GRASS GIS Debugging: See also http://grasswiki.osgeo.org/wiki/GRASS_Debugging ---------------------------------------------------- At user level: Print debugging message if variable DEBUG is set to level equal or greater g.gisenv set="DEBUG=3" Levels: (recommended levels) * 0 - silence * 1 - message is printed once or few times per module * 3 - each row (raster) or line (vector) * 5 - each cell (raster) or point (vector) Further hints: > How can I force gcc, to complain about missing header file? '-Wimplicit-function-declaration' '-Werror-implicit-function-declaration' Give a warning (or error) whenever a function is used before being declared. ---------------------------------------------------- To make gcc less tolerant in accepting errors and code flaws, compile with (see also ../INSTALL): export CFLAGS='-g -ansi -Wall -D_BSD_SOURCE=1 -D_SVID_SOURCE=1 -D_POSIX_SOURCE=1 -D_POSIX_C_SOURCE=199506L' Also nice to emulate gcc/MacOSX compiler: CFLAGS='-fno-common' It is a good idea to use '-Wall -Werror' as gcc options. This means it treats the warnings as errors, i.e. it stops on them. So you have time to read them then. The gcc switch -Wimplicit-function-declaration (implied by -Wall) should report missing prototypes (use -Werror-implicit-function-declaration to make it an error rather than a warning). The linker switch --warn-common (e.g. LDFLAGS='-Wl,--warn-common') might be useful for catching multiply-defined symbols. Be sure to compile using debug flags (gcc -g) and don't "strip" the binaries after compiling. ---------------------------------------------------- C Code debugging Software: 1) Debugger (command-line) gdb `which r.plane` r bt full To debug in a running process, find out the process ID (PID) ps -aef and then use gdb --pid=PID to attach to running process PID. It will stop, enter 'c' to continue and so forth (bt full for backtrace). 2a) Graphical front-end for command-line debugger: ddd ddd `which r.plane` RUN -> here enter Parameters/Flags http://www.gnu.org/software/ddd/ (GNU DDD is a graphical front-end for command-line debuggers such as GDB, DBX, WDB, Ladebug, JDB, XDB, the Perl debugger, the bash debugger, or the Python debugger. ) See mini tutorial here: http://grass.osgeo.org/wiki/GRASS_Debugging 2b) Graphical front-end for command-line debugger: kdbg Use the menus ---------------------------------------------------- Debugging on Mac OS X The 'ldd' command doesn't exist, but otool -L does almost the same job. ---------------------------------------------------- Using valgrind to find memory leaks (http://valgrind.org/): * Memory note for vector modules: Support structures are not released by default because it take long time and it is much faster if it is done by system. You have to call Vect_set_release_support() before Vect_close() if you want to use valgrind. * Example (see also http://bambi.otago.ac.nz/hamish/grass/memleak/v.in.ascii/): CMD="v.in.ascii -zt z=3 in=lidaratm2_250k.txt out=lidaratm2_250k fs=," valgrind -v --tool=addrcheck --leak-check=yes --show-reachable=yes $CMD --o * On 64bit boxed valgrind is not supported. An alternative is 'memusage': memusage -t -T v.in.ogr -o dsn=clcit2000 layer=LAB,ARC \ type=centroid,boundary output=corine2000_it ---------------------------------------------------- Profiling GRASS with GCC: Profiling allows the compiler to insert code that collects various statistics for later analysis. Profiling with GCC is particularly useful for quickly locating bottleneck functions, determining how much time is spent in a particular function, and how many times that function was called. To profile the entire GRASS package, the following steps should be followed for success: * Before running 'configure', both the CFLAGS and LDFLAGS environment variables need to be altered by adding the -pg flag to enable profiling. This can be accomplished by the following: CFLAGS='-pg' LDFLAGS='-pg' ./configure ... CFLAGS and LINK_FLAGS in include/Make/Platform.make can be manually edited after running 'configure', also. * 'configure' must be called with --disable-shared if you intend to profile GRASS libraries (recommended) * make GRASS as normal * In order to run GRASS without errors, lib/init must be recompiled without linking using the -pg flag. Edit include/Make/Platform.make and remove -pg from LINK_FLAGS. 'cd lib/init; make clean; make'. GRASS can now be installed as normal. When running a GRASS C module, a file called gmon.out is created when the module completes execution. This file can be analyzed with the GCC tool 'gprof'. Note that when 'make distclean' is run, the manual changes to include/Make/Platform.make are also removed.