Compiler option revert-strings with value strip has different treatments in legacy and IR pipeline #16465
Description
Description
The compiler option revert-strings in CLI or revertStrings in standard JSON Input/Output when configured with the value "strip" produces different code depending on the legacy or IR pipeline.
While the IR pipeline removes strings and custom errors from the generated code for require, the legacy pipeline will only remove strings.
In both pipelines, the branch for the false condition of require generates a revert, so the behavior of the code is the same, but legacy pipeline will not suppress the custom error. This creates a "semantic" difference between the pipelines.
Steps to Reproduce
Use this Solidity code
error MyError(string emsg);
contract C {
function f() pure external {
require(false, MyError("abc"));
}
}compile with both pipelines and then check the generated code to verify that in legacy the custom error is present as argument to a revert instruction:
Legacy pipeline
solc test.sol --debug-info none --revert-strings strip --asm
generated assembly:
mstore(0x40, 0x80)
callvalue
dup1
iszero
tag_1
jumpi
revert(0x00, 0x00)
tag_1:
pop
dataSize(sub_0)
dup1
dataOffset(sub_0)
0x00
codecopy
0x00
return
stop
sub_0: assembly {
mstore(0x40, 0x80)
callvalue
dup1
iszero
tag_1
jumpi
revert(0x00, 0x00)
tag_1:
pop
jumpi(tag_2, lt(calldatasize, 0x04))
shr(0xe0, calldataload(0x00))
dup1
0x26121ff0
eq
tag_3
jumpi
tag_2:
revert(0x00, 0x00)
tag_3:
tag_4
tag_5
jump // in
tag_4:
stop
tag_5:
mload(0x40)
shl(0xe0, 0x8b3d2d43)
dup2
mstore
0x20
0x04
dup3
add
mstore
0x03
0x24
dup3
add
mstore
shl(0xe8, 0x616263)
0x44
dup3
add
mstore
0x64
add
mload(0x40)
dup1
swap2
sub
swap1
revert
auxdata: 0xa26469706673582212201cbe11542190a594b908ff4413cc2ee54cfe3d65d7c38cf79ccf95d10fdfc24064736f6c63430008210033
}
IR pipeline
solc test.sol --debug-info none --revert-strings strip --asm --via-ir
generated assembly:
EVM assembly:
0x80
dup1
0x40
mstore
jumpi(tag_1, callvalue)
dataSize(sub_0)
swap1
dup2
dataOffset(sub_0)
dup3
codecopy
return
tag_1:
0x00
dup1
revert
stop
sub_0: assembly {
0x00
dup1
revert
auxdata: 0xa2646970667358221220bd58da9e3f0aafbdbaf47ad5b1a5e02d60030b3e4811bc3e1aa83946e06b77ca64736f6c63430008210033
}