chore(forge): filter out unsupported solidity versions [solar]

crates/cli/src/opts/build/mod.rs

@@ -9,7 +9,7 @@ mod paths;
 pub use self::paths::ProjectPathOpts;
 
 mod utils;
-pub use self::utils::{configure_pcx, configure_pcx_from_compile_output, configure_pcx_from_solc};
+pub use self::utils::*;
 
 // A set of solc compiler settings that can be set via command line arguments, which are intended
 // to be merged into an existing `foundry_config::Config`.

crates/cli/src/opts/build/utils.rs

@@ -7,12 +7,14 @@ use foundry_compilers::{
 };
 use foundry_config::{Config, semver::Version};
 use rayon::prelude::*;
-use solar::sema::ParsingContext;
+use solar::{interface::MIN_SOLIDITY_VERSION as MSV, sema::ParsingContext};
 use std::{
     collections::{HashSet, VecDeque},
     path::{Path, PathBuf},
 };
 
+const MIN_SUPPORTED_VERSION: Version = Version::new(MSV.0, MSV.1, MSV.2);
+
 /// Configures a [`ParsingContext`] from [`Config`].
 ///
 /// - Configures include paths, remappings
@@ -49,7 +51,7 @@ pub fn configure_pcx(
 
     // Only process sources with latest Solidity version to avoid conflicts.
     let graph = Graph::<MultiCompilerParser>::resolve_sources(&project.paths, sources)?;
-    let (version, sources, _) = graph
+    let (version, sources) = graph
         // Resolve graph into mapping language -> version -> sources
         .into_sources_by_version(project)?
         .sources
@@ -59,9 +61,15 @@ pub fn configure_pcx(
         .ok_or_else(|| eyre::eyre!("no Solidity sources"))?
         .1
         .into_iter()
+        // Filter unsupported versions
+        .filter(|(v, _, _)| v >= &MIN_SUPPORTED_VERSION)
         // Always pick the latest version
         .max_by(|(v1, _, _), (v2, _, _)| v1.cmp(v2))
-        .unwrap();
+        .map_or((MIN_SUPPORTED_VERSION, Sources::default()), |(v, s, _)| (v, s));
+
+    if sources.is_empty() {
+        sh_warn!("no files found. Solar doesn't support Solidity versions prior to 0.8.0")?;
+    }
 
     let solc = SolcVersionedInput::build(
         sources,
@@ -75,18 +83,17 @@ pub fn configure_pcx(
     Ok(())
 }
 
-/// Configures a [`ParsingContext`] from a [`ProjectCompileOutput`] and [`SolcVersionedInput`].
+/// Extracts Solar-compatible sources from a [`ProjectCompileOutput`].
 ///
 /// # Note:
 /// uses `output.graph().source_files()` and `output.artifact_ids()` rather than `output.sources()`
 /// because sources aren't populated when build is skipped when there are no changes in the source
 /// code. <https://github.com/foundry-rs/foundry/issues/12018>
-pub fn configure_pcx_from_compile_output(
-    pcx: &mut ParsingContext<'_>,
+pub fn get_solar_sources_from_compile_output(
     config: &Config,
     output: &ProjectCompileOutput,
     target_paths: Option<&[PathBuf]>,
-) -> Result<()> {
+) -> Result<SolcVersionedInput> {
     let is_solidity_file = |path: &Path| -> bool {
         path.extension().and_then(|s| s.to_str()).is_some_and(|ext| SOLC_EXTENSIONS.contains(&ext))
     };
@@ -125,12 +132,14 @@ pub fn configure_pcx_from_compile_output(
 
     // Read all sources and find the latest version.
     let (version, sources) = {
-        let (mut max_version, mut sources) = (Version::new(0, 0, 0), Sources::new());
+        let (mut max_version, mut sources) = (MIN_SUPPORTED_VERSION, Sources::new());
         for (id, _) in output.artifact_ids() {
             if let Ok(path) = dunce::canonicalize(&id.source)
                 && source_paths.remove(&path)
             {
-                if id.version > max_version {
+                if id.version < MIN_SUPPORTED_VERSION {
+                    continue;
+                } else if max_version < id.version {
                     max_version = id.version;
                 };
 
@@ -149,6 +158,17 @@ pub fn configure_pcx_from_compile_output(
         version,
     );
 
+    Ok(solc)
+}
+
+/// Configures a [`ParsingContext`] from a [`ProjectCompileOutput`].
+pub fn configure_pcx_from_compile_output(
+    pcx: &mut ParsingContext<'_>,
+    config: &Config,
+    output: &ProjectCompileOutput,
+    target_paths: Option<&[PathBuf]>,
+) -> Result<()> {
+    let solc = get_solar_sources_from_compile_output(config, output, target_paths)?;
     configure_pcx_from_solc(pcx, &config.project_paths(), &solc, true);
     Ok(())
 }

crates/forge/src/cmd/build.rs

@@ -3,7 +3,7 @@ use clap::Parser;
 use eyre::{Context, Result};
 use forge_lint::{linter::Linter, sol::SolidityLinter};
 use foundry_cli::{
-    opts::BuildOpts,
+    opts::{BuildOpts, configure_pcx_from_solc, get_solar_sources_from_compile_output},
     utils::{LoadConfig, cache_local_signatures},
 };
 use foundry_common::{compile::ProjectCompiler, shell};
@@ -174,10 +174,31 @@ impl BuildArgs {
                 })
                 .collect::<Vec<_>>();
 
-            if !input_files.is_empty() {
-                let compiler = output.parser_mut().solc_mut().compiler_mut();
-                linter.lint(&input_files, config.deny, compiler)?;
+            let solar_sources =
+                get_solar_sources_from_compile_output(config, output, Some(&input_files))?;
+            if solar_sources.input.sources.is_empty() {
+                if !input_files.is_empty() {
+                    sh_warn!(
+                        "unable to lint. Solar only supports Solidity versions prior to 0.8.0"
+                    )?;
+                }
+                return Ok(());
             }
+
+            // NOTE(rusowsky): Once solar can drop unsupported versions, rather than creating a new
+            // compiler, we should reuse the parser from the project output.
+            let mut compiler = solar::sema::Compiler::new(
+                solar::interface::Session::builder().with_stderr_emitter().build(),
+            );
+
+            // Load the solar-compatible sources to the pcx before linting
+            compiler.enter_mut(|compiler| {
+                let mut pcx = compiler.parse();
+                configure_pcx_from_solc(&mut pcx, &config.project_paths(), &solar_sources, true);
+                pcx.set_resolve_imports(true);
+                pcx.parse();
+            });
+            linter.lint(&input_files, config.deny, &mut compiler)?;
         }
 
         Ok(())

crates/forge/src/cmd/lint.rs

@@ -5,7 +5,7 @@ use forge_lint::{
     sol::{SolLint, SolLintError, SolidityLinter},
 };
 use foundry_cli::{
-    opts::BuildOpts,
+    opts::{BuildOpts, configure_pcx_from_solc, get_solar_sources_from_compile_output},
     utils::{FoundryPathExt, LoadConfig},
 };
 use foundry_common::{compile::ProjectCompiler, shell};
@@ -69,15 +69,15 @@ impl LintArgs {
                     } else if path.is_sol() {
                         inputs.push(path.to_path_buf());
                     } else {
-                        warn!("Cannot process path {}", path.display());
+                        warn!("cannot process path {}", path.display());
                     }
                 }
                 inputs
             }
         };
 
         if input.is_empty() {
-            sh_println!("Nothing to lint")?;
+            sh_println!("nothing to lint")?;
             return Ok(());
         }
 
@@ -95,7 +95,7 @@ impl LintArgs {
         let severity = self.severity.unwrap_or(config.lint.severity.clone());
 
         if project.compiler.solc.is_none() {
-            return Err(eyre!("Linting not supported for this language"));
+            return Err(eyre!("linting not supported for this language"));
         }
 
         let linter = SolidityLinter::new(path_config)
@@ -106,9 +106,28 @@ impl LintArgs {
             .with_severity(if severity.is_empty() { None } else { Some(severity) })
             .with_mixed_case_exceptions(&config.lint.mixed_case_exceptions);
 
-        let mut output = ProjectCompiler::new().files(input.iter().cloned()).compile(&project)?;
-        let compiler = output.parser_mut().solc_mut().compiler_mut();
-        linter.lint(&input, config.deny, compiler)?;
+        let output = ProjectCompiler::new().files(input.iter().cloned()).compile(&project)?;
+        let solar_sources = get_solar_sources_from_compile_output(&config, &output, Some(&input))?;
+        if solar_sources.input.sources.is_empty() {
+            return Err(eyre!(
+                "unable to lint. Solar only supports Solidity versions prior to 0.8.0"
+            ));
+        }
+
+        // NOTE(rusowsky): Once solar can drop unsupported versions, rather than creating a new
+        // compiler, we should reuse the parser from the project output.
+        let mut compiler = solar::sema::Compiler::new(
+            solar::interface::Session::builder().with_stderr_emitter().build(),
+        );
+
+        // Load the solar-compatible sources to the pcx before linting
+        compiler.enter_mut(|compiler| {
+            let mut pcx = compiler.parse();
+            pcx.set_resolve_imports(true);
+            configure_pcx_from_solc(&mut pcx, &config.project_paths(), &solar_sources, true);
+            pcx.parse();
+        });
+        linter.lint(&input, config.deny, &mut compiler)?;
 
         Ok(())
     }

crates/forge/src/multi_runner.rs

@@ -575,10 +575,7 @@ impl MultiContractRunnerBuilder {
                 if files.is_empty() { None } else { Some(&files) },
             )?;
             pcx.parse();
-            // Check if any sources exist, to avoid logging `error: no files found`
-            if !compiler.sess().source_map().is_empty() {
-                let _ = compiler.lower_asts();
-            }
+            let _ = compiler.lower_asts();
             Ok(())
         })?;
 

crates/forge/tests/cli/lint.rs

@@ -48,6 +48,10 @@ import { ContractWithLints } from "./ContractWithLints.sol";
 
 import { _PascalCaseInfo } from "./ContractWithLints.sol";
 import "./ContractWithLints.sol";
+
+contract Dummy {
+    bool foo;
+}
 "#;
 
 const COUNTER_A: &str = r#"
@@ -778,3 +782,42 @@ fn ensure_no_privileged_lint_id() {
         assert_ne!(lint.id(), "all", "lint-id 'all' is reserved. Please use a different id");
     }
 }
+
+forgetest!(skips_linting_for_old_solidity_versions, |prj, cmd| {
+    const OLD_CONTRACT: &str = r#"
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.7.0;
+
+contract OldContract {
+    uint256 VARIABLE_MIXED_CASE_INFO;
+
+    function FUNCTION_MIXED_CASE_INFO() public {}
+}
+"#;
+
+    // Add a contract with Solidity 0.7.x which has lint issues
+    prj.add_source("OldContract", OLD_CONTRACT);
+    prj.update_config(|config| {
+        config.lint = LinterConfig {
+            severity: vec![],
+            exclude_lints: vec![],
+            ignore: vec![],
+            lint_on_build: true,
+            ..Default::default()
+        };
+    });
+
+    // Run forge build - should SUCCEED without linting
+    cmd.arg("build").assert_success().stderr_eq(str![[
+        r#"Warning: unable to lint. Solar only supports Solidity versions prior to 0.8.0
+
+"#
+    ]]);
+
+    // Run forge lint - should FAIL
+    cmd.forge_fuse().arg("lint").assert_failure().stderr_eq(str![[
+        r#"Error: unable to lint. Solar only supports Solidity versions prior to 0.8.0
+
+"#
+    ]]);
+});

crates/lint/src/sol/mod.rs

@@ -8,6 +8,7 @@ use foundry_common::{
         inline_config::{InlineConfig, InlineConfigItem},
     },
     errors::convert_solar_errors,
+    sh_warn,
 };
 use foundry_compilers::{ProjectPathsConfig, solc::SolcLanguage};
 use foundry_config::{DenyLevel, lint::Severity};
@@ -258,7 +259,10 @@ impl<'a> Linter for SolidityLinter<'a> {
             input.par_iter().for_each(|path| {
                 let path = &self.path_config.root.join(path);
                 let Some((_, ast_source)) = gcx.get_ast_source(path) else {
-                    panic!("AST source not found for {}", path.display());
+                    // issue a warning rather than panicking, in case that some (but not all) of the
+                    // input files have old solidity versions which are not supported by solar.
+                    _ = sh_warn!("AST source not found for {}", path.display());
+                    return;
                 };
                 let Some(ast) = &ast_source.ast else {
                     panic!("AST missing for {}", path.display());