Auto merge of #27176 - alexcrichton:fix-stock-llvm, r=brson

This commit moves the IR files in the distribution, rust_try.ll,
rust_try_msvc_64.ll, and rust_try_msvc_32.ll into the compiler from the main
distribution. There's a few reasons for this change:

* LLVM changes its IR syntax from time to time, so it's very difficult to
  have these files build across many LLVM versions simultaneously. We'll likely
  want to retain this ability for quite some time into the future.
* The implementation of these files is closely tied to the compiler and runtime
  itself, so it makes sense to fold it into a location which can do more
  platform-specific checks for various implementation details (such as MSVC 32
  vs 64-bit).
* This removes LLVM as a build-time dependency of the standard library. This may
  end up becoming very useful if we move towards building the standard library
  with Cargo.

In the immediate future, however, this commit should restore compatibility with
LLVM 3.5 and 3.6.

Author: bors

mk/rt.mk

@@ -54,15 +54,6 @@ NATIVE_DEPS_miniz_$(1) = miniz.c
 NATIVE_DEPS_rust_builtin_$(1) := rust_builtin.c \
 			rust_android_dummy.c
 NATIVE_DEPS_rustrt_native_$(1) := arch/$$(HOST_$(1))/record_sp.S
-ifeq ($$(findstring msvc,$(1)),msvc)
-ifeq ($$(findstring i686,$(1)),i686)
-NATIVE_DEPS_rustrt_native_$(1) += rust_try_msvc_32.ll
-else
-NATIVE_DEPS_rustrt_native_$(1) += rust_try_msvc_64.ll
-endif
-else
-NATIVE_DEPS_rustrt_native_$(1) += rust_try.ll
-endif
 NATIVE_DEPS_rust_test_helpers_$(1) := rust_test_helpers.c
 NATIVE_DEPS_morestack_$(1) := arch/$$(HOST_$(1))/morestack.S
 
@@ -76,14 +67,6 @@ NATIVE_DEPS_morestack_$(1) := arch/$$(HOST_$(1))/morestack.S
 
 RT_OUTPUT_DIR_$(1) := $(1)/rt
 
-$$(RT_OUTPUT_DIR_$(1))/%.o: $(S)src/rt/%.ll $$(MKFILE_DEPS) \
-	    $$(LLVM_CONFIG_$$(CFG_BUILD))
-	@mkdir -p $$(@D)
-	@$$(call E, compile: $$@)
-	$$(Q)$$(LLC_$$(CFG_BUILD)) $$(CFG_LLC_FLAGS_$(1)) \
-	    -filetype=obj -mtriple=$$(CFG_LLVM_TARGET_$(1)) \
-	    -relocation-model=pic -o $$@ $$<
-
 $$(RT_OUTPUT_DIR_$(1))/%.o: $(S)src/rt/%.c $$(MKFILE_DEPS)
 	@mkdir -p $$(@D)
 	@$$(call E, compile: $$@)
@@ -122,7 +105,6 @@ define THIRD_PARTY_LIB
 OBJS_$(2)_$(1) := $$(NATIVE_DEPS_$(2)_$(1):%=$$(RT_OUTPUT_DIR_$(1))/%)
 OBJS_$(2)_$(1) := $$(OBJS_$(2)_$(1):.c=.o)
 OBJS_$(2)_$(1) := $$(OBJS_$(2)_$(1):.cpp=.o)
-OBJS_$(2)_$(1) := $$(OBJS_$(2)_$(1):.ll=.o)
 OBJS_$(2)_$(1) := $$(OBJS_$(2)_$(1):.S=.o)
 NATIVE_$(2)_$(1) := $$(call CFG_STATIC_LIB_NAME_$(1),$(2))
 $$(RT_OUTPUT_DIR_$(1))/$$(NATIVE_$(2)_$(1)): $$(OBJS_$(2)_$(1))

src/libcore/intrinsics.rs

@@ -602,4 +602,10 @@ extern "rust-intrinsic" {
     /// Returns the value of the discriminant for the variant in 'v',
     /// cast to a `u64`; if `T` has no discriminant, returns 0.
     pub fn discriminant_value<T>(v: &T) -> u64;
+
+    /// Rust's "try catch" construct which invokes the function pointer `f` with
+    /// the data pointer `data`, returning the exception payload if an exception
+    /// is thrown (aka the thread panics).
+    #[cfg(not(stage0))]
+    pub fn try(f: fn(*mut u8), data: *mut u8) -> *mut u8;
 }

src/librustc/middle/lang_items.rs

@@ -326,6 +326,8 @@ lets_do_this! {
     StartFnLangItem,                 "start",                   start_fn;
 
     EhPersonalityLangItem,           "eh_personality",          eh_personality;
+    EhPersonalityCatchLangItem,      "eh_personality_catch",    eh_personality_catch;
+    MSVCTryFilterLangItem,           "msvc_try_filter",         msvc_try_filter;
 
     ExchangeHeapLangItem,            "exchange_heap",           exchange_heap;
     OwnedBoxLangItem,                "owned_box",               owned_box;

src/librustc/middle/weak_lang_items.rs

@@ -119,7 +119,7 @@ impl<'a, 'v> Visitor<'v> for Context<'a> {
 ) }
 
 weak_lang_items! {
-    panic_fmt,          PanicFmtLangItem,            rust_begin_unwind;
+    panic_fmt,          PanicFmtLangItem,           rust_begin_unwind;
     stack_exhausted,    StackExhaustedLangItem,     rust_stack_exhausted;
     eh_personality,     EhPersonalityLangItem,      rust_eh_personality;
 }

src/librustc_llvm/lib.rs

@@ -134,7 +134,7 @@ pub enum DLLStorageClassTypes {
 }
 
 bitflags! {
-    flags Attribute : u32 {
+    flags Attribute : u64 {
         const ZExt            = 1 << 0,
         const SExt            = 1 << 1,
         const NoReturn        = 1 << 2,
@@ -161,6 +161,7 @@ bitflags! {
         const ReturnsTwice    = 1 << 29,
         const UWTable         = 1 << 30,
         const NonLazyBind     = 1 << 31,
+        const OptimizeNone    = 1 << 42,
     }
 }
 
@@ -2193,7 +2194,8 @@ pub fn ConstFCmp(pred: RealPredicate, v1: ValueRef, v2: ValueRef) -> ValueRef {
 
 pub fn SetFunctionAttribute(fn_: ValueRef, attr: Attribute) {
     unsafe {
-        LLVMAddFunctionAttribute(fn_, FunctionIndex as c_uint, attr.bits() as uint64_t)
+        LLVMAddFunctionAttribute(fn_, FunctionIndex as c_uint,
+                                 attr.bits() as uint64_t)
     }
 }
 

src/librustc_trans/trans/build.rs

@@ -1042,6 +1042,10 @@ pub fn LandingPad(cx: Block, ty: Type, pers_fn: ValueRef,
     B(cx).landing_pad(ty, pers_fn, num_clauses, cx.fcx.llfn)
 }
 
+pub fn AddClause(cx: Block, landing_pad: ValueRef, clause: ValueRef) {
+    B(cx).add_clause(landing_pad, clause)
+}
+
 pub fn SetCleanup(cx: Block, landing_pad: ValueRef) {
     B(cx).set_cleanup(landing_pad)
 }

src/librustc_trans/trans/builder.rs

@@ -937,6 +937,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         }
     }
 
+    pub fn add_clause(&self, landing_pad: ValueRef, clause: ValueRef) {
+        unsafe {
+            llvm::LLVMAddClause(landing_pad, clause);
+        }
+    }
+
     pub fn set_cleanup(&self, landing_pad: ValueRef) {
         self.count_insn("setcleanup");
         unsafe {

src/librustc_trans/trans/callee.rs

@@ -620,16 +620,17 @@ pub fn trans_lang_call<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     }, ArgVals(args), dest)
 }
 
-/// This behemoth of a function translates function calls. Unfortunately, in order to generate more
-/// efficient LLVM output at -O0, it has quite a complex signature (refactoring this into two
-/// functions seems like a good idea).
+/// This behemoth of a function translates function calls. Unfortunately, in
+/// order to generate more efficient LLVM output at -O0, it has quite a complex
+/// signature (refactoring this into two functions seems like a good idea).
 ///
-/// In particular, for lang items, it is invoked with a dest of None, and in that case the return
-/// value contains the result of the fn. The lang item must not return a structural type or else
-/// all heck breaks loose.
+/// In particular, for lang items, it is invoked with a dest of None, and in
+/// that case the return value contains the result of the fn. The lang item must
+/// not return a structural type or else all heck breaks loose.
 ///
-/// For non-lang items, `dest` is always Some, and hence the result is written into memory
-/// somewhere. Nonetheless we return the actual return value of the function.
+/// For non-lang items, `dest` is always Some, and hence the result is written
+/// into memory somewhere. Nonetheless we return the actual return value of the
+/// function.
 pub fn trans_call_inner<'a, 'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
                                            debug_loc: DebugLoc,
                                            get_callee: F,

src/librustc_trans/trans/cleanup.rs

@@ -122,11 +122,9 @@ pub use self::Heap::*;
 use llvm::{BasicBlockRef, ValueRef};
 use trans::base;
 use trans::build;
-use trans::callee;
 use trans::common;
-use trans::common::{Block, FunctionContext, ExprId, NodeIdAndSpan};
+use trans::common::{Block, FunctionContext, NodeIdAndSpan};
 use trans::debuginfo::{DebugLoc, ToDebugLoc};
-use trans::declare;
 use trans::glue;
 use middle::region;
 use trans::type_::Type;
@@ -833,53 +831,7 @@ impl<'blk, 'tcx> CleanupHelperMethods<'blk, 'tcx> for FunctionContext<'blk, 'tcx
                                     &[Type::i8p(self.ccx), Type::i32(self.ccx)],
                                     false);
 
-        // The exception handling personality function.
-        //
-        // If our compilation unit has the `eh_personality` lang item somewhere
-        // within it, then we just need to translate that. Otherwise, we're
-        // building an rlib which will depend on some upstream implementation of
-        // this function, so we just codegen a generic reference to it. We don't
-        // specify any of the types for the function, we just make it a symbol
-        // that LLVM can later use.
-        //
-        // Note that MSVC is a little special here in that we don't use the
-        // `eh_personality` lang item at all. Currently LLVM has support for
-        // both Dwarf and SEH unwind mechanisms for MSVC targets and uses the
-        // *name of the personality function* to decide what kind of unwind side
-        // tables/landing pads to emit. It looks like Dwarf is used by default,
-        // injecting a dependency on the `_Unwind_Resume` symbol for resuming
-        // an "exception", but for MSVC we want to force SEH. This means that we
-        // can't actually have the personality function be our standard
-        // `rust_eh_personality` function, but rather we wired it up to the
-        // CRT's custom personality function, which forces LLVM to consider
-        // landing pads as "landing pads for SEH".
-        let target = &self.ccx.sess().target.target;
-        let llpersonality = match pad_bcx.tcx().lang_items.eh_personality() {
-            Some(def_id) if !target.options.is_like_msvc => {
-                callee::trans_fn_ref(pad_bcx.ccx(), def_id, ExprId(0),
-                                     pad_bcx.fcx.param_substs).val
-            }
-            _ => {
-                let mut personality = self.ccx.eh_personality().borrow_mut();
-                match *personality {
-                    Some(llpersonality) => llpersonality,
-                    None => {
-                        let name = if !target.options.is_like_msvc {
-                            "rust_eh_personality"
-                        } else if target.arch == "x86" {
-                            "_except_handler3"
-                        } else {
-                            "__C_specific_handler"
-                        };
-                        let fty = Type::variadic_func(&[], &Type::i32(self.ccx));
-                        let f = declare::declare_cfn(self.ccx, name, fty,
-                                                     self.ccx.tcx().types.i32);
-                        *personality = Some(f);
-                        f
-                    }
-                }
-            }
-        };
+        let llpersonality = pad_bcx.fcx.eh_personality();
 
         // The only landing pad clause will be 'cleanup'
         let llretval = build::LandingPad(pad_bcx, llretty, llpersonality, 1);

src/librustc_trans/trans/closure.rs

@@ -163,11 +163,10 @@ pub fn get_or_create_declaration_if_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tc
         mangle_internal_name_by_path_and_seq(path, "closure")
     });
 
-    // Currently there’s only a single user of get_or_create_declaration_if_closure and it
-    // unconditionally defines the function, therefore we use define_* here.
-    let llfn = declare::define_internal_rust_fn(ccx, &symbol[..], function_type).unwrap_or_else(||{
-        ccx.sess().bug(&format!("symbol `{}` already defined", symbol));
-    });
+    // Currently there’s only a single user of
+    // get_or_create_declaration_if_closure and it unconditionally defines the
+    // function, therefore we use define_* here.
+    let llfn = declare::define_internal_rust_fn(ccx, &symbol[..], function_type);
 
     // set an inline hint for all closures
     attributes::inline(llfn, attributes::InlineAttr::Hint);
@@ -388,11 +387,8 @@ fn trans_fn_once_adapter_shim<'a, 'tcx>(
 
     // Create the by-value helper.
     let function_name = link::mangle_internal_name_by_type_and_seq(ccx, llonce_fn_ty, "once_shim");
-    let lloncefn = declare::define_internal_rust_fn(ccx, &function_name[..], llonce_fn_ty)
-        .unwrap_or_else(||{
-            ccx.sess().bug(&format!("symbol `{}` already defined", function_name));
-        });
-
+    let lloncefn = declare::define_internal_rust_fn(ccx, &function_name,
+                                                    llonce_fn_ty);
     let sig = tcx.erase_late_bound_regions(&llonce_bare_fn_ty.sig);
     let (block_arena, fcx): (TypedArena<_>, FunctionContext);
     block_arena = TypedArena::new();