minimal-printf: Enable by a target config parameter

Author: hugueskamba

targets/targets.json

@@ -15,6 +15,7 @@
         "default_lib": "std",
         "bootloader_supported": false,
         "static_memory_defines": true,
+        "printf_lib": "std",
         "config": {
             "console-uart": {
                 "help": "Target has UART console on pins STDIO_UART_TX, STDIO_UART_RX. Value is only significant if target has SERIAL device.",

tools/toolchains/arm.py

@@ -81,6 +81,12 @@ def __init__(self, target, notify=None, macros=None,
             if "--library_type=microlib" not in self.flags['common']:
                 self.flags['common'].append("--library_type=microlib")
 
+        if (
+            target.printf_lib == "minimal-printf" and
+            "-DMBED_MINIMAL_PRINTF" not in self.flags['common']
+        ):
+            self.flags["common"].append("-DMBED_MINIMAL_PRINTF")
+
         cpu = {
             "Cortex-M0+": "Cortex-M0plus",
             "Cortex-M4F": "Cortex-M4.fp.sp",
@@ -568,6 +574,12 @@ def __init__(self, target, *args, **kwargs):
             if "--library_type=microlib" not in self.flags['asm']:
                 self.flags['asm'].append("--library_type=microlib")
 
+        if (
+            target.printf_lib == "minimal-printf" and
+            "-DMBED_MINIMAL_PRINTF" not in self.flags["common"]
+        ):
+            self.flags["common"].append("-DMBED_MINIMAL_PRINTF")
+
         if target.is_TrustZone_secure_target:
             if kwargs.get('build_dir', False):
                 # Output secure import library

tools/toolchains/gcc.py

@@ -58,6 +58,25 @@ def __init__(self, target,  notify=None, macros=None, build_profile=None,
             self.flags["common"].append("-DMBED_RTOS_SINGLE_THREAD")
             self.flags["ld"].append("--specs=nano.specs")
 
+        if target.printf_lib == "minimal-printf":
+            if "-DMBED_MINIMAL_PRINTF" not in self.flags['common']:
+                self.flags["common"].append("-DMBED_MINIMAL_PRINTF")
+
+            minimal_printf_wraps = [
+                "-Wl,--wrap,printf",
+                "-Wl,--wrap,sprintf",
+                "-Wl,--wrap,snprintf",
+                "-Wl,--wrap,vprintf",
+                "-Wl,--wrap,vsprintf",
+                "-Wl,--wrap,vsnprintf",
+                "-Wl,--wrap,fprintf",
+                "-Wl,--wrap,vfprintf",
+            ]
+
+            for minimal_printf_wrap in minimal_printf_wraps:
+                if minimal_printf_wrap not in self.flags["ld"]:
+                    self.flags["ld"].add(minimal_printf_wrap)
+
         self.cpu = []
         if target.is_TrustZone_secure_target:
             # Enable compiler security extensions

tools/toolchains/iar.py

@@ -69,6 +69,12 @@ def __init__(self, target, notify=None, macros=None, build_profile=None,
             define_string = self.make_ld_define("DOMAIN_NS", "0x1")
             self.flags["ld"].append(define_string)
 
+        if (
+            target.printf_lib == "minimal-printf" and
+            "-DMBED_MINIMAL_PRINTF" not in self.flags["common"]
+        ):
+            self.flags["common"].append("-DMBED_MINIMAL_PRINTF")
+
         core = target.core_without_NS
         cpu = {
             "Cortex-M7F": "Cortex-M7.fp.sp",