Modularize CMake build configuration

Build type no longer defaults to Release (!)
have separate options for extra warning flags and sanitizers

toss DEVELOP macro

Fix sanitizers with CMake while I'm at it :|

CMakeLists.txt

@@ -12,18 +12,6 @@ cmake_policy(VERSION 3.0)
 project(rgbds
         LANGUAGES C)
 
-option(DEVELOP "build in development mode" OFF)
-
-set(DEFAULT_BUILD_TYPE "Release")
-set(DEVELOP_BUILD_TYPE "Debug")
-if(NOT CMAKE_BUILD_TYPE)
-  if(DEVELOP)
-    set(CMAKE_BUILD_TYPE "${DEVELOP_BUILD_TYPE}")
-  else()
-    set(CMAKE_BUILD_TYPE "${DEFAULT_BUILD_TYPE}")
-  endif()
-endif()
-
 # get real path of source and binary directories
 get_filename_component(srcdir "${CMAKE_SOURCE_DIR}" REALPATH)
 get_filename_component(bindir "${CMAKE_BINARY_DIR}" REALPATH)
@@ -37,16 +25,26 @@ endif()
 
 include_directories("${PROJECT_SOURCE_DIR}/include")
 
-if(DEVELOP)
-  add_definitions(-DDEVELOP)
-endif()
+option(SANITIZERS "Build with sanitizers enabled" OFF)
+option(MORE_WARNINGS "Turn on more warnings" OFF)
 
 if(MSVC)
   add_compile_options(/W1 /MP)
   add_definitions(/D_CRT_SECURE_NO_WARNINGS)
 else()
-  if(DEVELOP)
-    add_compile_options(-Werror -Wall -Wextra -pedantic -Wno-type-limits
+  add_compile_options(-Wall -pedantic)
+  if(SANITIZERS)
+    set(SAN_FLAGS -fsanitize=shift -fsanitize=integer-divide-by-zero
+                  -fsanitize=unreachable -fsanitize=vla-bound
+                  -fsanitize=signed-integer-overflow -fsanitize=bounds
+                  -fsanitize=object-size -fsanitize=bool -fsanitize=enum
+                  -fsanitize=alignment -fsanitize=null)
+    add_compile_options(${SAN_FLAGS})
+    link_libraries(${SAN_FLAGS})
+  endif()
+
+  if(MORE_WARNINGS)
+    add_compile_options(-Werror -Wextra -Wno-type-limits
                         -Wno-sign-compare -Wformat -Wformat-security -Wformat-overflow=2
                         -Wformat-truncation=1 -Wformat-y2k -Wswitch-enum -Wunused
                         -Wuninitialized -Wunknown-pragmas -Wstrict-overflow=5
@@ -54,14 +52,6 @@ else()
                         -Wfloat-equal -Wshadow -Wcast-qual -Wcast-align -Wlogical-op
                         -Wnested-externs -Wno-aggressive-loop-optimizations -Winline
                         -Wundef -Wstrict-prototypes -Wold-style-definition)
-
-     link_libraries(-fsanitize=shift -fsanitize=integer-divide-by-zero
-                    -fsanitize=unreachable -fsanitize=vla-bound
-                    -fsanitize=signed-integer-overflow -fsanitize=bounds
-                    -fsanitize=object-size -fsanitize=bool -fsanitize=enum
-                    -fsanitize=alignment -fsanitize=null)
-  else()
-    add_compile_options(-Wall -pedantic)
   endif()
 endif()