Rollup merge of #47710 - alexcrichton:llvm-6-compat, r=nikomatsakis

First round of LLVM 6.0.0 compatibility

This includes a number of commits for the first round of upgrading to LLVM 6. There are still [lingering bugs](https://github.com/rust-lang/rust/issues/47683) but I believe all of this will nonetheless be necessary!

src/ci/docker/dist-i686-freebsd/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:16.04
+FROM ubuntu:18.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
   clang \

src/ci/docker/dist-x86_64-freebsd/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:16.04
+FROM ubuntu:18.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
   clang \

src/librustc_back/target/mod.rs

@@ -320,8 +320,8 @@ pub struct TargetOptions {
     /// Relocation model to use in object file. Corresponds to `llc
     /// -relocation-model=$relocation_model`. Defaults to "pic".
     pub relocation_model: String,
-    /// Code model to use. Corresponds to `llc -code-model=$code_model`. Defaults to "default".
-    pub code_model: String,
+    /// Code model to use. Corresponds to `llc -code-model=$code_model`.
+    pub code_model: Option<String>,
     /// TLS model to use. Options are "global-dynamic" (default), "local-dynamic", "initial-exec"
     /// and "local-exec". This is similar to the -ftls-model option in GCC/Clang.
     pub tls_model: String,
@@ -483,7 +483,7 @@ impl Default for TargetOptions {
             only_cdylib: false,
             executables: false,
             relocation_model: "pic".to_string(),
-            code_model: "default".to_string(),
+            code_model: None,
             tls_model: "global-dynamic".to_string(),
             disable_redzone: false,
             eliminate_frame_pointer: true,
@@ -736,7 +736,7 @@ impl Target {
         key!(only_cdylib, bool);
         key!(executables, bool);
         key!(relocation_model);
-        key!(code_model);
+        key!(code_model, optional);
         key!(tls_model);
         key!(disable_redzone, bool);
         key!(eliminate_frame_pointer, bool);

src/librustc_llvm/ffi.rs

@@ -299,12 +299,11 @@ pub enum RelocMode {
 #[repr(C)]
 pub enum CodeModel {
     Other,
-    Default,
-    JITDefault,
     Small,
     Kernel,
     Medium,
     Large,
+    None,
 }
 
 /// LLVMRustDiagnosticKind
@@ -331,7 +330,6 @@ pub enum DiagnosticKind {
 pub enum ArchiveKind {
     Other,
     K_GNU,
-    K_MIPS64,
     K_BSD,
     K_COFF,
 }

src/librustc_llvm/lib.rs

@@ -105,7 +105,6 @@ impl FromStr for ArchiveKind {
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         match s {
             "gnu" => Ok(ArchiveKind::K_GNU),
-            "mips64" => Ok(ArchiveKind::K_MIPS64),
             "bsd" => Ok(ArchiveKind::K_BSD),
             "coff" => Ok(ArchiveKind::K_COFF),
             _ => Err(()),

src/librustc_trans/back/write.rs

@@ -69,8 +69,7 @@ pub const RELOC_MODEL_ARGS : [(&'static str, llvm::RelocMode); 7] = [
     ("ropi-rwpi", llvm::RelocMode::ROPI_RWPI),
 ];
 
-pub const CODE_GEN_MODEL_ARGS : [(&'static str, llvm::CodeModel); 5] = [
-    ("default", llvm::CodeModel::Default),
+pub const CODE_GEN_MODEL_ARGS: &[(&str, llvm::CodeModel)] = &[
     ("small", llvm::CodeModel::Small),
     ("kernel", llvm::CodeModel::Kernel),
     ("medium", llvm::CodeModel::Medium),
@@ -171,20 +170,23 @@ pub fn target_machine_factory(sess: &Session)
     let ffunction_sections = sess.target.target.options.function_sections;
     let fdata_sections = ffunction_sections;
 
-    let code_model_arg = match sess.opts.cg.code_model {
-        Some(ref s) => &s,
-        None => &sess.target.target.options.code_model,
-    };
+    let code_model_arg = sess.opts.cg.code_model.as_ref().or(
+        sess.target.target.options.code_model.as_ref(),
+    );
 
-    let code_model = match CODE_GEN_MODEL_ARGS.iter().find(
-        |&&arg| arg.0 == code_model_arg) {
-        Some(x) => x.1,
-        _ => {
-            sess.err(&format!("{:?} is not a valid code model",
-                              code_model_arg));
-            sess.abort_if_errors();
-            bug!();
+    let code_model = match code_model_arg {
+        Some(s) => {
+            match CODE_GEN_MODEL_ARGS.iter().find(|arg| arg.0 == s) {
+                Some(x) => x.1,
+                _ => {
+                    sess.err(&format!("{:?} is not a valid code model",
+                                      code_model_arg));
+                    sess.abort_if_errors();
+                    bug!();
+                }
+            }
         }
+        None => llvm::CodeModel::None,
     };
 
     let singlethread = sess.target.target.options.singlethread;
@@ -746,7 +748,7 @@ unsafe fn codegen(cgcx: &CodegenContext,
             // We can't use the same module for asm and binary output, because that triggers
             // various errors like invalid IR or broken binaries, so we might have to clone the
             // module to produce the asm output
-            let llmod = if config.emit_obj {
+            let llmod = if config.emit_obj && !asm2wasm {
                 llvm::LLVMCloneModule(llmod)
             } else {
                 llmod
@@ -755,7 +757,7 @@ unsafe fn codegen(cgcx: &CodegenContext,
                 write_output_file(diag_handler, tm, cpm, llmod, &path,
                                   llvm::FileType::AssemblyFile)
             })?;
-            if config.emit_obj {
+            if config.emit_obj && !asm2wasm {
                 llvm::LLVMDisposeModule(llmod);
             }
             timeline.record("asm");

src/llvm-emscripten

@@ -0,0 +1 @@
+Subproject commit 2717444753318e461e0c3b30dacd03ffbac96903

src/rustllvm/ArchiveWrapper.cpp

@@ -42,7 +42,6 @@ struct RustArchiveIterator {
 enum class LLVMRustArchiveKind {
   Other,
   GNU,
-  MIPS64,
   BSD,
   COFF,
 };
@@ -51,8 +50,6 @@ static Archive::Kind fromRust(LLVMRustArchiveKind Kind) {
   switch (Kind) {
   case LLVMRustArchiveKind::GNU:
     return Archive::K_GNU;
-  case LLVMRustArchiveKind::MIPS64:
-    return Archive::K_MIPS64;
   case LLVMRustArchiveKind::BSD:
     return Archive::K_BSD;
   case LLVMRustArchiveKind::COFF:
@@ -235,9 +232,16 @@ LLVMRustWriteArchive(char *Dst, size_t NumMembers,
       Members.push_back(std::move(*MOrErr));
     }
   }
-  auto Pair = writeArchive(Dst, Members, WriteSymbtab, Kind, true, false);
-  if (!Pair.second)
+  auto Result = writeArchive(Dst, Members, WriteSymbtab, Kind, true, false);
+#if LLVM_VERSION_GE(6, 0)
+  if (!Result)
     return LLVMRustResult::Success;
-  LLVMRustSetLastError(Pair.second.message().c_str());
+  LLVMRustSetLastError(toString(std::move(Result)).c_str());
+#else
+  if (!Result.second)
+    return LLVMRustResult::Success;
+  LLVMRustSetLastError(Result.second.message().c_str());
+#endif
+
   return LLVMRustResult::Failure;
 }

src/rustllvm/PassWrapper.cpp

@@ -23,9 +23,15 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 
+#if LLVM_VERSION_GE(6, 0)
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
+#include "llvm/IR/IntrinsicInst.h"
+#else
+#include "llvm/Target/TargetSubtargetInfo.h"
+#endif
+
 #if LLVM_VERSION_GE(4, 0)
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
@@ -210,20 +216,15 @@ extern "C" bool LLVMRustHasFeature(LLVMTargetMachineRef TM,
 
 enum class LLVMRustCodeModel {
   Other,
-  Default,
-  JITDefault,
   Small,
   Kernel,
   Medium,
   Large,
+  None,
 };
 
 static CodeModel::Model fromRust(LLVMRustCodeModel Model) {
   switch (Model) {
-  case LLVMRustCodeModel::Default:
-    return CodeModel::Default;
-  case LLVMRustCodeModel::JITDefault:
-    return CodeModel::JITDefault;
   case LLVMRustCodeModel::Small:
     return CodeModel::Small;
   case LLVMRustCodeModel::Kernel:
@@ -360,7 +361,6 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     bool TrapUnreachable,
     bool Singlethread) {
 
-  auto CM = fromRust(RustCM);
   auto OptLevel = fromRust(RustOptLevel);
   auto RM = fromRust(RustReloc);
 
@@ -399,6 +399,13 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     Options.ThreadModel = ThreadModel::Single;
   }
 
+#if LLVM_VERSION_GE(6, 0)
+  Optional<CodeModel::Model> CM;
+#else
+  CodeModel::Model CM = CodeModel::Model::Default;
+#endif
+  if (RustCM != LLVMRustCodeModel::None)
+    CM = fromRust(RustCM);
   TargetMachine *TM = TheTarget->createTargetMachine(
       Trip.getTriple(), RealCPU, Feature, Options, RM, CM, OptLevel);
   return wrap(TM);

src/rustllvm/RustWrapper.cpp

@@ -315,7 +315,11 @@ extern "C" void LLVMRustRemoveFunctionAttributes(LLVMValueRef Fn,
 // enable fpmath flag UnsafeAlgebra
 extern "C" void LLVMRustSetHasUnsafeAlgebra(LLVMValueRef V) {
   if (auto I = dyn_cast<Instruction>(unwrap<Value>(V))) {
+#if LLVM_VERSION_GE(6, 0)
+    I->setFast(true);
+#else
     I->setHasUnsafeAlgebra(true);
+#endif
   }
 }