fix(coverage): keep EVM version when normalizing for ir-minimum (#9768)

Author: DaniPopes

crates/config/src/lib.rs

@@ -226,8 +226,11 @@ pub struct Config {
     ///
     /// **Note** for backwards compatibility reasons this also accepts solc_version from the toml
     /// file, see `BackwardsCompatTomlProvider`.
+    ///
+    /// Avoid using this field directly; call the related `solc` methods instead.
+    #[doc(hidden)]
     pub solc: Option<SolcReq>,
-    /// whether to autodetect the solc compiler version to use
+    /// Whether to autodetect the solc compiler version to use.
     pub auto_detect_solc: bool,
     /// Offline mode, if set, network access (downloading solc) is disallowed.
     ///
@@ -801,7 +804,7 @@ impl Config {
 
         self.fs_permissions.join_all(&root);
 
-        if let Some(ref mut model_checker) = self.model_checker {
+        if let Some(model_checker) = &mut self.model_checker {
             model_checker.contracts = std::mem::take(&mut model_checker.contracts)
                 .into_iter()
                 .map(|(path, contracts)| {
@@ -850,12 +853,9 @@ impl Config {
         }
     }
 
-    /// Returns the normalized [EvmVersion] if a [SolcReq] is set to a valid version or if the solc
-    /// path is a valid solc binary.
-    ///
-    /// Otherwise it returns the configured [EvmVersion].
+    /// Returns the normalized [EvmVersion] for the current solc version, or the configured one.
     pub fn get_normalized_evm_version(&self) -> EvmVersion {
-        if let Some(version) = self.solc.as_ref().and_then(|solc| solc.try_version().ok()) {
+        if let Some(version) = self.solc_version() {
             if let Some(evm_version) = self.evm_version.normalize_version_solc(&version) {
                 return evm_version;
             }
@@ -1118,7 +1118,8 @@ impl Config {
                 Err(RecvTimeoutError::Disconnected) => panic!("sender dropped"),
             };
         }
-        if let Some(ref solc) = self.solc {
+
+        if let Some(solc) = &self.solc {
             let solc = match solc {
                 SolcReq::Version(version) => {
                     if let Some(solc) = Solc::find_svm_installed_version(version)? {
@@ -1216,6 +1217,11 @@ impl Config {
         }
     }
 
+    /// Returns the solc version, if any.
+    pub fn solc_version(&self) -> Option<Version> {
+        self.solc.as_ref().and_then(|solc| solc.try_version().ok())
+    }
+
     /// Returns configured [Vyper] compiler.
     pub fn vyper_compiler(&self) -> Result<Option<Vyper>, SolcError> {
         // Only instantiate Vyper if there are any Vyper files in the project.

crates/forge/bin/cmd/coverage.rs

@@ -22,7 +22,7 @@ use foundry_compilers::{
     compilers::multi::MultiCompiler,
     Artifact, ArtifactId, Project, ProjectCompileOutput, ProjectPathsConfig,
 };
-use foundry_config::{Config, SolcReq};
+use foundry_config::Config;
 use rayon::prelude::*;
 use semver::{Version, VersionReq};
 use std::{
@@ -150,32 +150,29 @@ impl CoverageArgs {
                 "See more: https://github.com/foundry-rs/foundry/issues/3357",
             ))?;
 
-            // Enable viaIR with minimum optimization
-            // https://github.com/ethereum/solidity/issues/12533#issuecomment-1013073350
-            // And also in new releases of solidity:
-            // https://github.com/ethereum/solidity/issues/13972#issuecomment-1628632202
+            // Enable viaIR with minimum optimization: https://github.com/ethereum/solidity/issues/12533#issuecomment-1013073350
+            // And also in new releases of Solidity: https://github.com/ethereum/solidity/issues/13972#issuecomment-1628632202
             project.settings.solc.settings =
                 project.settings.solc.settings.with_via_ir_minimum_optimization();
-            let version = if let Some(SolcReq::Version(version)) = &config.solc {
-                version
-            } else {
-                // Sanitize settings for solc 0.8.4 if version cannot be detected.
-                // See <https://github.com/foundry-rs/foundry/issues/9322>.
-                &Version::new(0, 8, 4)
-            };
-            project.settings.solc.settings.sanitize(version, SolcLanguage::Solidity);
+
+            // Sanitize settings for solc 0.8.4 if version cannot be detected: https://github.com/foundry-rs/foundry/issues/9322
+            // But keep the EVM version: https://github.com/ethereum/solidity/issues/15775
+            let evm_version = project.settings.solc.evm_version;
+            let version = config.solc_version().unwrap_or_else(|| Version::new(0, 8, 4));
+            project.settings.solc.settings.sanitize(&version, SolcLanguage::Solidity);
+            project.settings.solc.evm_version = evm_version;
         } else {
             project.settings.solc.optimizer.disable();
             project.settings.solc.optimizer.runs = None;
             project.settings.solc.optimizer.details = None;
             project.settings.solc.via_ir = None;
         }
+
         let mut warning =
             "optimizer settings have been disabled for accurate coverage reports".to_string();
         if !self.ir_minimum {
             warning += ", if you encounter \"stack too deep\" errors, consider using `--ir-minimum` which enables viaIR with minimum optimization resolving most of the errors";
         }
-
         sh_warn!("{warning}")?;
 
         let output = ProjectCompiler::default()