Add possibility to control variable trace from make

build_keyboard.mk

@@ -180,7 +180,13 @@ ifeq ($(strip $(SERIAL_LINK_ENABLE)), yes)
 	VAPTH += $(SERIAL_PATH)
 endif
 
-SRC += $(QUANTUM_DIR)/variable_trace.c
+ifneq ($(strip $(VARIABLE_TRACE)),)
+	SRC += $(QUANTUM_DIR)/variable_trace.c
+	OPT_DEFS += -DNUM_TRACED_VARIABLES=$(strip $(VARIABLE_TRACE))
+ifneq ($(strip $(MAX_VARIABLE_TRACE_SIZE)),)
+	OPT_DEFS += -DMAX_VARIABLE_TRACE_SIZE=$(strip $(MAX_VARIABLE_TRACE_SIZE))
+endif
+endif
 
 # Optimize size but this may cause error "relocation truncated to fit"
 #EXTRALDFLAGS = -Wl,--relax

quantum/variable_trace.c

@@ -12,7 +12,9 @@
 
 
 #define NUM_TRACED_VARIABLES 1
-#define MAX_TRACE_SIZE 4
+#ifndef MAX_VARIABLE_TRACE_SIZE
+    #define MAX_VARIABLE_TRACE_SIZE 4
+#endif
 
 typedef struct {
     const char* name;
@@ -20,7 +22,7 @@ typedef struct {
     unsigned size;
     const char* func;
     int line;
-    uint8_t last_value[MAX_TRACE_SIZE];
+    uint8_t last_value[MAX_VARIABLE_TRACE_SIZE];
 
 } traced_variable_t;
 
@@ -28,13 +30,13 @@ static traced_variable_t traced_variables[NUM_TRACED_VARIABLES];
 
 void add_traced_variable(const char* name, void* addr, unsigned size, const char* func, int line) {
     verify_traced_variables(func, line);
-    if (size > MAX_TRACE_SIZE) {
+    if (size > MAX_VARIABLE_TRACE_SIZE) {
 #if defined(__AVR__)
        xprintf("Traced variable \"%S\" exceeds the maximum size %d\n", name, size);
 #else
        xprintf("Traced variable \"%s\" exceeds the maximum size %d\n", name, size);
 #endif
-       size = MAX_TRACE_SIZE;
+       size = MAX_VARIABLE_TRACE_SIZE;
     }
     int index = -1;
     for (int i = 0; i < NUM_TRACED_VARIABLES; i++) {

quantum/variable_trace.h

@@ -0,0 +1,25 @@
+#ifndef VARIABLE_TRACE_H
+#define VARIABLE_TRACE_H
+
+#include "print.h"
+
+#ifdef NUM_TRACED_VARIABLES
+
+#define ADD_TRACED_VARIABLE(name, addr, size) \
+    add_traced_variable(PSTR(name), (void*)addr, size, PSTR(__FILE__), __LINE__)
+#define REMOVE_TRACED_VARIABLE(name) remove_traced_variable(PSTR(name), PSTR(__FILE__), __LINE__)
+#define VERIFY_TRACED_VARIABLES() verify_traced_variables(PSTR(__FILE__), __LINE__)
+
+#else
+
+#define ADD_TRACED_VARIABLE(name, addr, size)
+#define REMOVE_TRACED_VARIABLE(name)
+#define VERIFY_TRACED_VARIABLES()
+
+#endif
+
+// Don't call directly, use the macros instead
+void add_traced_variable(const char* name, void* addr, unsigned size, const char* func, int line);
+void remove_traced_variable(const char* name, const char* func, int line);
+void verify_traced_variables(const char* func, int line);
+#endif