Outparamdel

Blog entry.

Running Outparamdel

• Produce a list of files to run

find ~/work/ff-build/ -name \*.ii

• Optional: produce a list of outparams to rewrite. Can use dehydra to detect them

../../pork-barrel/pork-barrel  --save-output .outparamdel 4 /tmp/list.txt ./dehydra -dehydra-javascript dehydra_scripts/outparams.js 2> /tmp/outparams.err
find ~/work/ff-build/ -name \*.outparamdel|xargs cat|sort|uniq |grep OUTPARAMS:|sed 's/OUTPARAMS://' > /tmp/outparams

• Run outparamdel

../../pork-barrel/pork-barrel 4 /tmp/list.txt ./outparamdel -od-list /tmp/outparams  > outparams.diff 2> /tmp/outparams.err

TODO

Manual Mozilla changes

• Convert NS_ERROR errors to constants

Automatically Detect Outparam Candidates (dehydra_scripts/outparams.js)

• Process function body ensuring that only errors codes can be returned. NS_OK + some error
• Then check the class hierarchy if this is the only implementation of the method
• Use class hierarchy to start rewriting at the oldest virtual method that target method overloads
• Ensure that the virtual method isn't originally defined by XPIDL
• Ensure that all overloads of this method will be rewritten (can't change return value otherwise)

Near Future

• Write an optimizer for ?: caller rewrites
• Need a macro to annotate getters where assigning NULL to the outparam has a special meaning. ie nsresult getterFunc(NOT_NULL(nsISupports **outval))