Debugging using vscode

You should have the following project tree:

<project root>/   <==== open this directory in vscode
   .vscode/
      c_cpp_properties.json
      launch.json
      settings.json
   CMakeLists.txt
   notify.cpp
   build/         (Created by build step)
      clsdk -> ....
      notify-debug.wasm
      notify.abi
      notify.wasm
      wasi-sdk -> ....

launch.json sets the following nodeos options. Adjust them to your needs:

-d data --config-dir config
--plugin eosio::chain_api_plugin
--plugin eosio::producer_api_plugin
--plugin eosio::debug_plugin
--subst clsdk/contracts/token.wasm:clsdk/contracts/token-debug.wasm
--subst notify.wasm:notify-debug.wasm
-e -p eosio

Open notify.cpp and set some break points. You may also add break points to build/clsdk/contracts/token/src/token.cpp.

Start the debugger. nodeos will start running. To see its log, switch to the "cppdbg: nodeos" terminal.

From another terminal, use these commands to install and exercise the contracts. The debugger should hit the breakpoints you set in the contracts and pause.

cd build

# Create some users
cleos create account eosio alice EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV
cleos create account eosio bob EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV

# Set up eosio.token
# Note: the build system created a symlink to clsdk for easy access to the token contract
cleos create account eosio eosio.token EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV
cleos set abi eosio.token clsdk/contracts/token.abi
cleos set code eosio.token clsdk/contracts/token.wasm

cleos push action eosio.token create '["eosio", "1000000000.0000 EOS"]' -p eosio.token
cleos push action eosio.token issue '["eosio", "1000000000.0000 EOS", ""]' -p eosio
cleos push action eosio.token open '["alice", "4,EOS", "alice"]' -p alice
cleos push action eosio.token open '["bob", "4,EOS", "bob"]' -p bob
cleos push action eosio.token transfer '["eosio", "alice", "10000.0000 EOS", "have some"]' -p eosio
cleos push action eosio.token transfer '["eosio", "bob", "10000.0000 EOS", "have some"]' -p eosio

# Install the notify contract
cleos create account eosio notify EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV
cleos set abi notify notify.abi
cleos set code notify notify.wasm

# Try out the notify contract
cleos push action eosio.token transfer '["alice", "notify", "300.0000 EOS", "for purchases"]' -p alice
cleos push action eosio.token transfer '["bob", "notify", "300.0000 EOS", "for purchases"]' -p bob

cleos push action notify buydog '["alice", "fido", "100.0000 EOS"]' -p alice
cleos push action notify buydog '["alice", "rex", "120.0000 EOS"]' -p alice
cleos push action notify buydog '["bob", "lambo", "70.0000 EOS"]' -p bob

# See the remaining balances and the purchased animals
cleos get table notify notify balance
cleos get table notify notify animal

Debugging functionality

The following are available:

• breakpoints
• step in
• step out
• step over
• continue
• call stack

The following are not available

• examining variables
• examining memory

Corrupted database recovery

The debugger can cause nodeos to corrupt its database. There are 2 options to recover from the corruption:

• Wipe the database and start over: from the build directory, run rm -rf data
• Force a replay. This can trigger breakpoints (helpful for reproductions). From the build directory, run rm -rf data/state data/blocks/reversible. Alternatively, add --hard-replay-blockchain to the nodeos options in launch.json.

You can start nodeos again in the debugger after doing one of the above.