Merge pull request #10010 from ethereum/develop

Merge develop into breaking.

docs/bugs.json

@@ -1,11 +1,11 @@
 [
-	{
-		"name": "DynamicArrayCleanup",
-		"summary": "When assigning a dynamically-sized array with types of size at most 16 bytes in storage causing the assigned array to shrink, some parts of deleted slots were not zeroed out.",
-		"description": "Consider a dynamically-sized array in storage whose base-type is small enough such that multiple values can be packed into a single slot, such as `uint128[]`. Let us define its length to be `l`. When this array gets assigned from another array with a smaller length, say `m`, the slots between elements `m` and `l` have to be cleaned by zeroing them out. However, this cleaning was not performed properly. Specifically, after the slot corresponding to `m`, only the first packed value was cleaned up. If this array gets resized to a length larger than `m`, the indices corresponding to the unclean parts of the slot contained the original value, instead of 0. The resizing here is performed by assigning to the array `length`, by a `push()` or via inline assembly. You are not affected if you are only using `.push(<arg>)` or if you assign a value (even zero) to the new elements after increasing the length of the array.",
-		"fixed": "0.7.3",
-		"severity": "medium"
-	},
+    {
+        "name": "DynamicArrayCleanup",
+        "summary": "When assigning a dynamically-sized array with types of size at most 16 bytes in storage causing the assigned array to shrink, some parts of deleted slots were not zeroed out.",
+        "description": "Consider a dynamically-sized array in storage whose base-type is small enough such that multiple values can be packed into a single slot, such as `uint128[]`. Let us define its length to be `l`. When this array gets assigned from another array with a smaller length, say `m`, the slots between elements `m` and `l` have to be cleaned by zeroing them out. However, this cleaning was not performed properly. Specifically, after the slot corresponding to `m`, only the first packed value was cleaned up. If this array gets resized to a length larger than `m`, the indices corresponding to the unclean parts of the slot contained the original value, instead of 0. The resizing here is performed by assigning to the array `length`, by a `push()` or via inline assembly. You are not affected if you are only using `.push(<arg>)` or if you assign a value (even zero) to the new elements after increasing the length of the array.",
+        "fixed": "0.7.3",
+        "severity": "medium"
+    },
     {
         "name": "FreeFunctionRedefinition",
         "summary": "The compiler does not flag an error when two or more free functions with the same name and parameter types are defined in a source unit or when an imported free function alias shadows another free function with a different name but identical parameter types.",

docs/control-structures.rst

@@ -519,7 +519,6 @@ An ``assert``-style exception is generated in the following situations:
 #. If you access an array or an array slice at a too large or negative index (i.e. ``x[i]`` where ``i >= x.length`` or ``i < 0``).
 #. If you access a fixed-length ``bytesN`` at a too large or negative index.
 #. If you divide or modulo by zero (e.g. ``5 / 0`` or ``23 % 0``).
-#. If you shift by a negative amount.
 #. If you convert a value too big or negative into an enum type.
 #. If you call a zero-initialized variable of internal function type.
 #. If you call ``assert`` with an argument that evaluates to false.

docs/index.rst

@@ -26,42 +26,58 @@ a 0.x version number `to indicate this fast pace of change <https://semver.org/#
 
 .. warning::
 
-  Solidity recently released the 0.6.x version that introduced a lot of breaking
-  changes. Make sure you read :doc:`the full list <060-breaking-changes>`.
+  Solidity recently released the 0.7.x version that introduced a lot of breaking
+  changes. Make sure you read :doc:`the full list <070-breaking-changes>`.
 
-Language Documentation
-----------------------
+Ideas for improving Solidity or this documentation are always welcome,
+read our :doc:`contributors guide <contributing>` for more details.
 
-If you are new to the concept of smart contracts we recommend you start with
-:ref:`an example smart contract <simple-smart-contract>` written
-in Solidity. When you are ready for more detail, we recommend you read the
-:doc:`"Solidity by Example" <solidity-by-example>` and
-"Language Description" sections to learn the core concepts of the language.
+Getting Started
+---------------
 
-For further reading, try :ref:`the basics of blockchains <blockchain-basics>`
-and details of the :ref:`Ethereum Virtual Machine <the-ethereum-virtual-machine>`.
+**1. Understand the Smart Contract Basics**
+
+If you are new to the concept of smart contracts we recommend you to get started by digging
+into the "Introduction to Smart Contracts" section, which covers:
+* :ref:`A simple example smart contract <simple-smart-contract>` written in Solidity.
+* :ref:`Blockchain Basics <blockchain-basics>`.
+* :ref:`The Ethereum Virtual Machine <the-ethereum-virtual-machine>`.
+
+**2. Get to Know Solidity**
+
+Once you are accustomed to the basics, we recommend you read the :doc:`"Solidity by Example" <solidity-by-example>`
+and “Language Description” sections to understand the core concepts of the language.
+
+**3. Install the Solidity Compiler**
+
+There are various ways to install the Solidity compiler,
+simply choose your preferred option and follow the steps outlined on the :ref:`installation page <installing-solidity>`.
 
 .. hint::
-  You can always try out code examples in your browser with the
+  You can try out code examples directly in your browser with the
   `Remix IDE <https://remix.ethereum.org>`_. Remix is a web browser based IDE
-  that allows you to write Solidity smart contracts, then deploy and run the
-  smart contracts. It can take a while to load, so please be patient.
+  that allows you to write, deploy and administer Solidity smart contracts, without
+  the need to install Solidity locally.
 
 .. warning::
     As humans write software, it can have bugs. You should follow established
-    software development best-practices when writing your smart contracts, this
+    software development best-practices when writing your smart contracts. This
     includes code review, testing, audits, and correctness proofs. Smart contract
     users are sometimes more confident with code than their authors, and
     blockchains and smart contracts have their own unique issues to
     watch out for, so before working on production code, make sure you read the
     :ref:`security_considerations` section.
 
-If you have any questions, you can try searching for answers or asking on the
-`Ethereum Stackexchange <https://ethereum.stackexchange.com/>`_, or
-our `gitter channel <https://gitter.im/ethereum/solidity/>`_.
+**4. Learn More**
 
-Ideas for improving Solidity or this documentation are always welcome,
-read our :doc:`contributors guide <contributing>` for more details.
+If you want to learn more about building decentralized applications on Ethereum, the
+`Ethereum Developer Resources <https://ethereum.org/en/developers/>`_
+can help you with further general documentation around Ethereum, and a wide selection of tutorials,
+tools and development frameworks.
+
+If you have any questions, you can try searching for answers or asking on the
+`Ethereum StackExchange <https://ethereum.stackexchange.com/>`_, or
+our `Gitter channel <https://gitter.im/ethereum/solidity/>`_.
 
 .. _translations:
 

docs/layout-of-source-files.rst

@@ -111,6 +111,14 @@ activate it using ``pragma experimental ABIEncoderV2;`` - we kept
 the same pragma, even though it is not considered experimental
 anymore.
 
+The set of types supported by the new encoder is a strict superset of
+the ones supported by the old one. Contracts that use it can interact with ones
+that do not without limitations. The reverse is possible only as long as the
+non-``ABIEncoderV2`` contract does not try to make calls that would require
+decoding types only supported by the new encoder. The compiler can detect this
+and will issue an error. Simply enabling ``ABIEncoderV2`` for your contract is
+enough to make the error go away.
+
 .. _smt_checker:
 
 SMTChecker