CDRIVER-4596 Reducing Warnings - MSVC and MinGW Warnings in libbson (#1221)

* bson-check-depth.c: address C4018 signedness mismatch warnings

* bson-decimal128.c: address C4018 signedness mismatch warnings

* bson-decimal128.c: address C4267 size_t conversion warnings

* bson-iter.c: address C4267 size_t conversion warnings

* bson-json.c: address C4018 signedness mismatch warnings

* bson-json.c: address C4267 size_t conversion warnings

* bson-json.c: address C4146 unsigned unary negation warnings

* bson-metrics.c: address C4244 narrowing conversion warnings

* bson-timegm.c: address C4028 parameter inconsistency warnings

* bson-timegm.c: address C4244 narrowing conversion warnings

* bson.c: address C4018 signedness mismatch warnings

* test-b64.c: address C4267 size_t conversion warnings

* test-iso8601.c: address C4267 size_t conversion warnings

* test-json.c: address C4244 narrowing conversion warnings

* test-json.c: address C4267 size_t conversion warnings

* bson-memory.c: address -Wunused-result warnings

* mongoc-util.c: address scan-build unix.cstring.NullArg warnings

* Disable C4756 when compiling with VS 2013 or older

* Remove obsolete checks for INFINITY and NAN

* bson-timegm.c: remove use of register for parameters and variables

Author: eramongodb

src/libbson/CMakeLists.txt

@@ -210,6 +210,13 @@ set (HEADERS_FORWARDING
 )
 
 add_library (bson_shared SHARED ${SOURCES} ${HEADERS} ${HEADERS_FORWARDING})
+if (MSVC AND MSVC_VERSION VERSION_LESS 1900)
+   message (STATUS "Disabling warning C4756 for VS 2013 and older")
+   # Macro constant INFINITY triggers constant arithmetic overflow warnings in
+   # VS 2013, but VS 2013 doesn't support inline warning suppression.
+   # Remove once support for VS 2013 is dropped.
+   target_compile_options(bson_shared PRIVATE /wd4756)
+endif ()
 set (CMAKE_CXX_VISIBILITY_PRESET hidden)
 target_compile_definitions (bson_shared
    PRIVATE
@@ -278,6 +285,13 @@ endif ()
 
 if (MONGOC_ENABLE_STATIC_BUILD)
    add_library (bson_static STATIC ${SOURCES} ${HEADERS} ${HEADERS_FORWARDING})
+   if (MSVC AND MSVC_VERSION VERSION_LESS 1900)
+      message (STATUS "Disabling warning C4756 for VS 2013 and older")
+      # Macro constant INFINITY triggers constant arithmetic overflow warnings in
+      # VS 2013, but VS 2013 doesn't support inline warning suppression.
+      # Remove once support for VS 2013 is dropped.
+      target_compile_options(bson_static PRIVATE /wd4756)
+   endif ()
    target_compile_definitions (bson_static
       PUBLIC
          BSON_STATIC

src/libbson/examples/bson-check-depth.c

@@ -19,12 +19,13 @@
 #include <bson/bson.h>
 
 #include <assert.h>
+#include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 typedef struct {
    uint32_t depth;
-   int max_depth;
+   uint32_t max_depth;
    bool valid;
 } check_depth_t;
 
@@ -74,7 +75,7 @@ _check_depth_document (const bson_iter_t *iter,
 }
 
 void
-check_depth (const bson_t *bson, int max_depth)
+check_depth (const bson_t *bson, uint32_t max_depth)
 {
    bson_iter_t iter;
    check_depth_t state = {0};
@@ -87,7 +88,8 @@ check_depth (const bson_t *bson, int max_depth)
    state.max_depth = max_depth;
    _check_depth_document (&iter, NULL, bson, &state);
    if (!state.valid) {
-      printf ("document exceeds maximum depth of %d\n", state.max_depth);
+      printf ("document exceeds maximum depth of %" PRIu32 "\n",
+              state.max_depth);
    } else {
       char *as_json = bson_as_canonical_extended_json (bson, NULL);
       printf ("document %s ", as_json);
@@ -102,26 +104,27 @@ main (int argc, char **argv)
    bson_reader_t *bson_reader;
    const bson_t *bson;
    bool reached_eof;
-   char *filename;
    bson_error_t error;
-   int max_depth;
 
    if (argc != 3) {
       fprintf (stderr, "usage: %s FILE MAX_DEPTH\n", argv[0]);
       fprintf (stderr, "Checks that the depth of the BSON contained in FILE\n");
       fprintf (stderr, "does not exceed MAX_DEPTH\n");
    }
 
-   filename = argv[1];
-   max_depth = atoi (argv[2]);
+   const char *const filename = argv[1];
+   const int max_depth = atoi (argv[2]);
+
    bson_reader = bson_reader_new_from_file (filename, &error);
    if (!bson_reader) {
       printf ("could not read %s: %s\n", filename, error.message);
       return 1;
    }
 
+   BSON_ASSERT (bson_in_range_signed (uint32_t, max_depth));
+
    while ((bson = bson_reader_read (bson_reader, &reached_eof))) {
-      check_depth (bson, max_depth);
+      check_depth (bson, (uint32_t) max_depth);
    }
 
    if (!reached_eof) {

src/libbson/examples/bson-metrics.c

@@ -81,8 +81,12 @@ static bson_metrics_state_t state;
 static int
 compar_bson_type_metrics (const void *a, const void *b)
 {
-   return (((bson_type_metrics_t *) b)->count -
-           ((bson_type_metrics_t *) a)->count);
+   const uint64_t a_count = ((bson_type_metrics_t *) a)->count;
+   const uint64_t b_count = ((bson_type_metrics_t *) b)->count;
+   if (a_count == b_count) {
+      return 0;
+   }
+   return a_count < b_count ? -1 : 1;
 }
 
 /*

src/libbson/src/bson/bson-decimal128.c

@@ -19,6 +19,7 @@
 #include <string.h>
 #include <ctype.h>
 
+#include "bson-cmp.h"
 #include "bson-decimal128.h"
 #include "bson-types.h"
 #include "bson-macros.h"
@@ -155,8 +156,6 @@ bson_decimal128_to_string (const bson_decimal128_t *dec, /* IN  */
    uint8_t significand_msb; /* the most signifcant significand bits (50-46) */
    _bson_uint128_t
       significand128; /* temporary storage for significand decoding */
-   size_t i;          /* indexing variables */
-   int j, k;
 
    memset (significand_str, 0, sizeof (significand_str));
 
@@ -212,7 +211,7 @@ bson_decimal128_to_string (const bson_decimal128_t *dec, /* IN  */
        */
       is_zero = true;
    } else {
-      for (k = 3; k >= 0; k--) {
+      for (int k = 3; k >= 0; k--) {
          uint32_t least_digits = 0;
          _bson_uint128_divide1B (
             significand128, &significand128, &least_digits);
@@ -223,7 +222,7 @@ bson_decimal128_to_string (const bson_decimal128_t *dec, /* IN  */
             continue;
          }
 
-         for (j = 8; j >= 0; j--) {
+         for (int j = 8; j >= 0; j--) {
             significand[k * 9 + j] = least_digits % 10;
             least_digits /= 10;
          }
@@ -264,7 +263,8 @@ bson_decimal128_to_string (const bson_decimal128_t *dec, /* IN  */
          *(str_out++) = '.';
       }
 
-      for (i = 0; i < significand_digits && (str_out - str) < 36; i++) {
+      for (uint32_t i = 0; i < significand_digits && (str_out - str) < 36;
+           i++) {
          *(str_out++) = *(significand_read++) + '0';
       }
       /* Exponent */
@@ -273,15 +273,16 @@ bson_decimal128_to_string (const bson_decimal128_t *dec, /* IN  */
    } else {
       /* Regular format with no decimal place */
       if (exponent >= 0) {
-         for (i = 0; i < significand_digits && (str_out - str) < 36; i++) {
+         for (uint32_t i = 0; i < significand_digits && (str_out - str) < 36;
+              i++) {
             *(str_out++) = *(significand_read++) + '0';
          }
          *str_out = '\0';
       } else {
          int32_t radix_position = significand_digits + exponent;
 
          if (radix_position > 0) { /* non-zero digits before radix */
-            for (i = 0;
+            for (int32_t i = 0;
                  i < radix_position && (str_out - str) < BSON_DECIMAL128_STRING;
                  i++) {
                *(str_out++) = *(significand_read++) + '0';
@@ -295,8 +296,9 @@ bson_decimal128_to_string (const bson_decimal128_t *dec, /* IN  */
             *(str_out++) = '0';
          }
 
-         for (i = 0;
-              (i < significand_digits - BSON_MAX (radix_position - 1, 0)) &&
+         for (uint32_t i = 0;
+              bson_cmp_greater_us (significand_digits - i,
+                                   BSON_MAX (radix_position - 1, 0)) &&
               (str_out - str) < BSON_DECIMAL128_STRING;
               i++) {
             *(str_out++) = *(significand_read++) + '0';
@@ -623,10 +625,12 @@ bson_decimal128_from_string_w_len (const char *string,     /* IN */
    /* to represent user input */
 
    /* Overflow prevention */
-   if (exponent <= radix_position && radix_position - exponent > (1 << 14)) {
+   if (bson_cmp_less_equal_su (exponent, radix_position) &&
+       bson_cmp_greater_us (radix_position, exponent + (1 << 14))) {
       exponent = BSON_DECIMAL128_EXPONENT_MIN;
    } else {
-      exponent -= radix_position;
+      BSON_ASSERT (bson_in_range_unsigned (int32_t, radix_position));
+      exponent -= (int32_t) radix_position;
    }
 
    /* Attempt to normalize the exponent */

src/libbson/src/bson/bson-iter.c

@@ -110,8 +110,13 @@ bson_iter_init_from_data (bson_iter_t *iter,   /* OUT */
       return false;
    }
 
+   if (BSON_UNLIKELY (!bson_in_range_unsigned (uint32_t, length))) {
+      memset (iter, 0, sizeof *iter);
+      return false;
+   }
+
    iter->raw = (uint8_t *) data;
-   iter->len = length;
+   iter->len = (uint32_t) length;
    iter->off = 0;
    iter->type = 0;
    iter->key = 0;

src/libbson/src/bson/bson-json.c

@@ -628,7 +628,13 @@ _bson_json_read_integer (bson_json_reader_t *reader, uint64_t val, int64_t sign)
          bson_append_int32 (
             STACK_BSON_CHILD, key, (int) len, (int) (val * sign));
       } else if (sign == -1) {
+#if defined(_WIN32) && !defined(__MINGW32__)
+         // Unary negation of unsigned integer is deliberate.
+#pragma warning(suppress : 4146)
          bson_append_int64 (STACK_BSON_CHILD, key, (int) len, (int64_t) -val);
+#else
+         bson_append_int64 (STACK_BSON_CHILD, key, (int) len, (int64_t) -val);
+#endif // defined(_WIN32) && !defined(__MINGW32__)
       } else {
          bson_append_int64 (STACK_BSON_CHILD, key, (int) len, (int64_t) val);
       }
@@ -735,33 +741,19 @@ _bson_json_parse_double (bson_json_reader_t *reader,
    *d = strtod (val, NULL);
 
 #ifdef _MSC_VER
+   const double pos_inf = INFINITY;
+   const double neg_inf = -pos_inf;
+
    /* Microsoft's strtod parses "NaN", "Infinity", "-Infinity" as 0 */
    if (*d == 0.0) {
       if (!_strnicmp (val, "nan", vlen)) {
-#ifdef NAN
          *d = NAN;
-#else
-         /* Visual Studio 2010 doesn't define NAN or INFINITY
-          * https://msdn.microsoft.com/en-us/library/w22adx1s(v=vs.100).aspx */
-         unsigned long nan[2] = {0xffffffff, 0x7fffffff};
-         *d = *(double *) nan;
-#endif
          return true;
       } else if (!_strnicmp (val, "infinity", vlen)) {
-#ifdef INFINITY
-         *d = INFINITY;
-#else
-         unsigned long inf[2] = {0x00000000, 0x7ff00000};
-         *d = *(double *) inf;
-#endif
+         *d = pos_inf;
          return true;
       } else if (!_strnicmp (val, "-infinity", vlen)) {
-#ifdef INFINITY
-         *d = -INFINITY;
-#else
-         unsigned long inf[2] = {0x00000000, 0xfff00000};
-         *d = *(double *) inf;
-#endif
+         *d = neg_inf;
          return true;
       }
    }
@@ -831,7 +823,7 @@ static bool
 _unhexlify_uuid (const char *uuid, uint8_t *out, size_t max)
 {
    unsigned int byte;
-   int x = 0;
+   size_t x = 0;
    int i = 0;
 
    BSON_ASSERT (strlen (uuid) == 32);
@@ -1186,8 +1178,9 @@ _bson_json_read_start_map (bson_json_reader_t *reader) /* IN */
           * expected a legacy Binary format. now we see the second "{", so
           * backtrack and parse $type query operator. */
          bson->read_state = BSON_JSON_IN_START_MAP;
+         BSON_ASSERT (bson_in_range_unsigned (int, len));
          STACK_PUSH_DOC (bson_append_document_begin (
-            STACK_BSON_PARENT, key, len, STACK_BSON_CHILD));
+            STACK_BSON_PARENT, key, (int) len, STACK_BSON_CHILD));
          _bson_json_save_map_key (bson, (const uint8_t *) "$type", 5);
          break;
       case BSON_JSON_LF_CODE:
@@ -2233,8 +2226,11 @@ bson_json_reader_read (bson_json_reader_t *reader, /* IN */
 
          /* accumulate a key or string value */
          if (reader->json_text_pos != -1) {
-            if (reader->json_text_pos < reader->json->pos) {
-               accum = BSON_MIN (reader->json->pos - reader->json_text_pos, r);
+            if (bson_cmp_less_su (reader->json_text_pos, reader->json->pos)) {
+               BSON_ASSERT (
+                  bson_in_range_unsigned (ssize_t, reader->json->pos));
+               accum = BSON_MIN (
+                  (ssize_t) reader->json->pos - reader->json_text_pos, r);
                /* if this chunk stopped mid-token, buf_offset is how far into
                 * our current chunk the token begins. */
                buf_offset = AT_LEAST_0 (reader->json_text_pos - start_pos);

src/libbson/src/bson/bson-memory.c

@@ -40,7 +40,10 @@ _aligned_alloc_impl (size_t alignment, size_t num_bytes)
 #elif defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L
 {
    void *mem = NULL;
-   (void) posix_memalign (&mem, alignment, num_bytes);
+
+   // Workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425.
+   BSON_MAYBE_UNUSED int ret = posix_memalign (&mem, alignment, num_bytes);
+
    return mem;
 }
 #else