Revert "Persist ThinLTO import data in incr. comp. session directory."

This reverts commit 8dc7ddb9.

src/librustc_codegen_llvm/back/lto.rs

@@ -27,16 +27,10 @@
 use libc;
 
 use std::ffi::{CString, CStr};
-use std::fs::File;
-use std::io;
-use std::mem;
-use std::path::Path;
 use std::ptr;
 use std::slice;
 use std::sync::Arc;
 
-pub const THIN_LTO_IMPORTS_INCR_COMP_FILE_NAME: &str = "thin-lto-imports.bin";
-
 pub fn crate_type_allows_lto(crate_type: config::CrateType) -> bool {
     match crate_type {
         config::CrateTypeExecutable |
@@ -200,7 +194,7 @@ pub(crate) fn run(cgcx: &CodegenContext,
         }
         Lto::Thin |
         Lto::ThinLocal => {
-            thin_lto(cgcx, &diag_handler, modules, upstream_modules, &arr, timeline)
+            thin_lto(&diag_handler, modules, upstream_modules, &arr, timeline)
         }
         Lto::No => unreachable!(),
     }
@@ -353,8 +347,7 @@ fn drop(&mut self) {
 /// calculating the *index* for ThinLTO. This index will then be shared amongst
 /// all of the `LtoModuleCodegen` units returned below and destroyed once
 /// they all go out of scope.
-fn thin_lto(cgcx: &CodegenContext,
-            diag_handler: &Handler,
+fn thin_lto(diag_handler: &Handler,
             modules: Vec<ModuleCodegen>,
             serialized_modules: Vec<(SerializedModule, CString)>,
             symbol_white_list: &[*const libc::c_char],
@@ -432,18 +425,6 @@ fn thin_lto(cgcx: &CodegenContext,
             let msg = format!("failed to prepare thin LTO context");
             return Err(write::llvm_err(&diag_handler, msg))
         }
-
-        // Save the ThinLTO import information for incremental compilation.
-        if let Some(ref incr_comp_session_dir) = cgcx.incr_comp_session_dir {
-            let path = incr_comp_session_dir.join(THIN_LTO_IMPORTS_INCR_COMP_FILE_NAME);
-            let imports = ThinLTOImports::from_thin_lto_data(data);
-            if let Err(err) = imports.save_to_file(&path) {
-                let msg = format!("Error while writing ThinLTO import data: {}",
-                                  err);
-                return Err(write::llvm_err(&diag_handler, msg));
-            }
-        }
-
         let data = ThinData(data);
         info!("thin LTO data created");
         timeline.record("data");
@@ -806,12 +787,6 @@ pub struct ThinLTOImports {
 
 impl ThinLTOImports {
 
-    pub fn new_empty() -> ThinLTOImports {
-        ThinLTOImports {
-            imports: FxHashMap(),
-        }
-    }
-
     /// Load the ThinLTO import map from ThinLTOData.
     unsafe fn from_thin_lto_data(data: *const llvm::ThinLTOData) -> ThinLTOImports {
         let raw_data: *const llvm::ThinLTOModuleImports =
@@ -867,58 +842,4 @@ unsafe fn from_thin_lto_data(data: *const llvm::ThinLTOData) -> ThinLTOImports {
             imports
         }
     }
-
-    pub fn save_to_file(&self, path: &Path) -> io::Result<()> {
-        use std::io::Write;
-
-        let file = File::create(path)?;
-        let mut writer = io::BufWriter::new(file);
-
-        for (importing_module_name, imported_modules) in &self.imports {
-            writeln!(writer, "{}", importing_module_name)?;
-
-            for imported_module in imported_modules {
-                writeln!(writer, "  {}", imported_module)?;
-            }
-
-            writeln!(writer)?;
-        }
-
-        Ok(())
-    }
-
-    pub fn load_from_file(path: &Path) -> io::Result<ThinLTOImports> {
-        use std::io::BufRead;
-
-        let mut imports = FxHashMap();
-        let mut current_module = None;
-        let mut current_imports = vec![];
-
-        let file = File::open(path)?;
-
-        for line in io::BufReader::new(file).lines() {
-            let line = line?;
-
-            if line.is_empty() {
-                let importing_module = current_module
-                    .take()
-                    .expect("Importing module not set");
-
-                imports.insert(importing_module,
-                               mem::replace(&mut current_imports, vec![]));
-            } else if line.starts_with(" ") {
-                // This is an imported module
-                assert_ne!(current_module, None);
-                current_imports.push(line.trim().to_string());
-            } else {
-                // This is the beginning of a new module
-                assert_eq!(current_module, None);
-                current_module = Some(line.trim().to_string());
-            }
-        }
-
-        Ok(ThinLTOImports {
-            imports
-        })
-    }
 }

src/librustc_codegen_llvm/base.rs

@@ -29,7 +29,7 @@
 use super::ModuleKind;
 
 use abi;
-use back::{link, lto};
+use back::link;
 use back::write::{self, OngoingCodegen, create_target_machine};
 use llvm::{ContextRef, ModuleRef, ValueRef, Vector, get_param};
 use llvm;
@@ -1370,27 +1370,6 @@ fn hash_stable<W: StableHasherResult>(&self,
     }
 }
 
-#[allow(unused)]
-fn load_thin_lto_imports(sess: &Session) -> lto::ThinLTOImports {
-    let path = rustc_incremental::in_incr_comp_dir_sess(
-        sess,
-        lto::THIN_LTO_IMPORTS_INCR_COMP_FILE_NAME
-    );
-
-    if !path.exists() {
-        return lto::ThinLTOImports::new_empty();
-    }
-
-    match lto::ThinLTOImports::load_from_file(&path) {
-        Ok(imports) => imports,
-        Err(e) => {
-            let msg = format!("Error while trying to load ThinLTO import data \
-                               for incremental compilation: {}", e);
-            sess.fatal(&msg)
-        }
-    }
-}
-
 pub fn define_custom_section(cx: &CodegenCx, def_id: DefId) {
     use rustc::mir::interpret::GlobalId;
 
@@ -1429,4 +1408,3 @@ pub fn define_custom_section(cx: &CodegenCx, def_id: DefId) {
         );
     }
 }
-

src/librustc_codegen_llvm/lib.rs

@@ -90,7 +90,7 @@ mod back {
     mod command;
     pub mod linker;
     pub mod link;
-    pub mod lto;
+    mod lto;
     pub mod symbol_export;
     pub mod write;
     mod rpath;

src/librustc_incremental/lib.rs

@@ -44,7 +44,6 @@
 pub use persist::save_dep_graph;
 pub use persist::save_work_product_index;
 pub use persist::in_incr_comp_dir;
-pub use persist::in_incr_comp_dir_sess;
 pub use persist::prepare_session_directory;
 pub use persist::finalize_session_directory;
 pub use persist::delete_workproduct_files;

src/librustc_incremental/persist/mod.rs

@@ -23,7 +23,6 @@
 pub use self::fs::finalize_session_directory;
 pub use self::fs::garbage_collect_session_directories;
 pub use self::fs::in_incr_comp_dir;
-pub use self::fs::in_incr_comp_dir_sess;
 pub use self::fs::prepare_session_directory;
 pub use self::load::dep_graph_tcx_init;
 pub use self::load::load_dep_graph;