fix: pass sancov or sancov-module

.gitignore

@@ -13,4 +13,4 @@ result
 flake.lock
 
 # vim
-**/*.rs.bk
+**/*.rs.bk

Cargo.toml

@@ -27,6 +27,7 @@ maintenance = { status = "actively-developed" }
 
 [dependencies]
 arbitrary = "1"
+rustc_version = "0.4"
 
 [dev-dependencies]
 rand = "0.8"

src/bin/cargo-hfuzz.rs

@@ -181,8 +181,22 @@ fn hfuzz_build<T>(args: T, crate_root: &Path, build_type: &BuildType) where T: s
             ");
 
             if *build_type == BuildType::ReleaseInstrumented {
+                // The new LLVM pass manager was not enabled in rustc 1.57 as expected:
+                // https://github.com/rust-lang/rust/pull/91263
+                // The fix for now is to pass `-C passes=sancov-module` only to nightly
+                // compilers for which the LLVM version is >= 13.
+                let version_meta = rustc_version::version_meta().unwrap();
+                if version_meta.channel == rustc_version::Channel::Nightly && version_meta.llvm_version.map_or(true, |v| v.major >= 13) {
+                    rustflags.push_str("\
+                    -C passes=sancov-module \
+                    ");
+                } else {
+                    rustflags.push_str("\
+                    -C passes=sancov \
+                    ");
+                };
+
                 rustflags.push_str("\
-                -C passes=sancov \
                 -C llvm-args=-sanitizer-coverage-level=4 \
                 -C llvm-args=-sanitizer-coverage-trace-pc-guard \
                 -C llvm-args=-sanitizer-coverage-trace-divs \