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irgen built a slice's data as a read and a write, and a read or write moves at most one word, so only the first 32 bytes were copied. Add a copy IR instruction (CALLDATACOPY from calldata, MCOPY from memory) and emit it for the slice's data.
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* bugc: compile `!` as a logical not * bugc: link the changelog entry to #353 * bugc: end each source range at its last token * bugc: link the changelog entry to #362 * bugc: add block.prevrandao * bugc: link the changelog entries to #363 * bugc: hash several value-type words with keccak256 * bugc: link the changelog entries to #365 * bugc: slice a fixed-size bytes value by its bytes * bugc: link the changelog entry to #357 * bugc: hash the data of dynamic bytes and strings * bugc: link the changelog entry to #360 * bugc: give a caller's call JUMP the invoke's arguments * bugc: list variables before a function's first statement * bugc: store a memory string's bytes when assigning it to storage A storage write took its value as a word, so a memory string or bytes reference wrote its memory address into the slot. Code generation now encodes the referenced bytes as Solidity does: inline with length * 2 up to 31 bytes, else length * 2 + 1 in the slot and the data from keccak256(slot), with the last word's trailing bytes cleared. A slice now carries the bytes type, so its value is recognized too. * bugc: link the changelog entry to #355 * bugc: say why the bytes test slices without naming the copy width * bugc: copy all of a slice's bytes irgen built a slice's data as a read and a write, and a read or write moves at most one word, so only the first 32 bytes were copied. Add a copy IR instruction (CALLDATACOPY from calldata, MCOPY from memory) and emit it for the slice's data. * bugc: link the changelog entries to #359 * bugc: copy a struct read from storage into memory * bugc: link the changelog entries to #361 * bugc: lay storage arrays out as Solidity does * bugc: add push to dynamic arrays in storage
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A slice copied only its first 32 bytes.
msg.data[4:]with 100 bytes of calldata, orm[1:40]of a longer memorybytes, had the right length but zeros after byte 32. irgen built the slice's data as areadfrom the source and awriteto the new memory, and a read or write moves at most one word.This adds a
copyIR instruction: copylengthbytes fromsourcein memory or calldata to memory atoffset. It compiles toMCOPYfrom memory andCALLDATACOPYfrom calldata, so a slice costs the same code at any length. A slice now emitscopyin place of the read and write. The optimizer passes, liveness and memory analysis treat it as a memory write with three operands, and the IR formatter and the bugc-react IR view print it asmemory[offset: %d, length: %n] = copy calldata[%s].The new test slices
msg.dataand a memorybytesto 0, 31, 32, 33 and 100 bytes at levels 0 to 3, and reads every byte back. A new local-variable soundness case has a 34-byte slice local, whose pointer did not read the program's value before this change. Bytecode and debug info change only for the programs inexamples/that slice.