lmttag wrote:
We have developed a number of different applications (ASP.NET web site,
Windows services, DLLs, Windows forms, etc.) in C# 2.0. We have developed
and unit tested all these applications/components using Debug mode. Now we
are ready to compile everything for release to production. However, we don’t
know whether we should compile all the applications/components/assemblies
using Release mode (or keep everything in Debug mode).
Release. Debug gains you nothing unless you actually plan on debugging the
application in the field, which is rare. What debugging does, mainly, is
turn off most aggressive optimizations (like eliminating local variables,
extracting loop invariants and other things that make your code run faster
but weaken the connection between the binary and the source). It may insert
extra information to allow for edit-and-continue sessions. Some constructs
like P/Invoke and dynamic code generation may deliberately use slower but
more predictable implementations to help you detect problems (this may just
be restricted to when you're actually running the code under a debugger,
though, I'm not certain). None of this helps your customer much, and the
code may run slower.
For managed code, the differences between debug and release code tend to be
less dramatic than for unmanaged code, mainly because it's all JIT-compiled
bytecode anyway. That said, you may experience rare cases where a debug
build doesn't have a problem experienced by a release build (and vice versa)
due to initialization or timing issues. These usually indicate a subtle bug
that's simply doesn't manifest under certain conditions. You should always
perform any tests on the release version as well, as a sanity check.
Nothing's more embarrassing than having to say "but it worked on my machine".
A debug build is ideal for quickly diagnosing and fixing problems, but you
can still debug a release build if necessary, and it's important to be able
to replicate your customer's situation. What you should always do is have
the compiler produce debugging symbols (.PDB) for your application, even in
release mode. In Visual Studio, producing these is controlled by the options
onder project properties -Build -Advanced.
These symbols are not for distribution to your customer (unless you don't
mind them seeing your source file names and line numbers...) but they will
help you in debugging an issue on the same binary the customer has, should
this turn out to be necessary.
--
J.
