1 files changed, 160 insertions, 0 deletions
diff --git a/tools/generation/lib/template.py b/tools/generation/lib/template.py
new file mode 100644
index 000000000..fa891f00b
--- /dev/null
+++ b/tools/generation/lib/template.py
@@ -0,0 +1,160 @@
+# Copyright (C) 2016 the V8 project authors. All rights reserved.
+# This code is governed by the BSD license found in the LICENSE file.
+
+import os, re
+import codecs, yaml
+
+from util.find_comments import find_comments
+from util.parse_yaml import parse_yaml
+from test import Test
+
+indentPattern = re.compile(r'^(\s*)')
+interpolatePattern = re.compile(r'\{\s*(\S+)\s*\}')
+
+def indent(text, prefix = '    '):
+    '''Prefix a block of text (as defined by the "line break" control
+    character) with some character sequence.'''
+
+    if isinstance(text, list):
+        lines = text
+    else:
+        lines = text.split('\n')
+
+    return prefix + ('\n' + prefix).join(lines)
+
+class Template:
+    def __init__(self, filename):
+        self.filename = filename
+
+        with open(filename) as template_file:
+            self.source = template_file.read()
+
+        self.attribs = dict()
+        self.regions = []
+
+        self._parse()
+
+    def _remove_comment(self, comment):
+        '''Create a region that is not intended to be referenced by any case,
+        ensuring that the comment is not emitted in the rendered file.'''
+        name = '__remove_comment_' + str(comment['firstchar']) + '__'
+
+        # When a removed comment ends the line, the following newline character
+        # should also be removed from the generated file.
+        lastchar = comment['lastchar']
+        if self.source[lastchar] == '\n':
+            comment['lastchar'] = comment['lastchar'] + 1
+
+        self.regions.insert(0, dict(name=name, **comment))
+
+    def _parse(self):
+        for comment in find_comments(self.source):
+            meta = parse_yaml(comment['source'])
+
+            # Do not emit the template's frontmatter in generated files
+            # (file-specific frontmatter is generated as part of the rendering
+            # process)
+            if meta:
+                self.attribs['meta'] = meta
+                self._remove_comment(comment)
+                continue
+
+            # Do not emit license information in generated files (recognized as
+            # comments preceeding the YAML frontmatter)
+            if not self.attribs.get('meta'):
+                self._remove_comment(comment)
+                continue
+
+            match = interpolatePattern.match(comment['source'])
+
+            if match == None:
+                continue
+
+            self.regions.insert(0, dict(name=match.group(1), **comment))
+
+    def expand_regions(self, source, context):
+        lines = source.split('\n')
+
+        for region in self.regions:
+            whitespace = indentPattern.match(lines[region['lineno']]).group(1)
+            value = context['regions'].get(region['name'], '')
+            source = source[:region['firstchar']] + \
+                indent(value, whitespace).lstrip() + \
+                source[region['lastchar']:]
+
+        setup = context['regions'].get('setup')
+
+        if setup:
+            source = setup + '\n' + source
+
+        teardown = context['regions'].get('teardown')
+
+        if teardown:
+            source += '\n' + teardown + '\n'
+
+        return source
+
+    def _frontmatter(self, case_filename, case_values):
+        description = case_values['meta']['desc'].strip() + \
+            ' (' + self.attribs['meta']['name'].strip() + ')'
+        lines = []
+
+        lines += [
+            '// This file was procedurally generated from the following sources:',
+            '// - ' + case_filename,
+            '// - ' + self.filename,
+            '/*---',
+            'description: ' + description,
+        ]
+
+        esid = self.attribs['meta'].get('esid')
+        if esid:
+            lines.append('esid: ' + esid)
+
+        es6id = self.attribs['meta'].get('es6id')
+        if es6id:
+            lines.append('es6id: ' + es6id)
+
+        features = []
+        features += case_values['meta'].get('features', [])
+        features += self.attribs['meta'].get('features', [])
+        if len(features):
+            lines += ['features: ' + yaml.dump(features)]
+
+        flags = ['generated']
+        flags += case_values['meta'].get('flags', [])
+        flags += self.attribs['meta'].get('flags', [])
+        lines += ['flags: ' + yaml.dump(flags).strip()]
+
+        includes = []
+        includes += case_values['meta'].get('includes', [])
+        includes += self.attribs['meta'].get('includes', [])
+        if len(includes):
+            lines += ['includes: ' + yaml.dump(includes).strip()]
+
+        if case_values['meta'].get('negative'):
+            lines += ['negative: ' + case_values['meta'].get('negative')]
+
+        info = []
+
+        if 'info' in self.attribs['meta']:
+            info.append(indent(self.attribs['meta']['info']))
+        if 'info' in case_values['meta']:
+            if len(info):
+                info.append('')
+            info.append(indent(case_values['meta']['info']))
+
+        if len(info):
+            lines.append('info: >')
+            lines += info
+
+        lines.append('---*/')
+
+        return '\n'.join(lines)
+
+    def expand(self, case_filename, case_name, case_values, encoding):
+        frontmatter = self._frontmatter(case_filename, case_values)
+        body = self.expand_regions(self.source, case_values)
+
+        return Test(self.attribs['meta']['path'] + case_name + '.js',
+            source=codecs.encode(frontmatter + '\n' + body, encoding))