Installation failed in Mac OS Big Sur

Hi,
First of all, I thank you for your code.
I recently tried to install ATAT on my new mac, but it has failed with the following error messages.

./patchlang < linsolve.c++ > linsolve.cc
g++ -O3 -c -o linsolve.o linsolve.cc
./patchlang < getvalue.c++ > getvalue.cc
g++ -O3 -c -o getvalue.o getvalue.cc
getvalue.cc:45:10: warning: enumeration values ‘TITLEVAL’ and ‘LISTVAL’ not handled in switch [-Wswitch]
switch (label[i].vartype) {
^
getvalue.cc:45:10: note: add missing switch cases
switch (label[i].vartype) {
^
getvalue.cc:123:15: warning: enumeration values ‘TITLEVAL’ and ‘LISTVAL’ not handled in switch [-Wswitch]
switch (label[i].vartype){
^
getvalue.cc:123:15: note: add missing switch cases
switch (label[i].vartype){
^
getvalue.cc:266:1: warning: non-void function does not return a value in all control paths [-Wreturn-type]
}
^
3 warnings generated.

I hope you know how to fix it.
Thnak you!

Same issue here with Mac Monteray