diff options
Diffstat (limited to 'docs/yul.rst')
| -rw-r--r-- | docs/yul.rst | 52 |
1 files changed, 41 insertions, 11 deletions
diff --git a/docs/yul.rst b/docs/yul.rst index 9e9fac8e..9e50f126 100644 --- a/docs/yul.rst +++ b/docs/yul.rst @@ -369,10 +369,10 @@ The following functions must be available: +---------------------------------------------+-----------------------------------------------------------------+ | gtu256(x:u256, y:u256) -> z:bool | true if x > y, false otherwise | +---------------------------------------------+-----------------------------------------------------------------+ -| sltu256(x:s256, y:s256) -> z:bool | true if x < y, false otherwise | +| lts256(x:s256, y:s256) -> z:bool | true if x < y, false otherwise | | | (for signed numbers in two's complement) | +---------------------------------------------+-----------------------------------------------------------------+ -| sgtu256(x:s256, y:s256) -> z:bool | true if x > y, false otherwise | +| gts256(x:s256, y:s256) -> z:bool | true if x > y, false otherwise | | | (for signed numbers in two's complement) | +---------------------------------------------+-----------------------------------------------------------------+ | equ256(x:u256, y:u256) -> z:bool | true if x == y, false otherwise | @@ -391,7 +391,7 @@ The following functions must be available: +---------------------------------------------+-----------------------------------------------------------------+ | shru256(x:u256, y:u256) -> z:u256 | logical right shift of x by y | +---------------------------------------------+-----------------------------------------------------------------+ -| saru256(x:u256, y:u256) -> z:u256 | arithmetic right shift of x by y | +| sars256(x:s256, y:u256) -> z:u256 | arithmetic right shift of x by y | +---------------------------------------------+-----------------------------------------------------------------+ | byte(n:u256, x:u256) -> v:u256 | nth byte of x, where the most significant byte is the 0th byte | | | Cannot this be just replaced by and256(shr256(n, x), 0xff) and | @@ -515,6 +515,16 @@ The following functions must be available: +---------------------------------------------+-----------------------------------------------------------------+ | keccak256(p:u256, s:u256) -> v:u256 | keccak(mem[p...(p+s))) | +---------------------------------------------+-----------------------------------------------------------------+ +| *Object access* | | ++---------------------------------------------+-----------------------------------------------------------------+ +| datasize(name:string) -> size:u256 | size of the data object in bytes, name has to be string literal | ++---------------------------------------------+-----------------------------------------------------------------+ +| dataoffset(name:string) -> offset:u256 | offset of the data object inside the data area in bytes, | +| | name has to be string literal | ++---------------------------------------------+-----------------------------------------------------------------+ +| datacopy(dst:u256, src:u256, len:u256) | copy len bytes from the data area starting at offset src bytes | +| | to memory at position dst | ++---------------------------------------------+-----------------------------------------------------------------+ Backends -------- @@ -540,12 +550,18 @@ TBD Specification of Yul Object =========================== +Yul objects are used to group named code and data sections. +The functions ``datasize``, ``dataoffset`` and ``datacopy`` +can be used to access these sections from within code. +Hex strings can be used to specify data in hex encoding, +regular strings in native encoding. For code, +``datacopy`` will access its assembled binary representation. + Grammar:: - TopLevelObject = 'object' '{' Code? ( Object | Data )* '}' - Object = 'object' StringLiteral '{' Code? ( Object | Data )* '}' + Object = 'object' StringLiteral '{' Code ( Object | Data )* '}' Code = 'code' Block - Data = 'data' StringLiteral HexLiteral + Data = 'data' StringLiteral ( HexLiteral | StringLiteral ) HexLiteral = 'hex' ('"' ([0-9a-fA-F]{2})* '"' | '\'' ([0-9a-fA-F]{2})* '\'') StringLiteral = '"' ([^"\r\n\\] | '\\' .)* '"' @@ -558,14 +574,28 @@ An example Yul Object is shown below: // Code consists of a single object. A single "code" node is the code of the object. // Every (other) named object or data section is serialized and // made accessible to the special built-in functions datacopy / dataoffset / datasize - object { + // Access to nested objects can be performed by joining the names using ``.``. + // The current object and sub-objects and data items inside the current object + // are in scope without nested access. + object "Contract1" { code { - let size = datasize("runtime") + // first create "runtime.Contract2" + let size = datasize("runtime.Contract2") let offset = allocate(size) // This will turn into a memory->memory copy for eWASM and // a codecopy for EVM - datacopy(dataoffset("runtime"), offset, size) - // this is a constructor and the runtime code is returned + datacopy(offset, dataoffset("runtime.Contract2"), size) + // constructor parameter is a single number 0x1234 + mstore(add(offset, size), 0x1234) + create(offset, add(size, 32)) + + // now return the runtime object (this is + // constructor code) + size := datasize("runtime") + offset := allocate(size) + // This will turn into a memory->memory copy for eWASM and + // a codecopy for EVM + datacopy(offset, dataoffset("runtime"), size) return(offset, size) } @@ -579,7 +609,7 @@ An example Yul Object is shown below: let offset = allocate(size) // This will turn into a memory->memory copy for eWASM and // a codecopy for EVM - datacopy(dataoffset("Contract2"), offset, size) + datacopy(offset, dataoffset("Contract2"), size) // constructor parameter is a single number 0x1234 mstore(add(offset, size), 0x1234) create(offset, add(size, 32)) |