further simplifications

* only support the CMake standard way to define variables via `-DFOO=On`
  and not via the environment
* clean-up switches only used for unit tests
* mingw's ID is "gcc", so we match on the full compiler name instead
* use `CMAKE_SYSTEM_NAME` instead of `$ENV{PLATFORM}`
* unconditionally set {C,LD}FLAGS passed by user

Signed-off-by: Steffen Jaeckel <[email protected]>

Author: sjaeckel

CMakeLists.txt

@@ -26,30 +26,16 @@ option(BUILD_SHARED_LIBS "Build shared library and only the shared library if \"
 # Basic set
 set(LTM_C_FLAGS  -Wall -Wsign-compare -Wextra -Wshadow)
 set(LTM_C_FLAGS  ${LTM_C_FLAGS} -Wdeclaration-after-statement -Wbad-function-cast -Wcast-align)
-set(LTM_C_FLAGS  ${LTM_C_FLAGS} -Wstrict-prototypes -Wpointer-arith)
+set(LTM_C_FLAGS  ${LTM_C_FLAGS} -Wstrict-prototypes -Wpointer-arith -Wsystem-headers)
 
-# Do we run the sanitizer?
-if(DEFINED ENV{SANITIZER})
-    set(LTM_C_FLAGS  ${LTM_C_FLAGS} -fsanitize=undefined -fno-sanitize-recover=all -fno-sanitize=float-divide-by-zero)
-endif()
-
-if(DEFINED ENV{CONV_WARNINGS})
-    set(LTM_C_FLAGS  ${LTM_C_FLAGS} -std=c89 -Wconversion -Wsign-conversion)
-    if($ENV{CONV_WARNINGS} EQUAL "strict")
-        set(LTM_C_FLAGS  ${LTM_C_FLAGS} -Wc++-compat)
-    endif()
-else()
-    set(LTM_C_FLAGS  ${LTM_C_FLAGS} -Wsystem-headers)
-endif()
-
-if(DEFINED ENV{COMPILE_DEBUG})
+if(COMPILE_DEBUG)
     set(LTM_C_FLAGS  ${LTM_C_FLAGS} -g3)
 endif()
 
-if(DEFINED ENV{COMPILE_SIZE})
+if(COMPILE_SIZE)
     set(LTM_C_FLAGS  ${LTM_C_FLAGS} -Os)
 else()
-    if(NOT DEFINED ENV{IGNORE_SPEED})
+    if(NOT IGNORE_SPEED)
         set(LTM_C_FLAGS  ${LTM_C_FLAGS} -O3 -funroll-loops)
         #x86 optimizations [should be valid for any GCC install though]
         set(LTM_C_FLAGS  ${LTM_C_FLAGS} -fomit-frame-pointer)
@@ -67,33 +53,28 @@ endif()
 
 # What compiler do we have and what are their...uhm... peculiarities
 # TODO: is the check for a C++ compiler necessary?
-if( (CMAKE_C_COMPILER_ID MATCHES "(C|c?)lang") OR (CMAKE_CXX_COMPILER_ID MATCHES "(C|c?)lang"))
+if(CMAKE_C_COMPILER_ID MATCHES "(C|c?)lang")
     set(LTM_C_FLAGS  ${LTM_C_FLAGS} -Wno-typedef-redefinition -Wno-tautological-compare -Wno-builtin-requires-header)
 endif()
-
-if( (CMAKE_C_COMPILER_ID MATCHES "mingw") OR (CMAKE_CXX_COMPILER_ID MATCHES "mingw"))
+if(CMAKE_C_COMPILER MATCHES "mingw")
     set(LTM_C_FLAGS  ${LTM_C_FLAGS}  -Wno-shadow)
 endif()
 
-if(DEFINED ENV{PLATFORM})
-    if($ENV{PLATFORM} MATCHES "Darwin")
-        set(LTM_C_FLAGS  ${LTM_C_FLAGS}  -Wno-nullability-completeness)
-    endif()
-    if($ENV{PLATFORM} MATCHES "CYGWIN")
-        set(LTM_C_FLAGS  ${LTM_C_FLAGS} -no-undefined)
-    endif()
+if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    set(LTM_C_FLAGS  ${LTM_C_FLAGS}  -Wno-nullability-completeness)
+endif()
+if(CMAKE_SYSTEM_NAME MATCHES "CYGWIN")
+    set(LTM_C_FLAGS  ${LTM_C_FLAGS} -no-undefined)
 endif()
 
 # TODO: coverage (lgcov)
 
 # If the user set the environment variables at generate-time, append them
 # in order to allow overriding our defaults.
-if(DEFINED ENV{LTM_CFLAGS})
-   set(LTM_C_FLAGS  ${LTM_C_FLAGS} $ENV{LTM_CFLAGS})
-endif()
-if(DEFINED ENV{LTM_LDFLAGS})
-   set(LTM_LD_FLAGS  ${LTM_LD_FLAGS} $ENV{LTM_LDFLAGS})
-endif()
+# ${LTM_CFLAGS} means the user passed it via sth like:
+# $ cmake -DLTM_CFLAGS="foo"
+set(LTM_C_FLAGS  ${LTM_C_FLAGS} ${LTM_CFLAGS})
+set(LTM_LD_FLAGS  ${LTM_LD_FLAGS} ${LTM_LDFLAGS})
 
 #-----------------------------------------------------------------------------
 # library target