CMake: Use string/list(APPEND foo ...) instead of set(foo ${foo} ...)

cmake/macros/AddBisonTarget.cmake

@@ -21,9 +21,9 @@ function(add_bison_target output_cxx input_yxx)
       set(keyword "PREFIX")
 
     elseif(keyword STREQUAL "PREFIX")
-      set(arguments ${arguments} -p "${arg}")
+      list(APPEND arguments -p "${arg}")
     elseif(keyword STREQUAL "DEFINES")
-      set(arguments ${arguments} --defines="${arg}")
+      list(APPEND arguments --defines="${arg}")
       list(APPEND outputs "${arg}")
 
     else()
@@ -61,7 +61,7 @@ function(add_bison_target output_cxx input_yxx)
       endif()
 
       list(APPEND depends "${prebuilt_file}")
-      set(commands ${commands} COMMAND ${CMAKE_COMMAND} -E copy ${prebuilt_file} ${output})
+      list(APPEND commands COMMAND ${CMAKE_COMMAND} -E copy ${prebuilt_file} ${output})
     endforeach()
 
     add_custom_command(

cmake/macros/AddFlexTarget.cmake

@@ -20,12 +20,12 @@ function(add_flex_target output_cxx input_lxx)
     elseif(arg STREQUAL "PREFIX")
       set(keyword "PREFIX")
     elseif(arg STREQUAL "CASE_INSENSITIVE")
-      set(arguments ${arguments} -i)
+      list(APPEND arguments -i)
 
     elseif(keyword STREQUAL "PREFIX")
-      set(arguments ${arguments} -P "${arg}")
+      list(APPEND arguments -P "${arg}")
     elseif(keyword STREQUAL "DEFINES")
-      set(arguments ${arguments} --header-file="${arg}")
+      list(APPEND arguments --header-file="${arg}")
       list(APPEND outputs "${arg}")
 
     else()
@@ -63,7 +63,7 @@ function(add_flex_target output_cxx input_lxx)
       endif()
 
       list(APPEND depends "${prebuilt_file}")
-      set(commands ${commands} COMMAND ${CMAKE_COMMAND} -E copy ${prebuilt_file} ${output})
+      list(APPEND commands COMMAND ${CMAKE_COMMAND} -E copy ${prebuilt_file} ${output})
     endforeach()
 
     add_custom_command(

cmake/macros/PackageConfig.cmake

@@ -288,10 +288,10 @@ function(export_packages filename)
   set(exports "# Exports for Panda3D PKG:: packages\n")
 
   foreach(pkg ${_ALL_PACKAGE_OPTIONS})
-    set(exports "${exports}\n# Create imported target PKG::${pkg}\n")
-    set(exports "${exports}add_library(PKG::${pkg} INTERFACE IMPORTED)\n\n")
+    string(APPEND exports "\n# Create imported target PKG::${pkg}\n")
+    string(APPEND exports "add_library(PKG::${pkg} INTERFACE IMPORTED)\n\n")
 
-    set(exports "${exports}set_target_properties(PKG::${pkg} PROPERTIES\n")
+    string(APPEND exports "set_target_properties(PKG::${pkg} PROPERTIES\n")
     foreach(prop
         INTERFACE_COMPILE_DEFINITIONS
         INTERFACE_COMPILE_FEATURES
@@ -304,7 +304,7 @@ function(export_packages filename)
        #INTERFACE_SYSTEM_INCLUDE_DIRECTORIES  # Let the consumer dictate this
         INTERFACE_SOURCES)
       set(prop_ex "$<TARGET_PROPERTY:PKG::${pkg},${prop}>")
-      set(exports "${exports}$<$<BOOL:${prop_ex}>:  ${prop} \"${prop_ex}\"\n>")
+      string(APPEND exports "$<$<BOOL:${prop_ex}>:  ${prop} \"${prop_ex}\"\n>")
     endforeach(prop)
 
     # Ugh, INTERFACE_LINK_LIBRARIES isn't transitive.  Fine.  Take care of it
@@ -382,9 +382,9 @@ function(export_packages filename)
       endif()
     endwhile(stack)
 
-    set(exports "${exports}  INTERFACE_LINK_LIBRARIES \"${libraries}\"\n")
+    string(APPEND exports "  INTERFACE_LINK_LIBRARIES \"${libraries}\"\n")
 
-    set(exports "${exports})\n")
+    string(APPEND exports ")\n")
   endforeach(pkg)
 
   file(GENERATE OUTPUT "${filename}" CONTENT "${exports}")

cmake/modules/FindCg.cmake

@@ -122,7 +122,7 @@ if(NOT CG_LIBRARY_DIR OR NOT CG_INCLUDE_DIRS)
     cmake_find_frameworks(Cg)
     if(Cg_FRAMEWORKS)
       foreach(dir ${Cg_FRAMEWORKS})
-        set(CG_INCLUDES ${CG_INCLUDES} ${dir}/Headers ${dir}/PrivateHeaders)
+        list(APPEND CG_INCLUDES ${dir}/Headers ${dir}/PrivateHeaders)
       endforeach(dir)
       unset(Cg_FRAMEWORKS)
 

dtool/CompilerFlags.cmake

@@ -13,9 +13,9 @@ include(CheckCXXCompilerFlag)
 if(CMAKE_VERSION VERSION_LESS "3.1")
   check_cxx_compiler_flag("-std=gnu++11" COMPILER_SUPPORTS_CXX11)
   if(COMPILER_SUPPORTS_CXX11)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
+    string(APPEND CMAKE_CXX_FLAGS " -std=gnu++11")
   else()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++0x")
+    string(APPEND CMAKE_CXX_FLAGS " -std=gnu++0x")
   endif()
 else()
   set(CMAKE_CXX_STANDARD 11)
@@ -50,23 +50,23 @@ endif()
 
 # Set warning levels
 if(MSVC)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /W3")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W3")
+  string(APPEND CMAKE_C_FLAGS " /W3")
+  string(APPEND CMAKE_CXX_FLAGS " /W3")
 else()
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
+  string(APPEND CMAKE_C_FLAGS " -Wall")
+  string(APPEND CMAKE_CXX_FLAGS " -Wall")
 endif()
 if(NOT "x${CMAKE_CXX_COMPILER_ID}" STREQUAL "xMSVC")
   set(disable_flags "-Wno-unused-function -Wno-unused-parameter")
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${disable_flags}")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${disable_flags} -Wno-reorder")
-  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Wno-unused-variable")
-  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -Wno-unused-variable")
-  set(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL} -Wno-unused-variable")
+  string(APPEND CMAKE_C_FLAGS " ${disable_flags}")
+  string(APPEND CMAKE_CXX_FLAGS " ${disable_flags} -Wno-reorder")
+  string(APPEND CMAKE_CXX_FLAGS_RELEASE " -Wno-unused-variable")
+  string(APPEND CMAKE_CXX_FLAGS_RELWITHDEBINFO " -Wno-unused-variable")
+  string(APPEND CMAKE_CXX_FLAGS_MINSIZEREL " -Wno-unused-variable")
 
   if(MSVC)
     # Clang behaving as MSVC
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-command-line-argument")
+    string(APPEND CMAKE_C_FLAGS " -Wno-unused-command-line-argument")
     set(CMAKE_CXX_FLAGS
       "${CMAKE_CXX_FLAGS} -Wno-microsoft-template -Wno-unused-command-line-argument")
   endif()