make all non hardware_ libraries foo add C preprocessor definition LIB_FOO=1, and remove bespoke definitions which were all undocumented anyway (#374)

src/rp2_common/pico_printf/CMakeLists.txt

@@ -1,12 +1,9 @@
 if (NOT TARGET pico_printf)
     # library to be depended on - we make this depend on particular implementations using per target generator expressions
-    add_library(pico_printf INTERFACE)
+    pico_add_impl_library(pico_printf)
 
     # no custom implementation; falls thru to compiler
-    add_library(pico_printf_compiler INTERFACE)
-    target_compile_definitions(pico_printf_compiler INTERFACE
-            PICO_PRINTF_COMPILER=1
-    )
+    pico_add_impl_library(pico_printf_compiler)
 
     add_library(pico_printf_headers INTERFACE)
     target_include_directories(pico_printf_headers INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
@@ -20,28 +17,20 @@ if (NOT TARGET pico_printf)
     target_link_libraries(pico_printf INTERFACE
             $<IF:$<BOOL:$<TARGET_PROPERTY:PICO_TARGET_PRINTF_IMPL>>,$<TARGET_PROPERTY:PICO_TARGET_PRINTF_IMPL>,${PICO_DEFAULT_PRINTF_IMPL}>)
 
-    add_library(pico_printf_pico INTERFACE)
+    pico_add_impl_library(pico_printf_pico)
     target_sources(pico_printf_pico INTERFACE
             ${CMAKE_CURRENT_LIST_DIR}/printf.c
     )
 
-    target_compile_definitions(pico_printf_pico INTERFACE
-            PICO_PRINTF_PICO=1
-    )
-
     target_link_libraries(pico_printf_pico INTERFACE pico_printf_headers)
 
-    add_library(pico_printf_none INTERFACE)
+    pico_add_impl_library(pico_printf_none)
     target_sources(pico_printf_none INTERFACE
             ${CMAKE_CURRENT_LIST_DIR}/printf_none.S
     )
 
     target_link_libraries(pico_printf_none INTERFACE pico_printf_headers)
 
-    target_compile_definitions(pico_printf_none INTERFACE
-        PICO_PRINTF_NONE=1
-    )
-
     function(wrap_printf_functions TARGET)
         # note that printf and vprintf are in pico_stdio so we can provide thread safety
         pico_wrap_function(${TARGET} sprintf)

src/rp2_common/pico_printf/include/pico/printf.h

@@ -55,7 +55,7 @@ extern "C" {
 #endif
 #endif
 
-#if PICO_PRINTF_PICO
+#if LIB_PICO_PRINTF_PICO
 // weak raw printf may be a puts if printf has not been called,
 // so that we can support gc of printf when it isn't called
 //

src/rp2_common/pico_printf/printf.c

@@ -918,7 +918,7 @@ int vfctprintf(void (*out)(char character, void *arg), void *arg, const char *fo
     return _vsnprintf(_out_fct, (char *) (uintptr_t) &out_fct_wrap, (size_t) -1, format, va);
 }
 
-#if PICO_PRINTF_PICO
+#if LIB_PICO_PRINTF_PICO
 #if !PICO_PRINTF_ALWAYS_INCLUDED
 bool weak_raw_printf(const char *fmt, ...) {
     va_list va;