Auto merge of #55835 - alexcrichton:llvm-upgrade, r=nikomatsakis

Upgrade LLVM to trunk, still version 8

This commit upgrades the LLVM/LLD/compiler-rt submodules used to the current trunk versions in upstream. Some activity has happened on the wasm SIMD side of things as well as LLD which we'd like to pick up!

7 files changed, 27 insertions, 4 deletions

diff --git a/.travis.yml b/.travis.yml
index 14fb17aeedd..fa66220f442 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,7 +30,7 @@ matrix:
 
     - env: >
         RUST_CHECK_TARGET=dist
-        RUST_CONFIGURE_ARGS="--enable-extended --enable-profiler --enable-lldb --set rust.jemalloc"
+        RUST_CONFIGURE_ARGS="--enable-extended --enable-profiler --set rust.jemalloc"
         SRC=.
         DEPLOY_ALT=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
@@ -87,7 +87,7 @@ matrix:
     # OSX 10.7 and `xcode7` is the latest Xcode able to compile LLVM for 10.7.
     - env: >
         RUST_CHECK_TARGET=dist
-        RUST_CONFIGURE_ARGS="--build=i686-apple-darwin --enable-full-tools --enable-profiler --enable-lldb --set rust.jemalloc"
+        RUST_CONFIGURE_ARGS="--build=i686-apple-darwin --enable-full-tools --enable-profiler --set rust.jemalloc"
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
@@ -102,7 +102,7 @@ matrix:
 
     - env: >
         RUST_CHECK_TARGET=dist
-        RUST_CONFIGURE_ARGS="--target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-full-tools --enable-sanitizers --enable-profiler --enable-lldb --set rust.jemalloc"
+        RUST_CONFIGURE_ARGS="--target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-full-tools --enable-sanitizers --enable-profiler --set rust.jemalloc"
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
diff --git a/src/libcompiler_builtins b/src/libcompiler_builtins
-Subproject 939cbca6e9d829265d6cf006d3532142a4061cd
+Subproject fe74674f6e4be76d47b66f67d529ebf4186f4eb
diff --git a/src/librustc_codegen_ssa/back/linker.rs b/src/librustc_codegen_ssa/back/linker.rs
index ec5ca580104..f3cc344254f 100644
--- a/src/librustc_codegen_ssa/back/linker.rs
+++ b/src/librustc_codegen_ssa/back/linker.rs
@@ -1037,6 +1037,17 @@ impl<'a> Linker for WasmLd<'a> {
         // indicative of bugs, let's prevent them.
         self.cmd.arg("--fatal-warnings");
 
+        // The symbol visibility story is a bit in flux right now with LLD.
+        // It's... not entirely clear to me what's going on, but this looks to
+        // make everything work when `export_symbols` isn't otherwise called for
+        // things like executables.
+        self.cmd.arg("--export-dynamic");
+
+        // LLD only implements C++-like demangling, which doesn't match our own
+        // mangling scheme. Tell LLD to not demangle anything and leave it up to
+        // us to demangle these symbols later.
+        self.cmd.arg("--no-demangle");
+
         ::std::mem::replace(&mut self.cmd, Command::new(""))
     }
 
diff --git a/src/llvm b/src/llvm
-Subproject 7051ead40a5f825878b59bf08d4e768be9e99a4
+Subproject 21a0c9ebc285d794a298e97717abad8d6135fa8
diff --git a/src/rustllvm/PassWrapper.cpp b/src/rustllvm/PassWrapper.cpp
index 3b0046222a9..06de0d6509b 100644
--- a/src/rustllvm/PassWrapper.cpp
+++ b/src/rustllvm/PassWrapper.cpp
@@ -922,7 +922,11 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules,
                               GlobalValue::LinkageTypes NewLinkage) {
     ResolvedODR[ModuleIdentifier][GUID] = NewLinkage;
   };
+#if LLVM_VERSION_GE(8, 0)
+  thinLTOResolvePrevailingInIndex(Ret->Index, isPrevailing, recordNewLinkage);
+#else
   thinLTOResolveWeakForLinkerInIndex(Ret->Index, isPrevailing, recordNewLinkage);
+#endif
 
   // Here we calculate an `ExportedGUIDs` set for use in the `isExported`
   // callback below. This callback below will dictate the linkage for all
@@ -977,7 +981,11 @@ extern "C" bool
 LLVMRustPrepareThinLTOResolveWeak(const LLVMRustThinLTOData *Data, LLVMModuleRef M) {
   Module &Mod = *unwrap(M);
   const auto &DefinedGlobals = Data->ModuleToDefinedGVSummaries.lookup(Mod.getModuleIdentifier());
+#if LLVM_VERSION_GE(8, 0)
+  thinLTOResolvePrevailingInModule(Mod, DefinedGlobals);
+#else
   thinLTOResolveWeakForLinkerModule(Mod, DefinedGlobals);
+#endif
   return true;
 }
 
diff --git a/src/rustllvm/RustWrapper.cpp b/src/rustllvm/RustWrapper.cpp
index f423503e19f..b6e07942f86 100644
--- a/src/rustllvm/RustWrapper.cpp
+++ b/src/rustllvm/RustWrapper.cpp
@@ -708,7 +708,11 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateStaticVariable(
   llvm::DIGlobalVariableExpression *VarExpr = Builder->createGlobalVariableExpression(
       unwrapDI<DIDescriptor>(Context), Name, LinkageName,
       unwrapDI<DIFile>(File), LineNo, unwrapDI<DIType>(Ty), IsLocalToUnit,
-      InitExpr, unwrapDIPtr<MDNode>(Decl), AlignInBits);
+      InitExpr, unwrapDIPtr<MDNode>(Decl),
+#if LLVM_VERSION_GE(8, 0)
+      /* templateParams */ nullptr,
+#endif
+      AlignInBits);
 
   InitVal->setMetadata("dbg", VarExpr);
 
diff --git a/src/tools/lld b/src/tools/lld
-Subproject 2a9b88b8b419d094fb2185c0ca31c28d31bdca0
+Subproject 1928c5eeb613a4c6d232fc47ae91914bbfd92a7