Revert "Have JIT execution take ownership of the LLVMContextRef"

This reverts commit 5c5095d.

Conflicts:
	src/librusti/rusti.rc

Author: brson

src/librustc/back/link.rs

@@ -102,7 +102,7 @@ pub mod jit {
     use back::link::llvm_err;
     use driver::session::Session;
     use lib::llvm::llvm;
-    use lib::llvm::{ModuleRef, PassManagerRef, ContextRef};
+    use lib::llvm::{ModuleRef, PassManagerRef};
     use metadata::cstore;
 
     use core::cast;
@@ -125,7 +125,6 @@ pub mod jit {
 
     pub fn exec(sess: Session,
                 pm: PassManagerRef,
-                c: ContextRef,
                 m: ModuleRef,
                 opt: c_int,
                 stacks: bool) {
@@ -154,43 +153,26 @@ pub mod jit {
                     });
             }
 
-            // We custom-build a JIT execution engine via some rust wrappers
-            // first. This wrappers takes ownership of the module passed in.
-            let ee = llvm::LLVMRustBuildJIT(manager, pm, m, opt, stacks);
-            if ee.is_null() {
-                llvm::LLVMContextDispose(c);
-                llvm_err(sess, ~"Could not create the JIT");
-            }
+            // The execute function will return a void pointer
+            // to the _rust_main function. We can do closure
+            // magic here to turn it straight into a callable rust
+            // closure. It will also cleanup the memory manager
+            // for us.
 
-            // Next, we need to get a handle on the _rust_main function by
-            // looking up it's corresponding ValueRef and then requesting that
-            // the execution engine compiles the function.
-            let fun = do str::as_c_str("_rust_main") |entry| {
-                llvm::LLVMGetNamedFunction(m, entry)
-            };
-            if fun.is_null() {
-                llvm::LLVMDisposeExecutionEngine(ee);
-                llvm::LLVMContextDispose(c);
-                llvm_err(sess, ~"Could not find _rust_main in the JIT");
-            }
+            let entry = llvm::LLVMRustExecuteJIT(manager,
+                                                 pm, m, opt, stacks);
 
-            // Finally, once we have the pointer to the code, we can do some
-            // closure magic here to turn it straight into a callable rust
-            // closure
-            let code = llvm::LLVMGetPointerToGlobal(ee, fun);
-            assert!(!code.is_null());
-            let closure = Closure {
-                code: code,
-                env: ptr::null()
-            };
-            let func: &fn() = cast::transmute(closure);
-            func();
-
-            // Sadly, there currently is no interface to re-use this execution
-            // engine, so it's disposed of here along with the context to
-            // prevent leaks.
-            llvm::LLVMDisposeExecutionEngine(ee);
-            llvm::LLVMContextDispose(c);
+            if ptr::is_null(entry) {
+                llvm_err(sess, ~"Could not JIT");
+            } else {
+                let closure = Closure {
+                    code: entry,
+                    env: ptr::null()
+                };
+                let func: &fn() = cast::transmute(closure);
+
+                func();
+            }
         }
     }
 }
@@ -207,7 +189,6 @@ pub mod write {
     use driver::session;
     use lib::llvm::llvm;
     use lib::llvm::{ModuleRef, mk_pass_manager, mk_target_data};
-    use lib::llvm::{ContextRef};
     use lib;
 
     use back::passes;
@@ -226,7 +207,6 @@ pub mod write {
     }
 
     pub fn run_passes(sess: Session,
-                      llcx: ContextRef,
                       llmod: ModuleRef,
                       output_type: output_type,
                       output: &Path) {
@@ -301,7 +281,7 @@ pub mod write {
                     // JIT execution takes ownership of the module,
                     // so don't dispose and return.
 
-                    jit::exec(sess, pm.llpm, llcx, llmod, CodeGenOptLevel, true);
+                    jit::exec(sess, pm.llpm, llmod, CodeGenOptLevel, true);
 
                     if sess.time_llvm_passes() {
                         llvm::LLVMRustPrintPassTimings();
@@ -369,7 +349,6 @@ pub mod write {
                 // Clean up and return
 
                 llvm::LLVMDisposeModule(llmod);
-                llvm::LLVMContextDispose(llcx);
                 if sess.time_llvm_passes() {
                     llvm::LLVMRustPrintPassTimings();
                 }
@@ -388,7 +367,6 @@ pub mod write {
             }
 
             llvm::LLVMDisposeModule(llmod);
-            llvm::LLVMContextDispose(llcx);
             if sess.time_llvm_passes() { llvm::LLVMRustPrintPassTimings(); }
         }
     }

src/librustc/driver/driver.rs

@@ -216,7 +216,7 @@ pub fn compile_rest(sess: Session,
 
     let mut crate = crate_opt.unwrap();
 
-    let (llcx, llmod, link_meta) = {
+    let (llmod, link_meta) = {
     crate = time(time_passes, ~"intrinsic injection", ||
                  front::intrinsic_inject::inject_intrinsic(sess, crate));
 
@@ -339,14 +339,14 @@ pub fn compile_rest(sess: Session,
         let obj_filename = outputs.obj_filename.with_filetype("s");
 
         time(time_passes, ~"LLVM passes", ||
-            link::write::run_passes(sess, llcx, llmod, output_type,
-                                    &obj_filename));
+            link::write::run_passes(sess, llmod, output_type,
+                            &obj_filename));
 
         link::write::run_ndk(sess, &obj_filename, &outputs.obj_filename);
     } else {
         time(time_passes, ~"LLVM passes", ||
-            link::write::run_passes(sess, llcx, llmod, sess.opts.output_type,
-                                    &outputs.obj_filename));
+            link::write::run_passes(sess, llmod, sess.opts.output_type,
+                                &outputs.obj_filename));
     }
 
     let stop_after_codegen =

src/librustc/lib/llvm.rs

@@ -205,8 +205,6 @@ pub enum BasicBlock_opaque {}
 pub type BasicBlockRef = *BasicBlock_opaque;
 pub enum Builder_opaque {}
 pub type BuilderRef = *Builder_opaque;
-pub enum ExecutionEngine_opaque {}
-pub type ExecutionEngineRef = *ExecutionEngine_opaque;
 pub enum MemoryBuffer_opaque {}
 pub type MemoryBufferRef = *MemoryBuffer_opaque;
 pub enum PassManager_opaque {}
@@ -225,7 +223,7 @@ pub enum Pass_opaque {}
 pub type PassRef = *Pass_opaque;
 
 pub mod llvm {
-    use super::{AtomicBinOp, AtomicOrdering, BasicBlockRef, ExecutionEngineRef};
+    use super::{AtomicBinOp, AtomicOrdering, BasicBlockRef};
     use super::{Bool, BuilderRef, ContextRef, MemoryBufferRef, ModuleRef};
     use super::{ObjectFileRef, Opcode, PassManagerRef, PassManagerBuilderRef};
     use super::{SectionIteratorRef, TargetDataRef, TypeKind, TypeRef, UseRef};
@@ -365,10 +363,6 @@ pub mod llvm {
         pub unsafe fn LLVMGetPointerAddressSpace(PointerTy: TypeRef)
                                               -> c_uint;
         #[fast_ffi]
-        pub unsafe fn LLVMGetPointerToGlobal(EE: ExecutionEngineRef,
-                                             V: ValueRef)
-                                              -> *();
-        #[fast_ffi]
         pub unsafe fn LLVMGetVectorSize(VectorTy: TypeRef) -> c_uint;
 
         /* Operations on other types */
@@ -1009,8 +1003,6 @@ pub mod llvm {
                                                 Name: *c_char);
         #[fast_ffi]
         pub unsafe fn LLVMDisposeBuilder(Builder: BuilderRef);
-        #[fast_ffi]
-        pub unsafe fn LLVMDisposeExecutionEngine(EE: ExecutionEngineRef);
 
         /* Metadata */
         #[fast_ffi]
@@ -1827,11 +1819,11 @@ pub mod llvm {
 
         /** Execute the JIT engine. */
         #[fast_ffi]
-        pub unsafe fn LLVMRustBuildJIT(MM: *(),
+        pub unsafe fn LLVMRustExecuteJIT(MM: *(),
                               PM: PassManagerRef,
                               M: ModuleRef,
                               OptLevel: c_int,
-                              EnableSegmentedStacks: bool) -> ExecutionEngineRef;
+                              EnableSegmentedStacks: bool) -> *();
 
         /** Parses the bitcode in the given memory buffer. */
         #[fast_ffi]

src/librustc/middle/trans/base.rs

@@ -3018,7 +3018,7 @@ pub fn trans_crate(sess: session::Session,
                    tcx: ty::ctxt,
                    output: &Path,
                    emap2: resolve::ExportMap2,
-                   maps: astencode::Maps) -> (ContextRef, ModuleRef, LinkMeta) {
+                   maps: astencode::Maps) -> (ModuleRef, LinkMeta) {
 
     let symbol_hasher = @mut hash::default_state();
     let link_meta = link::build_link_meta(sess, crate, output, symbol_hasher);
@@ -3040,11 +3040,9 @@ pub fn trans_crate(sess: session::Session,
     let llmod_id = link_meta.name.to_owned() + ".rc";
 
     unsafe {
-        // FIXME(#6511): get LLVM building with --enable-threads so this
-        //               function can be called
-        // if !llvm::LLVMRustStartMultithreading() {
-        //     sess.bug("couldn't enable multi-threaded LLVM");
-        // }
+        if !llvm::LLVMRustStartMultithreading() {
+            sess.bug("couldn't enable multi-threaded LLVM");
+        }
         let llcx = llvm::LLVMContextCreate();
         set_task_llcx(llcx);
         let llmod = str::as_c_str(llmod_id, |buf| {
@@ -3180,8 +3178,7 @@ pub fn trans_crate(sess: session::Session,
                 io::println(fmt!("%-7u %s", v, k));
             }
         }
-        unset_task_llcx();
-        return (llcx, llmod, link_meta);
+        return (llmod, link_meta);
     }
 }
 
@@ -3192,10 +3189,8 @@ pub fn task_llcx() -> ContextRef {
     *opt.expect("task-local LLVMContextRef wasn't ever set!")
 }
 
-unsafe fn set_task_llcx(c: ContextRef) {
-    local_data::local_data_set(task_local_llcx_key, @c);
-}
-
-unsafe fn unset_task_llcx() {
-    local_data::local_data_pop(task_local_llcx_key);
+fn set_task_llcx(c: ContextRef) {
+    unsafe {
+        local_data::local_data_set(task_local_llcx_key, @c);
+    }
 }

src/librusti/rusti.rc

@@ -648,5 +648,9 @@ mod tests {
             fn f() {}
             f()
         ");
+
+        debug!("regression test for #5803");
+        run_cmds(["spawn( || println(\"Please don't segfault\") );",
+                  "do spawn { println(\"Please?\"); }"]);
     }
 }

src/rustllvm/RustWrapper.cpp

@@ -329,12 +329,12 @@ LLVMRustLoadCrate(void* mem, const char* crate) {
   return true;
 }
 
-extern "C" LLVMExecutionEngineRef
-LLVMRustBuildJIT(void* mem,
-                 LLVMPassManagerRef PMR,
-                 LLVMModuleRef M,
-                 CodeGenOpt::Level OptLevel,
-                 bool EnableSegmentedStacks) {
+extern "C" void*
+LLVMRustExecuteJIT(void* mem,
+                   LLVMPassManagerRef PMR,
+                   LLVMModuleRef M,
+                   CodeGenOpt::Level OptLevel,
+                   bool EnableSegmentedStacks) {
 
   InitializeNativeTarget();
   InitializeNativeTargetAsmPrinter();
@@ -371,15 +371,21 @@ LLVMRustBuildJIT(void* mem,
 
   if(!EE || Err != "") {
     LLVMRustError = Err.c_str();
-    // The EngineBuilder only takes ownership of these two structures if the
-    // create() call is successful, but here it wasn't successful.
-    LLVMDisposeModule(M);
-    delete MM;
-    return NULL;
+    return 0;
   }
 
   MM->invalidateInstructionCache();
-  return wrap(EE);
+  Function* func = EE->FindFunctionNamed("_rust_main");
+
+  if(!func || Err != "") {
+    LLVMRustError = Err.c_str();
+    return 0;
+  }
+
+  void* entry = EE->getPointerToFunction(func);
+  assert(entry);
+
+  return entry;
 }
 
 extern "C" bool

src/rustllvm/rustllvm.def.in

@@ -6,14 +6,13 @@ LLVMRustConstSmallInt
 LLVMRustConstInt
 LLVMRustLoadCrate
 LLVMRustPrepareJIT
-LLVMRustBuildJIT
+LLVMRustExecuteJIT
 LLVMRustParseBitcode
 LLVMRustParseAssemblyFile
 LLVMRustPrintPassTimings
 LLVMRustStartMultithreading
 LLVMCreateObjectFile
 LLVMDisposeObjectFile
-LLVMDisposeExecutionEngine
 LLVMGetSections
 LLVMDisposeSectionIterator
 LLVMIsSectionIteratorAtEnd
@@ -357,7 +356,6 @@ LLVMGetParamParent
 LLVMGetParamTypes
 LLVMGetParams
 LLVMGetPointerAddressSpace
-LLVMGetPointerToGlobal
 LLVMGetPreviousBasicBlock
 LLVMGetPreviousFunction
 LLVMGetPreviousGlobal

src/rustllvm/rustllvm.h

@@ -45,7 +45,6 @@
 #include "llvm/Transforms/Vectorize.h"
 #include "llvm-c/Core.h"
 #include "llvm-c/BitReader.h"
-#include "llvm-c/ExecutionEngine.h"
 #include "llvm-c/Object.h"
 
 // Used by RustMCJITMemoryManager::getPointerToNamedFunction()