Information Technology Reference
In-Depth Information
When a project has different targets, it's possible to select a different compiler for each target. While Xcode al-
lows you to do this, it's not a common requirement. Note also that when you switch compilers, some of the
switches and options displayed under the Build Settings tab change too. Because you don't usually need to fine-
tune the default settings, you can leave these alone, but it's worth being aware that LLVM has a slightly smaller se-
lection of options.
CROSS-REFERENCE
For more information about compiler technology, see Appendix C.
Controlling warnings
You can use the Warnings section toward the bottom of the full list of build settings to enable and disable spe-
cific warning messages, as shown in Figure 13.6.
The master switch is called Inhibit All Warnings. When this is enabled, the compiler ignores the other warning
switches and suppresses all warnings, without exception. This is a dangerous option.
Most of the other options are self-explanatory, to varying degrees. For example, unused variables and unused
values produce warnings by default. Unused functions don't. It's worth exploring the list to fine-tune the op-
tions to match your programming style.
FIGURE 13.6
Selecting warning messages
