@@ -173,8 +173,8 @@ Using Emacs as an IDE is discussed in <<emacs>>.
[[tools-compiling]]
== Compiling with `cc`
-This section deals with the gcc and clang compilers for C and C++, since they come with the FreeBSD base system.
-Starting with FreeBSD 10.X `clang` is installed as `cc`.
+This section deals with the clang compiler for C and C++, as it's installed with the FreeBSD base system.
+Starting with FreeBSD 10.X `clang` is installed as `cc`; the GNU compiler package:devel/gcc[gcc] is available in the Ports Collection.
The details of producing a program with an interpreter vary considerably between interpreters, and are usually well covered in the documentation and on-line help for the interpreter.
Once you have written your masterpiece, the next step is to convert it into something that will (hopefully!) run on FreeBSD.
@@ -208,7 +208,7 @@ If you have more than one file to compile, just do something like
% cc foo.c bar.c
....
-Note that the syntax checking is just that-checking the syntax.
+Note that the syntax checking is just that - checking the syntax.
It will not check for any logical mistakes you may have made, like putting the program into an infinite loop,
or using a bubble sort when you meant to use a binary sort.footnote:[In case you did not know, a binary sort is an efficient way of sorting things into order and a bubble sort is not.]
@@ -278,12 +278,12 @@ Despite the name, it does not guarantee strictly that your code will comply to t
Turn off _all_ ``cc``'s non-ANSI C features.
Without these flags, `cc` will allow you to use some of its non-standard extensions to the standard.
-Some of these are very useful, but will not work with other compilers-in fact,
+Some of these are very useful, but will not work with other compilers - in fact,
one of the main aims of the standard is to allow people to write code that will work with any compiler on any system.
This is known as _portable code_.
Generally, you should try to make your code as portable as possible,
-as otherwise you may have to completely rewrite the program later to get it to work somewhere else-and who knows what you may be using in a few years time?
+as otherwise you may have to completely rewrite the program later to get it to work somewhere else - and who knows what you may be using in a few years time?
[source,bash]
....
@@ -321,79 +321,6 @@ This will both produce an executable [.filename]#foobar# from the C++ source fil
=== Common `cc` Queries and Problems
-==== I am trying to write a program which uses the sin() function and I get an error like this. What does it mean?
-
-[source,bash]
-....
-/var/tmp/cc0143941.o: Undefined symbol `_sin' referenced from text segment
-....
-
-When using mathematical functions like `sin()`, you have to tell `cc` to link in the math library, like so:
-
-[source,bash]
-....
-% cc -o foobar foobar.c -lm
-....
-
-==== All right, I wrote this simple program to practice using -lm. All it does is raise 2.1 to the power of 6.
-
-[.programlisting]
-....
-#include <stdio.h>
-
-int main() {
- float f;
-
- f = pow(2.1, 6);
- printf("2.1 ^ 6 = %f\n", f);
- return 0;
-}
-....
-
-and I compiled it as:
-
-[source,bash]
-....
-% cc temp.c -lm
-....
-
-like you said I should, but I get this when I run it:
-
-[source,bash]
-....
-% ./a.out
-2.1 ^ 6 = 1023.000000
-....
-
-This is not the right answer! What is going on?
-
-When the compiler sees you call a function, it checks if it has already seen a prototype for it.
-If it has not, it assumes the function returns an int, which is definitely not what you want here.
-
-==== So how do I fix this?
-
-The prototypes for the mathematical functions are in [.filename]#math.h#.
-If you include this file, the compiler will be able to find the prototype and it will stop doing strange things to your calculation!
-
-[.programlisting]
-....
-#include <math.h>
-#include <stdio.h>
-
-int main() {
-...
-....
-
-After recompiling it as you did before, run it:
-
-[source,bash]
-....
-% ./a.out
-2.1 ^ 6 = 85.766121
-....
-
-If you are using any of the mathematical functions, _always_ include [.filename]#math.h# and remember to link in the math library.
-
==== I compiled a file called foobar.c and I cannot find an executable called foobar. Where has it gone?
Remember, `cc` will call the executable [.filename]#a.out# unless you tell it differently.