v.pref: support `v -skip-unused run examples/hello_world.v`

pull/8575/head
Delyan Angelov 2021-02-05 10:42:52 +02:00
parent 80697ec7f3
commit 40fff7b56a
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6 changed files with 109 additions and 34 deletions

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@ -12,8 +12,6 @@ import v.pref
import v.util import v.util
import v.errors import v.errors
import v.pkgconfig import v.pkgconfig
import v.walker
import time
const ( const (
max_nr_errors = 300 max_nr_errors = 300
@ -229,26 +227,8 @@ pub fn (mut c Checker) check_files(ast_files []ast.File) {
} else if !has_main_fn { } else if !has_main_fn {
c.error('function `main` must be declared in the main module', token.Position{}) c.error('function `main` must be declared in the main module', token.Position{})
} }
// Walk the tree starting at main() and mark all used fns. if c.pref.skip_unused {
if c.pref.experimental { c.mark_used(ast_files)
println('walking the ast')
// c.is_recursive = true
// c.fn_decl(mut c.table2.main_fn_decl_node)
t := time.ticks()
mut walker := walker.Walker{
files: ast_files
}
for stmt in c.main_fn_decl_node.stmts {
walker.stmt(stmt)
}
// walker.fn_decl(mut c.table2.main_fn_decl_node)
println('time = ${time.ticks() - t}ms, nr used fns=$walker.used_fns.len')
for key, _ in walker.used_fns {
println(key)
}
// println(walker.used_fns)
// c.walk(ast_files)
} }
} }

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@ -0,0 +1,92 @@
module checker
import v.ast
import v.table
import v.checker.mark_used_walker
// mark_used walks the AST, starting at main() and marks all used fns transitively
fn (mut c Checker) mark_used(ast_files []ast.File) {
// println('walking the ast')
// c.is_recursive = true
// c.fn_decl(mut c.table2.main_fn_decl_node)
// c.timing_measure(@FN)
mut walker := mark_used_walker.Walker{
files: ast_files
}
// TODO: walking over the AST using roots != main.main, like `panic`
// for example, will potentially eliminate many cases where manual
// whitelisting is needed.
// TODO: use the full name of the functions in the map. For now the
// receiver type is skipped, so we can not distinguish between
// array.trim and string.trim etc.
for stmt in c.main_fn_decl_node.stmts {
walker.stmt(stmt)
}
// walker.fn_decl(mut c.table2.main_fn_decl_node)
// println('time = ${time.ticks() - t}ms, nr used fns=$walker.used_fns.len')
/*
for key, _ in walker.used_fns {
println(key)
}
*/
c.table.used_fns = walker.used_fns
// Whitelist some functions that are used by cgen directly:
c.table.used_fns['tos'] = true
c.table.used_fns['tos2'] = true
c.table.used_fns['v_panic'] = true
c.table.used_fns['panic'] = true
c.table.used_fns['eprintln'] = true
c.table.used_fns['print_backtrace_skipping_top_frames'] = true
c.table.used_fns['print_backtrace_skipping_top_frames_linux'] = true
c.table.used_fns['new_array_from_c_array'] = true
c.table.used_fns['__new_array_with_default'] = true
c.table.used_fns['__new_array'] = true
c.table.used_fns['vcalloc'] = true
c.table.used_fns['set_unsafe'] = true
c.table.used_fns['get_unsafe'] = true
c.table.used_fns['push'] = true
c.table.used_fns['ensure_cap'] = true
c.table.used_fns['v_realloc'] = true
c.table.used_fns['all_before'] = true
c.table.used_fns['all_after'] = true
c.table.used_fns['add'] = true
c.table.used_fns['isnil'] = true
c.table.used_fns['vstrlen'] = true
c.table.used_fns['trim_space'] = true
c.table.used_fns['malloc'] = true
c.table.used_fns['trim'] = true
c.table.used_fns['at'] = true
c.table.used_fns['replace'] = true
c.table.used_fns['index_'] = true
c.table.used_fns['index_after'] = true
c.table.used_fns['index_kmp'] = true
c.table.used_fns['substr'] = true
c.table.used_fns['clone'] = true
c.table.used_fns['free'] = true
c.table.used_fns['has_index'] = true
c.table.used_fns['key'] = true
c.table.used_fns['set'] = true
c.table.used_fns['get'] = true
c.table.used_fns['new_node'] = true
c.table.used_fns['eq'] = true
c.table.used_fns['ne'] = true
c.table.used_fns['lt'] = true
c.table.used_fns['gt'] = true
c.table.used_fns['le'] = true
c.table.used_fns['ge'] = true
c.table.used_fns['split_child'] = true
c.table.used_fns['bytes'] = true
c.table.used_fns['utf8_char_len'] = true
c.table.used_fns['utf8_str_visible_length'] = true
c.table.used_fns['main.main'] = true
c.table.used_fns['builtin_init'] = true
c.table.used_fns['memdup'] = true
// c.timing_measure(@FN)
// println(walker.used_fns)
// c.walk(ast_files)
}

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@ -1,9 +1,8 @@
// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved. // Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license that can be found in the LICENSE file. // Use of this source code is governed by an MIT license that can be found in the LICENSE file.
module walker module mark_used_walker
// This module walks the entire program starting at fn main and marks used (called) // This module walks the entire program starting at fn main and marks used (called) functions.
// functions.
// Unused functions can be safely skipped by the backends to save CPU time and space. // Unused functions can be safely skipped by the backends to save CPU time and space.
import v.ast import v.ast
@ -91,7 +90,7 @@ pub fn (mut w Walker) fn_decl(mut node ast.FnDecl) {
if node.language == .c { if node.language == .c {
return return
} }
println('fn decl $fn_name') // println('fn decl $fn_name')
w.used_fns[fn_name] = true w.used_fns[fn_name] = true
for stmt in node.stmts { for stmt in node.stmts {
w.stmt(stmt) w.stmt(stmt)
@ -102,7 +101,7 @@ pub fn (mut w Walker) fn_decl(mut node ast.FnDecl) {
pub fn (mut w Walker) call_expr(mut node ast.CallExpr) { pub fn (mut w Walker) call_expr(mut node ast.CallExpr) {
fn_name := if node.is_method { node.receiver_type.str() + '.' + node.name } else { node.name } fn_name := if node.is_method { node.receiver_type.str() + '.' + node.name } else { node.name }
// fn_name := node.name // fn_name := node.name
println('call_expr $fn_name') // println('call_expr $fn_name')
// if node.is_method { // if node.is_method {
// println('M $node.name $node.receiver_type') // println('M $node.name $node.receiver_type')
//} //}

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@ -27,13 +27,12 @@ fn (mut g Gen) gen_fn_decl(node ast.FnDecl, skip bool) {
} }
} }
*/ */
if g.pref.experimental { if g.pref.skip_unused {
if f := g.table.find_fn(node.name) { is_used_by_main := g.table.used_fns[ node.name ]
println('> usages: ${f.usages:-10} | node.name: $node.name') // println('> is_used_by_main: $is_used_by_main | node.name: $node.name')
if f.usages == 0 { if !is_used_by_main {
g.writeln('// fn $node.name UNUSED') g.writeln('// fn $node.name UNUSED')
return return
}
} }
} }

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@ -136,6 +136,7 @@ pub mut:
is_vweb bool // skip _ var warning in templates is_vweb bool // skip _ var warning in templates
only_check_syntax bool // when true, just parse the files, then stop, before running checker only_check_syntax bool // when true, just parse the files, then stop, before running checker
experimental bool // enable experimental features experimental bool // enable experimental features
skip_unused bool // skip generating C code for functions, that are not used
show_timings bool // show how much time each compiler stage took show_timings bool // show how much time each compiler stage took
is_ios_simulator bool is_ios_simulator bool
is_apk bool // build as Android .apk format is_apk bool // build as Android .apk format
@ -221,6 +222,9 @@ pub fn parse_args(args []string) (&Preferences, string) {
res.autofree = false res.autofree = false
res.build_options << arg res.build_options << arg
} }
'-skip-unused' {
res.skip_unused = true
}
'-compress' { '-compress' {
res.compress = true res.compress = true
} }

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@ -19,6 +19,7 @@ pub mut:
fn_gen_types map[string][][]Type // for generic functions fn_gen_types map[string][][]Type // for generic functions
cmod_prefix string // needed for table.type_to_str(Type) while vfmt; contains `os.` cmod_prefix string // needed for table.type_to_str(Type) while vfmt; contains `os.`
is_fmt bool is_fmt bool
used_fns map[string]bool // filled in by the checker, when pref.skip_unused = true;
} }
pub struct Fn { pub struct Fn {