Reorganise driver code.

The goal of this refactoring is to make the rustc driver code easier to understand and use. Since this is as close to an API as we have, I think it is important that it is nice. On getting stuck in, I found that there wasn't as much to change as I'd hoped to make the stage... fns easier to use by tools.

This patch only moves code around - mostly just moving code to different files, but a few extracted method refactorings too. To summarise the changes: I added driver::config which handles everything about configuring the compiler. driver::session now just defines and builds session objects. I moved driver code from librustc/lib.rs to librustc/driver/mod.rs so all the code is one place. I extracted methods to make emulating the compiler without being the compiler a little easier. Within the driver directory, I moved code around to more logically fit in the modules.

Author: nrc

src/librustc/back/arm.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use back::target_strs;
-use driver::session::sess_os_to_meta_os;
+use driver::config::cfg_os_to_meta_os;
 use metadata::loader::meta_section_name;
 use syntax::abi;
 
@@ -22,7 +22,7 @@ pub fn get_target_strs(target_triple: ~str, target_os: abi::Os) -> target_strs::
     return target_strs::t {
         module_asm: "".to_owned(),
 
-        meta_sect_name: meta_section_name(sess_os_to_meta_os(target_os)).to_owned(),
+        meta_sect_name: meta_section_name(cfg_os_to_meta_os(target_os)).to_owned(),
 
         data_layout: match target_os {
           abi::OsMacos => {

src/librustc/back/link.rs

@@ -12,8 +12,9 @@ use back::archive::{Archive, METADATA_FILENAME};
 use back::rpath;
 use back::svh::Svh;
 use driver::driver::{CrateTranslation, OutputFilenames};
-use driver::session::{NoDebugInfo, Session};
-use driver::session;
+use driver::config::NoDebugInfo;
+use driver::session::Session;
+use driver::config;
 use lib::llvm::llvm;
 use lib::llvm::ModuleRef;
 use lib;
@@ -92,8 +93,9 @@ pub mod write {
     use back::link::{OutputTypeExe, OutputTypeLlvmAssembly};
     use back::link::{OutputTypeObject};
     use driver::driver::{CrateTranslation, OutputFilenames};
-    use driver::session::{NoDebugInfo, Session};
-    use driver::session;
+    use driver::config::NoDebugInfo;
+    use driver::session::Session;
+    use driver::config;
     use lib::llvm::llvm;
     use lib::llvm::{ModuleRef, TargetMachineRef, PassManagerRef};
     use lib;
@@ -139,10 +141,10 @@ pub mod write {
             }
 
             let opt_level = match sess.opts.optimize {
-              session::No => lib::llvm::CodeGenLevelNone,
-              session::Less => lib::llvm::CodeGenLevelLess,
-              session::Default => lib::llvm::CodeGenLevelDefault,
-              session::Aggressive => lib::llvm::CodeGenLevelAggressive,
+              config::No => lib::llvm::CodeGenLevelNone,
+              config::Less => lib::llvm::CodeGenLevelLess,
+              config::Default => lib::llvm::CodeGenLevelDefault,
+              config::Aggressive => lib::llvm::CodeGenLevelAggressive,
             };
             let use_softfp = sess.opts.cg.soft_float;
 
@@ -231,7 +233,7 @@ pub mod write {
             // emitting an rlib. Whenever an rlib is created, the bytecode is
             // inserted into the archive in order to allow LTO against it.
             if sess.opts.cg.save_temps ||
-               (sess.crate_types.borrow().contains(&session::CrateTypeRlib) &&
+               (sess.crate_types.borrow().contains(&config::CrateTypeRlib) &&
                 sess.opts.output_types.contains(&OutputTypeExe)) {
                 output.temp_path(OutputTypeBitcode).with_c_str(|buf| {
                     llvm::LLVMWriteBitcodeToFile(llmod, buf);
@@ -378,10 +380,10 @@ pub mod write {
         // Copy what clang does by turning on loop vectorization at O2 and
         // slp vectorization at O3
         let vectorize_loop = !sess.opts.cg.no_vectorize_loops &&
-                             (sess.opts.optimize == session::Default ||
-                              sess.opts.optimize == session::Aggressive);
+                             (sess.opts.optimize == config::Default ||
+                              sess.opts.optimize == config::Aggressive);
         let vectorize_slp = !sess.opts.cg.no_vectorize_slp &&
-                            sess.opts.optimize == session::Aggressive;
+                            sess.opts.optimize == config::Aggressive;
 
         let mut llvm_c_strs = Vec::new();
         let mut llvm_args = Vec::new();
@@ -823,14 +825,14 @@ fn is_writeable(p: &Path) -> bool {
     }
 }
 
-pub fn filename_for_input(sess: &Session, crate_type: session::CrateType,
+pub fn filename_for_input(sess: &Session, crate_type: config::CrateType,
                           id: &CrateId, out_filename: &Path) -> Path {
     let libname = output_lib_filename(id);
     match crate_type {
-        session::CrateTypeRlib => {
+        config::CrateTypeRlib => {
             out_filename.with_filename(format!("lib{}.rlib", libname))
         }
-        session::CrateTypeDylib => {
+        config::CrateTypeDylib => {
             let (prefix, suffix) = match sess.targ_cfg.os {
                 abi::OsWin32 => (loader::WIN32_DLL_PREFIX, loader::WIN32_DLL_SUFFIX),
                 abi::OsMacos => (loader::MACOS_DLL_PREFIX, loader::MACOS_DLL_SUFFIX),
@@ -840,16 +842,16 @@ pub fn filename_for_input(sess: &Session, crate_type: session::CrateType,
             };
             out_filename.with_filename(format!("{}{}{}", prefix, libname, suffix))
         }
-        session::CrateTypeStaticlib => {
+        config::CrateTypeStaticlib => {
             out_filename.with_filename(format!("lib{}.a", libname))
         }
-        session::CrateTypeExecutable => out_filename.clone(),
+        config::CrateTypeExecutable => out_filename.clone(),
     }
 }
 
 fn link_binary_output(sess: &Session,
                       trans: &CrateTranslation,
-                      crate_type: session::CrateType,
+                      crate_type: config::CrateType,
                       outputs: &OutputFilenames,
                       id: &CrateId) -> Path {
     let obj_filename = outputs.temp_path(OutputTypeObject);
@@ -877,16 +879,16 @@ fn link_binary_output(sess: &Session,
     }
 
     match crate_type {
-        session::CrateTypeRlib => {
+        config::CrateTypeRlib => {
             link_rlib(sess, Some(trans), &obj_filename, &out_filename);
         }
-        session::CrateTypeStaticlib => {
+        config::CrateTypeStaticlib => {
             link_staticlib(sess, &obj_filename, &out_filename);
         }
-        session::CrateTypeExecutable => {
+        config::CrateTypeExecutable => {
             link_natively(sess, trans, false, &obj_filename, &out_filename);
         }
-        session::CrateTypeDylib => {
+        config::CrateTypeDylib => {
             link_natively(sess, trans, true, &obj_filename, &out_filename);
         }
     }
@@ -1045,7 +1047,7 @@ fn link_natively(sess: &Session, trans: &CrateTranslation, dylib: bool,
     let mut cc_args = sess.targ_cfg.target_strs.cc_args.clone();
     cc_args.push_all_move(link_args(sess, dylib, tmpdir.path(), trans,
                                     obj_filename, out_filename));
-    if (sess.opts.debugging_opts & session::PRINT_LINK_ARGS) != 0 {
+    if (sess.opts.debugging_opts & config::PRINT_LINK_ARGS) != 0 {
         println!("{} link args: '{}'", cc_prog, cc_args.connect("' '"));
     }
 
@@ -1161,8 +1163,8 @@ fn link_args(sess: &Session,
 
         // GNU-style linkers support optimization with -O. GNU ld doesn't need a
         // numeric argument, but other linkers do.
-        if sess.opts.optimize == session::Default ||
-           sess.opts.optimize == session::Aggressive {
+        if sess.opts.optimize == config::Default ||
+           sess.opts.optimize == config::Aggressive {
             args.push("-Wl,-O1".to_owned());
         }
     } else if sess.targ_cfg.os == abi::OsMacos {
@@ -1373,9 +1375,9 @@ fn add_upstream_rust_crates(args: &mut Vec<~str>, sess: &Session,
     // involves just passing the right -l flag.
 
     let data = if dylib {
-        trans.crate_formats.get(&session::CrateTypeDylib)
+        trans.crate_formats.get(&config::CrateTypeDylib)
     } else {
-        trans.crate_formats.get(&session::CrateTypeExecutable)
+        trans.crate_formats.get(&config::CrateTypeExecutable)
     };
 
     // Invoke get_used_crates to ensure that we get a topological sorting of
@@ -1403,7 +1405,7 @@ fn add_upstream_rust_crates(args: &mut Vec<~str>, sess: &Session,
     }
 
     // Converts a library file-stem into a cc -l argument
-    fn unlib(config: &session::Config, stem: &str) -> ~str {
+    fn unlib(config: &config::Config, stem: &str) -> ~str {
         if stem.starts_with("lib") && config.os != abi::OsWin32 {
             stem.slice(3, stem.len()).to_owned()
         } else {

src/librustc/back/lto.rs

@@ -11,6 +11,7 @@
 use back::archive::ArchiveRO;
 use back::link;
 use driver::session;
+use driver::config;
 use lib::llvm::{ModuleRef, TargetMachineRef, llvm, True, False};
 use metadata::cstore;
 use util::common::time;
@@ -29,7 +30,7 @@ pub fn run(sess: &session::Session, llmod: ModuleRef,
     // Make sure we actually can run LTO
     for crate_type in sess.crate_types.borrow().iter() {
         match *crate_type {
-            session::CrateTypeExecutable | session::CrateTypeStaticlib => {}
+            config::CrateTypeExecutable | config::CrateTypeStaticlib => {}
             _ => {
                 sess.fatal("lto can only be run for executables and \
                             static library outputs");

src/librustc/back/mips.rs

@@ -9,15 +9,15 @@
 // except according to those terms.
 
 use back::target_strs;
-use driver::session::sess_os_to_meta_os;
+use driver::config::cfg_os_to_meta_os;
 use metadata::loader::meta_section_name;
 use syntax::abi;
 
 pub fn get_target_strs(target_triple: ~str, target_os: abi::Os) -> target_strs::t {
     return target_strs::t {
         module_asm: "".to_owned(),
 
-        meta_sect_name: meta_section_name(sess_os_to_meta_os(target_os)).to_owned(),
+        meta_sect_name: meta_section_name(cfg_os_to_meta_os(target_os)).to_owned(),
 
         data_layout: match target_os {
           abi::OsMacos => {

src/librustc/back/x86.rs

@@ -10,15 +10,15 @@
 
 
 use back::target_strs;
-use driver::session::sess_os_to_meta_os;
+use driver::config::cfg_os_to_meta_os;
 use metadata::loader::meta_section_name;
 use syntax::abi;
 
 pub fn get_target_strs(target_triple: ~str, target_os: abi::Os) -> target_strs::t {
     return target_strs::t {
         module_asm: "".to_owned(),
 
-        meta_sect_name: meta_section_name(sess_os_to_meta_os(target_os)).to_owned(),
+        meta_sect_name: meta_section_name(cfg_os_to_meta_os(target_os)).to_owned(),
 
         data_layout: match target_os {
           abi::OsMacos => {

src/librustc/back/x86_64.rs

@@ -10,15 +10,15 @@
 
 
 use back::target_strs;
-use driver::session::sess_os_to_meta_os;
+use driver::config::cfg_os_to_meta_os;
 use metadata::loader::meta_section_name;
 use syntax::abi;
 
 pub fn get_target_strs(target_triple: ~str, target_os: abi::Os) -> target_strs::t {
     return target_strs::t {
         module_asm: "".to_owned(),
 
-        meta_sect_name: meta_section_name(sess_os_to_meta_os(target_os)).to_owned(),
+        meta_sect_name: meta_section_name(cfg_os_to_meta_os(target_os)).to_owned(),
 
         data_layout: match target_os {
           abi::OsMacos => {