Initial commit

tools/ninja_syntax.py

@@ -0,0 +1,223 @@
+# Copyright 2011 Google Inc. All Rights Reserved.
+#
+# 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.
+
+"""Python module for generating .ninja files.
+
+Note that this is emphatically not a required piece of Ninja; it's
+just a helpful utility for build-file-generation systems that already
+use Python.
+"""
+
+import re
+import textwrap
+
+
+def escape_path(word):
+    return word.replace("$ ", "$$ ").replace(" ", "$ ").replace(":", "$:")
+
+
+class Writer(object):
+    def __init__(self, output, width=78):
+        self.output = output
+        self.width = width
+
+    def newline(self):
+        self.output.write("\n")
+
+    def comment(self, text):
+        for line in textwrap.wrap(
+            text, self.width - 2, break_long_words=False, break_on_hyphens=False
+        ):
+            self.output.write("# " + line + "\n")
+
+    def variable(self, key, value, indent=0):
+        if value is None:
+            return
+        if isinstance(value, list):
+            value = " ".join(filter(None, value))  # Filter out empty strings.
+        self._line("%s = %s" % (key, value), indent)
+
+    def pool(self, name, depth):
+        self._line("pool %s" % name)
+        self.variable("depth", depth, indent=1)
+
+    def rule(
+        self,
+        name,
+        command,
+        description=None,
+        depfile=None,
+        generator=False,
+        pool=None,
+        restat=False,
+        rspfile=None,
+        rspfile_content=None,
+        deps=None,
+    ):
+        self._line("rule %s" % name)
+        self.variable("command", command, indent=1)
+        if description:
+            self.variable("description", description, indent=1)
+        if depfile:
+            self.variable("depfile", depfile, indent=1)
+        if generator:
+            self.variable("generator", "1", indent=1)
+        if pool:
+            self.variable("pool", pool, indent=1)
+        if restat:
+            self.variable("restat", "1", indent=1)
+        if rspfile:
+            self.variable("rspfile", rspfile, indent=1)
+        if rspfile_content:
+            self.variable("rspfile_content", rspfile_content, indent=1)
+        if deps:
+            self.variable("deps", deps, indent=1)
+
+    def build(
+        self,
+        outputs,
+        rule,
+        inputs=None,
+        implicit=None,
+        order_only=None,
+        variables=None,
+        implicit_outputs=None,
+        pool=None,
+        dyndep=None,
+    ):
+        outputs = as_list(outputs)
+        out_outputs = [escape_path(x) for x in outputs]
+        all_inputs = [escape_path(x) for x in as_list(inputs)]
+
+        if implicit:
+            implicit = [escape_path(x) for x in as_list(implicit)]
+            all_inputs.append("|")
+            all_inputs.extend(implicit)
+        if order_only:
+            order_only = [escape_path(x) for x in as_list(order_only)]
+            all_inputs.append("||")
+            all_inputs.extend(order_only)
+        if implicit_outputs:
+            implicit_outputs = [escape_path(x) for x in as_list(implicit_outputs)]
+            out_outputs.append("|")
+            out_outputs.extend(implicit_outputs)
+
+        self._line(
+            "build %s: %s" % (" ".join(out_outputs), " ".join([rule] + all_inputs))
+        )
+        if pool is not None:
+            self._line("  pool = %s" % pool)
+        if dyndep is not None:
+            self._line("  dyndep = %s" % dyndep)
+
+        if variables:
+            if isinstance(variables, dict):
+                iterator = iter(variables.items())
+            else:
+                iterator = iter(variables)
+
+            for key, val in iterator:
+                self.variable(key, val, indent=1)
+
+        return outputs
+
+    def include(self, path):
+        self._line("include %s" % path)
+
+    def subninja(self, path):
+        self._line("subninja %s" % path)
+
+    def default(self, paths):
+        self._line("default %s" % " ".join(as_list(paths)))
+
+    def _count_dollars_before_index(self, s, i):
+        """Returns the number of '$' characters right in front of s[i]."""
+        dollar_count = 0
+        dollar_index = i - 1
+        while dollar_index > 0 and s[dollar_index] == "$":
+            dollar_count += 1
+            dollar_index -= 1
+        return dollar_count
+
+    def _line(self, text, indent=0):
+        """Write 'text' word-wrapped at self.width characters."""
+        leading_space = "  " * indent
+        while len(leading_space) + len(text) > self.width:
+            # The text is too wide; wrap if possible.
+
+            # Find the rightmost space that would obey our width constraint and
+            # that's not an escaped space.
+            available_space = self.width - len(leading_space) - len(" $")
+            space = available_space
+            while True:
+                space = text.rfind(" ", 0, space)
+                if space < 0 or self._count_dollars_before_index(text, space) % 2 == 0:
+                    break
+
+            if space < 0:
+                # No such space; just use the first unescaped space we can find.
+                space = available_space - 1
+                while True:
+                    space = text.find(" ", space + 1)
+                    if (
+                        space < 0
+                        or self._count_dollars_before_index(text, space) % 2 == 0
+                    ):
+                        break
+            if space < 0:
+                # Give up on breaking.
+                break
+
+            self.output.write(leading_space + text[0:space] + " $\n")
+            text = text[space + 1 :]
+
+            # Subsequent lines are continuations, so indent them.
+            leading_space = "  " * (indent + 2)
+
+        self.output.write(leading_space + text + "\n")
+
+    def close(self):
+        self.output.close()
+
+
+def as_list(input):
+    if input is None:
+        return []
+    if isinstance(input, list):
+        return input
+    return [input]
+
+
+def escape(string):
+    """Escape a string such that it can be embedded into a Ninja file without
+    further interpretation."""
+    assert "\n" not in string, "Ninja syntax does not allow newlines"
+    # We only have one special metacharacter: '$'.
+    return string.replace("$", "$$")
+
+
+def expand(string, vars, local_vars={}):
+    """Expand a string containing $vars as Ninja would.
+
+    Note: doesn't handle the full Ninja variable syntax, but it's enough
+    to make configure.py's use of it work.
+    """
+
+    def exp(m):
+        var = m.group(1)
+        if var == "$":
+            return "$"
+        return local_vars.get(var, vars.get(var, ""))
+
+    return re.sub(r"\$(\$|\w*)", exp, string)