fish-shell/build_tools/find_globals.fish
2021-11-23 09:49:45 +01:00

110 lines
3.4 KiB
Fish
Executable file

#!/usr/bin/env fish
# Finds global variables by parsing the output of 'nm'
# for object files in this directory.
# This was written for macOS nm.
set -l FISH_SOURCE_DIR $argv[1]
if not test -d "$FISH_SOURCE_DIR"
echo "FISH_SOURCE_DIR not given"
exit 1
end
set -g whitelist \
# unclear what this is \
l_constinit \
# hacks to work around missing ncurses strings on mac \
sitm_esc ritm_esc dim_esc
# In our nm regex, we are interested in data (dD) and bss (bB) segments.
set -g nm_regex '^([^ ]+) ([dDbB])'
set -l total_globals 0
set -l boring_files \
fish_key_reader.cpp.o \
fish_tests.cpp.o \
fish_indent.cpp.o
# return if we should ignore the given symbol name
function should_ignore
set -l symname $argv[1]
string match -q '*guard variable for*' $symname
and return 0
contains $symname $whitelist
and return 0
return 1
end
# echo a cleaned-up symbol name, e.g. replacing template gunk
function cleanup_syname
set -l symname $argv[1]
set symname (string replace --all 'std::__1::basic_string<wchar_t, std::__1::char_traits<wchar_t>, std::__1::allocator<wchar_t> >' 'wcstring' $symname)
set symname (string replace --all 'std::__1::vector<wcstring, std::__1::allocator<wcstring > >' 'wcstring_list_t' $symname)
echo $symname
end
# Output the declaration for a symbol name in a given file.
function print_decl -a FISH_SOURCE_DIR objfile symname
set -l varname (string split '::' $symname)[-1]
set -l srcfile (basename $objfile .o)
set -l srcpath $FISH_SOURCE_DIR/src/$srcfile
# A leading underscore indicates a global, strip it.
set varname (string replace --regex '^_' '' $varname)
if not test -f "$srcpath"
echo "Could not find $srcpath"
end
# Guess the variable as the first usage of the name.
# Strip everything after the first =.
set -l vardecl (egrep -m 1 " $varname\\b" $srcpath | cut -f -1 -d '=' | string trim)
if test -z "$vardecl"
echo "COULD_NOT_FIND_$varname"
return 1
end
echo $vardecl
return 0
end
# Return if a variable declaration is "thread safe".
function decl_is_threadsafe
set -l vardecl $argv[1]
# decls starting with 'const ' or containing ' const ' are assumed safe.
string match -q --regex '(^|\\*| )const ' $vardecl
and return 0
# Ordinary types indicating a safe variable.
set -l safes relaxed_atomic_bool_t std::mutex std::condition_variable std::once_flag sig_atomic_t
for safe in $safes
string match -q "*$safe*" $vardecl
and return 0
end
# Template types indicate a safe variable.
set safes owning_lock mainthread_t std::atomic relaxed_atomic_t latch_t
for safe in $safes
string match -q "*$safe<*" $vardecl
and return 0
end
end
for file in ./**.o
set -l filename (basename $file)
# Skip boring files.
contains $filename $boring_files
and continue
for line in (nm -p -P -U $file | egrep $nm_regex)
set -l matches (string match --regex $nm_regex -- $line)
or continue
set -l symname (cleanup_syname (echo $matches[2] | c++filt))
should_ignore $symname
and continue
set -l vardecl (print_decl $FISH_SOURCE_DIR $filename $symname)
decl_is_threadsafe $vardecl
and continue
echo $filename $symname $matches[3] ":" $vardecl
set total_globals (math $total_globals + 1)
end
end
echo "Total: $total_globals"