How can I compile Valgrind on Snow Leopard?
Assuming you've got XCode tools installed and an SVN client, here it goes.
Go to some directory you keep stuff in. Checkout valgrind sources
svn co svn://svn.valgrind.org/valgrind/tags/VALGRIND_3_5_0 valgrind
Download Greg Parker's 10.6 patch
curl http://bugsfiles.kde.org/attachment.cgi?id=36999 > 10.6.patch
mv 10.6.patch ./valgrind
Apply the patch
cd valgrind
patch -p0 < 10.6.patch
Compile valgrind
./autogen.sh
./configure
make
Install it
sudo make install
Run it
valgrind --leak-check=full --show-reachable=yes /tmp/a.out
In addition to the (almost) perfect answer of diciu. For compiling a 64 bit version of valgrind (required for 64 bit executables, aka. the standard in OS 10.6). You will need to edit the configure file and set host_cpu="x86_64".
diciu's answer worked flawlessly for a 32 bit build, but I couldn't get a 64 bit build working by adapting those instructions.
Found some other working instructions for getting a 64bit build of valgrind though.
(replicated here, slightly adapted, since wget is not installed by default on os x)
svn co -r 11104 svn://svn.valgrind.org/valgrind/trunk valgrind
cd valgrind
curl http://bugsfiles.kde.org/attachment.cgi?id=40091 -o snow-leopard.patch
curl http://bugsfiles.kde.org/attachment.cgi?id=40900 -o arc4random.patch
curl http://bugsfiles.kde.org/attachment.cgi?id=42530 -o sidt.patch
curl http://bugsfiles.kde.org/attachment.cgi?id=42892 -o signal.patch
patch -p0 < snow-leopard.patch
patch -p0 < arc4random.patch
patch -p1 < signal.patch
cd VEX; patch -p0 < ../sidt.patch ; cd ..
touch darwin10-drd.supp
touch darwin10.supp
./autogen.sh || autoreconf -fvi
./configure --prefix=`pwd`/inst64 --build=amd64-darwin
make -j 8 && make install
Edit: in response to the comments, to have both 32 and 64 bit also do the following commands: (note that I have no need for a 32bit valgrind, so I didn't try this, but it should work)
make clean
./configure --prefix=`pwd`/inst32
make -j 8 && make install
Both will be located in inst32/ and inst64/ afterwards.
using the --enable-only64bit configure flag avoided having to hack host_cpu="x86_64" into the configure script (using the patch diciu posted)
FYI, Valgrind 3.6 (released October 21, 2010) officially supports Snow Leopard out-of-the-box.