mirror of
https://github.com/ArduPilot/ardupilot.git
synced 2026-10-11 20:59:22 +08:00
Thomas WatsonandPeter Barker
529bf321be
Ensures subnormals aren't formatted grossly wrong nor cause hangs. Reveals two additional bugs: * The requested number of digits is not always produced. * The precision isn't enough to distinguish every float. Outputs from the (nominally) original assembly implementation running on a real AVR (avr-gcc 7.3.0) are included. That implementation exhibits none of these flaws so it's likely they have been introduced during the C port. Co-authored-by: Peter Barker <pbarker@barker.dropbear.id.au>
117 lines
4.5 KiB
C++
117 lines
4.5 KiB
C++
#include <AP_gtest.h>
|
|
#include <AP_HAL/HAL.h>
|
|
#include <AP_HAL/Util.h>
|
|
|
|
const AP_HAL::HAL& hal = AP_HAL::get_HAL();
|
|
|
|
#define streq(x, y) (!strcmp(x, y))
|
|
|
|
// from the GNU snprintf manpage:
|
|
|
|
// The functions snprintf() and vsnprintf() do not write more than size
|
|
// bytes (including the terminating null byte ('\0')). If the output was
|
|
// truncated due to this limit, then the return value is the number of
|
|
// characters (excluding the terminating null byte) which would have been
|
|
// written to the final string if enough space had been available. Thus,
|
|
// a return value of size or more means that the output was truncated.
|
|
|
|
TEST(vsnprintf_Test, Basic)
|
|
{
|
|
char output[300];
|
|
{
|
|
int bytes_required = hal.util->snprintf(output, ARRAY_SIZE(output), "Fred: %u", 37);
|
|
EXPECT_TRUE(streq(output, "Fred: 37"));
|
|
EXPECT_EQ(bytes_required, 8);
|
|
}
|
|
{
|
|
int bytes_required = hal.util->snprintf(output, 3, "Fred: %u", 37);
|
|
EXPECT_TRUE(streq(output, "Fr"));
|
|
EXPECT_EQ(bytes_required, 8);
|
|
}
|
|
{
|
|
snprintf(output, ARRAY_SIZE(output), "0123");
|
|
int bytes_required = hal.util->snprintf(output, 0, "Fred: %u", 37);
|
|
EXPECT_TRUE(streq(output, "0123"));
|
|
EXPECT_EQ(bytes_required, 8);
|
|
}
|
|
{ // ensure rest of buffer survives
|
|
memset(output, 'A', 10);
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wformat-truncation"
|
|
const int bytes_required = snprintf(output, 5, "012345678");
|
|
#pragma GCC diagnostic pop
|
|
EXPECT_TRUE(streq(output, "0123"));
|
|
EXPECT_EQ(bytes_required, 9);
|
|
EXPECT_EQ(output[6], 'A');
|
|
}
|
|
{ // simple float
|
|
const int bytes_required = hal.util->snprintf(output, ARRAY_SIZE(output), "%f", 1/3.0);
|
|
EXPECT_EQ(bytes_required, 8);
|
|
EXPECT_TRUE(streq(output, "0.333333"));
|
|
}
|
|
{ // less simple float
|
|
const int bytes_required = hal.util->snprintf(output, ARRAY_SIZE(output), "%30.9f", 1/3.0);
|
|
EXPECT_EQ(bytes_required, 28);
|
|
EXPECT_TRUE(streq(output, " 0.3333333"));
|
|
}
|
|
|
|
{ // simple string
|
|
const int bytes_required = hal.util->snprintf(output, ARRAY_SIZE(output), "%s %s %c", "ABC", "DEF", 'x');
|
|
EXPECT_EQ(bytes_required, 9);
|
|
EXPECT_TRUE(streq(output, "ABC DEF x"));
|
|
}
|
|
}
|
|
|
|
static const char* do_subnormal_format(uint32_t val_hex) {
|
|
// format float represented as a hex number long enough to see all digits
|
|
|
|
// note that something else is wrong here and all the strings should be the
|
|
// same width of 99 chars (or whatever the format string means)! when that
|
|
// is fixed, update the test and add an assert here.
|
|
|
|
static char buf[256];
|
|
|
|
float val;
|
|
static_assert(sizeof(uint32_t) == sizeof(float));
|
|
memcpy(&val, &val_hex, sizeof(float));
|
|
|
|
hal.util->snprintf(buf, ARRAY_SIZE(buf), "%.99f", val);
|
|
|
|
return buf;
|
|
}
|
|
|
|
TEST(vsnprintf_Test, SubnormalFormat)
|
|
{
|
|
// arbitrary small number (1e-31)
|
|
// EXPECT_STREQ("0.000000000000000000000000000000099999998000000000000000000000000000000000000000000000000000000000000",
|
|
EXPECT_STREQ("0.0000000000000000000000000000001000000",
|
|
do_subnormal_format(0x0C01CEB3));
|
|
|
|
// smallest normal (1.1754944e-38)
|
|
// EXPECT_STREQ("0.000000000000000000000000000000000000011754944000000000000000000000000000000000000000000000000000000",
|
|
EXPECT_STREQ("0.00000000000000000000000000000000000001175494",
|
|
do_subnormal_format(0x00800000));
|
|
|
|
// largest subnormal (1.1754942e-38)
|
|
// EXPECT_STREQ("0.000000000000000000000000000000000000011754942000000000000000000000000000000000000000000000000000000",
|
|
EXPECT_STREQ("0.00000000000000000000000000000000000001175494", // !! same as above
|
|
do_subnormal_format(0x007FFFFF));
|
|
|
|
// moderate subnormal (1.1478e-41)
|
|
// EXPECT_STREQ("0.000000000000000000000000000000000000000011478036000000000000000000000000000000000000000000000000000",
|
|
EXPECT_STREQ("0.00000000000000000000000000000000000000001147804",
|
|
do_subnormal_format(0x00001FFF));
|
|
|
|
// smallest subnormal (1e-45)
|
|
// EXPECT_STREQ("0.000000000000000000000000000000000000000000001401290000000000000000000000000000000000000000000000000",
|
|
EXPECT_STREQ("0.00000000000000000000000000000000000000000000140130",
|
|
do_subnormal_format(0x00000001));
|
|
|
|
// zero
|
|
EXPECT_STREQ("0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
|
|
do_subnormal_format(0x00000000));
|
|
}
|
|
|
|
|
|
AP_GTEST_MAIN()
|