solc auto-detect not working as expected

[moodmosaic]

Φοβερή δουλειά! Great job!

It looks like forge's solc auto-detect not working as expected(?)

I just run

cargo install --git https://github.com/gakonst/foundry --bin forge --locked

followed by

forge init

then

forge build

then replaced what's inside src/Contract.sol with the following (notice ^0.4.0)

// SPDX-License-Identifier: Unlicense
pragma solidity ^0.4.0;

contract Counter {
    uint public count;

    // Function to get the current count.
    function get() public returns (uint) {
        return count;
    }

    // Function to increment count by 1.
    function inc() public {
        count += 1;
    }

    // Function to decrement count by 1.
    function dec() public {
        count -= 1;
    }
}

and then on purpose I declared get() as view which I would expect to break with ^0.4.0

diff --git a/src/Contract.sol b/src/Contract.sol
index c116a9e..cdf66eb 100644
--- a/src/Contract.sol
+++ b/src/Contract.sol
@@ -5,7 +5,7 @@ contract Counter {
     uint public count;

     // Function to get the current count
-    function get() public returns (uint) {
+    function get() public view returns (uint) {
         return count;
     }

run

forge build

and got success. instead of a compilation error (e.g. Remix gives an error since view doesn't exist in ^0.4.0.

---

Expected output:

src/Contract.sol:9:27: Error: Expected token LBrace got 'View'
    function get() public view returns (uint) {
                          ^

Actual output:

success.

[mattsse]

can you try running with RUST_LOG=ethers=trace this should show you the solc being used.

Auto-detection is based on semver, and ^4.0.0 allows everything from 4.0.0 to <5.0.0.

So solc will try to find a compatible, already downloaded, solc install

It seems like that this doesn't necessarily hold for solc though

[moodmosaic]

@mattsse, thanks for the quick response. Here's the output:

Dec 11 12:29:57.354 TRACE compile: ethers_solc: sources
Dec 11 12:29:57.356 TRACE compile: ethers_solc: done
Dec 11 12:29:57.356 TRACE compile: ethers_solc: auto-compile
Dec 11 12:29:57.357 TRACE compile:svm_compile: ethers_solc: detecting solc version for "../forge/src/Contract.sol"
Dec 11 12:29:57.395 TRACE compile:svm_compile: ethers_solc: found installed solc "0.4.26"
Dec 11 12:29:57.398 TRACE compile:svm_compile: ethers_solc: detecting solc version for "../forge/src/test/Contract.t.sol"
Dec 11 12:29:57.398 TRACE compile:svm_compile: ethers_solc: found installed solc "0.8.10"
Dec 11 12:29:57.400 TRACE compile:svm_compile: ethers_solc: compiling sources with viable solc versions
Dec 11 12:29:57.857 TRACE compile:svm_compile:solc{0.4.26}: ethers_solc: compiling_with_version
Dec 11 12:29:57.858 TRACE compile:svm_compile:solc{0.4.26}:compiling: ethers_solc: resolving libraries
Dec 11 12:29:57.859 TRACE compile:svm_compile:solc{0.4.26}:compiling: ethers_solc: resolved libraries
Dec 11 12:29:57.860 TRACE compile:svm_compile:solc{0.4.26}:compiling: ethers_solc: reading solfiles cache for incremental compilation
Dec 11 12:29:57.861 TRACE compile:svm_compile:solc{0.4.26}:compiling:sol-files-cache::read: ethers_solc::cache: reading solfiles cache at ../forge/cache/solidity-files-cache.json
Dec 11 12:29:57.862 TRACE compile:svm_compile:solc{0.4.26}:compiling:sol-files-cache::read: ethers_solc::cache: done
Dec 11 12:29:57.863 TRACE compile:svm_compile:solc{0.4.26}:compiling: ethers_solc: done reading solfiles cache for incremental compilation
Dec 11 12:29:57.864 TRACE compile:svm_compile:solc{0.4.26}:compiling: ethers_solc: reading artifacts from cache..
Dec 11 12:29:57.899 TRACE compile:svm_compile:solc{0.4.26}:compiling: ethers_solc: done reading artifacts from cache
Dec 11 12:29:57.900 TRACE compile:svm_compile:solc{0.4.26}:compiling: ethers_solc: no change
Dec 11 12:29:57.901 TRACE compile:svm_compile:solc{0.4.26}: ethers_solc: done compiling_with_version
Dec 11 12:29:58.041 TRACE compile:svm_compile:solc{0.8.10}: ethers_solc: compiling_with_version
Dec 11 12:29:58.042 TRACE compile:svm_compile:solc{0.8.10}:compiling: ethers_solc: resolving libraries
Dec 11 12:29:58.043 TRACE compile:svm_compile:solc{0.8.10}:compiling: ethers_solc: resolved libraries
Dec 11 12:29:58.046 TRACE compile:svm_compile:solc{0.8.10}:compiling: ethers_solc: reading solfiles cache for incremental compilation
Dec 11 12:29:58.047 TRACE compile:svm_compile:solc{0.8.10}:compiling:sol-files-cache::read: ethers_solc::cache: reading solfiles cache at ../forge/cache/solidity-files-cache.json
Dec 11 12:29:58.049 TRACE compile:svm_compile:solc{0.8.10}:compiling:sol-files-cache::read: ethers_solc::cache: done
Dec 11 12:29:58.050 TRACE compile:svm_compile:solc{0.8.10}:compiling: ethers_solc: done reading solfiles cache for incremental compilation
Dec 11 12:29:58.054 TRACE compile:svm_compile:solc{0.8.10}:compiling: ethers_solc: reading artifacts from cache..
Dec 11 12:29:58.097 TRACE compile:svm_compile:solc{0.8.10}:compiling: ethers_solc: done reading artifacts from cache
Dec 11 12:29:58.098 TRACE compile:svm_compile:solc{0.8.10}:compiling: ethers_solc: no change
Dec 11 12:29:58.099 TRACE compile:svm_compile:solc{0.8.10}: ethers_solc: done compiling_with_version
Dec 11 12:29:58.100 TRACE compile:svm_compile: ethers_solc: compiled sources with viable solc versions
no files changed, compilation skippped.

[moodmosaic]

Hmm... I guess it'll favor the solc used in the test(s)?

[mattsse]

yes, forge test only deploys contracts with test* functions.
And it seems your test/Contract.t.sol allows 0.8.10?

There are currently some limitations when it comes to dependency graphs, so if you could share the imports and pragma of test/Contract.t.sol, that'd be helpful.

[moodmosaic]

// SPDX-License-Identifier: Unlicense
pragma solidity 0.8.10;

import "ds-test/test.sol";

Something tells me that view simply exists in 0.4.26 (which is the one that's picked up by forge build as per the above output).

[moodmosaic]

Yes! If I specify pragma solidity 0.4.0; then indeed it fails:

diff --git a/src/Contract.sol b/src/Contract.sol
index c116a9e..3ee7dc0 100644
--- a/src/Contract.sol
+++ b/src/Contract.sol
@@ -1,11 +1,11 @@
 // SPDX-License-Identifier: Unlicense
-pragma solidity ^0.4.0;
+pragma solidity 0.4.0;

 contract Counter {
     uint public count;

     // Function to get the current count
-    function get() public returns (uint) {
+    function get() public view returns (uint) {
         return count;
     }

---

It'd be nice if we could get the actual compiler error/output from forge build but I guess that's for a separate issue:

$ RUST_LOG=ethers=trace forge build
Dec 11 12:50:30.638 TRACE compile: ethers_solc: sources
Dec 11 12:50:30.640 TRACE compile: ethers_solc: done
Dec 11 12:50:30.640 TRACE compile: ethers_solc: auto-compile
Dec 11 12:50:30.641 TRACE compile:svm_compile: ethers_solc: detecting solc version for "../src/Contract.sol"
Dec 11 12:50:30.698 TRACE compile:svm_compile: ethers_solc: found installed solc "0.4.0"
Dec 11 12:50:30.706 TRACE compile:svm_compile: ethers_solc: detecting solc version for "../src/test/Contract.t.sol"
Dec 11 12:50:30.708 TRACE compile:svm_compile: ethers_solc: found installed solc "0.8.10"
Dec 11 12:50:30.712 TRACE compile:svm_compile: ethers_solc: compiling sources with viable solc versions
Dec 11 12:50:31.340 TRACE compile:svm_compile:solc{0.4.0}: ethers_solc: compiling_with_version
Dec 11 12:50:31.341 TRACE compile:svm_compile:solc{0.4.0}:compiling: ethers_solc: resolving libraries
Dec 11 12:50:31.342 TRACE compile:svm_compile:solc{0.4.0}:compiling: ethers_solc: resolved libraries
Dec 11 12:50:31.343 TRACE compile:svm_compile:solc{0.4.0}:compiling: ethers_solc: reading solfiles cache for incremental compilation
Dec 11 12:50:31.344 TRACE compile:svm_compile:solc{0.4.0}:compiling:sol-files-cache::read: ethers_solc::cache: reading solfiles cache at ../cache/solidity-files-cache.json
Dec 11 12:50:31.345 TRACE compile:svm_compile:solc{0.4.0}:compiling:sol-files-cache::read: ethers_solc::cache: done
Dec 11 12:50:31.346 TRACE compile:svm_compile:solc{0.4.0}:compiling: ethers_solc: done reading solfiles cache for incremental compilation
Dec 11 12:50:31.347 TRACE compile:svm_compile:solc{0.4.0}:compiling: ethers_solc: reading artifacts from cache..
Dec 11 12:50:31.389 TRACE compile:svm_compile:solc{0.4.0}:compiling: ethers_solc: done reading artifacts from cache
Dec 11 12:50:31.421 TRACE compile:svm_compile:solc{0.4.0}:compiling: ethers_solc: calling solc
Error: EOF while parsing a value at line 1 column 0

Location:
    /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/result.rs:1914:27

Expected output:

src/Contract.sol:9:27: Error: Expected token LBrace got 'View'
    function get() public view returns (uint) {
                          ^

Actual output:

Error: EOF while parsing a value at line 1 column 0

Location:
    /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/result.rs:1914:27

[mattsse]

any chance you built with hardhat in the meantime?

[moodmosaic]

any chance you built with hardhat in the meantime?

Sure.

However, on the expected/actual solc output above, do you think I should open an issue?

[mattsse]

I think the root problem is, that solc not necessarily abide to semver rules.
perhaps our auto detection is too optimistic in some scenarios, we're using https://github.com/roynalnaruto/svm-rs so you can also install svm install "0.4.0" manually which should then be picked up

[moodmosaic]

I think I finally got forge build to error out, it's just that the error isn't the actual solc compiler output/error:

Expected output:

src/Contract.sol:9:27: Error: Expected token LBrace got 'View'
    function get() public view returns (uint) {
                          ^

Actual output:

Error: EOF while parsing a value at line 1 column 0

Location:
    /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/result.rs:1914:27

Ping me and I'll make an issue for it. Closing this one for now.

[mattsse]

any chance you built with hardhat in the meantime?

Sure.

ethers-solc uses a different artifact format by default, but the same cache format as hardhat, so this can happen, I think we should find a way around that

However, on the expected/actual solc output above, do you think I should open an issue?

I think It's worth discussing if we want to follow always semver or if we need some additional checks, +1