Add macro CMakeParseArguments() and use it in FPHSA()

This adds a macro cmake_parse_arguments() (as discussed on cmake-devel)
which can be used in macros or functions to help with parsing its
arguments. Detailled docs are included.
find_package_handle_standard_args() is the first user of this new macro.

Alex

1 files changed, 137 insertions, 0 deletions

diff --git a/Modules/CMakeParseArguments.cmake b/Modules/CMakeParseArguments.cmake
new file mode 100644
index 0000000..c7148ae
--- /dev/null
+++ b/Modules/CMakeParseArguments.cmake
@@ -0,0 +1,137 @@
+# CMAKE_PARSE_ARGUMENTS(<prefix> <options> <one_value_keywords> <multi_value_keywords> args...)
+#
+# CMAKE_PARSE_ARGUMENTS() is intended to be used in macros or functions for
+# parsing the arguments given to that macro or function.
+# It processes the arguments and defines a set of variables which hold the
+# values of the respective options.
+#
+# The <options> argument contains all options for the respective macro,
+# i.e. keywords which can be used when calling the macro without any value
+# following, like e.g. the OPTIONAL keyword of the install() command.
+#
+# The <one_value_keywords> argument contains all keywords for this macro
+# which are followed by one value, like e.g. DESTINATION keyword of the
+# install() command.
+#
+# The <multi_value_keywords> argument contains all keywords for this macro
+# which can be followed by more than one value, like e.g. the TARGETS or
+# FILES keywords of the install() command.
+#
+# When done, CMAKE_PARSE_ARGUMENTS() will have defined for each of the
+# keywords listed in <options>, <one_value_keywords> and
+# <multi_value_keywords> a variable composed of the given <prefix>
+# followed by "_" and the name of the respective keyword.
+# These variables will then hold the respective value from the argument list.
+# For the <options> keywords this will be TRUE or FALSE.
+#
+# All remaining arguments are collected in a variable
+# <prefix>_UNPARSED_ARGUMENTS, this can be checked afterwards to see whether
+# your macro was called with unrecognized parameters.
+#
+# As an example here a my_install() macro, which takes similar arguments as the
+# real install() command:
+#
+#   function(MY_INSTALL)
+#     set(options OPTIONAL FAST)
+#     set(oneValueArgs DESTINATION RENAME)
+#     set(multiValueArgs TARGETS CONFIGURATIONS)
+#     cmake_parse_arguments(MY_INSTALL "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN} )
+#     ...
+#
+# Assume my_install() has been called like this:
+#   my_install(TARGETS foo bar DESTINATION bin OPTIONAL blub)
+#
+# After the cmake_parse_arguments() call the macro will have set the following
+# variables:
+#   MY_INSTALL_OPTIONAL = TRUE
+#   MY_INSTALL_FAST = FALSE (this option was not used when calling my_install()
+#   MY_INSTALL_DESTINATION = "bin"
+#   MY_INSTALL_RENAME = "" (was not used)
+#   MY_INSTALL_TARGETS = "foo;bar"
+#   MY_INSTALL_CONFIGURATIONS = "" (was not used)
+#   MY_INSTALL_UNPARSED_ARGUMENTS = "blub" (no value expected after "OPTIONAL"
+#
+# You can the continue and process these variables.
+#
+# Keywords terminate lists of values, e.g. if directly after a one_value_keyword
+# another recognized keyword follows, this is interpreted as the beginning of
+# the new option.
+# E.g. my_install(TARGETS foo DESTINATION OPTIONAL) would result in
+# MY_INSTALL_DESTINATION set to "OPTIONAL", but MY_INSTALL_DESTINATION would
+# be empty and MY_INSTALL_OPTIONAL would be set to TRUE therefor.
+
+# Copyright (c) 2010, Alexander Neundorf, <neundorf@kde.org>
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distributed this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+
+if(__CMAKE_PARSE_ARGUMENTS_INCLUDED)
+  return()
+endif()
+set(__CMAKE_PARSE_ARGUMENTS_INCLUDED TRUE)
+
+
+function(CMAKE_PARSE_ARGUMENTS prefix _optionNames _singleArgNames _multiArgNames)
+  # first set all result variables to empty/FALSE
+  foreach(arg_name ${_singleArgNames} ${_multiArgNames})
+    set(${prefix}_${arg_name})
+  endforeach(arg_name)
+
+  foreach(option ${_optionNames})
+    set(${prefix}_${option} FALSE)
+  endforeach(option)
+
+  set(${prefix}_UNPARSED_ARGUMENTS)
+
+  set(insideValues FALSE)
+  set(currentArgName)
+
+  # now iterate over all arguments and fill the result variables
+  foreach(currentArg ${ARGN})
+    list(FIND _optionNames "${currentArg}" optionIndex)  # ... then this marks the end of the arguments belonging to this keyword
+    list(FIND _singleArgNames "${currentArg}" singleArgIndex)  # ... then this marks the end of the arguments belonging to this keyword
+    list(FIND _multiArgNames "${currentArg}" multiArgIndex)  # ... then this marks the end of the arguments belonging to this keyword
+
+    if(${optionIndex} EQUAL -1  AND  ${singleArgIndex} EQUAL -1  AND  ${multiArgIndex} EQUAL -1)
+      if(insideValues)
+        if("${insideValues}" STREQUAL "SINGLE")
+          set(${prefix}_${currentArgName} ${currentArg})
+          set(insideValues FALSE)
+        elseif("${insideValues}" STREQUAL "MULTI")
+          list(APPEND ${prefix}_${currentArgName} ${currentArg})
+        endif()
+      else(insideValues)
+        list(APPEND ${prefix}_UNPARSED_ARGUMENTS ${currentArg})
+      endif(insideValues)
+    else()
+      if(NOT ${optionIndex} EQUAL -1)
+        set(${prefix}_${currentArg} TRUE)
+        set(insideValues FALSE)
+      elseif(NOT ${singleArgIndex} EQUAL -1)
+        set(currentArgName ${currentArg})
+        set(${prefix}_${currentArgName})
+        set(insideValues "SINGLE")
+      elseif(NOT ${multiArgIndex} EQUAL -1)
+        set(currentArgName ${currentArg})
+        set(${prefix}_${currentArgName})
+        set(insideValues "MULTI")
+      endif()
+    endif()
+
+  endforeach(currentArg)
+
+  # propagate the result variables to the caller:
+  foreach(arg_name ${_singleArgNames} ${_multiArgNames} ${_optionNames})
+    set(${prefix}_${arg_name}  ${${prefix}_${arg_name}} PARENT_SCOPE)
+  endforeach(arg_name)
+  set(${prefix}_UNPARSED_ARGUMENTS ${${prefix}_UNPARSED_ARGUMENTS} PARENT_SCOPE)
+
+endfunction(CMAKE_PARSE_ARGUMENTS _options _singleArgs _multiArgs)