From 5e6469596c8613c686e6d07eb9b3ac0c785e055b Mon Sep 17 00:00:00 2001
From: Ivan Kravets <me@ikravets.com>
Date: Sat, 17 Sep 2016 23:46:53 +0300
Subject: [PATCH] Dynamic variables/templates for "platformio.ini" // Resolve
 #705

---
 HISTORY.rst                |  2 +
 docs/projectconf.rst       | 80 ++++++++++++++++++++++++++++++++++++--
 platformio/__init__.py     |  2 +-
 platformio/commands/ci.py  | 15 ++-----
 platformio/commands/run.py |  6 +--
 platformio/exception.py    |  5 ---
 platformio/util.py         | 40 +++++++++++++++----
 7 files changed, 117 insertions(+), 33 deletions(-)

diff --git a/HISTORY.rst b/HISTORY.rst
index f3ba1727..73e959b2 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -7,6 +7,8 @@ PlatformIO 3.0
 3.1.0 (2016-09-??)
 ~~~~~~~~~~~~~~~~~~
 
+* New! Dynamic variables/templates for `Project Configuration File "platformio.ini" <http://docs.platformio.org/en/stable/projectconf.html>`__
+  (`issue #705 <https://github.com/platformio/platformio/issues/705>`_)
 * Implemented LocalCache system for API and improved a work in off-line mode
 * Improved Project Generator when custom ``--project-option`` is passed to
   `platformio init <http://docs.platformio.org/en/stable/userguide/cmd_init.html>`__
diff --git a/docs/projectconf.rst b/docs/projectconf.rst
index 7c31c9f5..14af3c7b 100644
--- a/docs/projectconf.rst
+++ b/docs/projectconf.rst
@@ -21,13 +21,73 @@ The Project configuration file is named ``platformio.ini``. This is a
 key / value pairs within the sections. Lines beginning with ``;``
 are ignored and may be used to provide comments.
 
-The sections and their allowable values are described below.
+There are 2 system reserved sections:
+
+* Base PlatformIO settings: :ref:`projectconf_section_platformio`
+* Build Environment settings: :ref:`projectconf_section_env`
+
+The other sections can be used by users, for example, for
+:ref:`projectconf_dynamic_vars`. The sections and their allowable values are
+described below.
 
 .. contents::
+  :depth: 2
+
+.. _projectconf_dynamic_vars:
+
+Dynamic variables
+-----------------
+
+.. versionadded:: 3.1
+
+Dynamic variables/templates are useful when you have common configuration data
+between build environments. For examples, common :ref:`projectconf_build_flags`
+or project dependencies :ref:`projectconf_lib_deps`.
+
+Each variable should have a next format: ``${<section>.<option>}``, where
+``<section>`` is a value from ``[<section>]`` group, and ``<option>`` is a
+first item from pair ``<option> = value``.
+
+* Variable can be applied only for the option's value
+* Multiple variables are allowed
+* The ``platformio`` section is reserved and could not be used as custom
+  section. Some good section names might be ``common`` or ``global``.
+
+Example:
+
+.. code-block:: ini
+
+    [common]
+    build_flags = -D VERSION=1.2.3 -D DEBUG=1
+    lib_deps_builtin = SPI, Wire
+    lib_deps_external = ArduinoJson@>5.6.0
+
+    [env:uno]
+    platform = atmelavr
+    framework = arduino
+    board = uno
+    build_flags = ${common.build_flags}
+    lib_deps = ${common.lib_deps_builtin}, ${common.lib_deps_external}
+
+    [env:nodemcuv2]
+    platform = espressif8266
+    framework = arduino
+    board = nodemcuv2
+    build_flags = ${common.build_flags} -DSSID_NAME=HELLO -DSSID_PASWORD=WORLD
+    lib_deps =
+      ${common.lib_deps_builtin}
+      ${common.lib_deps_external}
+      PubSubClient@2.6
+      OneWire
+
+.. _projectconf_section_platformio:
 
 Section ``[platformio]``
 ------------------------
 
+.. contents::
+    :local:
+
 A ``platformio`` section is used for overriding default configuration options
 
 .. note::
@@ -45,7 +105,8 @@ Options
 ^^^^^^^^^^^^
 
 Is used to store platform toolchains, frameworks, global libraries for
-:ref: `ldf`, service data and etc.
+:ref: `ldf`, service data and etc. The size of this folder will depend on
+number of installed development platforms.
 
 A default value is User's home directory:
 
@@ -55,6 +116,13 @@ A default value is User's home directory:
 This option can be overridden by global environment variable
 :envvar:`PLATFORMIO_HOME_DIR`.
 
+Example:
+
+.. code-block:: ini
+
+    [platformio]
+    home_dir = /path/to/custom/pio/storage
+
 .. _projectconf_pio_lib_dir:
 
 ``lib_dir``
@@ -223,11 +291,14 @@ Multiple environments are allowed if they are separated with ", "
     board = lpmsp430g2553
     build_flags = -D LED_BUILTIN=RED_LED
 
-----------
+.. _projectconf_section_env:
 
 Section ``[env:NAME]``
 ----------------------
 
+.. contents::
+    :local:
+
 A section with ``env:`` prefix is used to define virtual environment with
 specific options that will be processed with :ref:`cmd_run` command. You can
 define unlimited numbers of environments.
@@ -703,6 +774,9 @@ Specify project dependencies that should be installed automatically to
 :ref:`projectconf_pio_libdeps_dir` before environment processing.
 Multiple dependencies are allowed (multi-lines or separated with comma+space ", ").
 
+If you have multiple build environments that depend on the same libraries,
+you can use :ref:`projectconf_dynamic_vars` to use common configuration.
+
 **Valid forms**
 
 .. code-block:: ini
diff --git a/platformio/__init__.py b/platformio/__init__.py
index 5cd7d774..aa5375e8 100644
--- a/platformio/__init__.py
+++ b/platformio/__init__.py
@@ -14,7 +14,7 @@
 
 import sys
 
-VERSION = (3, 1, "0a3")
+VERSION = (3, 1, "0a4")
 __version__ = ".".join([str(s) for s in VERSION])
 
 __title__ = "platformio"
diff --git a/platformio/commands/ci.py b/platformio/commands/ci.py
index cdfc004c..39e328db 100644
--- a/platformio/commands/ci.py
+++ b/platformio/commands/ci.py
@@ -26,12 +26,6 @@ from platformio.commands.init import validate_boards
 from platformio.commands.run import cli as cmd_run
 from platformio.exception import CIBuildEnvsEmpty
 
-# pylint: disable=wrong-import-order
-try:
-    from configparser import ConfigParser
-except ImportError:
-    from ConfigParser import ConfigParser
-
 
 def validate_path(ctx, param, value):  # pylint: disable=unused-argument
     invalid_path = None
@@ -175,9 +169,8 @@ def _exclude_contents(dst_dir, patterns):
 
 
 def _copy_project_conf(build_dir, project_conf):
-    cp = ConfigParser()
-    cp.read(project_conf)
-    if cp.has_section("platformio"):
-        cp.remove_section("platformio")
+    config = util.load_project_config(project_conf)
+    if config.has_section("platformio"):
+        config.remove_section("platformio")
     with open(join(build_dir, "platformio.ini"), "w") as fp:
-        cp.write(fp)
+        config.write(fp)
diff --git a/platformio/commands/run.py b/platformio/commands/run.py
index a07e63b8..676c3924 100644
--- a/platformio/commands/run.py
+++ b/platformio/commands/run.py
@@ -82,12 +82,8 @@ def cli(ctx, environment, target, upload_port, project_dir, silent, verbose,
 
         results = []
         for section in config.sections():
-            # skip main configuration section
-            if section == "platformio":
-                continue
-
             if not section.startswith("env:"):
-                raise exception.InvalidEnvName(section)
+                continue
 
             envname = section[4:]
             skipenv = any([environment and envname not in environment,
diff --git a/platformio/exception.py b/platformio/exception.py
index 478fb515..cafd084b 100644
--- a/platformio/exception.py
+++ b/platformio/exception.py
@@ -131,11 +131,6 @@ class ProjectEnvsNotAvailable(PlatformioException):
     MESSAGE = "Please setup environments in `platformio.ini` file"
 
 
-class InvalidEnvName(PlatformioException):
-
-    MESSAGE = "Invalid environment '{0}'. The name must start with 'env:'"
-
-
 class UnknownEnvNames(PlatformioException):
 
     MESSAGE = "Unknown environment names '{0}'. Valid names are '{1}'"
diff --git a/platformio/util.py b/platformio/util.py
index 19fb8e02..c6d9c273 100644
--- a/platformio/util.py
+++ b/platformio/util.py
@@ -33,13 +33,35 @@ import requests
 
 from platformio import __apiurl__, __version__, exception
 
-# pylint: disable=wrong-import-order
+# pylint: disable=wrong-import-order, too-many-ancestors
+
 try:
     from configparser import ConfigParser
 except ImportError:
     from ConfigParser import ConfigParser
 
 
+class ProjectConfig(ConfigParser):
+
+    VARTPL_RE = re.compile(r"\$\{([^\.\}]+)\.([^\}]+)\}")
+
+    def items(self, section, **_):
+        ConfigParser.items()
+        items = []
+        for option in ConfigParser.options(self, section):
+            items.append((option, self.get(section, option)))
+        return items
+
+    def get(self, section, option, **kwargs):
+        value = ConfigParser.get(self, section, option, **kwargs)
+        if "${" not in value or "}" not in value:
+            return value
+        return self.VARTPL_RE.sub(self._re_sub_handler, value)
+
+    def _re_sub_handler(self, match):
+        return self.get(match.group(1), match.group(2))
+
+
 class AsyncPipe(Thread):
 
     def __init__(self, outcallback=None):
@@ -256,13 +278,15 @@ def get_projectdata_dir():
                                     join(get_project_dir(), "data"))
 
 
-def load_project_config(project_dir=None):
-    if not project_dir:
-        project_dir = get_project_dir()
-    if not is_platformio_project(project_dir):
-        raise exception.NotPlatformIOProject(project_dir)
-    cp = ConfigParser()
-    cp.read(join(project_dir, "platformio.ini"))
+def load_project_config(path=None):
+    if not path or isdir(path):
+        project_dir = path or get_project_dir()
+        if not is_platformio_project(project_dir):
+            raise exception.NotPlatformIOProject(project_dir)
+        path = join(project_dir, "platformio.ini")
+    assert isfile(path)
+    cp = ProjectConfig()
+    cp.read(path)
     return cp