.. _run-prereq:

Compilation prerequisites
=========================

If the traces are intended to be used for :ref:`source coverage analysis <scov>`,
regardless of the actual criteria to be assessed afterwards, sources must be
compiled with :option:`-g -fpreserve-control-flow -fdump-scos` to control
optimizations and allow mapping trace info to source constructs.
:option:`-gno-strict-dwarf` is required in addition for VxWorks targets,
together with :option:`-mlongcall` for PowerPC configurations.  Optimization is
supported up to :option:`-O1`, with inlining allowed.

The :option:`-fprofile-arcs` compilation switch, intended for analysis with
the gcov tool, is incompatible with the needs of |gcp| and must not be
used. Likewise for the :option:`-gnatV` family of GNAT Pro switches requesting
data validity checks other than those mandated by the Ada RM (special case of
:option:`-gnatVd`).

For object coverage assessments, only :option:`-g` is of possible use, if you
intend to produce annotated sources as coverage reports. If source coverage
analysis is to be performed *as well*, and you have no particular constraint
on the form of the machine code for which object coverage is needed, the whole
process might turn simpler if the same compilation options are used for both
kinds of analysis. There is no incompatibility with object coverage analysis
incurred by compiling the code compiled with options required for source
coverage.