(c2rust-analyze/tests) Add tests for string literals and casts (#838)

Add tests for string literals and casts.

They are currently unsupported:
- #833
- #837

so for now the tests are skipped over with `#[cfg(any())]`. Once those
issues are fixed, these tests will be turned back on, but it's easier to
start with the tests existing.

These tests just check if `c2rust-analyze` doesn't crash on them,
similar to the existing `lighttpd-minimal` test. For the `FileCheck`
tests, `FileCheck` requires at least one `CHECK:` command, which we
don't want. Thus, I've renamed `lighttpd.rs` to `analyze.rs` and it'll
be for `c2rust-analyze`-only tests, as opposed to `filecheck.rs` for
`c2rust-analyze` + `FileCheck` tests.

Furthermore, running `cargo` concurrently (due to multiple tests) for
`c2rust-analyze` crashes in macOS CI, so now the `c2rust-analyze` binary
is found to run directly, rather than going through `cargo` again.

Skipping going through `cargo` makes the tests run much faster, but more
importantly, prevents them from competing for the `target/` lock, which
caused issues in CI on macOS sometimes. It's also a bit simpler now, not
needing to go through `cargo`.

c2rust-analyze/tests/analyze.rs

@@ -0,0 +1,18 @@
+use common::Analyze;
+
+pub mod common;
+
+#[test]
+fn string_literals() {
+    Analyze::resolve().run("tests/analyze/string_literals.rs");
+}
+
+#[test]
+fn string_casts() {
+    Analyze::resolve().run("tests/analyze/string_casts.rs");
+}
+
+#[test]
+fn lighttpd_minimal() {
+    Analyze::resolve().run("../analysis/tests/lighttpd-minimal/src/main.rs");
+}

c2rust-analyze/tests/analyze/string_casts.rs

@@ -0,0 +1,9 @@
+#[cfg(any())]
+fn cast_only(s: *const u8) {
+    s as *const core::ffi::c_char;
+}
+
+#[cfg(any())]
+fn cast_from_literal() {
+    b"" as *const u8 as *const core::ffi::c_char;
+}

c2rust-analyze/tests/analyze/string_literals.rs

@@ -0,0 +1,9 @@
+#[cfg(any())]
+fn str() {
+    "";
+}
+
+#[cfg(any())]
+fn bstr() {
+    b"";
+}

c2rust-analyze/tests/common/mod.rs

@@ -8,18 +8,23 @@ use std::{
 use c2rust_build_paths::find_llvm_config;
 
 #[derive(Default)]
-pub struct Analyze;
+pub struct Analyze {
+    path: PathBuf,
+}
 
 impl Analyze {
-    pub fn new() -> Self {
-        Self
+    pub fn resolve() -> Self {
+        let current_exe = env::current_exe().unwrap();
+        let bin_deps_dir = current_exe.parent().unwrap();
+        let bin_dir = bin_deps_dir.parent().unwrap();
+        let path = bin_dir.join(env!("CARGO_PKG_NAME"));
+        Self { path }
     }
 
     fn run_(&self, rs_path: &Path) -> PathBuf {
         let dir = Path::new(env!("CARGO_MANIFEST_DIR"));
         let lib_dir = Path::new(env!("C2RUST_TARGET_LIB_DIR"));
 
-        let manifest_path = dir.join("Cargo.toml");
         let rs_path = dir.join(rs_path); // allow relative paths, or override with an absolute path
         let output_path = {
             let mut file_name = rs_path.file_name().unwrap().to_owned();
@@ -29,12 +34,8 @@ impl Analyze {
         let output_stdout = File::create(&output_path).unwrap();
         let output_stderr = File::try_clone(&output_stdout).unwrap();
 
-        let mut cmd = Command::new("cargo");
-        cmd.arg("run")
-            .arg("--manifest-path")
-            .arg(&manifest_path)
-            .arg("--")
-            .arg(&rs_path)
+        let mut cmd = Command::new(&self.path);
+        cmd.arg(&rs_path)
             .arg("-L")
             .arg(lib_dir)
             .arg("--crate-type")

c2rust-analyze/tests/filecheck.rs

@@ -6,7 +6,7 @@ use common::{Analyze, FileCheck};
 
 #[test]
 fn filecheck() {
-    let analyze = Analyze::new();
+    let analyze = Analyze::resolve();
     let file_check = FileCheck::resolve();
 
     for entry in fs::read_dir("tests/filecheck").unwrap() {