Xcode 8.2.1 Not Showing Documentation Description on Autocomplete

Swift method documentation - not showing in autocomplete

The reason is that Xcode parse the documentation displayed in the popover from a separate doc-set and not from the class files themselves.

Have a look here: https://stackoverflow.com/a/43982094/1415898
for a more complete answer.

Why isn't Xcode showing test coverage?

Works fine on my machine:

Don't forget to choose Editor > Show Code Coverage (you didn't mention that in your little checklist).

does Every single call to mysql_real_escape_string require another trip to the database?

The fact that it uses the mysql library does not mean it does a round trip with the server.

It runs code from the mysql client library, loaded in the same process as your php interpreter. You do need a connection though - that function needs to know some server settings to operate properly. But those settings are cached in the connection information on the PHP side.

If you want to verify this (and you're on linux), write a simple script like:

<?php
$link = mysql_connect('localhost', 'user', 'pass');
echo "Connection done\n";
echo mysql_real_escape_string("this ' is a test");
?>

And run it through strace:

$ strace php t.php
....            # here comes the connection to mysql, socket fd == 3
connect(3, {sa_family=AF_FILE, path="/var/run/mysqld/mysqld.sock"}, 110) = 0
fcntl(3, F_SETFL, O_RDWR)               = 0
setsockopt(3, SOL_SOCKET, SO_RCVTIMEO, "\2003\341\1\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0
....            # talking with mysql here
poll([{fd=3, events=POLLIN}], 1, 60000) = 1 ([{fd=3, revents=POLLIN}])
read(3, "8\0\0\0\n5.1.58-log\0\3\0\0\0K-?4'fL+\0\377\367!"..., 16384) = 60
...
read(3, "\7\0\0\2\0\0\0\2\0\0\0", 16384) = 11
                # first php echo
write(1, "Connection done\n", 16Connection done    )       = 16
                # second php echo
write(1, "this \\' is a test", 17this \' is a test)      = 17
munmap(0x7f62e187a000, 528384)          = 0
....

The only important thing there is that the two writes caused by the echo statements have no other syscall in between - no network communication is possible without a syscall (from userspace in linux anyway).

does Every single call to mysql_real_escape_string require another trip to the database?

The fact that it uses the mysql library does not mean it does a round trip with the server.

It runs code from the mysql client library, loaded in the same process as your php interpreter. You do need a connection though - that function needs to know some server settings to operate properly. But those settings are cached in the connection information on the PHP side.

If you want to verify this (and you're on linux), write a simple script like:

<?php
$link = mysql_connect('localhost', 'user', 'pass');
echo "Connection done\n";
echo mysql_real_escape_string("this ' is a test");
?>

And run it through strace:

$ strace php t.php
....            # here comes the connection to mysql, socket fd == 3
connect(3, {sa_family=AF_FILE, path="/var/run/mysqld/mysqld.sock"}, 110) = 0
fcntl(3, F_SETFL, O_RDWR)               = 0
setsockopt(3, SOL_SOCKET, SO_RCVTIMEO, "\2003\341\1\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0
....            # talking with mysql here
poll([{fd=3, events=POLLIN}], 1, 60000) = 1 ([{fd=3, revents=POLLIN}])
read(3, "8\0\0\0\n5.1.58-log\0\3\0\0\0K-?4'fL+\0\377\367!"..., 16384) = 60
...
read(3, "\7\0\0\2\0\0\0\2\0\0\0", 16384) = 11
                # first php echo
write(1, "Connection done\n", 16Connection done    )       = 16
                # second php echo
write(1, "this \\' is a test", 17this \' is a test)      = 17
munmap(0x7f62e187a000, 528384)          = 0
....

The only important thing there is that the two writes caused by the echo statements have no other syscall in between - no network communication is possible without a syscall (from userspace in linux anyway).

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