build: add some build options to customise library functionality

CMakeLists.txt

@@ -9,7 +9,19 @@ set(CMAKE_C_EXTENSIONS OFF)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake)
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
+if (NOT DEFINED fx_modules)
 	set(fx_modules core ds serial term cmd io compress)
+endif ()
+
+if (NOT DEFINED fx_enable_floating_point)
+	set(fx_enable_floating_point 1)
+endif ()
+
+if (NOT DEFINED fx_enable_tests)
+	set(fx_enable_tests 1)
+endif ()
+
+message(STATUS "Floating point support: ${fx_enable_floating_point}")
 
 set(fx_system_name ${CMAKE_SYSTEM_NAME})
 string(TOLOWER ${fx_system_name} fx_system_name)
@@ -25,7 +37,7 @@ foreach (module ${fx_modules})
 	if (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/test/${module})
 		message(STATUS "Building unit tests for module ${module}")
 
-		if (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/test/${module}/${module}-units.c)
+		if (fx_enable_tests AND EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/test/${module}/${module}-units.c)
 			add_executable(fx-${module}-units
 				test/${module}/${module}-units.c
 				misc/AllTests.c
@@ -34,12 +46,12 @@ foreach (module ${fx_modules})
 			target_link_libraries(fx-${module}-units fx-${module})
 			target_include_directories(fx-${module}-units PRIVATE misc/)
 			set_target_properties(fx-${module}-units PROPERTIES FOLDER "Tests/${module}")
-
 		endif ()
 
 		file(GLOB test_sources test/${module}/*.c)
 		list(REMOVE_ITEM test_sources "${CMAKE_CURRENT_SOURCE_DIR}/test/${module}/${module}-units.c")
 
+		if (fx_enable_tests)
 			foreach (test_file ${test_sources})
 				get_filename_component(test_name ${test_file} NAME_WE)
 				add_executable(fx-${module}-${test_name} ${test_file})
@@ -49,8 +61,10 @@ foreach (module ${fx_modules})
 				target_link_libraries(fx-${module}-${test_name} fx-${module})
 			endforeach (test_file)
 		endif ()
+	endif ()
 endforeach (module)
 
+if (fx_enable_tests)
 	file(GLOB test_sources test/*.c)
 	list(REMOVE_ITEM test_sources "${CMAKE_CURRENT_SOURCE_DIR}/test/units.c")
 
@@ -64,3 +78,4 @@ foreach (test_file ${test_sources})
 			target_link_libraries(fx-${test_name} fx-${module})
 		endforeach (module)
 	endforeach (test_file)
+endif ()

cmake/Templates.cmake

@@ -50,11 +50,13 @@ function(add_fx_module)
 
 	target_compile_definitions(fx-${module_name} PUBLIC
 		${module_preproc_token}
-		FX_EXPORT=1)
+		FX_EXPORT=1
+		FX_ENABLE_FLOATING_POINT=${fx_enable_floating_point})
 	target_compile_definitions(fx-${module_name}-s PUBLIC
 		${module_preproc_token}
 		FX_EXPORT=1
-		FX_STATIC=1)
+		FX_STATIC=1
+		FX_ENABLE_FLOATING_POINT=${fx_enable_floating_point})
 
 	set_target_properties(fx-${module_name}
 		PROPERTIES POSITION_INDEPENDENT_CODE ON)

core/mt19937.c

@@ -217,6 +217,7 @@ static uint64_t genrand64_int64(struct fx_random_ctx *context)
 #endif
 }
 
+#if FX_ENABLE_FLOATING_POINT == 1
 /* generates a random number on [0,1]-real-interval */
 double genrand64_real1(struct fx_random_ctx *context)
 {
@@ -235,6 +236,7 @@ double genrand64_real3(struct fx_random_ctx *context)
 	return ((genrand64_int64(context) >> 12) + 0.5)
 	     * (1.0 / 4503599627370496.0);
 }
+#endif
 
 struct fx_random_algorithm z__fx_gen_mt19937 = {
 	.gen_name = "mt19937",

core/printf.c

@@ -45,6 +45,11 @@
 
 #include "printf.h"
 
+#if FX_ENABLE_FLOATING_POINT == 0
+#define PRINTF_SUPPORT_DECIMAL_SPECIFIERS     0
+#define PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS 0
+#endif
+
 #ifdef __cplusplus
 #include <climits>
 #include <cstdint>

core/random.c

@@ -60,6 +60,7 @@ unsigned long long fx_random_next_int64(struct fx_random_ctx *ctx)
 	return ctx->__a->gen_getrand(ctx);
 }
 
+#if FX_ENABLE_FLOATING_POINT
 double fx_random_next_double(struct fx_random_ctx *ctx)
 {
 	unsigned long long v = fx_random_next_int64(ctx);
@@ -69,8 +70,10 @@ double fx_random_next_double(struct fx_random_ctx *ctx)
 
 	return (double)(v >> 11) * (1.0 / 9007199254740991.0);
 }
+#endif
 
-void fx_random_next_bytes(struct fx_random_ctx *ctx, unsigned char *out, size_t nbytes)
+void fx_random_next_bytes(
+	struct fx_random_ctx *ctx, unsigned char *out, size_t nbytes)
 {
 	size_t n_qwords = 0;
 	n_qwords = nbytes >> 3;