Merge pull request #4814 from mensinda/astVisitor

rewriter: Rewrote the meson rewriter - now works with AST modification

1 files changed, 203 insertions, 0 deletions

diff --git a/mesonbuild/ast/printer.py b/mesonbuild/ast/printer.py
new file mode 100644
index 0000000..60e0b0d
--- /dev/null
+++ b/mesonbuild/ast/printer.py
@@ -0,0 +1,203 @@
+# Copyright 2019 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This class contains the basic functionality needed to run any interpreter
+# or an interpreter-based tool
+
+from .. import mparser
+from . import AstVisitor
+import re
+
+arithmic_map = {
+    'add': '+',
+    'sub': '-',
+    'mod': '%',
+    'mul': '*',
+    'div': '/'
+}
+
+class AstPrinter(AstVisitor):
+    def __init__(self, indent: int = 2, arg_newline_cutoff: int = 5):
+        self.result = ''
+        self.indent = indent
+        self.arg_newline_cutoff = arg_newline_cutoff
+        self.ci = ''
+        self.is_newline = True
+        self.last_level = 0
+
+    def post_process(self):
+        self.result = re.sub(r'\s+\n', '\n', self.result)
+
+    def append(self, data: str, node: mparser.BaseNode):
+        level = 0
+        if node and hasattr(node, 'level'):
+            level = node.level
+        else:
+            level = self.last_level
+        self.last_level = level
+        if self.is_newline:
+            self.result += ' ' * (level * self.indent)
+        self.result += data
+        self.is_newline = False
+
+    def append_padded(self, data: str, node: mparser.BaseNode):
+        if self.result[-1] not in [' ', '\n']:
+            data = ' ' + data
+        self.append(data + ' ', node)
+
+    def newline(self):
+        self.result += '\n'
+        self.is_newline = True
+
+    def visit_BooleanNode(self, node: mparser.BooleanNode):
+        self.append('true' if node.value else 'false', node)
+
+    def visit_IdNode(self, node: mparser.IdNode):
+        self.append(node.value, node)
+
+    def visit_NumberNode(self, node: mparser.NumberNode):
+        self.append(str(node.value), node)
+
+    def visit_StringNode(self, node: mparser.StringNode):
+        self.append("'" + node.value + "'", node)
+
+    def visit_ContinueNode(self, node: mparser.ContinueNode):
+        self.append('continue', node)
+
+    def visit_BreakNode(self, node: mparser.BreakNode):
+        self.append('break', node)
+
+    def visit_ArrayNode(self, node: mparser.ArrayNode):
+        self.append('[', node)
+        node.args.accept(self)
+        self.append(']', node)
+
+    def visit_DictNode(self, node: mparser.DictNode):
+        self.append('{', node)
+        node.args.accept(self)
+        self.append('}', node)
+
+    def visit_OrNode(self, node: mparser.OrNode):
+        node.left.accept(self)
+        self.append_padded('or', node)
+        node.right.accept(self)
+
+    def visit_AndNode(self, node: mparser.AndNode):
+        node.left.accept(self)
+        self.append_padded('and', node)
+        node.right.accept(self)
+
+    def visit_ComparisonNode(self, node: mparser.ComparisonNode):
+        node.left.accept(self)
+        self.append_padded(mparser.comparison_map[node.ctype], node)
+        node.right.accept(self)
+
+    def visit_ArithmeticNode(self, node: mparser.ArithmeticNode):
+        node.left.accept(self)
+        self.append_padded(arithmic_map[node.operation], node)
+        node.right.accept(self)
+
+    def visit_NotNode(self, node: mparser.NotNode):
+        self.append_padded('not', node)
+        node.value.accept(self)
+
+    def visit_CodeBlockNode(self, node: mparser.CodeBlockNode):
+        for i in node.lines:
+            i.accept(self)
+            self.newline()
+
+    def visit_IndexNode(self, node: mparser.IndexNode):
+        self.append('[', node)
+        node.index.accept(self)
+        self.append(']', node)
+
+    def visit_MethodNode(self, node: mparser.MethodNode):
+        node.source_object.accept(self)
+        self.append('.' + node.name + '(', node)
+        node.args.accept(self)
+        self.append(')', node)
+
+    def visit_FunctionNode(self, node: mparser.FunctionNode):
+        self.append(node.func_name + '(', node)
+        node.args.accept(self)
+        self.append(')', node)
+
+    def visit_AssignmentNode(self, node: mparser.AssignmentNode):
+        self.append(node.var_name + ' = ', node)
+        node.value.accept(self)
+
+    def visit_PlusAssignmentNode(self, node: mparser.PlusAssignmentNode):
+        self.append(node.var_name + ' += ', node)
+        node.value.accept(self)
+
+    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode):
+        varnames = [x.value for x in node.varnames]
+        self.append_padded('foreach', node)
+        self.append_padded(', '.join(varnames), node)
+        self.append_padded(':', node)
+        node.items.accept(self)
+        self.newline()
+        node.block.accept(self)
+        self.append('endforeach', node)
+
+    def visit_IfClauseNode(self, node: mparser.IfClauseNode):
+        prefix = ''
+        for i in node.ifs:
+            self.append_padded(prefix + 'if', node)
+            prefix = 'el'
+            i.accept(self)
+        if node.elseblock:
+            self.append('else', node)
+            node.elseblock.accept(self)
+        self.append('endif', node)
+
+    def visit_UMinusNode(self, node: mparser.UMinusNode):
+        self.append_padded('-', node)
+        node.value.accept(self)
+
+    def visit_IfNode(self, node: mparser.IfNode):
+        node.condition.accept(self)
+        self.newline()
+        node.block.accept(self)
+
+    def visit_TernaryNode(self, node: mparser.TernaryNode):
+        node.condition.accept(self)
+        self.append_padded('?', node)
+        node.trueblock.accept(self)
+        self.append_padded(':', node)
+        node.falseblock.accept(self)
+
+    def visit_ArgumentNode(self, node: mparser.ArgumentNode):
+        break_args = True if (len(node.arguments) + len(node.kwargs)) > self.arg_newline_cutoff else False
+        for i in node.arguments + list(node.kwargs.values()):
+            if not isinstance(i, mparser.ElementaryNode):
+                break_args = True
+        if break_args:
+            self.newline()
+        for i in node.arguments:
+            i.accept(self)
+            self.append(', ', node)
+            if break_args:
+                self.newline()
+        for key, val in node.kwargs.items():
+            self.append(key, node)
+            self.append_padded(':', node)
+            val.accept(self)
+            self.append(', ', node)
+            if break_args:
+                self.newline()
+        if break_args:
+            self.result = re.sub(r', \n$', '\n', self.result)
+        else:
+            self.result = re.sub(r', $', '', self.result)