variables reevaluate block.timestamp when called

[FredCoen]

Component

Forge

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (49f35c7 2022-06-30T00:06:55.326479Z)

What command(s) is the bug in?

No response

Operating System

macOS (Apple Silicon)

Describe the bug

uint256 a = block.timestamp;
console2.log(a);
vm.warp(a+1);
console2.log(a);

This snippet prints 1 and 2 to the console. Seems block.timestamp gets reevaluated instead of using the stored value for a from the stack? Is this expected behaviour?

[onbjerg]

It's a Solidity optimization we can't get around. The compiler assumes block.timestamp evaluates to a constant so instead of pushing the value on the stack it just replaces all occurrences of a with a call to the TIMESTAMP opcode.

[FredCoen]

i see thanks @onbjerg is that the case even without the optimization pipeline?

[onbjerg]

I don't think so, but I'm not sure - this was reported once before in this issue: #1373 There is some additional context in there, but no clear solution