Improve unicode table handling (#286)

- Document table and index formats
- Add size statistics
- Fix UBSAN issue in `get_le24()`

Fixes #285

1 files changed, 86 insertions, 30 deletions

diff --git a/unicode_gen.c b/unicode_gen.c
index 9a7babb..14811ef 100644
--- a/unicode_gen.c
+++ b/unicode_gen.c
@@ -33,6 +33,11 @@
 
 #include "cutils.h"
 
+uint32_t total_tables;
+uint32_t total_table_bytes;
+uint32_t total_index;
+uint32_t total_index_bytes;
+
 /* define it to be able to test unicode.c */
 //#define USE_TEST
 /* profile tests */
@@ -1328,7 +1333,9 @@ void dump_case_conv_table(FILE *f)
     uint32_t v;
     const TableEntry *te;
 
-    fprintf(f, "static const uint32_t case_conv_table1[%u] = {", conv_table_len);
+    total_tables++;
+    total_table_bytes += conv_table_len * sizeof(uint32_t);
+    fprintf(f, "static const uint32_t case_conv_table1[%d] = {", conv_table_len);
     for(i = 0; i < conv_table_len; i++) {
         if (i % 4 == 0)
             fprintf(f, "\n   ");
@@ -1341,7 +1348,9 @@ void dump_case_conv_table(FILE *f)
     }
     fprintf(f, "\n};\n\n");
 
-    fprintf(f, "static const uint8_t case_conv_table2[%u] = {", conv_table_len);
+    total_tables++;
+    total_table_bytes += conv_table_len;
+    fprintf(f, "static const uint8_t case_conv_table2[%d] = {", conv_table_len);
     for(i = 0; i < conv_table_len; i++) {
         if (i % 8 == 0)
             fprintf(f, "\n   ");
@@ -1350,7 +1359,9 @@ void dump_case_conv_table(FILE *f)
     }
     fprintf(f, "\n};\n\n");
 
-    fprintf(f, "static const uint16_t case_conv_ext[%u] = {", ext_data_len);
+    total_tables++;
+    total_table_bytes += ext_data_len * sizeof(uint16_t);
+    fprintf(f, "static const uint16_t case_conv_ext[%d] = {", ext_data_len);
     for(i = 0; i < ext_data_len; i++) {
         if (i % 8 == 0)
             fprintf(f, "\n   ");
@@ -1470,6 +1481,9 @@ void compute_internal_props(void)
 void dump_byte_table(FILE *f, const char *cname, const uint8_t *tab, int len)
 {
     int i;
+
+    total_tables++;
+    total_table_bytes += len;
     fprintf(f, "static const uint8_t %s[%d] = {", cname, len);
     for(i = 0; i < len; i++) {
         if (i % 8 == 0)
@@ -1479,9 +1493,26 @@ void dump_byte_table(FILE *f, const char *cname, const uint8_t *tab, int len)
     fprintf(f, "\n};\n\n");
 }
 
+void dump_index_table(FILE *f, const char *cname, const uint8_t *tab, int len)
+{
+    int i, code, offset;
+
+    total_index++;
+    total_index_bytes += len;
+    fprintf(f, "static const uint8_t %s[%d] = {\n", cname, len);
+    for(i = 0; i < len; i += 3) {
+        code = tab[i] + (tab[i+1] << 8) + ((tab[i+2] & 0x1f) << 16);
+        offset = ((i / 3) + 1) * 32 + (tab[i+2] >> 5);
+        fprintf(f, "    0x%02x, 0x%02x, 0x%02x,", tab[i], tab[i+1], tab[i+2]);
+        fprintf(f, "  // %6.5X at %d%s\n", code, offset,
+                i == len - 3 ? " (upper bound)" : "");
+    }
+    fprintf(f, "};\n\n");
+}
+
 #define PROP_BLOCK_LEN 32
 
-void build_prop_table(FILE *f, int prop_index, BOOL add_index)
+void build_prop_table(FILE *f, const char *name, int prop_index, BOOL add_index)
 {
     int i, j, n, v, offset, code;
     DynBuf dbuf_s, *dbuf = &dbuf_s;
@@ -1533,6 +1564,14 @@ void build_prop_table(FILE *f, int prop_index, BOOL add_index)
             block_end_pos += PROP_BLOCK_LEN;
         }
 
+        /* Compressed byte encoding:
+           00..3F: 2 packed lengths: 3-bit + 3-bit
+           40..5F: 5-bits plus extra byte for length
+           60..7F: 5-bits plus 2 extra bytes for length
+           80..FF: 7-bit length
+           lengths must be incremented to get character count
+           Ranges alternate between false and true return value.
+         */
         v = buf[i];
         code += v + 1;
         bit ^= 1;
@@ -1573,7 +1612,7 @@ void build_prop_table(FILE *f, int prop_index, BOOL add_index)
     dump_byte_table(f, cname, dbuf->buf, dbuf->size);
     if (add_index) {
         snprintf(cname, sizeof(cname), "unicode_prop_%s_index", unicode_prop_name[prop_index]);
-        dump_byte_table(f, cname, dbuf2->buf, dbuf2->size);
+        dump_index_table(f, cname, dbuf2->buf, dbuf2->size);
     }
 
     dbuf_free(dbuf);
@@ -1583,10 +1622,10 @@ void build_prop_table(FILE *f, int prop_index, BOOL add_index)
 
 void build_flags_tables(FILE *f)
 {
-    build_prop_table(f, PROP_Cased1, TRUE);
-    build_prop_table(f, PROP_Case_Ignorable, TRUE);
-    build_prop_table(f, PROP_ID_Start, TRUE);
-    build_prop_table(f, PROP_ID_Continue1, TRUE);
+    build_prop_table(f, "Cased1", PROP_Cased1, TRUE);
+    build_prop_table(f, "Case_Ignorable", PROP_Case_Ignorable, TRUE);
+    build_prop_table(f, "ID_Start", PROP_ID_Start, TRUE);
+    build_prop_table(f, "ID_Continue1", PROP_ID_Continue1, TRUE);
 }
 
 void dump_name_table(FILE *f, const char *cname, const char **tab_name, int len,
@@ -1845,7 +1884,7 @@ void build_prop_list_table(FILE *f)
             i == PROP_ID_Continue1) {
             /* already generated */
         } else {
-            build_prop_table(f, i, FALSE);
+            build_prop_table(f, unicode_prop_name[i], i, FALSE);
         }
     }
 
@@ -1997,6 +2036,8 @@ void check_flags(void)
 
 void build_cc_table(FILE *f)
 {
+    // Compress combining class table
+    // see: https://www.unicode.org/reports/tr44/#Canonical_Combining_Class_Values
     int i, cc, n, type, n1, block_end_pos;
     DynBuf dbuf_s, *dbuf = &dbuf_s;
     DynBuf dbuf1_s, *dbuf1 = &dbuf1_s;
@@ -2055,6 +2096,13 @@ void build_cc_table(FILE *f)
 #if defined(DUMP_CC_TABLE) || defined(DUMP_TABLE_SIZE)
         cw_start = dbuf->size;
 #endif
+        /* Compressed run length encoding:
+           - 2 high order bits are combining class type
+           -         0:0, 1:230, 2:extra byte linear progression, 3:extra byte
+           - 00..2F: range length (add 1)
+           - 30..37: 3-bit range-length + 1 extra byte
+           - 38..3F: 3-bit range-length + 2 extra byte
+         */
         if (n1 < 48) {
             dbuf_putc(dbuf, n1 | (type << 6));
         } else if (n1 < 48 + (1 << 11)) {
@@ -2084,7 +2132,7 @@ void build_cc_table(FILE *f)
     dbuf_putc(dbuf1, v >> 16);
 
     dump_byte_table(f, "unicode_cc_table", dbuf->buf, dbuf->size);
-    dump_byte_table(f, "unicode_cc_index", dbuf1->buf, dbuf1->size);
+    dump_index_table(f, "unicode_cc_index", dbuf1->buf, dbuf1->size);
 
 #if defined(DUMP_CC_TABLE) || defined(DUMP_TABLE_SIZE)
     printf("CC table: size=%d (%d entries) [",
@@ -2765,8 +2813,9 @@ void build_decompose_table(FILE *f)
     }
 #endif
 
-    fprintf(f, "static const uint32_t unicode_decomp_table1[%u] = {",
-            array_len);
+    total_tables++;
+    total_table_bytes += array_len * sizeof(uint32_t);
+    fprintf(f, "static const uint32_t unicode_decomp_table1[%d] = {", array_len);
     count = 0;
     for(i = 0; i <= code_max; i++) {
         de = &tab_de[i];
@@ -2784,8 +2833,9 @@ void build_decompose_table(FILE *f)
     }
     fprintf(f, "\n};\n\n");
 
-    fprintf(f, "static const uint16_t unicode_decomp_table2[%u] = {",
-            array_len);
+    total_tables++;
+    total_table_bytes += array_len * sizeof(uint16_t);
+    fprintf(f, "static const uint16_t unicode_decomp_table2[%d] = {", array_len);
     count = 0;
     for(i = 0; i <= code_max; i++) {
         de = &tab_de[i];
@@ -2798,8 +2848,9 @@ void build_decompose_table(FILE *f)
     }
     fprintf(f, "\n};\n\n");
 
-    fprintf(f, "static const uint8_t unicode_decomp_data[%u] = {",
-            data_len);
+    total_tables++;
+    total_table_bytes += data_len;
+    fprintf(f, "static const uint8_t unicode_decomp_data[%d] = {", data_len);
     for(i = 0; i < data_len; i++) {
         if (i % 8 == 0)
             fprintf(f, "\n   ");
@@ -2890,8 +2941,9 @@ void build_compose_table(FILE *f, const DecompEntry *tab_de)
     }
 #endif
 
-    fprintf(f, "static const uint16_t unicode_comp_table[%u] = {",
-            tab_ce_len);
+    total_tables++;
+    total_table_bytes += tab_ce_len * sizeof(uint16_t);
+    fprintf(f, "static const uint16_t unicode_comp_table[%u] = {", tab_ce_len);
     for(i = 0; i < tab_ce_len; i++) {
         if (i % 8 == 0)
             fprintf(f, "\n   ");
@@ -3066,22 +3118,24 @@ void normalization_test(const char *filename)
 }
 #endif
 
-int main(int argc, char **argv)
+int main(int argc, char *argv[])
 {
     const char *unicode_db_path, *outfilename;
     char filename[1024];
-
-    if (argc < 2) {
-        printf("usage: %s unicode_db_path [output_file]\n"
-               "\n"
-               "If no output_file is given, a self test is done using the current unicode library\n",
-               argv[0]);
-        exit(1);
+    int arg = 1;
+
+    if (arg >= argc || (!strcmp(argv[arg], "-h") || !strcmp(argv[arg], "--help"))) {
+        printf("usage: %s PATH [OUTPUT]\n"
+               "  PATH    path to the Unicode database directory\n"
+               "  OUTPUT  name of the output file.  If omitted, a self test is performed\n"
+               "          using the files from the Unicode library\n"
+               , argv[0]);
+        return 1;
     }
-    unicode_db_path = argv[1];
+    unicode_db_path = argv[arg++];
     outfilename = NULL;
-    if (argc >= 3)
-        outfilename = argv[2];
+    if (arg < argc)
+        outfilename = argv[arg++];
 
     unicode_db = mallocz(sizeof(unicode_db[0]) * (CHARCODE_MAX + 1));
 
@@ -3163,6 +3217,8 @@ int main(int argc, char **argv)
         build_script_ext_table(fo);
         build_prop_list_table(fo);
         fprintf(fo, "#endif /* CONFIG_ALL_UNICODE */\n");
+        fprintf(fo, "/* %u tables / %u bytes, %u index / %u bytes */\n",
+                total_tables, total_table_bytes, total_index, total_index_bytes);
         fclose(fo);
     }
     return 0;