solidity/Changelog.md

0.4.0 (unreleased)

This release deliberately breaks backwards compatibility mostly to enforce some safety features. The most important change is ...

Breaking Changes:

• Source files have to specify the compiler version they are compatible with using e.g. pragma solidity ^0.4.0; or pragma solidity >=0.4.0 <0.4.8;
• Contracts that want to receive Ether have to implement a fallback function (contracts now throw if no fallback function is defined and no function matches the signature).
• Failing contract creation through "new" throws now.
• Throw on division / modulus by zero
• Function call throws if target contract does not have code
• Modifiers are required to contain _ (use if (false) _ as a workaround if needed).
• Modifiers: return does not skip part in modifier after _
• Placeholder statement _ in modifier now requires explicit ;.
• ecrecover now returns zero if the input is malformed (it previously returned garbage)
• Removed --interface (Solidity interface) output option
• JSON AST: General cleanup, renamed many nodes to match their C++ names.
• Json Output: srcmap-runtime renamed to srcmapRuntime
• Moved (and reworked) standard library contracts from inside the compiler to github.com/ethereum/solidity/std (import "std"; or import owned; do not work anymore).
• Confusing and undocumented keyword "after" was removed.
• New reserved words: hex, payable, abstract, static, interface

Features:

• Hexadecimal string literals: hex"ab1248fe"
• Internal: Inline assembly usable by the code generator.
• Commandline interface: Using - as filename allows reading from stdin.
• Interface Json: Fallback function is now part of the ABI.
• Interface: Version string now semver compatible.
• Code generator: Do not provide "new account gas" if we know the called account exists.

Bugfixes:

• JSON AST: nodes were added at wrong parent
• Why3 translator: crash fix for exponentiation
• Type Checker: Fallback function cannot return data anymore.
• Code Generator: Fix crash when sha3() was used on unsupported types.
• Code Generator: Manually set gas stipend for .send(0).

Lots of changes to the documentation mainly by voluntary external contributors.

0.3.6 (2016-08-10)

Features:

• Formal verification: Take external effects on a contract into account.
• Type Checker: Warning about unused return value of low-level calls and send.
• Output: Source location and node id as part of AST output
• Output: Source location mappings for bytecode
• Output: Formal verification as part of json compiler output.

Bugfixes:

• Commandline Interface: Do not crash if input is taken from stdin.
• Scanner: Correctly support unicode escape codes in strings.
• JSON output: Fix error about relative / absolute source file names.
• JSON output: Fix error about invalid utf8 strings.
• Code Generator: Dynamic allocation of empty array caused infinite loop.
• Code Generator: Correctly calculate gas requirements for memcpy precompile.
• Optimizer: Clear known state if two code paths are joined.

0.3.5 (2016-06-10)

Features:

• Context-dependent path remappings (different modules can use the same library in different versions)

Bugfixes:

• Type Checking: Dynamic return types were removed when fetching data from external calls, now they are replaced by an "unusable" type.
• Type Checking: Overrides by constructors were considered making a function non-abstract.

0.3.4 (2016-05-31)

No change outside documentation.

0.3.3 (2016-05-27)

• Allow internal library functions to be called (by "inlining")
• Fractional/rational constants (only usable with fixed point types, which are still in progress)
• Inline assembly has access to internal functions (as jump labels)
• Running solc without arguments on a terminal will print help.
• Bugfix: Remove some non-determinism in code generation.
• Bugfix: Corrected usage of not / bnot / iszero in inline assembly
• Bugfix: Correctly clean bytesNN types before comparison

0.3.2 (2016-04-18)

• Bugfix: Inline assembly parser: byte opcode was unusable
• Bugfix: Error reporting: tokens for variably-sized types were not converted to string properly
• Bugfix: Dynamic arrays of structs were not deleted correctly.
• Bugfix: Static arrays in constructor parameter list were not decoded correctly.

0.3.1 (2016-03-31)

• Inline assembly
• Bugfix: Code generation: array access with narrow types did not clean higher order bits
• Bugfix: Error reporting: error reporting with unknown source location caused a crash

0.3.0 (2016-03-11)

BREAKING CHANGES:

• Added new keywords assembly, foreign, fixed, ufixed, fixedNxM, ufixedNxM (for various values of M and N), timestamp
• Number constant division does not round to integer, but to a fixed point type (e.g. 1 / 2 != 1, but 1 / 2 == 0.5).
• Library calls now default to use DELEGATECALL (e.g. called library functions see the same value as the calling function for msg.value and msg.sender).
• <address>.delegatecall as a low-level calling interface

Bugfixes:

• Fixed a bug in the optimizer that resulted in comparisons being wrong.

0.2.2 (2016-02-17)

• Index access for types bytes1, ..., bytes32 (only read access for now).
• Bugfix: Type checker crash for wrong number of base constructor parameters.

0.2.1 (2016-01-30)

• Inline arrays, i.e. var y = [1,x,f()]; if there is a common type for 1, x and f(). Note that the result is always a fixed-length memory array and conversion to dynamic-length memory arrays is not yet possible.
• Import similar to ECMAScript6 import (import "abc.sol" as d and import {x, y} from "abc.sol").
• Commandline compiler solc automatically resolves missing imports and allows for "include directories".
• Conditional: x ? y : z
• Bugfix: Fixed several bugs where the optimizer generated invalid code.
• Bugfix: Enums and structs were not accessible to other contracts.
• Bugfix: Fixed segfault connected to function paramater types, appeared during gas estimation.
• Bugfix: Type checker crash for wrong number of base constructor parameters.
• Bugfix: Allow function overloads with different array types.
• Bugfix: Allow assignments of type (x) = 7.
• Bugfix: Type uint176 was not available.
• Bugfix: Fixed crash during type checking concerning constructor calls.
• Bugfix: Fixed crash during code generation concerning invalid accessors for struct types.
• Bugfix: Fixed crash during code generating concerning computing a hash of a struct type.

0.2.0 (2015-12-02)

• Breaking Change: new ContractName.value(10)() has to be written as (new ContractName).value(10)()
• Added selfdestruct as an alias for suicide.
• Allocation of memory arrays using new.
• Binding library functions to types via using x for y
• addmod and mulmod (modular addition and modular multiplication with arbitrary intermediate precision)
• Bugfix: Constructor arguments of fixed array type were not read correctly.
• Bugfix: Memory allocation of structs containing arrays or strings.
• Bugfix: Data location for explicit memory parameters in libraries was set to storage.

0.1.7 (2015-11-17)

• Improved error messages for unexpected tokens.
• Proof-of-concept transcompilation to why3 for formal verification of contracts.
• Bugfix: Arrays (also strings) as indexed parameters of events.
• Bugfix: Writing to elements of bytes or string overwrite others.
• Bugfix: "Successor block not found" on Windows.
• Bugfix: Using string literals in tuples.
• Bugfix: Cope with invalid commit hash in version for libraries.
• Bugfix: Some test framework fixes on windows.

0.1.6 (2015-10-16)

• .push() for dynamic storage arrays.
• Tuple expressions ((1,2,3) or return (1,2,3);)
• Declaration and assignment of multiple variables (var (x,y,) = (1,2,3,4,5); or var (x,y) = f();)
• Destructuring assignment ((x,y,) = (1,2,3))
• Bugfix: Internal error about usage of library function with invalid types.
• Bugfix: Correctly parse Library.structType a at statement level.
• Bugfix: Correctly report source locations of parenthesized expressions (as part of "tuple" story).

0.1.5 (2015-10-07)

• Breaking change in storage encoding: Encode short byte arrays and strings together with their length in storage.
• Report warnings
• Allow storage reference types for public library functions.
• Access to types declared in other contracts and libraries via ..
• Version stamp at beginning of runtime bytecode of libraries.
• Bugfix: Problem with initialized string state variables and dynamic data in constructor.
• Bugfix: Resolve dependencies concerning new automatically.
• Bugfix: Allow four indexed arguments for anonymous events.
• Bugfix: Detect too large integer constants in functions that accept arbitrary parameters.

0.1.4 (2015-09-30)

• Bugfix: Returning fixed-size arrays.
• Bugfix: combined-json output of solc.
• Bugfix: Accessing fixed-size array return values.
• Bugfix: Disallow assignment from literal strings to storage pointers.
• Refactoring: Move type checking into its own module.

0.1.3 (2015-09-25)

• throw statement.
• Libraries that contain functions which are called via CALLCODE.
• Linker stage for compiler to insert other contract's addresses (used for libraries).
• Compiler option to output runtime part of contracts.
• Compile-time out of bounds check for access to fixed-size arrays by integer constants.
• Version string includes libevmasm/libethereum's version (contains the optimizer).
• Bugfix: Accessors for constant public state variables.
• Bugfix: Propagate exceptions in clone contracts.
• Bugfix: Empty single-line comments are now treated properly.
• Bugfix: Properly check the number of indexed arguments for events.
• Bugfix: Strings in struct constructors.

0.1.2 (2015-08-20)

• Improved commandline interface.
• Explicit conversion between bytes and string.
• Bugfix: Value transfer used in clone contracts.
• Bugfix: Problem with strings as mapping keys.
• Bugfix: Prevent usage of some operators.

0.1.1 (2015-08-04)

• Strings can be used as mapping keys.
• Clone contracts.
• Mapping members are skipped for structs in memory.
• Use only a single stack slot for storage references.
• Improved error message for wrong argument count. (#2456)
• Bugfix: Fix comparison between bytesXX types. (#2087)
• Bugfix: Do not allow floats for integer literals. (#2078)
• Bugfix: Some problem with many local variables. (#2478)
• Bugfix: Correctly initialise string and bytes state variables.
• Bugfix: Correctly compute gas requirements for callcode.

0.1.0 (2015-07-10)