improve build-rerun condition

Signed-off-by: Jun Kimura <junkxdev@gmail.com>

Author: bluele

sgx-build/src/lib.rs

@@ -94,39 +94,6 @@ pub struct SgxBuilder {
 }
 
 impl SgxBuilder {
-    /// Get the target directory for EDL artifacts
-    fn get_edl_target_dir() -> PathBuf {
-        // First, try CARGO_TARGET_DIR which is explicitly set
-        if let Ok(target_dir) = env::var("CARGO_TARGET_DIR") {
-            return PathBuf::from(target_dir).join("edl");
-        }
-
-        // Otherwise, require OUT_DIR to be set (should always be set in build.rs context)
-        let out_dir = env::var("OUT_DIR")
-            .expect("OUT_DIR not set. This function should only be called from build.rs");
-
-        let out_path = PathBuf::from(out_dir);
-
-        // Find the target directory by looking for a directory named "target"
-        // while traversing up the directory tree
-        let mut current_dir = out_path.as_path();
-        loop {
-            if let Some(file_name) = current_dir.file_name() {
-                if file_name == "target" {
-                    return current_dir.join("edl");
-                }
-            }
-
-            match current_dir.parent() {
-                Some(parent) => current_dir = parent,
-                None => panic!(
-                    "Could not find 'target' directory in OUT_DIR path: {}",
-                    out_path.display()
-                ),
-            }
-        }
-    }
-
     /// Create a new EnclaveBuilder with default settings from environment
     pub fn new() -> Self {
         let sgx_sdk = env::var("SGX_SDK").unwrap_or_else(|_| "/opt/intel/sgxsdk".to_string());
@@ -141,8 +108,7 @@ impl SgxBuilder {
                 "x64".to_string()
             }
         });
-        let debug =
-            env::var("SGX_DEBUG").is_ok() || env::var("DEBUG").is_ok() || cfg!(debug_assertions);
+        let debug = env::var("SGX_DEBUG").unwrap_or_default() == "1" || cfg!(debug_assertions);
         let mitigation_cve_2020_0551 = match env::var("MITIGATION_CVE_2020_0551")
             .or_else(|_| env::var("MITIGATION-CVE-2020-0551"))
         {
@@ -164,6 +130,51 @@ impl SgxBuilder {
         }
     }
 
+    /// Print cargo rerun-if-env-changed for common environment variables
+    fn print_common_env_rerun() {
+        println!("cargo:rerun-if-env-changed=SGX_SDK");
+        println!("cargo:rerun-if-env-changed=SGX_MODE");
+        println!("cargo:rerun-if-env-changed=SGX_ARCH");
+        println!("cargo:rerun-if-env-changed=SGX_DEBUG");
+        println!("cargo:rerun-if-env-changed=MITIGATION_CVE_2020_0551");
+        println!("cargo:rerun-if-env-changed=MITIGATION-CVE-2020-0551");
+    }
+
+    /// Get the target directory for EDL artifacts
+    fn get_edl_target_dir() -> PathBuf {
+        // First, try CARGO_TARGET_DIR which is explicitly set
+        if let Ok(target_dir) = env::var("CARGO_TARGET_DIR") {
+            println!("cargo:rerun-if-env-changed=CARGO_TARGET_DIR");
+            return PathBuf::from(target_dir).join("edl");
+        }
+
+        // Otherwise, require OUT_DIR to be set (should always be set in build.rs context)
+        println!("cargo:rerun-if-env-changed=OUT_DIR");
+        let out_dir = env::var("OUT_DIR")
+            .expect("OUT_DIR not set. This function should only be called from build.rs");
+
+        let out_path = PathBuf::from(out_dir);
+
+        // Find the target directory by looking for a directory named "target"
+        // while traversing up the directory tree
+        let mut current_dir = out_path.as_path();
+        loop {
+            if let Some(file_name) = current_dir.file_name() {
+                if file_name == "target" {
+                    return current_dir.join("edl");
+                }
+            }
+
+            match current_dir.parent() {
+                Some(parent) => current_dir = parent,
+                None => panic!(
+                    "Could not find 'target' directory in OUT_DIR path: {}",
+                    out_path.display()
+                ),
+            }
+        }
+    }
+
     /// Detect GCC version
     fn detect_gcc_version() -> Option<(u32, u32, u32)> {
         let output = Command::new("gcc").arg("--version").output().ok()?;
@@ -233,6 +244,7 @@ impl SgxBuilder {
 
         // Add additional search paths if needed
         if let Ok(sgx_edl_search_paths) = env::var("SGX_EDL_SEARCH_PATHS") {
+            println!("cargo:rerun-if-env-changed=SGX_EDL_SEARCH_PATHS");
             for path in sgx_edl_search_paths.split(':') {
                 cmd.args(["--search-path", path]);
             }
@@ -507,6 +519,9 @@ impl SgxBuilder {
         // Tell cargo to rerun if EDL changes
         println!("cargo:rerun-if-changed={}", edl_path.display());
 
+        // Tell cargo to rerun if environment variables change
+        Self::print_common_env_rerun();
+
         Ok(())
     }
 
@@ -556,6 +571,9 @@ impl SgxBuilder {
         // Tell cargo to rerun if EDL changes
         println!("cargo:rerun-if-changed={}", edl_path.display());
 
+        // Tell cargo to rerun if environment variables change
+        Self::print_common_env_rerun();
+
         Ok(())
     }