Using SCons tools (#977)

Changing the SCons architecture to clean up SConstruct and isolating languages more

Author: Amaras

SConstruct

@@ -11,26 +11,51 @@ from pathlib import Path
 from collections import namedtuple
 import os
 
-
-rust_cargo_builder = Builder(action=['cargo build --bins --manifest-path $MANIFEST',
-                                     Move('$TARGET$PROGSUFFIX', '$SOURCE_DIR/target/debug/main$PROGSUFFIX')])
-
-rust_rustc_builder = Builder(action='rustc $SOURCE -o $TARGET$PROGSUFFIX')
-
-go_builder = Builder(action='go build -o $TARGET$PROGSUFFIX $SOURCE')
+import SCons
+SCons.Warnings.warningAsException()
 
 # For interpreted languages to copy to build directory
 copy_builder = Builder(action=Copy('$TARGET', '$SOURCE'))
 
-coconut_builder = Builder(action='coconut $COCONUTFLAGS $SOURCE $TARGET', src_suffix='.coco', target_suffix='.py')
-
 env = Environment(ENV=os.environ,
-                  BUILDERS={'rustc': rust_rustc_builder,
-                            'cargo': rust_cargo_builder,
-                            'Go': go_builder,
-                            'Copier': copy_builder,
-                            'Coconut': coconut_builder},
-                  tools=['gcc', 'gnulink', 'g++', 'gas', 'gfortran', 'javac'])
+                  BUILDERS={'Copier': copy_builder}, 
+                  tools=[
+                    'g++', 'gas', 'gcc', 'gfortran', 'gnulink', 'javac'],
+                  toolpath=['builders'])
+
+available_languages = {
+    'asm-x64',
+    'bash',
+    'c',
+    'cpp',
+    'fortran',
+    'java',
+    'julia',
+    'lolcode'
+    'lua',
+    'php',
+    'powershell',
+    'python',
+    'ruby',
+    'viml',
+}
+
+languages_to_import = {
+    'coconut': ['coconut'],
+    'go': ['go'],
+    'rust': ['rustc', 'cargo'],
+}
+
+for language, tools in languages_to_import.items():
+    for tool in tools:
+        try:
+            env.Tool(tool)
+        except SCons.Warnings.SConsWarning as w:
+            print(f'{w.args[0][0]}, ignoring')
+            break
+    else:
+        available_languages.add(language)
+
 
 Export('env')
 
@@ -69,11 +94,11 @@ env.CPlusPlus = env.Program
 env.X64 = env.Program
 env.Fortran = env.Program
 
-for language in languages:
+for language in available_languages:
     Alias(language, f'#/build/{language}')
 
 sconscripts = []
-files_to_compile = {language: [] for language in languages}
+files_to_compile = {language: [] for language in languages if language in available_languages}
 
 FileInformation = namedtuple('FileInformation', ['path', 'chapter', 'language'])
 
@@ -85,7 +110,7 @@ for chapter_dir in contents_path.iterdir():
         extended_chapter_path = code_dir.relative_to(contents_path).parent
 
         for language_dir in code_dir.iterdir():
-            if (language := language_dir.stem) in languages:
+            if (language := language_dir.stem) in available_languages:
                 new_files = [FileInformation(path=file_path,
                                              chapter=extended_chapter_path,
                                              language=language)

builders/cargo.py

@@ -0,0 +1,41 @@
+from SCons.Builder import Builder
+from SCons.Script import Move
+import SCons.Util
+
+class ToolCargoWarning(SCons.Warnings.SConsWarning):
+    pass
+
+class CargoNotFound(ToolCargoWarning):
+    pass
+
+SCons.Warnings.enableWarningClass(ToolCargoWarning)
+
+def _detect(env):
+    try:
+        return env['cargo']
+    except KeyError:
+        pass
+
+    cargo = env.WhereIs('cargo')
+    if cargo:
+        return cargo
+
+    SCons.Warnings.warn(CargoNotFound, 'Could not detect cargo')
+
+def exists(env):
+    return env.Detect('cargo')
+
+
+def generate(env):
+    env['CARGO'] = _detect(env)
+    env['CARGOFLAGS'] = []
+    env['MANIFEST'] = []
+
+    rust_cargo_builder = Builder(
+            action=['"$CARGO" build $CARGOFLAGS --bins --manifest-path $MANIFEST',
+                    Move('$TARGET$PROGSUFFIX', 
+                         '$SOURCE_DIR/target/debug/main$PROGSUFFIX')
+                    ],
+            suffix='$PROGSUFFIX',
+            )
+    env.Append(BUILDERS={'cargo': rust_cargo_builder})

builders/coconut.py

@@ -0,0 +1,40 @@
+from SCons.Builder import Builder
+import SCons.Util
+
+class ToolCocoWarning(SCons.Warnings.SConsWarning):
+    pass
+
+class CoconutNotFound(ToolCocoWarning):
+    pass
+
+SCons.Warnings.enableWarningClass(ToolCocoWarning)
+
+def _detect(env):
+    try:
+        return env['coconut']
+    except KeyError:
+        pass
+
+    coconut = env.WhereIs('coconut')
+    if coconut:
+        return coconut
+
+    SCons.Warnings.warn(CoconutNotFound, 'Could not find Coconut executable')
+
+
+def generate(env):
+    env['COCONUT'] = _detect(env)
+    env['COCONUTFLAGS'] = []
+
+    coconut_compiler = Builder(
+        action='"$COCONUT" $COCONUTFLAGS $SOURCE $TARGET',
+        src_suffix='.coco',
+        suffix='.py',
+    )
+
+    env.Append(BUILDERS={'Coconut': coconut_compiler})
+
+def exists(env):
+    return env.Detect('coconut')
+
+

builders/go.py

@@ -0,0 +1,37 @@
+from SCons.Builder import Builder
+import SCons.Util
+
+class ToolGoWarning(SCons.Warnings.SConsWarning):
+    pass
+
+class GoNotFound(ToolGoWarning):
+    pass
+
+SCons.Warnings.enableWarningClass(ToolGoWarning)
+
+def _detect(env):
+    try:
+        return env['go']
+    except KeyError:
+        pass
+
+    go = env.WhereIs('go')
+    if go:
+        return go
+
+    SCons.Warnings.warn(GoNotFound, 'Could not find go executable')
+
+def exists(env):
+    env.Detect('go')
+
+def generate(env):
+    env['GO'] = _detect(env)
+    env['GOFLAGS'] = []
+
+    go_builder = Builder(
+        action='"$GO" build -o $TARGET $GOFLAGS $SOURCE',
+        src_suffix='.go',
+        suffix='$PROGSUFFIX',
+    )
+
+    env.Append(BUILDERS={'Go': go_builder})

builders/rustc.py

@@ -0,0 +1,45 @@
+from SCons.Builder import Builder
+import SCons.Util
+
+class ToolRustcWarning(SCons.Warnings.SConsWarning):
+    pass
+
+class RustcNotFound(ToolRustcWarning):
+    pass
+
+SCons.Warnings.enableWarningClass(ToolRustcWarning)
+
+def _detect(env):
+    try:
+        return env['rustc']
+    except KeyError:
+        pass
+
+    cargo = env.WhereIs('rustc')
+    if cargo:
+        return cargo
+
+    SCons.Warnings.warn(RustcNotFound, 'Could not detect rustc')
+
+
+def exists(env):
+    return env.Detect('rustc')
+
+def rustc_emitter(target, source, env):
+    src_name = str(source[0])
+    pdb_name = src_name.replace(source[0].suffix, '.pdb')
+    env.SideEffect(pdb_name, target)
+    env.Clean(target, pdb_name)
+    return (target, source)
+
+def generate(env):
+    env['RUSTC'] = _detect(env)
+    env['RUSTCFLAGS'] = []
+
+    rust_cargo_builder = Builder(
+            action='"$RUSTC" $RUSTCFLAGS -o $TARGET $SOURCE',
+            suffix='$PROGSUFFIX',
+            src_suffix='.rs',
+            emitter=rustc_emitter,
+            )
+    env.Append(BUILDERS={'rustc': rust_cargo_builder})

contents/stacks_and_queues/code/rust/SConscript

@@ -3,8 +3,6 @@ from pathlib import Path
 
 dirname = Path.cwd().parents[1].stem
 
-env.rustc(f'#/build/rust/stack', '#/contents/stacks_and_queues/code/rust/Stack.rs')
-env.Clean('rust', f'#/build/rust/stack.pdb')
+env.rustc(f'#/build/rust/{dirname}/stack', '#/contents/stacks_and_queues/code/rust/Stack.rs')
 
-env.rustc(f'#/build/rust/queue', '#/contents/stacks_and_queues/code/rust/Queue.rs')
-env.Clean('rust', f'#/build/rust/queue.pdb')
+env.rustc(f'#/build/rust/{dirname}/queue', '#/contents/stacks_and_queues/code/rust/Queue.rs')

sconscripts/rust_SConscript

@@ -12,4 +12,4 @@ for file_info in files_to_compile:
         build_result = env.rustc(build_target, str(file_info.path))
         env.Clean('rust', f'{build_target}.pdb')
 
-    env.Alias(str(file_info.chapter), build_result)
+    env.Alias(str(file_info.chapter), build_result)