diff --git a/backend/auspost.c b/backend/auspost.c
index d757bfa8..910e4d1a 100644
--- a/backend/auspost.c
+++ b/backend/auspost.c
@@ -69,7 +69,7 @@ static inline char convert_pattern(char data, int shift) {
 
 /* Adds Reed-Solomon error correction to auspost */
 void rs_error(char data_pattern[]) {
-    int reader, triple_writer = 0;
+    size_t reader, triple_writer = 0;
     char triple[31], inv_triple[31];
     unsigned char result[5];
 
diff --git a/backend/aztec.c b/backend/aztec.c
index d771c912..f621a8ff 100644
--- a/backend/aztec.c
+++ b/backend/aztec.c
@@ -68,7 +68,7 @@ static void insert(char binary_string[], const size_t posn, const char newbit) {
 /**
  * Encode input data into a binary string
  */
-static int aztec_text_process(const unsigned char source[], const unsigned int src_len, char binary_string[], const int gs1, const int eci, int debug) {
+static int aztec_text_process(const unsigned char source[], const size_t src_len, char binary_string[], const int gs1, const int eci, const int debug) {
     int i, j, k, bytes;
     int curtable, newtable, lasttable, chartype, maplength, blocks;
 #ifndef _MSC_VER
@@ -812,7 +812,7 @@ static void populate_map() {
     AztecMap[(avoidReferenceGrid(77) * 151) + avoidReferenceGrid(76)] = 1;
 }
 
-int aztec(struct zint_symbol *symbol, unsigned char source[], int length) {
+int aztec(struct zint_symbol *symbol, unsigned char source[], const size_t length) {
     int x, y, i, j, p, data_blocks, ecc_blocks, layers, total_bits;
     char binary_string[20000], bit_pattern[20045], descriptor[42];
     char adjusted_string[20000];
diff --git a/backend/codablock.c b/backend/codablock.c
index 34459675..465eba14 100644
--- a/backend/codablock.c
+++ b/backend/codablock.c
@@ -629,7 +629,7 @@ void SumASCII(uchar **ppOutPos, int Sum, int CharacterSet)
 
 /* Main function called by zint framework
  */
-int codablock(struct zint_symbol *symbol, unsigned char source[], int length) {
+int codablock(struct zint_symbol *symbol,const unsigned char source[], const size_t length) {
     int charCur;
     int dataLength;
     int Error;
diff --git a/backend/code128.c b/backend/code128.c
index db2b784a..7d249bdc 100644
--- a/backend/code128.c
+++ b/backend/code128.c
@@ -291,9 +291,10 @@ void c128_set_c(unsigned char source_a, unsigned char source_b, char dest[], int
 }
 
 /* Handle Code 128 and NVE-18 */
-int code_128(struct zint_symbol *symbol, unsigned char source[], int length) {
+int code_128(struct zint_symbol *symbol, unsigned char source[], const size_t length) { 
     int i, j, k, values[170] = {0}, bar_characters, read, total_sum;
-    int error_number, indexchaine, indexliste, sourcelen, f_state;
+    int error_number, indexchaine, indexliste, f_state;
+    size_t sourcelen;
     char set[170] = {' '}, fset[170] = {' '}, mode, last_set, current_set = ' ';
     float glyph_count;
     char dest[1000];
diff --git a/backend/code16k.c b/backend/code16k.c
index cbef7153..8a76983e 100644
--- a/backend/code16k.c
+++ b/backend/code16k.c
@@ -52,6 +52,8 @@
 #define CANDB 98
 #define CANDBB 99
 
+extern int parunmodd(const unsigned char llyth);
+
 static int list[2][170];
 
 static const char *C16KTable[107] = {
@@ -86,20 +88,20 @@ static const int C16KStopValues[16] = {
     0, 1, 2, 3, 4, 5, 6, 7, 4, 5, 6, 7, 0, 1, 2, 3
 };
 
-void grwp16(int *indexliste) {
+static void grwp16(unsigned int *indexliste) {
     int i, j;
 
     /* bring together same type blocks */
     if (*(indexliste) > 1) {
         i = 1;
-        while (i < *(indexliste)) {
+        while(i < (int)*(indexliste)) {
             if (list[1][i - 1] == list[1][i]) {
                 /* bring together */
                 list[0][i - 1] = list[0][i - 1] + list[0][i];
                 j = i + 1;
 
                 /* decreace the list */
-                while (j < *(indexliste)) {
+                while(j < (int)*(indexliste)) {
                     list[0][j - 1] = list[0][j];
                     list[1][j - 1] = list[1][j];
                     j++;
@@ -113,10 +115,10 @@ void grwp16(int *indexliste) {
 }
 
 /* Implements rules from ISO 15417 Annex E */
-void dxsmooth16(int *indexliste) {
+static void dxsmooth16(unsigned int *indexliste) {
     int i, current, last, next, length;
 
-    for (i = 0; i < *(indexliste); i++) {
+    for(i = 0; i < (int)*(indexliste); i++) {
         current = list[1][i];
         length = list[0][i];
         if (i != 0) {
@@ -220,7 +222,7 @@ void dxsmooth16(int *indexliste) {
 
 }
 
-void c16k_set_a(unsigned char source, unsigned int values[], unsigned int *bar_chars) {
+static void c16k_set_a(const unsigned char source, unsigned int values[], unsigned int *bar_chars) {
     if (source > 127) {
         if (source < 160) {
             values[(*bar_chars)] = source + 64 - 128;
@@ -237,7 +239,7 @@ void c16k_set_a(unsigned char source, unsigned int values[], unsigned int *bar_c
     (*bar_chars)++;
 }
 
-void c16k_set_b(unsigned char source, unsigned int values[], unsigned int *bar_chars) {
+static void c16k_set_b(const unsigned char source, unsigned int values[], unsigned int *bar_chars) {
     if (source > 127) {
         values[(*bar_chars)] = source - 32 - 128;
     } else {
@@ -246,7 +248,7 @@ void c16k_set_b(unsigned char source, unsigned int values[], unsigned int *bar_c
     (*bar_chars)++;
 }
 
-void c16k_set_c(unsigned char source_a, unsigned char source_b, unsigned int values[], unsigned int *bar_chars) {
+static void c16k_set_c(const unsigned char source_a, unsigned char source_b, unsigned int values[], unsigned int *bar_chars) {
     int weight;
 
     weight = (10 * ctoi(source_a)) + ctoi(source_b);
@@ -254,17 +256,17 @@ void c16k_set_c(unsigned char source_a, unsigned char source_b, unsigned int val
     (*bar_chars)++;
 }
 
-int code16k(struct zint_symbol *symbol, unsigned char source[], int length) {
+int code16k(struct zint_symbol *symbol, unsigned char source[], const size_t length) {
     char width_pattern[100];
     int current_row, rows_needed, flip_flop, looper, first_check, second_check;
-    int indexliste, indexchaine, pads_needed, f_state;
+    int indexchaine, f_state;
     char set[160] = {' '}, fset[160] = {' '}, mode, last_set, current_set;
-    unsigned int i, j, k, m, read, mx_reader, writer;
+    unsigned int pads_needed, indexliste, i, j, k, m, read, mx_reader, writer;
     unsigned int values[160] = {0};
     unsigned int bar_characters;
     float glyph_count;
     int errornum, first_sum, second_sum;
-    int input_length;
+    size_t input_length;
     int gs1, c_count;
 
     errornum = 0;
@@ -483,7 +485,7 @@ int code16k(struct zint_symbol *symbol, unsigned char source[], int length) {
 
     /* Calculate how tall the symbol will be */
     glyph_count = glyph_count + 2.0;
-    i = glyph_count;
+    i = (int)glyph_count;
     rows_needed = (i / 5);
     if (i % 5 > 0) {
         rows_needed++;
diff --git a/backend/common.c b/backend/common.c
index 9abfa9ef..389ae366 100644
--- a/backend/common.c
+++ b/backend/common.c
@@ -106,18 +106,6 @@ int is_sane(const char test_string[], const unsigned char source[], const size_t
     return 0;
 }
 
-/* Returns the position of data in set_string */
-int posn(const char set_string[], const char data) {
-    size_t i, n = strlen(set_string);
-
-    for (i = 0; i < n; i++) {
-        if (data == set_string[i]) {
-            return i;
-        }
-    }
-    return 0;
-}
-
 /* Replaces huge switch statements for looking up in tables */
 void lookup(const char set_string[], const char *table[], const char data, char dest[]) {
     size_t i, n = strlen(set_string);
@@ -129,6 +117,18 @@ void lookup(const char set_string[], const char *table[], const char data, char
     }
 }
 
+/* Returns the position of data in set_string */
+int posn(const char set_string[], const char data) {
+    int i, n = (int)strlen(set_string);
+
+    for (i = 0; i < n; i++) {
+        if (data == set_string[i]) {
+         return i;
+        }
+    }
+   return 0;
+}
+
 /* Return true (1) if a module is dark/black, otherwise false (0) */
 int module_is_set(const struct zint_symbol *symbol, const int y_coord, const int x_coord) {
     return (symbol->encoded_data[y_coord][x_coord / 7] >> (x_coord % 7)) & 1;
@@ -180,12 +180,10 @@ void expand(struct zint_symbol *symbol, const char data[]) {
 
 /* Indicates which symbologies can have row binding */
 int is_stackable(const int symbology) {
-    int retval = 0;
-
     if (symbology < BARCODE_PDF417) {
-        retval = 1;
+        return 1;
     }
-
+    
     switch (symbology) {
         case BARCODE_CODE128B:
         case BARCODE_ISBNX:
@@ -197,10 +195,10 @@ int is_stackable(const int symbology) {
         case BARCODE_ITF14:
         case BARCODE_CODE32:
         case BARCODE_CODABLOCKF:
-            retval = 1;
+            return 1;
     }
 
-    return retval;
+    return 0;
 }
 
 /* Indicates which symbols can have addon (EAN-2 and EAN-5) */
@@ -240,8 +238,9 @@ int istwodigits(const unsigned char source[], const int position) {
     return 0;
 }
 
-int utf8toutf16(struct zint_symbol *symbol, const unsigned char source[], int vals[], int *length) {
-    int bpos, jpos, error_number;
+int utf8toutf16(struct zint_symbol *symbol, const unsigned char source[], int vals[], size_t *length) {
+    size_t bpos;
+    int    jpos, error_number;
     int next;
 
     bpos = 0;
@@ -291,7 +290,8 @@ int utf8toutf16(struct zint_symbol *symbol, const unsigned char source[], int va
     return error_number;
 }
 
-void set_minimum_height(struct zint_symbol *symbol, int min_height) {
+
+void set_minimum_height(struct zint_symbol *symbol, const int min_height) {
     /* Enforce minimum permissable height of rows */
     int fixed_height = 0;
     int zero_count = 0;
diff --git a/backend/common.h b/backend/common.h
index cfc8073a..9053f3d4 100644
--- a/backend/common.h
+++ b/backend/common.h
@@ -62,18 +62,16 @@ extern "C" {
     extern int is_sane(const char test_string[], const unsigned char source[], const size_t length);
     extern void lookup(const char set_string[], const char *table[], const char data, char dest[]);
     extern int posn(const char set_string[], const char data);
-    extern void expand(struct zint_symbol *symbol, const char data[]);
-    extern int is_stackable(const int symbology);
-    extern int is_extendable(const int symbology);
-    extern int roundup(const float input);
     extern int module_is_set(const struct zint_symbol *symbol, const int y_coord, const int x_coord);
     extern void set_module(struct zint_symbol *symbol, const int y_coord, const int x_coord);
-    extern void unset_module(struct zint_symbol *symbol, const int y_coord, const int x_coord);
     extern int istwodigits(const unsigned char source[], const int position);
-    extern double froundup(const double input);
     extern int parunmodd(const unsigned char llyth);
-    extern int utf8toutf16(struct zint_symbol *symbol, const unsigned char source[], int vals[], int *length);
-    extern void set_minimum_height(struct zint_symbol *symbol, int min_height);
+    extern void expand(struct zint_symbol *symbol, const char data[]);
+    extern void unset_module(struct zint_symbol *symbol, const int y_coord, const int x_coord);
+    extern int is_stackable(const int symbology);
+    extern int is_extendable(const int symbology);
+    extern int utf8toutf16(struct zint_symbol *symbol, const unsigned char source[], int vals[], size_t *length);
+    extern void set_minimum_height(struct zint_symbol *symbol, const int min_height);
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
diff --git a/backend/composite.c b/backend/composite.c
index 5751e463..59af0e6e 100644
--- a/backend/composite.c
+++ b/backend/composite.c
@@ -72,7 +72,7 @@ extern int rssexpanded(struct zint_symbol *symbol, unsigned char source[], int l
 
 static UINT pwr928[69][7];
 
-int _min(int first, int second) {
+static int _min(int first, int second) {
 
     if (first <= second)
         return first;
@@ -81,12 +81,12 @@ int _min(int first, int second) {
 }
 
 /* gets bit in bitString at bitPos */
-int getBit(UINT *bitStr, int bitPos) {
+static int getBit(UINT *bitStr, int bitPos) {
     return !!(bitStr[bitPos >> 4] & (0x8000 >> (bitPos & 15)));
 }
 
 /* initialize pwr928 encoding table */
-void init928(void) {
+static void init928(void) {
     int i, j, v;
     int cw[7];
     cw[6] = 1L;
@@ -106,7 +106,7 @@ void init928(void) {
 }
 
 /* converts bit string to base 928 values, codeWords[0] is highest order */
-int encode928(UINT bitString[], UINT codeWords[], int bitLng) {
+static int encode928(UINT bitString[], UINT codeWords[], int bitLng) {
     int i, j, b, bitCnt, cwNdx, cwCnt, cwLng;
     for (cwNdx = cwLng = b = 0; b < bitLng; b += 69, cwNdx += 7) {
         bitCnt = _min(bitLng - b, 69);
@@ -129,7 +129,7 @@ int encode928(UINT bitString[], UINT codeWords[], int bitLng) {
 }
 
 /* CC-A 2D component */
-int cc_a(struct zint_symbol *symbol, char source[], int cc_width) {
+static int cc_a(struct zint_symbol *symbol, char source[], int cc_width) { 
     int i, strpos, segment, bitlen, cwCnt, variant, rows;
     int k, offset, j, total, rsCodeWords[8];
     int LeftRAPStart, RightRAPStart, CentreRAPStart, StartCluster;
@@ -363,7 +363,7 @@ int cc_a(struct zint_symbol *symbol, char source[], int cc_width) {
 }
 
 /* CC-B 2D component */
-int cc_b(struct zint_symbol *symbol, char source[], int cc_width) {
+static int cc_b(struct zint_symbol *symbol, char source[], int cc_width) { 
     int length, i, binloc;
 #ifndef _MSC_VER
     unsigned char data_string[(strlen(source) / 8) + 3];
@@ -646,7 +646,7 @@ int cc_b(struct zint_symbol *symbol, char source[], int cc_width) {
 }
 
 /* CC-C 2D component - byte compressed PDF417 */
-int cc_c(struct zint_symbol *symbol, char source[], int cc_width, int ecc_level) {
+static int cc_c(struct zint_symbol *symbol, char source[], int cc_width, int ecc_level) { 
     int length, i, p, binloc;
 #ifndef _MSC_VER
     unsigned char data_string[(strlen(source) / 8) + 4];
@@ -789,12 +789,12 @@ int cc_c(struct zint_symbol *symbol, char source[], int cc_width, int ecc_level)
         symbol->row_height[i] = 3;
     }
     symbol->rows = (mclength / cc_width);
-    symbol->width = strlen(pattern);
+    symbol->width = (int)strlen(pattern);
 
     return 0;
 }
 
-int calc_padding_cca(int binary_length, int cc_width) {
+static int calc_padding_cca(int binary_length, int cc_width) {
     int target_bitsize = 0;
     
     switch (cc_width) {
@@ -1026,7 +1026,7 @@ int calc_padding_ccc(int binary_length, int *cc_width, int lin_width, int *ecc)
     return target_bitsize;
 }
 
-int cc_binary_string(struct zint_symbol *symbol, const char source[], char binary_string[], int cc_mode, int *cc_width, int *ecc, int lin_width) { /* Handles all data encodation from section 5 of ISO/IEC 24723 */
+static int cc_binary_string(struct zint_symbol *symbol, const char source[], char binary_string[], int cc_mode, int *cc_width, int *ecc, int lin_width) { /* Handles all data encodation from section 5 of ISO/IEC 24723 */
     int encoding_method, read_posn, d1, d2, value, alpha_pad;
     int i, j, mask, ai_crop, fnc1_latch;
     long int group_val;
@@ -1223,7 +1223,7 @@ int cc_binary_string(struct zint_symbol *symbol, const char source[], char binar
                 }
             }
 
-            next_ai_posn = 2 + strlen(ninety);
+            next_ai_posn = 2 + (int)strlen(ninety);
 
             if (source[next_ai_posn] == '[') {
                 /* There are more AIs afterwords */
@@ -1721,7 +1721,7 @@ int cc_binary_string(struct zint_symbol *symbol, const char source[], char binar
         }
     } while (i + latch < (int) strlen(general_field));
     
-    binary_length = strlen(binary_string);
+    binary_length = (int)strlen(binary_string);
     switch (cc_mode) {
         case 1:
             target_bitsize = calc_padding_cca(binary_length, *(cc_width));
@@ -1783,7 +1783,7 @@ int cc_binary_string(struct zint_symbol *symbol, const char source[], char binar
     }
 
 
-    binary_length = strlen(binary_string);
+    binary_length = (int)strlen(binary_string);
     switch (cc_mode) {
         case 1:
             target_bitsize = calc_padding_cca(binary_length, *(cc_width));
@@ -1825,55 +1825,6 @@ int cc_binary_string(struct zint_symbol *symbol, const char source[], char binar
     return 0;
 }
 
-void add_leading_zeroes(struct zint_symbol *symbol) {
-    int with_addon = 0;
-    int first_len = 0, second_len = 0, zfirst_len = 0, zsecond_len = 0, i, h, n = 0;
-
-    h = strlen(symbol->primary);
-    for (i = 0; i < h; i++) {
-        if (symbol->primary[i] == '+') {
-            with_addon = 1;
-        } else {
-            if (with_addon == 0) {
-                first_len++;
-            } else {
-                second_len++;
-            }
-        }
-    }
-
-    /* Calculate target lengths */
-    if (first_len <= 12) {
-        zfirst_len = 12;
-    }
-    if (first_len <= 7) {
-        zfirst_len = 7;
-    }
-    if (second_len <= 5) {
-        zsecond_len = 5;
-    }
-    if (second_len <= 2) {
-        zsecond_len = 2;
-    }
-    if (second_len == 0) {
-        zsecond_len = 0;
-    }
-
-    /* Add leading zeroes */
-    n = zfirst_len - first_len;
-    if (n > 0) {
-        memmove(symbol->primary + n, symbol->primary, h);
-        memset(symbol->primary, '0', n);
-    }
-    n += first_len + 1;
-    if (zsecond_len) {
-        memmove(symbol->primary + n + zsecond_len, symbol->primary + n, second_len);
-        memset(symbol->primary + n, '0', zsecond_len);
-        n += zsecond_len + second_len;
-    }
-    symbol->primary[n] = '\0';
-}
-
 int linear_dummy_run(unsigned char *source, int length) {
     struct zint_symbol *dummy;
     int error_number;
@@ -1912,7 +1863,7 @@ int composite(struct zint_symbol *symbol, unsigned char source[], int length) {
     
     /* Perform sanity checks on input options first */
     error_number = 0;
-    pri_len = strlen(symbol->primary);
+    pri_len = (int)strlen(symbol->primary);
     if (pri_len == 0) {
         strcpy(symbol->errtxt, "No primary (linear) message in 2D composite (D45)");
         return ZINT_ERROR_INVALID_OPTION;
diff --git a/backend/dmatrix.c b/backend/dmatrix.c
index 78f7ce60..113824fc 100644
--- a/backend/dmatrix.c
+++ b/backend/dmatrix.c
@@ -256,22 +256,22 @@ static void dminsert(char binary_string[], const int posn, const char newbit) {
     binary_string[posn] = newbit;
 }
 
-static void insert_value(unsigned char binary_stream[], const int posn, const int streamlen, const int newbit) {
+static void insert_value(unsigned char binary_stream[], const int posn, const size_t streamlen, const int newbit) {
     int i;
 
-    for (i = streamlen; i > posn; i--) {
+    for(i = (int)streamlen; i > posn; i--) {
         binary_stream[i] = binary_stream[i - 1];
     }
     binary_stream[posn] = (unsigned char) newbit;
 }
 
-static int p_r_6_2_1(const unsigned char inputData[], const int position, const int sourcelen) {
+static int p_r_6_2_1(const unsigned char inputData[], const int position, const size_t sourcelen) {
     /* Annex P section (r)(6)(ii)(I)
        "If one of the three X12 terminator/separator characters first
         occurs in the yet to be processed data before a non-X12 character..."
      */
 
-    int i;
+    size_t i;
     int nonX12Position = 0;
     int specialX12Position = 0;
     int retval = 0;
@@ -302,10 +302,11 @@ static int p_r_6_2_1(const unsigned char inputData[], const int position, const
 }
 
 /* 'look ahead test' from Annex P */
-static int look_ahead_test(const unsigned char inputData[], const int sourcelen, const int position, const int current_mode, const int gs1) {
+static int look_ahead_test(const unsigned char inputData[], const size_t sourcelen, const size_t position, const int current_mode, const int gs1) {
     float ascii_count, c40_count, text_count, x12_count, edf_count, b256_count, best_count;
     const float stiction = (1.0F / 24.0F); // smallest change to act on, to get around floating point inaccuracies
-    int sp, best_scheme;
+    int    best_scheme;
+    size_t sp;
 
     best_scheme = DM_NULL;
 
@@ -520,9 +521,6 @@ static int look_ahead_test(const unsigned char inputData[], const int sourcelen,
             }
         }
         
-        //printf("Char %d[%c]: ASC:%.2f C40:%.2f X12:%.2f TXT:%.2f EDI:%.2f BIN:%.2f\n", sp,
-        //        inputData[sp], ascii_count, c40_count, x12_count, text_count, edf_count, b256_count);
-
         sp++;
     } while (best_scheme == DM_NULL); // step (s)
 
@@ -531,11 +529,12 @@ static int look_ahead_test(const unsigned char inputData[], const int sourcelen,
 
 /* Encodes data using ASCII, C40, Text, X12, EDIFACT or Base 256 modes as appropriate
    Supports encoding FNC1 in supporting systems */
-static int dm200encode(struct zint_symbol *symbol, const unsigned char source[], unsigned char target[], int *last_mode, int *length_p, int process_buffer[], int *process_p) {
+static int dm200encode(struct zint_symbol *symbol, const unsigned char source[], unsigned char target[], int *last_mode, size_t *length_p, int process_buffer[], int *process_p) {
 
-    int sp, tp, i, gs1;
+    size_t sp;
+    int tp, i, gs1;
     int current_mode, next_mode;
-    int inputlen = *length_p;
+    size_t inputlen = *length_p;
     int debug = symbol->debug;
 #ifndef _MSC_VER
     char binary[2 * inputlen];
@@ -984,9 +983,9 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
     return tp;
 }
 
-static int dm200encode_remainder(unsigned char target[], int target_length, const unsigned char source[], const int inputlen, const int last_mode, const int process_buffer[], const int process_p, const int symbols_left) {
+static int dm200encode_remainder(unsigned char target[], int target_length, const unsigned char source[], const size_t inputlen, const int last_mode, const int process_buffer[], const int process_p, const int symbols_left) {
     int debug = 0;
-
+    
     switch (last_mode) {
         case DM_C40:
         case DM_TEXT:
@@ -1124,8 +1123,9 @@ static void add_tail(unsigned char target[], int tp, const int tail_length) {
     }
 }
 
-int data_matrix_200(struct zint_symbol *symbol, const unsigned char source[], const int in_length) {
-    int i, inputlen = in_length, skew = 0;
+int data_matrix_200(struct zint_symbol *symbol,const unsigned char source[], const size_t in_length) {
+	int i, skew = 0;
+   size_t inputlen=in_length;
     unsigned char binary[2200];
     int binlen;
     int process_buffer[8]; /* holds remaining data to finalised */
@@ -1284,7 +1284,7 @@ int data_matrix_200(struct zint_symbol *symbol, const unsigned char source[], co
     return error_number;
 }
 
-int dmatrix(struct zint_symbol *symbol, const unsigned char source[], const int in_length) {
+int dmatrix(struct zint_symbol *symbol, const unsigned char source[], const size_t in_length) {
     int error_number;
 
     if (symbol->option_1 <= 1) {
diff --git a/backend/dmatrix.h b/backend/dmatrix.h
index 94335af2..17ab21d5 100644
--- a/backend/dmatrix.h
+++ b/backend/dmatrix.h
@@ -44,7 +44,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-    extern int data_matrix_200(struct zint_symbol *symbol, const unsigned char source[], const int length);
+extern int data_matrix_200(struct zint_symbol *symbol, const unsigned char source[], const size_t length);
 
 #ifdef __cplusplus
 }
diff --git a/backend/dotcode.c b/backend/dotcode.c
index 914ab7d3..54737384 100644
--- a/backend/dotcode.c
+++ b/backend/dotcode.c
@@ -66,7 +66,7 @@ static const int dot_patterns[113] = {
     0x1b8, 0x1c6, 0x1cc
 };
 
-int get_dot(char Dots[], int Hgt, int Wid, int x, int y) {
+static int get_dot(char Dots[], const int Hgt, const int Wid, const int x, const int y) {
     int retval = 0;
 
     if ((x >= 0) && (x < Wid) && (y >= 0) && (y < Hgt)) {
@@ -78,7 +78,7 @@ int get_dot(char Dots[], int Hgt, int Wid, int x, int y) {
     return retval;
 }
 
-int clr_col(char *Dots, int Hgt, int Wid, int x) {
+static int clr_col(char *Dots, const int Hgt, const int Wid, const int x) {
     int y;
     for (y = x & 1; y < Hgt; y += 2) {
         if (get_dot(Dots, Hgt, Wid, x, y)) {
@@ -89,7 +89,7 @@ int clr_col(char *Dots, int Hgt, int Wid, int x) {
     return 1;
 }
 
-int clr_row(char *Dots, int Hgt, int Wid, int y) {
+static int clr_row(char *Dots, const int Hgt, const int Wid, const int y) {
     int x;
     for (x = y & 1; x < Wid; x += 2) {
         if (get_dot(Dots, Hgt, Wid, x, y)) {
@@ -101,7 +101,7 @@ int clr_row(char *Dots, int Hgt, int Wid, int y) {
 }
 
 /* Dot pattern scoring routine from Annex A */
-int score_array(char Dots[], int Hgt, int Wid) {
+const int score_array(char Dots[], int Hgt, int Wid) {
     int x, y, worstedge, first, last, sum;
     int penalty_local = 0;
     int penalty = 0;
@@ -1192,9 +1192,9 @@ void fold_dotstream(char dot_stream[], int width, int height, char dot_array[])
 
 int dotcode(struct zint_symbol *symbol, const unsigned char source[], int length) {
     int i, j, k;
-    size_t jc;
+    size_t jc, n_dots;
     int data_length, ecc_length;
-    int min_dots, n_dots, min_area;
+    int min_dots, min_area;
     int height, width;
     int mask_score[4];
     int weight;
diff --git a/backend/emf.c b/backend/emf.c
index 9865aaed..385938ea 100644
--- a/backend/emf.c
+++ b/backend/emf.c
@@ -35,6 +35,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <math.h>
+#include <malloc.h>
 #include "common.h"
 #include "emf.h"
 
diff --git a/backend/gridmtx.c b/backend/gridmtx.c
index d7652578..5e59cf16 100644
--- a/backend/gridmtx.c
+++ b/backend/gridmtx.c
@@ -43,12 +43,12 @@
 #include "gridmtx.h"
 #include "gb2312.h"
 
-int number_lat(int gbdata[], int length, int position) {
+int number_lat(int gbdata[], const size_t length, const size_t position) {
     /* Attempt to calculate the 'cost' of using numeric mode from a given position in number of bits */
     /* Also ensures that numeric mode is not selected when it cannot be used: for example in
        a string which has "2.2.0" (cannot have more than one non-numeric character for each
        block of three numeric characters) */
-    int sp;
+    size_t sp;
     int numb = 0, nonum = 0, done;
     int tally = 0;
 
@@ -118,14 +118,15 @@ int number_lat(int gbdata[], int length, int position) {
     return tally;
 }
 
-int seek_forward(int gbdata[], int length, int position, int current_mode) {
+static int seek_forward(int gbdata[], const size_t length, const size_t position, int current_mode) {
     /* In complete contrast to the method recommended in Annex D of the ANSI standard this
        code uses a look-ahead test in the same manner as Data Matrix. This decision was made
        because the "official" algorithm does not provide clear methods for dealing with all
        possible combinations of input data */
 
     int number_count, byte_count, mixed_count, upper_count, lower_count, chinese_count;
-    int sp, best_mode, done;
+    int    best_mode, done;
+   size_t sp;
     int best_count, last = -1;
     int debug = 0;
 
@@ -268,7 +269,7 @@ int seek_forward(int gbdata[], int length, int position, int current_mode) {
         if (sp != last) {
             if (((gbdata[sp] >= '0') && (gbdata[sp] <= '9')) && ((gbdata[sp + 1] >= '0') && (gbdata[sp + 1] <= '9'))) {
                 chinese_count -= 13;
-                last = sp + 1;
+                last = (int)(sp + 1);
             }
         }
     }
@@ -342,7 +343,7 @@ void add_shift_char(char binary[], int shifty) {
     bin_append(glyph, 6, binary);
 }
 
-int gm_encode(int gbdata[], int length, char binary[], int reader, int eci, int debug) {
+static int gm_encode(int gbdata[], const size_t length, char binary[], int reader, int eci, int debug) {
     /* Create a binary stream representation of the input data.
        7 sets are defined - Chinese characters, Numerals, Lower case letters, Upper case letters,
        Mixed numerals and latters, Control characters and 8-bit binary data */
@@ -987,7 +988,7 @@ void place_layer_id(char* grid, int size, int layers, int modules, int ecc_level
     }
 }
 
-int grid_matrix(struct zint_symbol *symbol, const unsigned char source[], int length) {
+int grid_matrix(struct zint_symbol *symbol, const unsigned char source[], size_t length) {
     int size, modules, dark, error_number;
     int auto_layers, min_layers, layers, auto_ecc_level, min_ecc_level, ecc_level;
     int x, y, i, j, glyph;
@@ -1049,7 +1050,7 @@ int grid_matrix(struct zint_symbol *symbol, const unsigned char source[], int le
     }
 
     /* Determine the size of the symbol */
-    data_cw = strlen(binary) / 7;
+    data_cw = (int)strlen(binary) / 7;
 
     auto_layers = 13;
     for (i = 12; i > 0; i--) {
diff --git a/backend/hanxin.c b/backend/hanxin.c
index b00da804..2ccf31bc 100644
--- a/backend/hanxin.c
+++ b/backend/hanxin.c
@@ -47,33 +47,33 @@
 /* Find which submode to use for a text character */
 int getsubmode(char input) {
     int submode = 2;
-
+    
     if ((input >= '0') && (input <= '9')) {
         submode = 1;
     }
-
+    
     if ((input >= 'A') && (input <= 'Z')) {
         submode = 1;
     }
-
+    
     if ((input >= 'a') && (input <= 'z')) {
         submode = 1;
     }
-
+    
     return submode;
 }
 
 /* Calculate the approximate length of the binary string */
-int calculate_binlength(char mode[], int source[], int length, int eci) {
+static int calculate_binlength(char mode[], int source[], const size_t length, int eci) {
     int i;
     char lastmode = 't';
     int est_binlen = 0;
     int submode = 1;
-
+    
     if (eci != 3) {
         est_binlen += 12;
     }
-
+    
     i = 0;
     do {
         switch (mode[i]) {
@@ -220,38 +220,38 @@ int isFourByte(int glyph, int glyph2) {
             }
         }
     }
-
+    
     return valid;
 }
 
 /* Calculate mode switching */
-void hx_define_mode(char mode[], int source[], int length) {
+static void hx_define_mode(char mode[], int source[], const size_t length) {
     int i;
     char lastmode = 't';
     int done;
-
+    
     i = 0;
     do {
         done = 0;
-
+        
         if (isRegion1(source[i])) {
             mode[i] = '1';
             done = 1;
             i++;
         }
-
+        
         if ((done == 0) && (isRegion2(source[i]))) {
             mode[i] = '2';
             done = 1;
             i++;
         }
-
+        
         if ((done == 0) && (isDoubleByte(source[i]))) {
             mode[i] = 'd';
             done = 1;
             i++;
         }
-
+        
         if ((done == 0) && (i < length - 1)) {
             if (isFourByte(source[i], source[i + 1])) {
                 mode[i] = 'f';
@@ -289,47 +289,47 @@ void hx_define_mode(char mode[], int source[], int length) {
 /* Convert Text 1 sub-mode character to encoding value, as given in table 3 */
 int lookup_text1(char input) {
     int encoding_value = 0;
-
+    
     if ((input >= '0') && (input <= '9')) {
         encoding_value = input - '0';
     }
-
+    
     if ((input >= 'A') && (input <= 'Z')) {
         encoding_value = input - 'A' + 10;
     }
-
+    
     if ((input >= 'a') && (input <= 'z')) {
         encoding_value = input - 'a' + 36;
     }
-
+    
     return encoding_value;
 }
 
 /* Convert Text 2 sub-mode character to encoding value, as given in table 4 */
 int lookup_text2(char input) {
     int encoding_value = 0;
-
+    
     if ((input >= 0) && (input <= 27)) {
         encoding_value = input;
     }
-
+    
     if ((input >= ' ') && (input <= '/')) {
         encoding_value = input - ' ' + 28;
     }
-
+    
     if ((input >= '[') && (input <= 96)) {
         encoding_value = input - '[' + 51;
     }
-
+    
     if ((input >= '{') && (input <= 127)) {
         encoding_value = input - '{' + 57;
     }
-
+    
     return encoding_value;
 }
 
 /* Convert input data to binary stream */
-void calculate_binary(char binary[], char mode[], int source[], int length, int eci, int debug) {
+static void calculate_binary(char binary[], char mode[], int source[], const size_t length, const int eci, int debug) {
     int block_length;
     int position = 0;
     int i, count, encoding_value;
@@ -1236,12 +1236,12 @@ int hx_apply_bitmask(unsigned char *grid, int size) {
             }
         }
     }
-
+    
     return best_pattern;
 }
 
 /* Han Xin Code - main */
-int han_xin(struct zint_symbol *symbol, const unsigned char source[], int length) {
+int han_xin(struct zint_symbol *symbol, const unsigned char source[], size_t length) {
     int est_binlen;
     int ecc_level = symbol->option_1;
     int i, j, version, posn = 0;
diff --git a/backend/large.c b/backend/large.c
index 025eb84f..d7fe2082 100644
--- a/backend/large.c
+++ b/backend/large.c
@@ -171,7 +171,7 @@ short int islarger(short int accum[], short int reg[]) {
     return larger;
 }
 
-void binary_load(short int reg[], char data[], const unsigned int src_len) {
+void binary_load(short int reg[], char data[], const size_t src_len) {
     int read, i;
     short int temp[112] = {0};
 
diff --git a/backend/large.h b/backend/large.h
index 28759524..818eb9a6 100644
--- a/backend/large.h
+++ b/backend/large.h
@@ -36,7 +36,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-extern void binary_load(short int reg[], char data[], const unsigned int src_len);
+extern void binary_load(short int reg[], char data[], const size_t src_len);
 extern void binary_add(short int accumulator[], short int input_buffer[]);
 extern void binary_subtract(short int accumulator[], short int input_buffer[]);
 extern void shiftdown(short int buffer[]);
diff --git a/backend/library.c b/backend/library.c
index 3e6b7b19..b529d18a 100644
--- a/backend/library.c
+++ b/backend/library.c
@@ -162,13 +162,13 @@ extern int itf14(struct zint_symbol *symbol, unsigned char source[], int length)
 extern int dpleit(struct zint_symbol *symbol, unsigned char source[], int length); /* Deutsche Post Leitcode */
 extern int dpident(struct zint_symbol *symbol, unsigned char source[], int length); /* Deutsche Post Identcode */
 extern int c93(struct zint_symbol *symbol, unsigned char source[], int length); /* Code 93 - a re-working of Code 39+, generates 2 check digits */
-extern int code_128(struct zint_symbol *symbol, unsigned char source[], int length); /* Code 128 and NVE-18 */
+extern int code_128(struct zint_symbol *symbol, unsigned char source[], const size_t length); /* Code 128 and NVE-18 */
 extern int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t length); /* EAN-128 (GS1-128) */
 extern int code_11(struct zint_symbol *symbol, unsigned char source[], int length); /* Code 11 */
 extern int msi_handle(struct zint_symbol *symbol, unsigned char source[], int length); /* MSI Plessey */
-extern int telepen(struct zint_symbol *symbol, unsigned char source[], int length); /* Telepen ASCII */
-extern int telepen_num(struct zint_symbol *symbol, unsigned char source[], int length); /* Telepen Numeric */
-extern int plessey(struct zint_symbol *symbol, unsigned char source[], int length); /* Plessey Code */
+extern int telepen(struct zint_symbol *symbol, unsigned char source[], const size_t length); /* Telepen ASCII */
+extern int telepen_num(struct zint_symbol *symbol, unsigned char source[], const size_t length); /* Telepen Numeric */
+extern int plessey(struct zint_symbol *symbol, unsigned char source[], const size_t length); /* Plessey Code */
 extern int pharma_one(struct zint_symbol *symbol, unsigned char source[], int length); /* Pharmacode One Track */
 extern int flattermarken(struct zint_symbol *symbol, unsigned char source[], int length); /* Flattermarken */
 extern int fim(struct zint_symbol *symbol, unsigned char source[], int length); /* Facing Identification Mark */
@@ -178,34 +178,34 @@ extern int planet_plot(struct zint_symbol *symbol, unsigned char source[], int l
 extern int imail(struct zint_symbol *symbol, unsigned char source[], int length); /* Intelligent Mail (aka USPS OneCode) */
 extern int royal_plot(struct zint_symbol *symbol, unsigned char source[], int length); /* RM4SCC */
 extern int australia_post(struct zint_symbol *symbol, unsigned char source[], int length); /* Australia Post 4-state */
-extern int code16k(struct zint_symbol *symbol, unsigned char source[], int length); /* Code 16k */
-extern int pdf417enc(struct zint_symbol *symbol, unsigned char source[], int length); /* PDF417 */
-extern int dmatrix(struct zint_symbol *symbol, const unsigned char source[], int length); /* Data Matrix (IEC16022) */
-extern int qr_code(struct zint_symbol *symbol, const unsigned char source[], int length); /* QR Code */
-extern int micro_pdf417(struct zint_symbol *symbol, unsigned char chaine[], int length); /* Micro PDF417 */
+extern int code16k(struct zint_symbol *symbol, unsigned char source[],const size_t length); /* Code 16k */
+extern int pdf417enc(struct zint_symbol *symbol, unsigned char source[], const size_t length); /* PDF417 */
+extern int micro_pdf417(struct zint_symbol *symbol, unsigned char chaine[], const size_t length); /* Micro PDF417 */
 extern int maxicode(struct zint_symbol *symbol, unsigned char source[], int length); /* Maxicode */
 extern int rss14(struct zint_symbol *symbol, unsigned char source[], int length); /* RSS-14 */
 extern int rsslimited(struct zint_symbol *symbol, unsigned char source[], int length); /* RSS Limited */
 extern int rssexpanded(struct zint_symbol *symbol, unsigned char source[], int length); /* RSS Expanded */
 extern int composite(struct zint_symbol *symbol, unsigned char source[], int length); /* Composite Symbology */
 extern int kix_code(struct zint_symbol *symbol, unsigned char source[], int length); /* TNT KIX Code */
-extern int aztec(struct zint_symbol *symbol, unsigned char source[], int length); /* Aztec Code */
+extern int aztec(struct zint_symbol *symbol, unsigned char source[], const size_t length); /* Aztec Code */
 extern int code32(struct zint_symbol *symbol, unsigned char source[], int length); /* Italian Pharmacode */
 extern int daft_code(struct zint_symbol *symbol, unsigned char source[], int length); /* DAFT Code */
 extern int ean_14(struct zint_symbol *symbol, unsigned char source[], int length); /* EAN-14 */
 extern int nve_18(struct zint_symbol *symbol, unsigned char source[], int length); /* NVE-18 */
-extern int microqr(struct zint_symbol *symbol, const unsigned char source[], int length); /* Micro QR Code */
+extern int microqr(struct zint_symbol *symbol, const unsigned char source[], size_t length); /* Micro QR Code */
 extern int aztec_runes(struct zint_symbol *symbol, unsigned char source[], int length); /* Aztec Runes */
 extern int korea_post(struct zint_symbol *symbol, unsigned char source[], int length); /* Korea Post */
 extern int japan_post(struct zint_symbol *symbol, unsigned char source[], int length); /* Japanese Post */
 extern int code_49(struct zint_symbol *symbol, unsigned char source[], const int length); /* Code 49 */
 extern int channel_code(struct zint_symbol *symbol, unsigned char source[], int length); /* Channel Code */
 extern int code_one(struct zint_symbol *symbol, unsigned char source[], int length); /* Code One */
-extern int grid_matrix(struct zint_symbol *symbol, const unsigned char source[], int length); /* Grid Matrix */
-extern int han_xin(struct zint_symbol * symbol, const unsigned char source[], int length); /* Han Xin */
+extern int grid_matrix(struct zint_symbol *symbol, const unsigned char source[], size_t length); /* Grid Matrix */
+extern int han_xin(struct zint_symbol * symbol, const unsigned char source[], size_t length); /* Han Xin */
 extern int dotcode(struct zint_symbol * symbol, const unsigned char source[], int length); /* DotCode */
-extern int codablock(struct zint_symbol * symbol, unsigned char source[], int length); /* Codablock */
+extern int codablock(struct zint_symbol * symbol, const unsigned char source[], const size_t length); /* Codablock */
 extern int upnqr(struct zint_symbol *symbol, const unsigned char source[], int length); /* UPNQR */
+extern int qr_code(struct zint_symbol *symbol, const unsigned char source[], size_t length); /* Data Matrix (IEC16022) */
+extern int dmatrix(struct zint_symbol *symbol, const unsigned char source[], const size_t in_length); /* QR Code */
 
 extern int plot_raster(struct zint_symbol *symbol, int rotate_angle, int file_type); /* Plot to PNG/BMP/PCX */
 extern int render_plot(struct zint_symbol *symbol, float width, float height); /* Plot to gLabels */
@@ -285,7 +285,8 @@ int dump_plot(struct zint_symbol *symbol) {
 
 /* Process health industry bar code data */
 static int hibc(struct zint_symbol *symbol, unsigned char source[], size_t length) {
-    int counter, error_number, i;
+    size_t i;
+    int    counter, error_number;
     char to_process[113], temp[2], check_digit;
 
     /* without "+" and check: max 110 characters in HIBC 2.6 */
@@ -812,17 +813,17 @@ static int reduced_charset(struct zint_symbol *symbol, const unsigned char *sour
     return error_number;
 }
 
-int ZBarcode_Encode(struct zint_symbol *symbol, unsigned char *source, int length) {
+int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source,int in_length) {
     int error_number, error_buffer, i;
 #ifdef _MSC_VER
     unsigned char* local_source;
 #endif
     error_number = 0;
 
-    if (length == 0) {
-        length = (int) ustrlen(source);
+    if (in_length == 0) {
+        in_length = (int)ustrlen(source);
     }
-    if (length == 0) {
+    if (in_length == 0) {
         strcpy(symbol->errtxt, "No input data (B05)");
         error_tag(symbol->errtxt, ZINT_ERROR_INVALID_DATA);
         return ZINT_ERROR_INVALID_DATA;
@@ -836,9 +837,9 @@ int ZBarcode_Encode(struct zint_symbol *symbol, unsigned char *source, int lengt
 #endif
     }
 #ifndef _MSC_VER
-    unsigned char local_source[length + 1];
+    unsigned char local_source[in_length + 1];
 #else
-    local_source = (unsigned char*) _alloca(length + 1);
+    local_source = (unsigned char*) _alloca(in_length + 1);
 #endif
 
     /* First check the symbology field */
@@ -992,25 +993,25 @@ int ZBarcode_Encode(struct zint_symbol *symbol, unsigned char *source, int lengt
     }
 
     if (symbol->input_mode == GS1_MODE) {
-        for (i = 0; i < length; i++) {
+        for (i = 0; i < in_length; i++) {
             if (source[i] == '\0') {
                 strcpy(symbol->errtxt, "NULL characters not permitted in GS1 mode (B19)");
                 return ZINT_ERROR_INVALID_DATA;
             }
         }
         if (gs1_compliant(symbol->symbology) == 1) {
-            error_number = ugs1_verify(symbol, source, length, local_source);
+            error_number = ugs1_verify(symbol, source, in_length, local_source);
             if (error_number != 0) {
                 return error_number;
             }
-            length = ustrlen(local_source);
+            in_length =(int)ustrlen(local_source);
         } else {
             strcpy(symbol->errtxt, "Selected symbology does not support GS1 mode (B20)");
             return ZINT_ERROR_INVALID_OPTION;
         }
     } else {
-        memcpy(local_source, source, length);
-        local_source[length] = '\0';
+        memcpy(local_source, source, in_length);
+        local_source[in_length] = '\0';
     }
     
     if ((symbol->dot_size < 0.01) || (symbol->dot_size > 20.0)) {
@@ -1024,17 +1025,17 @@ int ZBarcode_Encode(struct zint_symbol *symbol, unsigned char *source, int lengt
         case BARCODE_GRIDMATRIX:
         case BARCODE_HANXIN:
         case BARCODE_UPNQR:
-            error_number = extended_charset(symbol, local_source, length);
+            error_number = extended_charset(symbol, local_source, in_length);
             break;
         default:
-            error_number = reduced_charset(symbol, local_source, length);
+            error_number = reduced_charset(symbol, local_source, in_length);
             break;
     }
-
+    
     if ((error_number == ZINT_ERROR_INVALID_DATA) && (supports_eci(symbol->symbology)
             && (symbol->input_mode == UNICODE_MODE))) {
         /* Try another ECI mode */
-        symbol->eci = get_best_eci(local_source, length);
+        symbol->eci = get_best_eci(local_source, in_length);
             
         error_number = ZINT_WARN_USES_ECI;
         strcpy(symbol->errtxt, "Encoded data includes ECI codes (B22)");
@@ -1045,18 +1046,18 @@ int ZBarcode_Encode(struct zint_symbol *symbol, unsigned char *source, int lengt
             case BARCODE_MICROQR:
             case BARCODE_GRIDMATRIX:
             case BARCODE_HANXIN:
-                error_number = utf_to_eci(symbol->eci, source, local_source, &length);
-                error_number = extended_charset(symbol, local_source, length);
+                error_number = utf_to_eci(symbol->eci, source, local_source, &in_length);
+                error_number = extended_charset(symbol, local_source, in_length);
                 break;
             default:
-                error_number = reduced_charset(symbol, local_source, length);
+                error_number = reduced_charset(symbol, local_source, in_length);
                 break;
         }
         
     }
 
     if ((symbol->symbology == BARCODE_CODE128) || (symbol->symbology == BARCODE_CODE128B)) {
-        for (i = 0; i < length; i++) {
+        for (i = 0; i < in_length; i++) {
             if (local_source[i] == '\0') {
                 symbol->text[i] = ' ';
             } else {
diff --git a/backend/maxicode.c b/backend/maxicode.c
index c1952a20..50a629ad 100644
--- a/backend/maxicode.c
+++ b/backend/maxicode.c
@@ -503,7 +503,8 @@ int maxi_text_process(int mode, unsigned char source[], int length, int eci) {
 
 /* Format structured primary for Mode 2 */
 void maxi_do_primary_2(char postcode[], int country, int service) {
-    int postcode_length, postcode_num, i;
+    size_t postcode_length;
+   int    postcode_num, i;
 
     for (i = 0; i < 10; i++) {
         if ((postcode[i] < '0') || (postcode[i] > '9')) {
diff --git a/backend/pdf417.c b/backend/pdf417.c
index 39ac8d6f..2a50e283 100644
--- a/backend/pdf417.c
+++ b/backend/pdf417.c
@@ -557,7 +557,7 @@ void numbprocess(int *chainemc, int *mclength, char chaine[], int start, int len
 }
 
 /* 366 */
-int pdf417(struct zint_symbol *symbol, unsigned char chaine[], int length) {
+static int pdf417(struct zint_symbol *symbol, unsigned char chaine[], const size_t length) {
     int i, k, j, indexchaine, indexliste, mode, longueur, loop, mccorrection[520], offset;
     int total, chainemc[2700], mclength, c1, c2, c3, dummy[35], codeerr;
     char codebarre[140], pattern[580];
@@ -670,7 +670,7 @@ int pdf417(struct zint_symbol *symbol, unsigned char chaine[], int length) {
         symbol->option_2 = 30;
     }
     if (symbol->option_2 < 1) {
-        symbol->option_2 = 0.5 + sqrt((longueur + k) / 3.0);
+        symbol->option_2 =(int)(0.5 + sqrt((longueur + k) / 3.0));
     }
     if (((longueur + k) / symbol->option_2) > 90) {
         /* stop the symbol from becoming too high */
@@ -820,14 +820,14 @@ int pdf417(struct zint_symbol *symbol, unsigned char chaine[], int length) {
         
     }
     symbol->rows = (mclength / symbol->option_2);
-    symbol->width = strlen(pattern);
+    symbol->width =(int)strlen(pattern);
 
     /* 843 */
     return codeerr;
 }
 
 /* 345 */
-int pdf417enc(struct zint_symbol *symbol, unsigned char source[], int length) {
+int pdf417enc(struct zint_symbol *symbol, unsigned char source[], const size_t length) {
     int codeerr, error_number;
 
     error_number = 0;
@@ -877,7 +877,7 @@ int pdf417enc(struct zint_symbol *symbol, unsigned char source[], int length) {
 }
 
 /* like PDF417 only much smaller! */
-int micro_pdf417(struct zint_symbol *symbol, unsigned char chaine[], int length) {
+int micro_pdf417(struct zint_symbol *symbol, unsigned char chaine[], const size_t length) {
     int i, k, j, indexchaine, indexliste, mode, longueur, mccorrection[50], offset;
     int total, chainemc[2700], mclength, dummy[5], codeerr;
     char codebarre[100], pattern[580];
diff --git a/backend/plessey.c b/backend/plessey.c
index 4f3f7384..4c15c154 100644
--- a/backend/plessey.c
+++ b/backend/plessey.c
@@ -49,7 +49,7 @@ static const char *MSITable[10] = {
 };
 
 /* Not MSI/Plessey but the older Plessey standard */
-int plessey(struct zint_symbol *symbol, unsigned char source[], int length) {
+int plessey(struct zint_symbol *symbol, unsigned char source[], const size_t length) { 
 
     unsigned int i, check;
     unsigned char *checkptr;
@@ -110,9 +110,9 @@ int plessey(struct zint_symbol *symbol, unsigned char source[], int length) {
 }
 
 /* Plain MSI Plessey - does not calculate any check character */
-int msi_plessey(struct zint_symbol *symbol, unsigned char source[], int length) {
+int msi_plessey(struct zint_symbol *symbol, unsigned char source[], const size_t length) { 
 
-    unsigned int i;
+	size_t i;
     char dest[512]; /* 2 + 55 * 8 + 3 + 1 ~ 512 */
 
     if (length > 55) {
@@ -368,7 +368,8 @@ int msi_plessey_mod11(struct zint_symbol *symbol, unsigned char source[], const
  * Verified against http://www.bokai.com/BarcodeJSP/applet/BarcodeSampleApplet.htm */
 int msi_plessey_mod1110(struct zint_symbol *symbol, unsigned char source[], const unsigned int src_len) {
     /* Weighted using the IBM system */
-    unsigned long i, weight, x, check, wright, dau, pedwar, pump, h;
+    unsigned long i, weight, x, check, wright, dau, pedwar, pump;
+    size_t h;
     long si;
     char un[16], tri[16];
     int error_number;
diff --git a/backend/qr.c b/backend/qr.c
index 72cbc5c7..ee046b08 100644
--- a/backend/qr.c
+++ b/backend/qr.c
@@ -45,7 +45,7 @@
 extern int utf_to_eci(int eci, const unsigned char source[], unsigned char dest[], int *length); /* Convert Unicode to other encodings */
 
 /* Returns true if input glyph is in the Alphanumeric set */
-int in_alpha(int glyph) {
+static int in_alpha(const int glyph) {
     int retval = 0;
     char cglyph = (char) glyph;
 
@@ -72,9 +72,10 @@ int in_alpha(int glyph) {
     return retval;
 }
 
-void define_mode(char mode[], int jisdata[], int length, int gs1) {
+static void define_mode(char mode[],const int jisdata[], const size_t length,const int gs1) {
     /* Values placed into mode[] are: K = Kanji, B = Binary, A = Alphanumeric, N = Numeric */
-    int i, mlen, j;
+    size_t i;
+    int    mlen, j;
 
     for (i = 0; i < length; i++) {
         if (jisdata[i] > 0xff) {
@@ -129,8 +130,9 @@ void define_mode(char mode[], int jisdata[], int length, int gs1) {
 }
 
 /* Make an estimate (worst case scenario) of how long the binary string will be */
-int estimate_binary_length(char mode[], int length, int gs1, int eci) {
-    int i, count = 0;
+static int estimate_binary_length(const char mode[], const size_t length,const int gs1,const int eci) {
+    size_t i;
+    int    count = 0;
     char current = 0;
     int a_count = 0;
     int n_count = 0;
@@ -192,14 +194,14 @@ int estimate_binary_length(char mode[], int length, int gs1, int eci) {
     return count;
 }
 
-static void qr_bscan(char *binary, int data, int h) {
+static void qr_bscan(char *binary,const int data,int h) {
     for (; h; h >>= 1) {
         strcat(binary, data & h ? "1" : "0");
     }
 }
 
 /* Convert input data to a binary stream and add padding */
-void qr_binary(int datastream[], int version, int target_binlen, char mode[], int jisdata[], int length, int gs1, int eci, int est_binlen, int debug) {
+static void qr_binary(int datastream[], const int version, const int target_binlen, const char mode[], const int jisdata[], const size_t length, const int gs1, const int eci, const int est_binlen, int debug) {
     int position = 0;
     int short_data_block_length, i, scheme = 1;
     char data_block, padbits;
@@ -464,7 +466,7 @@ void qr_binary(int datastream[], int version, int target_binlen, char mode[], in
     /* Terminator */
     strcat(binary, "0000");
 
-    current_binlen = strlen(binary);
+    current_binlen = (int)strlen(binary);
     padbits = 8 - (current_binlen % 8);
     if (padbits == 8) {
         padbits = 0;
@@ -509,7 +511,7 @@ void qr_binary(int datastream[], int version, int target_binlen, char mode[], in
 }
 
 /* Split data into blocks, add error correction and then interleave the blocks and error correction data */
-void add_ecc(int fullstream[], int datastream[], int version, int data_cw, int blocks) {
+static void add_ecc(int fullstream[],const int datastream[],const int version,const int data_cw,const int blocks) {
     int ecc_cw = qr_total_codewords[version - 1] - data_cw;
     int short_data_block_length = data_cw / blocks;
     int qty_long_blocks = data_cw % blocks;
@@ -598,10 +600,10 @@ void add_ecc(int fullstream[], int datastream[], int version, int data_cw, int b
     }
 }
 
-void place_finder(unsigned char grid[], int size, int x, int y) {
+static void place_finder(unsigned char grid[],const int size,const int x,const int y) {
     int xp, yp;
 
-    int finder[] = {
+    static const int finder[] = {
         1, 1, 1, 1, 1, 1, 1,
         1, 0, 0, 0, 0, 0, 1,
         1, 0, 1, 1, 1, 0, 1,
@@ -622,10 +624,10 @@ void place_finder(unsigned char grid[], int size, int x, int y) {
     }
 }
 
-void place_align(unsigned char grid[], int size, int x, int y) {
+static void place_align(unsigned char grid[],const int size,int x,int y) {
     int xp, yp;
 
-    int alignment[] = {
+    static const int alignment[] = {
         1, 1, 1, 1, 1,
         1, 0, 0, 0, 1,
         1, 0, 1, 0, 1,
@@ -647,7 +649,7 @@ void place_align(unsigned char grid[], int size, int x, int y) {
     }
 }
 
-void setup_grid(unsigned char* grid, int size, int version) {
+static void setup_grid(unsigned char* grid,const int size,const int version) {
     int i, toggle = 1;
     int loopsize, x, y, xcoord, ycoord;
 
@@ -722,7 +724,7 @@ void setup_grid(unsigned char* grid, int size, int version) {
     }
 }
 
-int cwbit(int* datastream, int i) {
+static int cwbit(const int* datastream,const int i) {
     int resultant = 0;
 
     if (datastream[(i / 8)] & (0x80 >> (i % 8))) {
@@ -732,7 +734,7 @@ int cwbit(int* datastream, int i) {
     return resultant;
 }
 
-void populate_grid(unsigned char* grid, int size, int* datastream, int cw) {
+static void populate_grid(unsigned char* grid,const int size,const int* datastream,const int cw) {
     int direction = 1; /* up */
     int row = 0; /* right hand side */
 
@@ -808,7 +810,7 @@ int write_log(char log[]) {
 }
 #endif
 
-int evaluate(unsigned char *eval, int size, int pattern) {
+static int evaluate(unsigned char *eval,const int size,const int pattern) {
     int x, y, block, weight;
     int result = 0;
     char state;
@@ -1056,7 +1058,7 @@ int evaluate(unsigned char *eval, int size, int pattern) {
     return result;
 }
 
-void add_format_info_eval(unsigned char *eval, int size, int ecc_level, int pattern) {
+static void add_format_info_eval(unsigned char *eval,const int size,const int ecc_level,const int pattern) {
     /* Add format information to grid */
 
     int format = pattern;
@@ -1095,7 +1097,7 @@ void add_format_info_eval(unsigned char *eval, int size, int ecc_level, int patt
     eval[(8 * size) + 7] = (seq >> 8) & 0x01 ? (0x01 >> pattern) : 0x00;
 }
 
-int apply_bitmask(unsigned char *grid, int size, int ecc_level) {
+static int apply_bitmask(unsigned char *grid,const int size,const int ecc_level) {
     int x, y;
     unsigned char p;
     int pattern, penalty[8];
@@ -1199,7 +1201,7 @@ int apply_bitmask(unsigned char *grid, int size, int ecc_level) {
 }
 
 /* Add format information to grid */
-void add_format_info(unsigned char *grid, int size, int ecc_level, int pattern) {
+static void add_format_info(unsigned char *grid,const int size,const int ecc_level,const int pattern) {
     int format = pattern;
     unsigned int seq;
     int i;
@@ -1237,7 +1239,7 @@ void add_format_info(unsigned char *grid, int size, int ecc_level, int pattern)
 }
 
 /* Add version information */
-void add_version_info(unsigned char *grid, int size, int version) {
+static void add_version_info(unsigned char *grid,const int size,const int version) {
     int i;
 
     long int version_data = qr_annex_d[version - 7];
@@ -1252,7 +1254,7 @@ void add_version_info(unsigned char *grid, int size, int version) {
 }
 
 /* Choose from three numbers based on version */
-int tribus(int version, int a, int b, int c) {
+static int tribus(const int version,const int a,const int b,const int c) {
     int RetVal;
 
     RetVal = c;
@@ -1270,7 +1272,7 @@ int tribus(int version, int a, int b, int c) {
 
 /* Implements a custom optimisation algorithm, more efficient than that
    given in Annex J. */
-void applyOptimisation(int version, char inputMode[], int inputLength) {
+static void applyOptimisation(const int version,char inputMode[], const size_t inputLength) {
 
 
     int blockCount = 0, block;
@@ -1384,9 +1386,10 @@ void applyOptimisation(int version, char inputMode[], int inputLength) {
     free(blockMode);
 }
 
-int blockLength(int start, char inputMode[], int inputLength) {
+static int blockLength(const int start,const char inputMode[],const size_t inputLength) {
     /* Find the length of the block starting from 'start' */
-    int i, count;
+    size_t i;
+    int    count;
     char mode = inputMode[start];
 
     count = 0;
@@ -1399,10 +1402,11 @@ int blockLength(int start, char inputMode[], int inputLength) {
     return count;
 }
 
-int getBinaryLength(int version, char inputMode[], int inputData[], int inputLength, int gs1, int eci) {
+static int getBinaryLength(const int version,char inputMode[],const int inputData[],const size_t inputLength,const int gs1,const int eci) {
     /* Calculate the actual bitlength of the proposed binary string */
+    size_t i;
     char currentMode;
-    int i, j;
+    int    j;
     int count = 0;
 
     applyOptimisation(version, inputMode, inputLength);
@@ -1471,8 +1475,9 @@ int getBinaryLength(int version, char inputMode[], int inputData[], int inputLen
     return count;
 }
 
-int qr_code(struct zint_symbol *symbol, const unsigned char source[], int length) {
-    int error_number, i, j, glyph, est_binlen;
+int qr_code(struct zint_symbol *symbol, const unsigned char source[], size_t length) {
+    int i, j, est_binlen;
+    int error_number,glyph;
     int ecc_level, autosize, version, max_cw, target_binlen, blocks, size;
     int bitmask, gs1;
     int canShrink;
@@ -1721,7 +1726,7 @@ int qr_code(struct zint_symbol *symbol, const unsigned char source[], int length
 
 /* NOTE: From this point forward concerns Micro QR Code only */
 
-int micro_qr_intermediate(char binary[], int jisdata[], char mode[], int length, int *kanji_used, int *alphanum_used, int *byte_used, int debug) {
+static int micro_qr_intermediate(char binary[], const int jisdata[], const char mode[], const size_t length, int *kanji_used, int *alphanum_used, int *byte_used, int debug) {
     /* Convert input data to an "intermediate stage" where data is binary encoded but
        control information is not */
     int position = 0;
@@ -1940,8 +1945,9 @@ int micro_qr_intermediate(char binary[], int jisdata[], char mode[], int length,
     return 0;
 }
 
-void get_bitlength(int count[], char stream[]) {
-    int length, i;
+static void get_bitlength(int count[],const char stream[]) {
+    size_t length;
+    int    i;
 
     length = strlen(stream);
 
@@ -1987,8 +1993,9 @@ void get_bitlength(int count[], char stream[]) {
     } while (i < length);
 }
 
-void microqr_expand_binary(char binary_stream[], char full_stream[], int version) {
-    int i, length;
+static void microqr_expand_binary(const char binary_stream[], char full_stream[],const int version) {
+    int    i;
+    size_t length;
 
     length = strlen(binary_stream);
 
@@ -2070,7 +2077,7 @@ void microqr_expand_binary(char binary_stream[], char full_stream[], int version
     } while (i < length);
 }
 
-void micro_qr_m1(char binary_data[]) {
+static void micro_qr_m1(char binary_data[]) {
     int i, j, latch;
     int bits_total, bits_left, remainder;
     int data_codewords, ecc_codewords;
@@ -2080,7 +2087,7 @@ void micro_qr_m1(char binary_data[]) {
     latch = 0;
 
     /* Add terminator */
-    bits_left = bits_total - strlen(binary_data);
+    bits_left = bits_total - (int)strlen(binary_data);
     if (bits_left <= 3) {
         for (i = 0; i < bits_left; i++) {
             strcat(binary_data, "0");
@@ -2092,7 +2099,7 @@ void micro_qr_m1(char binary_data[]) {
 
     if (latch == 0) {
         /* Manage last (4-bit) block */
-        bits_left = bits_total - strlen(binary_data);
+        bits_left = bits_total - (int)strlen(binary_data);
         if (bits_left <= 4) {
             for (i = 0; i < bits_left; i++) {
                 strcat(binary_data, "0");
@@ -2112,7 +2119,7 @@ void micro_qr_m1(char binary_data[]) {
         }
 
         /* Add padding */
-        bits_left = bits_total - strlen(binary_data);
+        bits_left = bits_total - (int)strlen(binary_data);
         if (bits_left > 4) {
             remainder = (bits_left - 4) / 8;
             for (i = 0; i < remainder; i++) {
@@ -2153,10 +2160,10 @@ void micro_qr_m1(char binary_data[]) {
     }
 }
 
-void micro_qr_m2(char binary_data[], int ecc_mode) {
+static void micro_qr_m2(char binary_data[],const int ecc_mode) {
     int i, j, latch;
-    int bits_total, bits_left, remainder;
-    int data_codewords, ecc_codewords;
+    int bits_total=0, bits_left, remainder;
+    int data_codewords=0, ecc_codewords=0;
     unsigned char data_blocks[6], ecc_blocks[7];
 
     latch = 0;
@@ -2164,12 +2171,13 @@ void micro_qr_m2(char binary_data[], int ecc_mode) {
     if (ecc_mode == LEVEL_L) {
         bits_total = 40;
     }
-    if (ecc_mode == LEVEL_M) {
+    else if (ecc_mode == LEVEL_M) {
         bits_total = 32;
     }
+    else assert(0);
 
     /* Add terminator */
-    bits_left = bits_total - strlen(binary_data);
+    bits_left = bits_total - (int)strlen(binary_data);
     if (bits_left <= 5) {
         for (i = 0; i < bits_left; i++) {
             strcat(binary_data, "0");
@@ -2190,7 +2198,7 @@ void micro_qr_m2(char binary_data[], int ecc_mode) {
         }
 
         /* Add padding */
-        bits_left = bits_total - strlen(binary_data);
+        bits_left = bits_total - (int)strlen(binary_data);
         remainder = bits_left / 8;
         for (i = 0; i < remainder; i++) {
             strcat(binary_data, i & 1 ? "00010001" : "11101100");
@@ -2201,10 +2209,11 @@ void micro_qr_m2(char binary_data[], int ecc_mode) {
         data_codewords = 5;
         ecc_codewords = 5;
     }
-    if (ecc_mode == LEVEL_M) {
+    else if (ecc_mode == LEVEL_M) {
         data_codewords = 4;
         ecc_codewords = 6;
     }
+    else assert(0);
 
     /* Copy data into codewords */
     for (i = 0; i < data_codewords; i++) {
@@ -2231,10 +2240,10 @@ void micro_qr_m2(char binary_data[], int ecc_mode) {
     return;
 }
 
-void micro_qr_m3(char binary_data[], int ecc_mode) {
+static void micro_qr_m3(char binary_data[],const int ecc_mode) {
     int i, j, latch;
-    int bits_total, bits_left, remainder;
-    int data_codewords, ecc_codewords;
+    int bits_total=0, bits_left, remainder;
+    int data_codewords=0, ecc_codewords=0;
     unsigned char data_blocks[12], ecc_blocks[9];
 
     latch = 0;
@@ -2242,12 +2251,13 @@ void micro_qr_m3(char binary_data[], int ecc_mode) {
     if (ecc_mode == LEVEL_L) {
         bits_total = 84;
     }
-    if (ecc_mode == LEVEL_M) {
+    else if (ecc_mode == LEVEL_M) {
         bits_total = 68;
     }
+    else assert(0);
 
     /* Add terminator */
-    bits_left = bits_total - strlen(binary_data);
+    bits_left = bits_total - (int)strlen(binary_data);
     if (bits_left <= 7) {
         for (i = 0; i < bits_left; i++) {
             strcat(binary_data, "0");
@@ -2259,7 +2269,7 @@ void micro_qr_m3(char binary_data[], int ecc_mode) {
 
     if (latch == 0) {
         /* Manage last (4-bit) block */
-        bits_left = bits_total - strlen(binary_data);
+        bits_left = bits_total - (int)strlen(binary_data);
         if (bits_left <= 4) {
             for (i = 0; i < bits_left; i++) {
                 strcat(binary_data, "0");
@@ -2279,7 +2289,7 @@ void micro_qr_m3(char binary_data[], int ecc_mode) {
         }
 
         /* Add padding */
-        bits_left = bits_total - strlen(binary_data);
+        bits_left = bits_total - (int)strlen(binary_data);
         if (bits_left > 4) {
             remainder = (bits_left - 4) / 8;
             for (i = 0; i < remainder; i++) {
@@ -2293,10 +2303,11 @@ void micro_qr_m3(char binary_data[], int ecc_mode) {
         data_codewords = 11;
         ecc_codewords = 6;
     }
-    if (ecc_mode == LEVEL_M) {
+    else if (ecc_mode == LEVEL_M) {
         data_codewords = 9;
         ecc_codewords = 8;
     }
+    else assert(0);
 
     /* Copy data into codewords */
     for (i = 0; i < (data_codewords - 1); i++) {
@@ -2341,10 +2352,10 @@ void micro_qr_m3(char binary_data[], int ecc_mode) {
     return;
 }
 
-void micro_qr_m4(char binary_data[], int ecc_mode) {
+static void micro_qr_m4(char binary_data[],const int ecc_mode) {
     int i, j, latch;
-    int bits_total, bits_left, remainder;
-    int data_codewords, ecc_codewords;
+    int bits_total=0, bits_left, remainder;
+    int data_codewords=0, ecc_codewords=0;
     unsigned char data_blocks[17], ecc_blocks[15];
 
     latch = 0;
@@ -2352,15 +2363,16 @@ void micro_qr_m4(char binary_data[], int ecc_mode) {
     if (ecc_mode == LEVEL_L) {
         bits_total = 128;
     }
-    if (ecc_mode == LEVEL_M) {
+    else if (ecc_mode == LEVEL_M) {
         bits_total = 112;
     }
-    if (ecc_mode == LEVEL_Q) {
+    else if (ecc_mode == LEVEL_Q) {
         bits_total = 80;
     }
+    else assert(0);
 
     /* Add terminator */
-    bits_left = bits_total - strlen(binary_data);
+    bits_left = bits_total - (int)strlen(binary_data);
     if (bits_left <= 9) {
         for (i = 0; i < bits_left; i++) {
             strcat(binary_data, "0");
@@ -2381,7 +2393,7 @@ void micro_qr_m4(char binary_data[], int ecc_mode) {
         }
 
         /* Add padding */
-        bits_left = bits_total - strlen(binary_data);
+        bits_left = bits_total - (int)strlen(binary_data);
         remainder = bits_left / 8;
         for (i = 0; i < remainder; i++) {
             strcat(binary_data, i & 1 ? "00010001" : "11101100");
@@ -2392,14 +2404,15 @@ void micro_qr_m4(char binary_data[], int ecc_mode) {
         data_codewords = 16;
         ecc_codewords = 8;
     }
-    if (ecc_mode == LEVEL_M) {
+    else if (ecc_mode == LEVEL_M) {
         data_codewords = 14;
         ecc_codewords = 10;
     }
-    if (ecc_mode == LEVEL_Q) {
+    else if (ecc_mode == LEVEL_Q) {
         data_codewords = 10;
         ecc_codewords = 14;
     }
+    else assert(0);
 
     /* Copy data into codewords */
     for (i = 0; i < data_codewords; i++) {
@@ -2424,7 +2437,7 @@ void micro_qr_m4(char binary_data[], int ecc_mode) {
     }
 }
 
-void micro_setup_grid(unsigned char* grid, int size) {
+static void micro_setup_grid(unsigned char* grid,const int size) {
     int i, toggle = 1;
 
     /* Add timing patterns */
@@ -2459,11 +2472,11 @@ void micro_setup_grid(unsigned char* grid, int size) {
     grid[(8 * size) + 8] += 20;
 }
 
-void micro_populate_grid(unsigned char* grid, int size, char full_stream[]) {
+static void micro_populate_grid(unsigned char* grid,const int size,const char full_stream[]) {
     int direction = 1; /* up */
     int row = 0; /* right hand side */
-
-    int i, n, x, y;
+    size_t n;
+    int    i,x, y;
 
     n = strlen(full_stream);
     y = size - 1;
@@ -2511,7 +2524,7 @@ void micro_populate_grid(unsigned char* grid, int size, char full_stream[]) {
     } while (i < n);
 }
 
-int micro_evaluate(unsigned char *grid, int size, int pattern) {
+static int micro_evaluate(const unsigned char *grid,const int size,const int pattern) {
     int sum1, sum2, i, filter = 0, retval;
 
     switch (pattern) {
@@ -2545,7 +2558,7 @@ int micro_evaluate(unsigned char *grid, int size, int pattern) {
     return retval;
 }
 
-int micro_apply_bitmask(unsigned char *grid, int size) {
+static int micro_apply_bitmask(unsigned char *grid,const int size) {
     int x, y;
     unsigned char p;
     int pattern, value[8];
@@ -2627,11 +2640,13 @@ int micro_apply_bitmask(unsigned char *grid, int size) {
     return best_pattern;
 }
 
-int microqr(struct zint_symbol *symbol, const unsigned char source[], int length) {
-    int i, j, glyph, size;
+int microqr(struct zint_symbol *symbol, const unsigned char source[], size_t length) {
+    size_t i;
+    int    j,size;
     char binary_stream[200];
     char full_stream[200];
-    int utfdata[40];
+    int utfdata[40],glyph;
+
     int jisdata[40];
     char mode[40];
     int error_number, kanji_used = 0, alphanum_used = 0, byte_used = 0;
@@ -3057,4 +3072,4 @@ int upnqr(struct zint_symbol *symbol, const unsigned char source[], int length)
     }
 
     return 0;
-}
\ No newline at end of file
+}
diff --git a/backend/reedsol.c b/backend/reedsol.c
index baefd614..affe150a 100644
--- a/backend/reedsol.c
+++ b/backend/reedsol.c
@@ -116,7 +116,7 @@ void rs_init_code(const int nsym, int index) {
     }
 }
 
-void rs_encode(const int len, const unsigned char *data, unsigned char *res) {
+void rs_encode(const size_t len,const unsigned char *data, unsigned char *res) {
     int i, k, m;
     for (i = 0; i < rlen; i++)
         res[i] = 0;
diff --git a/backend/reedsol.h b/backend/reedsol.h
index 140f6586..24e336e6 100644
--- a/backend/reedsol.h
+++ b/backend/reedsol.h
@@ -39,7 +39,7 @@ extern "C" {
 
 extern void rs_init_gf(const int poly);
 extern void rs_init_code(const int nsym,int index);
-extern void rs_encode(const int len,const unsigned char *data, unsigned char *res);
+extern void rs_encode(const size_t len,const unsigned char *data, unsigned char *res);
 extern void rs_encode_long(const int len,const unsigned int *data, unsigned int *res);
     extern void rs_free(void);
 
diff --git a/backend/render.c b/backend/render.c
index 3fa52dcf..9f56b2a9 100644
--- a/backend/render.c
+++ b/backend/render.c
@@ -105,7 +105,7 @@ int render_plot(struct zint_symbol *symbol, const float width, const float heigh
     r = 0;
     /* Isolate add-on text */
     if (is_extendable(symbol->symbology)) {
-        for (i = 0; i < ustrlen(symbol->text); i++) {
+        for(i = 0; i < (int)ustrlen(symbol->text); i++) {
             if (latch == 1) {
                 addon[r] = symbol->text[i];
                 r++;
@@ -208,7 +208,7 @@ int render_plot(struct zint_symbol *symbol, const float width, const float heigh
         }
     }
 
-    total_symbol_width_x = main_symbol_width_x + addon_width_x;
+    total_symbol_width_x = 0.0 + main_symbol_width_x + addon_width_x;
     total_area_width_x = total_symbol_width_x + (2 * (symbol->border_width + symbol->whitespace_width));
 
     xoffset = symbol->border_width + symbol->whitespace_width;
diff --git a/backend/telepen.c b/backend/telepen.c
index beb80efc..0f012a7c 100644
--- a/backend/telepen.c
+++ b/backend/telepen.c
@@ -56,7 +56,7 @@ static char *TeleTable[] = {
     "3113111113", "11311111111111", "331111111111", "111113111113", "31111111111111", "111311111113", "131111111113"
 };
 
-int telepen(struct zint_symbol *symbol, unsigned char source[], int src_len) {
+int telepen(struct zint_symbol *symbol, unsigned char source[], const size_t src_len) {
     unsigned int i, count, check_digit;
     int error_number;
     char dest[512]; /*14 + 30 * 14 + 14 + 14 + 1 ~ 512 */
@@ -103,9 +103,10 @@ int telepen(struct zint_symbol *symbol, unsigned char source[], int src_len) {
     return error_number;
 }
 
-int telepen_num(struct zint_symbol *symbol, unsigned char source[], int src_len) {
-    unsigned int i, count, check_digit, glyph;
-    int error_number, temp_length = src_len;
+int telepen_num(struct zint_symbol *symbol, unsigned char source[], const size_t src_len) {
+    unsigned int count, check_digit, glyph;
+    int error_number;
+    size_t i,temp_length = src_len;
     char dest[1024]; /* 14 + 60 * 14 + 14 + 14 + 1 ~ 1024 */
     unsigned char temp[64];
 
diff --git a/backend/upcean.c b/backend/upcean.c
index 68508a4e..f258fe6c 100644
--- a/backend/upcean.c
+++ b/backend/upcean.c
@@ -505,7 +505,7 @@ char isbn_check(unsigned char source[]) {
 }
 
 /* Make an EAN-13 barcode from an SBN or ISBN */
-int isbn(struct zint_symbol *symbol, unsigned char source[], const unsigned int src_len, char dest[]) {
+static int isbn(struct zint_symbol *symbol, unsigned char source[], const size_t src_len, char dest[]) {
     int i, error_number;
     char check_digit;
 
diff --git a/backend/zint.h b/backend/zint.h
index 73a632b4..8f291acf 100644
--- a/backend/zint.h
+++ b/backend/zint.h
@@ -261,7 +261,7 @@ extern "C" {
     ZINT_EXTERN void ZBarcode_Clear(struct zint_symbol *symbol);
     ZINT_EXTERN void ZBarcode_Delete(struct zint_symbol *symbol);
 
-    ZINT_EXTERN int ZBarcode_Encode(struct zint_symbol *symbol, unsigned char *input, int length);
+    ZINT_EXTERN int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *input, int length);
     ZINT_EXTERN int ZBarcode_Encode_File(struct zint_symbol *symbol, char *filename);
     ZINT_EXTERN int ZBarcode_Print(struct zint_symbol *symbol, int rotate_angle);
     ZINT_EXTERN int ZBarcode_Encode_and_Print(struct zint_symbol *symbol, unsigned char *input, int length, int rotate_angle);
diff --git a/frontend/main.c b/frontend/main.c
index 1e3acbdc..3a17abc3 100644
--- a/frontend/main.c
+++ b/frontend/main.c
@@ -573,7 +573,7 @@ int main(int argc, char **argv) {
                         /* Zero and negative values are not permitted */
                         fprintf(stderr, "Invalid dot radius value (A06)\n");
                         fflush(stderr);
-                        my_symbol->dot_size = 4.0 / 5.0;
+                        my_symbol->dot_size = 4.0F / 5.0F;
                     }
                 }
                 if (!strcmp(long_options[option_index].name, "border")) {
diff --git a/win32/libzint.vcxproj b/win32/libzint.vcxproj
index d1c4c86b..e99a8e8a 100644
--- a/win32/libzint.vcxproj
+++ b/win32/libzint.vcxproj
@@ -177,6 +177,7 @@
     <ClCompile Include="..\backend\dmatrix.c" />
     <ClCompile Include="..\backend\dotcode.c" />
     <ClCompile Include="..\backend\eci.c" />
+    <ClCompile Include="..\backend\emf.c" />
     <ClCompile Include="..\backend\gif.c" />
     <ClCompile Include="..\backend\gridmtx.c" />
     <ClCompile Include="..\backend\gs1.c" />
@@ -199,6 +200,7 @@
     <ClCompile Include="..\backend\rss.c" />
     <ClCompile Include="..\backend\svg.c" />
     <ClCompile Include="..\backend\telepen.c" />
+    <ClCompile Include="..\backend\tif.c" />
     <ClCompile Include="..\backend\upcean.c" />
   </ItemGroup>
   <ItemGroup>
@@ -209,6 +211,7 @@
     <ClInclude Include="..\backend\composite.h" />
     <ClInclude Include="..\backend\dm200.h" />
     <ClInclude Include="..\backend\dmatrix.h" />
+    <ClInclude Include="..\backend\emf.h" />
     <ClInclude Include="..\backend\font.h" />
     <ClInclude Include="..\backend\gb2312.h" />
     <ClInclude Include="..\backend\gridmtx.h" />
@@ -223,6 +226,7 @@
     <ClInclude Include="..\backend\resource.h" />
     <ClInclude Include="..\backend\rss.h" />
     <ClInclude Include="..\backend\sjis.h" />
+    <ClInclude Include="..\backend\tif.h" />
     <ClInclude Include="..\backend\zint.h" />
   </ItemGroup>
   <ItemGroup>