refactor(gen): handling of comptime pseudo vars (#156)

- remove from Prefs and set them during codegen
- set only on usage
- properly print them in failed asserts

cli/bait.bt

@@ -29,7 +29,6 @@ fun main() {
 	args := os.user_args()
 	timers.start('PREFS')
 	mut prefs := preference.parse_args(args)
-	prefs.set_comptime_vars()
 	timers.set_show(prefs.show_timings)
 	timers.show('PREFS')
 

docs/docs.md

@@ -1,9 +1,10 @@
 <!--
-Copyright (c) 2023-present Lukas Neubert.
-This Documentation is subject to the terms of the Mozilla Public License 2.0.
+SPDX-FileCopyrightText: 2023-present Lukas Neubert <[email protected]>
+SPDX-License-Identifier: MPL-2.0
 -->
+
 # Bait Documentation
-> Documentation of the standard library is :construction:
+> Documentation of the standard library is work in progress :construction:
 
 ## Entry Point
 The entry point of any program is the `main` function. It is automatically called when the program starts.
@@ -424,28 +425,30 @@ struct FooBar {
 | ----------- | ------------------------------------------- | ------ |
 | `@required` | The field must be initialized with a value. | _none_ |
 
+
 ## Conditional Compilation
 ### Compile Time Pseudo Variables
-Bait supports a few pseudo variables of `string` type.
-They are replaced with the actual value during compilation.
-
-| Variable     | Description                         | Example                 |
-| ------------ | ----------------------------------- | ----------------------- |
-| `$PKG`       | Name of the current package.        | `main`                  |
-| `$FILE`      | Relative path of the source file.   | `lib/builtin/file.bt`   |
-| `$ABS_FILE`  | Absolute path of the source file.   | `/path/to/file.bt`      |
-| `$LINE`      | Line number of it's appearance.     | `123`                   |
-| `$FILE_LINE` | Relative path followed by the line. | `tests/my_test.bt:27`   |
-| `$FUN`       | Name of the current function.       | `test_read_line`        |
-| `$BAITEXE`   | Absolut path to the Bait compiler.  | `/path/to/bait/bait.js` |
-| `$BAITDIR`   | Directory where the compiler is in. | `/path/to/bait`         |
-| `$BAITHASH`  | Short commit hash of the compiler.  | `5e7fd6e`               |
+Bait supports a few pseudo variables, which are replaced by their actual values during compilation.
+They are all of the type `string`.
+
+| Variable     | Description                       | Example                 |
+| ------------ | --------------------------------- | ----------------------- |
+| `$PKG`       | Current package name              | `main`                  |
+| `$ABS_FILE`  | Absolute source file path         | `/path/to/file.bt`      |
+| `$FILE`      | Relative source file path         | `lib/builtin/file.bt`   |
+| `$LINE`      | Line number where it is used      | `123`                   |
+| `$FILE_LINE` | Relative path and the line        | `tests/my_test.bt:27`   |
+| `$FUN`       | Current function name             | `test_read_line`        |
+| `$BAITEXE`   | Absolut path to the Bait compiler | `/path/to/bait/bait.js` |
+| `$BAITDIR`   | Directory of the compiler         | `/path/to/bait`         |
+| `$BAITHASH`  | The compiler's short commit hash  | `5e7fd6e`               |
 
 They are useful for running external tools or debugging. For example:
 ```bait
 eprintln('error in file ${$FILE}, line ${$LINE}, function ${$PKG}.${$FUN}')
 ```
 
+
 ## Global Variables
 While the use of global variables is discouraged, they are important in some cases.
 

lib/bait/ast/ast.bt

@@ -7,7 +7,7 @@ import bait.errors
 
 type Stmt := AssertStmt | AssignStmt | ConstDecl | EnumDecl | ExprStmt | ForLoop | ForClassicLoop | ForInLoop | FunDecl | GlobalDecl | InterfaceDecl | ReturnStmt | StructDecl | TypeDecl | LoopControlStmt | EmptyStmt | MatchExpr | IfExpr
 
-type Expr := AnonFun | ArrayInit | AsCast | BoolLiteral | CallExpr | CharLiteral | CompTimeVar | EnumVal | FloatLiteral | HashExpr | Ident | IfExpr | IndexExpr | InfixExpr | IntegerLiteral | MatchExpr | MapInit | ParExpr | PrefixExpr | SelectorExpr | StringLiteral | StringInterLiteral | StructInit | TypeOf | EmptyExpr
+type Expr := AnonFun | ArrayInit | AsCast | BoolLiteral | CallExpr | CharLiteral | ComptimeVar | EnumVal | FloatLiteral | HashExpr | Ident | IfExpr | IndexExpr | InfixExpr | IntegerLiteral | MatchExpr | MapInit | ParExpr | PrefixExpr | SelectorExpr | StringLiteral | StringInterLiteral | StructInit | TypeOf | EmptyExpr
 
 pub struct AssertStmt {
 pub:
@@ -237,7 +237,7 @@ pub:
 	pos token.Pos
 }
 
-pub struct CompTimeVar{
+pub struct ComptimeVar{
 pub:
 	name string
 	pos token.Pos

lib/bait/checker/expr.bt

@@ -18,8 +18,8 @@ fun (mut c Checker) expr(expr ast.Expr) ast.Type {
 		return c.call_expr(expr)
 	} else if expr is ast.CharLiteral {
 		return ast.U8_TYPE
-	} else if expr is ast.CompTimeVar {
-		return c.comp_time_var(expr)
+	} else if expr is ast.ComptimeVar {
+		return c.comptime_var(expr)
 	} else if expr is ast.EnumVal {
 		return c.enum_val(expr)
 	} else if expr is ast.FloatLiteral {
@@ -155,7 +155,7 @@ const SUPPORTED_COMPTIME_VARS := [
 	'BAITHASH',
 ]
 
-fun (mut c Checker) comp_time_var(node ast.CompTimeVar) ast.Type {
+fun (mut c Checker) comptime_var(node ast.ComptimeVar) ast.Type {
 	if not SUPPORTED_COMPTIME_VARS.contains(node.name) {
 		c.error('unsupported comptime var "${node.name}"', node.pos)
 	}

lib/bait/gen/js/comptime.bt

@@ -0,0 +1,55 @@
+// SPDX-FileCopyrightText: 2023-present Lukas Neubert <[email protected]>
+// SPDX-License-Identifier: MPL-2.0
+package js
+
+import os
+import bait.ast
+import bait.token
+
+fun (mut g Gen) comptime_var(node ast.ComptimeVar){
+	g.write('from_js_string("')
+	g.write(g.get_comptime_val(node.name, node.pos))
+	g.write('")')
+}
+
+fun (mut g Gen) get_comptime_val(name string, pos token.Pos) string {
+	return match name {
+		// Dynamic
+		'PKG' { g.pkg }
+		'ABS_FILE' { os.abs_path(g.path).replace('\\', '\\\\') }
+		'FILE' { g.path.replace('\\', '\\\\') }
+		'LINE' { pos.line.str() }
+		'FILE_LINE' {
+			file := g.get_comptime_val('FILE', pos)
+			line := g.get_comptime_val('LINE', pos)
+			'${file}:${line}'
+		}
+		'FUN' { g.cur_fun.name }
+		// Cached
+		'BAITEXE' { g.comptime_baitexe() }
+		'BAITDIR' { g.comptime_baitdir() }
+		'BAITHASH' { g.comptime_baithash() }
+	}
+}
+
+fun (mut g Gen) comptime_baitexe() string {
+	if g.baitexe.length == 0 {
+		g.baitexe = os.executable().replace('\\', '\\\\')
+	}
+	return g.baitexe
+}
+
+fun (mut g Gen) comptime_baitdir() string {
+	if g.baitdir.length == 0 {
+		g.baitdir = os.dir(g.comptime_baitexe()).trim_right('\\')
+	}
+	return g.baitdir
+}
+
+fun (mut g Gen) comptime_baithash() string {
+	if g.baithash.length == 0 {
+		bd := g.comptime_baitdir()
+		g.baithash = os.exec('git -C ${bd} rev-parse --short HEAD').stdout.trim_space()
+	}
+	return g.baithash
+}

lib/bait/gen/js/expr.bt

@@ -21,8 +21,8 @@ fun (mut g Gen) expr(expr ast.Expr) {
 		g.call_expr(expr)
 	} else if expr is ast.CharLiteral {
 		g.char_literal(expr)
-	} else if expr is ast.CompTimeVar {
-		g.comp_time_var(expr)
+	} else if expr is ast.ComptimeVar {
+		g.comptime_var(expr)
 	} else if expr is ast.EnumVal {
 		g.enum_val(expr)
 	} else if expr is ast.FloatLiteral {
@@ -131,22 +131,6 @@ fun (mut g Gen) char_literal(node ast.CharLiteral) {
 	g.write('")')
 }
 
-fun (mut g Gen) comp_time_var(node ast.CompTimeVar){
-	g.write('from_js_string("')
-	match node.name{
-		'PKG' {g.write(g.pkg)}
-		'FILE' {g.write(g.path.replace('\\', '\\\\'))}
-		'ABS_FILE' {g.write(os.abs_path(g.path).replace('\\', '\\\\'))}
-		'LINE' {g.write('${node.pos.line}')}
-		'FILE_LINE' {g.write('${g.path.replace('\\', '\\\\')}:${node.pos.line}')}
-		'FUN' {g.write(g.cur_fun.name)}
-		'BAITEXE' {g.write(g.pref.baitexe)}
-		'BAITDIR' {g.write(g.pref.baitdir)}
-		'BAITHASH' {g.write(g.pref.baithash)}
-	}
-	g.write('")')
-}
-
 fun (mut g Gen) enum_val(node ast.EnumVal) {
 	g.write(js_name(node.name) + '.' + node.val)
 }

lib/bait/gen/js/jsgen.bt

@@ -63,6 +63,10 @@ mut:
 	is_for_loop_head bool
 	is_lhs_assign bool
 	is_array_map_set bool
+	// Cached comptime variables
+	baitexe string
+	baitdir string
+	baithash string
 }
 
 pub fun gen(files []ast.File, table ast.Table, pref preference.Prefs) string {

lib/bait/gen/js/stmt.bt

@@ -124,6 +124,9 @@ fun (mut g Gen) assert_side_expr(node ast.Expr) {
 	} else if node is ast.SelectorExpr {
 		g.assert_side_expr(node.expr)
 		g.write('.${node.field_name}')
+	} else if node is ast.ComptimeVar {
+		g.write('$')
+		g.write(node.name)
 	} else {
 		g.write('UNHANDLED EXPR')
 	}

lib/bait/parser/expr.bt

@@ -32,7 +32,7 @@ fun (mut p Parser) single_expr() ast.Expr {
 			return p.char_literal()
 		}
 		.dollar {
-			return p.comp_time_var()
+			return p.comptime_var()
 		}
 		.dot {
 			return p.enum_val(false)
@@ -191,11 +191,11 @@ fun (mut p Parser) char_literal()ast.CharLiteral{
 	}
 }
 
-fun (mut p Parser) comp_time_var() ast.CompTimeVar{
+fun (mut p Parser) comptime_var() ast.ComptimeVar{
 	pos := p.pos()
 	p.next()
 	name := p.check_name()
-	return ast.CompTimeVar{
+	return ast.ComptimeVar{
 		name = name
 		pos = pos
 	}

lib/bait/preference/preference.bt

@@ -35,11 +35,6 @@ pub mut:
 	// Error related
 	hide_warnings bool
 	warn_is_error bool
-
-	// Values for compile time pseudo variables
-	baitexe string
-	baitdir string
-	baithash string
 }
 
 pub fun parse_args(args []string) Prefs {
@@ -152,12 +147,6 @@ pub fun parse_args(args []string) Prefs {
 	return p
 }
 
-pub fun (mut p Prefs) set_comptime_vars() {
-	p.baitexe = os.executable().replace('\\', '\\\\')
-	p.baitdir = os.dir(p.baitexe).trim_right('\\')
-	p.baithash = os.exec('git -C ${p.baitdir} rev-parse --short HEAD').stdout.trim_space()
-}
-
 fun backend_from_string(s string) Backend {
 	return match s {
 		'js' { Backend.js }

tests/other/comptime_vars_test.bt

@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: 2023-present Lukas Neubert <[email protected]>
+// SPDX-License-Identifier: MPL-2.0
+
+import os
+
+fun test_comptime_vars() {
+	assert $PKG == 'main'
+	assert $FILE == 'tests/other/comptime_vars_test.bt'.replace('/', os.PATH_SEP)
+	assert $LINE == '9'
+	assert $FILE_LINE == 'tests/other/comptime_vars_test.bt:10'.replace('/', os.PATH_SEP)
+	assert $FUN == 'test_comptime_vars'
+
+	// The following vars are hard to test
+
+	assert $ABS_FILE.length > $FILE.length
+
+	assert $BAITEXE.length > 0
+
+	assert $BAITDIR.length < $BAITEXE.length
+
+	assert $BAITHASH.length == 7
+}

tests/other/number_test.bt

@@ -1,5 +1,5 @@
-// Copyright (c) 2023-present Lukas Neubert.
-// This Source Codeubject to the terms of the Mozilla Public License 2.0.
+// SPDX-FileCopyrightText: 2023-present Lukas Neubert <[email protected]>
+// SPDX-License-Identifier: MPL-2.0
 
 fun test_floats() {
 	f := 1.23

tests/other/ptr_deref_test.bt

@@ -1,5 +1,5 @@
-// Copyright (c) 2023-present Lukas Neubert.
-// This Source Codeubject to the terms of the Mozilla Public License 2.0.
+// SPDX-FileCopyrightText: 2023-present Lukas Neubert <[email protected]>
+// SPDX-License-Identifier: MPL-2.0
 
 fun test_pointer_deref() {
 	n := 42

tests/other/u8_test.bt

@@ -1,5 +1,5 @@
-// Copyright (c) 2023-present Lukas Neubert.
-// This Source Codeubject to the terms of the Mozilla Public License 2.0.
+// SPDX-FileCopyrightText: 2023-present Lukas Neubert <[email protected]>
+// SPDX-License-Identifier: MPL-2.0
 
 fun test_u8_operations() {
 	a := `a`