C/C++: add extra input files via environment SCCACHE_EXTRAFILES (#1125)

This is similar to CCACHE_EXTRAFILES and ICECC_EXTRAFILES: the extra
files are hashed for caching and packaged for sccache-dist.

Possibly the same variable CCACHE_EXTRAFILES could be used instead of
a distinct one?

This can be implemented in one place for the C/C++ compilers, but not
also for Rust, which currently doesn't have extra_hash_files, so that
remains TODO.

Author: mistmist

src/compiler/c.rs

@@ -252,14 +252,22 @@ impl<T: CommandCreatorSync, I: CCompilerImpl> Compiler<T> for CCompiler<I> {
         &self,
         arguments: &[OsString],
         cwd: &Path,
+        env_vars: &[(OsString, OsString)],
     ) -> CompilerArguments<Box<dyn CompilerHasher<T> + 'static>> {
         match self.compiler.parse_arguments(arguments, cwd) {
-            CompilerArguments::Ok(args) => CompilerArguments::Ok(Box::new(CCompilerHasher {
-                parsed_args: args,
-                executable: self.executable.clone(),
-                executable_digest: self.executable_digest.clone(),
-                compiler: self.compiler.clone(),
-            })),
+            CompilerArguments::Ok(mut args) => {
+                for (k, v) in env_vars.iter() {
+                    if k.as_os_str() == OsStr::new("SCCACHE_EXTRAFILES") {
+                        args.extra_hash_files.extend(std::env::split_paths(&v))
+                    }
+                }
+                CompilerArguments::Ok(Box::new(CCompilerHasher {
+                    parsed_args: args,
+                    executable: self.executable.clone(),
+                    executable_digest: self.executable_digest.clone(),
+                    compiler: self.compiler.clone(),
+                }))
+            }
             CompilerArguments::CannotCache(why, extra_info) => {
                 CompilerArguments::CannotCache(why, extra_info)
             }

src/compiler/compiler.rs

@@ -126,6 +126,7 @@ where
         &self,
         arguments: &[OsString],
         cwd: &Path,
+        env_vars: &[(OsString, OsString)],
     ) -> CompilerArguments<Box<dyn CompilerHasher<T> + 'static>>;
     fn box_clone(&self) -> Box<dyn Compiler<T>>;
 }
@@ -1348,7 +1349,7 @@ LLVM version: 6.0",
                     &creator,
                     Ok(MockChild::new(exit_status(0), "preprocessor output", "")),
                 );
-                let hasher = match c.parse_arguments(&arguments, ".".as_ref()) {
+                let hasher = match c.parse_arguments(&arguments, ".".as_ref(), &[]) {
                     CompilerArguments::Ok(h) => h,
                     o => panic!("Bad result from parse_arguments: {:?}", o),
                 };
@@ -1422,7 +1423,7 @@ LLVM version: 6.0",
         });
         let cwd = f.tempdir.path();
         let arguments = ovec!["-c", "foo.c", "-o", "foo.o"];
-        let hasher = match c.parse_arguments(&arguments, ".".as_ref()) {
+        let hasher = match c.parse_arguments(&arguments, ".".as_ref(), &[]) {
             CompilerArguments::Ok(h) => h,
             o => panic!("Bad result from parse_arguments: {:?}", o),
         };
@@ -1527,7 +1528,7 @@ LLVM version: 6.0",
         ));
         let cwd = f.tempdir.path();
         let arguments = ovec!["-c", "foo.c", "-o", "foo.o"];
-        let hasher = match c.parse_arguments(&arguments, ".".as_ref()) {
+        let hasher = match c.parse_arguments(&arguments, ".".as_ref(), &[]) {
             CompilerArguments::Ok(h) => h,
             o => panic!("Bad result from parse_arguments: {:?}", o),
         };
@@ -1638,7 +1639,7 @@ LLVM version: 6.0",
         });
         let cwd = f.tempdir.path();
         let arguments = ovec!["-c", "foo.c", "-o", "foo.o"];
-        let hasher = match c.parse_arguments(&arguments, ".".as_ref()) {
+        let hasher = match c.parse_arguments(&arguments, ".".as_ref(), &[]) {
             CompilerArguments::Ok(h) => h,
             o => panic!("Bad result from parse_arguments: {:?}", o),
         };
@@ -1719,7 +1720,7 @@ LLVM version: 6.0",
         }
         let cwd = f.tempdir.path();
         let arguments = ovec!["-c", "foo.c", "-o", "foo.o"];
-        let hasher = match c.parse_arguments(&arguments, ".".as_ref()) {
+        let hasher = match c.parse_arguments(&arguments, ".".as_ref(), &[]) {
             CompilerArguments::Ok(h) => h,
             o => panic!("Bad result from parse_arguments: {:?}", o),
         };
@@ -1824,7 +1825,7 @@ LLVM version: 6.0",
         );
         let cwd = f.tempdir.path();
         let arguments = ovec!["-c", "foo.c", "-o", "foo.o"];
-        let hasher = match c.parse_arguments(&arguments, ".".as_ref()) {
+        let hasher = match c.parse_arguments(&arguments, ".".as_ref(), &[]) {
             CompilerArguments::Ok(h) => h,
             o => panic!("Bad result from parse_arguments: {:?}", o),
         };
@@ -1908,7 +1909,7 @@ LLVM version: 6.0",
         }
         let cwd = f.tempdir.path();
         let arguments = ovec!["-c", "foo.c", "-o", "foo.o"];
-        let hasher = match c.parse_arguments(&arguments, ".".as_ref()) {
+        let hasher = match c.parse_arguments(&arguments, ".".as_ref(), &[]) {
             CompilerArguments::Ok(h) => h,
             o => panic!("Bad result from parse_arguments: {:?}", o),
         };

src/compiler/rust.rs

@@ -474,6 +474,7 @@ where
         &self,
         arguments: &[OsString],
         cwd: &Path,
+        _env_vars: &[(OsString, OsString)],
     ) -> CompilerArguments<Box<dyn CompilerHasher<T> + 'static>> {
         match parse_arguments(arguments, cwd) {
             CompilerArguments::Ok(args) => CompilerArguments::Ok(Box::new(RustHasher {

src/server.rs

@@ -1055,7 +1055,7 @@ where
                 debug!("check_compiler: Supported compiler");
                 // Now check that we can handle this compiler with
                 // the provided commandline.
-                match c.parse_arguments(&cmd, &cwd) {
+                match c.parse_arguments(&cmd, &cwd, &env_vars) {
                     CompilerArguments::Ok(hasher) => {
                         debug!("parse_arguments: Ok: {:?}", cmd);
                         stats.requests_executed += 1;