrCat("Keywords missing values:\n  ",
-                             cmJoin(cmMakeRange(kwbegin, kwend), "\n  ")));
+  if (!keywordsMissingValues.empty()) {
+    status.SetError(
+      cmStrCat("Keywords missing values:\n  ",
+               cmJoin(cmMakeRange(keywordsMissingValues), "\n  ")));
     cmSystemTools::SetFatalErrorOccurred();
     return false;
   }
@@ -3620,9 +3604,9 @@ bool HandleChmodCommandImpl(std::vector<std::string> const& args, bool recurse,
 
   struct Arguments
   {
-    std::vector<std::string> Permissions;
-    std::vector<std::string> FilePermissions;
-    std::vector<std::string> DirectoryPermissions;
+    ArgumentParser::NonEmpty<std::vector<std::string>> Permissions;
+    ArgumentParser::NonEmpty<std::vector<std::string>> FilePermissions;
+    ArgumentParser::NonEmpty<std::vector<std::string>> DirectoryPermissions;
   };
 
   static auto const parser =