Use cargo build -Z build-std for ASAN

This is recommended and increases coverage.

.github/workflows/main.yml

@@ -89,6 +89,8 @@ jobs:
       with:
         # All -Z options require running nightly
         rust-version: nightly
+        # ASAN uses `cargo build -Zbuild-std` which requires the rust-src component
+        components: rust-src
     - name: Install deps
       run: |
         sudo apt install gettext libncurses5-dev libpcre2-dev python3-pip tmux

cmake/Rust.cmake

@@ -15,9 +15,19 @@ set(fish_rust_target "fish-rust")
 
 set(fish_autocxx_gen_dir "${CMAKE_BINARY_DIR}/fish-autocxx-gen/")
 
+if(NOT DEFINED CARGO_FLAGS)
+    # Corrosion doesn't like an empty string as FLAGS. This is basically a no-op alternative.
+    # See https://github.com/corrosion-rs/corrosion/issues/356
+    set(CARGO_FLAGS "--config" "foo=0")
+endif()
+if(DEFINED ASAN)
+    list(APPEND CARGO_FLAGS "-Z" "build-std")
+endif()
+
 corrosion_import_crate(
     MANIFEST_PATH "${CMAKE_SOURCE_DIR}/fish-rust/Cargo.toml"
     FEATURES "fish-ffi-tests"
+    FLAGS "${CARGO_FLAGS}"
 )
 
 # We need the build dir because cxx puts our headers in there.

cmake/Tests.cmake

@@ -193,7 +193,7 @@ endif()
 if(NOT DEFINED ASAN)
     add_test(
         NAME "cargo-test"
-        COMMAND cargo test --target-dir target ${cargo_target_opt}
+        COMMAND cargo test ${CARGO_FLAGS} --target-dir target ${cargo_target_opt}
         WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}/fish-rust"
     )
     set_tests_properties("cargo-test" PROPERTIES SKIP_RETURN_CODE ${SKIP_RETURN_CODE})
@@ -202,7 +202,7 @@ endif()
 
 add_test(
     NAME "cargo-test-widestring"
-    COMMAND cargo test --target-dir target ${cargo_target_opt}
+    COMMAND cargo test ${CARGO_FLAGS} --target-dir target ${cargo_target_opt}
     WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}/fish-rust/widestring-suffix/"
 )
 add_test_target("cargo-test-widestring")