qmk_firmware/quantum/variable_trace.c

/* Copyright 2016 Fred Sundvik
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "variable_trace.h"
#include <stddef.h>
#include <string.h>

#ifdef NO_PRINT
#    error "You need undef NO_PRINT to use the variable trace feature"
#endif

#ifndef CONSOLE_ENABLE
#    error "The console needs to be enabled in the makefile to use the variable trace feature"
#endif

#define NUM_TRACED_VARIABLES 1
#ifndef MAX_VARIABLE_TRACE_SIZE
#    define MAX_VARIABLE_TRACE_SIZE 4
#endif

typedef struct {
    const char* name;
    void*       addr;
    unsigned    size;
    const char* func;
    int         line;
    uint8_t     last_value[MAX_VARIABLE_TRACE_SIZE];

} traced_variable_t;

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_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_VARIABLE_TRACE_SIZE;
    }
    int index = -1;
    for (int i = 0; i < NUM_TRACED_VARIABLES; i++) {
        if (index == -1 && traced_variables[i].addr == NULL) {
            index = i;
        } else if (strcmp_P(name, traced_variables[i].name) == 0) {
            index = i;
            break;
        }
    }

    if (index == -1) {
        xprintf("You can only trace %d variables at the same time\n", NUM_TRACED_VARIABLES);
        return;
    }

    traced_variable_t* t = &traced_variables[index];
    t->name              = name;
    t->addr              = addr;
    t->size              = size;
    t->func              = func;
    t->line              = line;
    memcpy(&t->last_value[0], addr, size);
}

void remove_traced_variable(const char* name, const char* func, int line) {
    verify_traced_variables(func, line);
    for (int i = 0; i < NUM_TRACED_VARIABLES; i++) {
        if (strcmp_P(name, traced_variables[i].name) == 0) {
            traced_variables[i].name = 0;
            traced_variables[i].addr = NULL;
            break;
        }
    }
}

void verify_traced_variables(const char* func, int line) {
    for (int i = 0; i < NUM_TRACED_VARIABLES; i++) {
        traced_variable_t* t = &traced_variables[i];
        if (t->addr != NULL && t->name != NULL) {
            if (memcmp(t->last_value, t->addr, t->size) != 0) {
#if defined(__AVR__)
                xprintf("Traced variable \"%S\" has been modified\n", t->name);
                xprintf("Between %S:%d\n", t->func, t->line);
                xprintf("And %S:%d\n", func, line);

#else
                xprintf("Traced variable \"%s\" has been modified\n", t->name);
                xprintf("Between %s:%d\n", t->func, t->line);
                xprintf("And %s:%d\n", func, line);
#endif
                xprintf("Previous value ");
                for (int j = 0; j < t->size; j++) {
                    print_hex8(t->last_value[j]);
                }
                xprintf("\nNew value ");
                uint8_t* addr = (uint8_t*)(t->addr);
                for (int j = 0; j < t->size; j++) {
                    print_hex8(addr[j]);
                }
                xprintf("\n");
                memcpy(t->last_value, addr, t->size);
            }
        }

        t->func = func;
        t->line = line;
    }
}