bump minimum LLVM version to 5.0

Author: gnzlbg

.travis.yml

@@ -12,7 +12,7 @@ matrix:
   fast_finish: true
   include:
     # Images used in testing PR and try-build should be run first.
-    - env: IMAGE=x86_64-gnu-llvm-3.9 RUST_BACKTRACE=1
+    - env: IMAGE=x86_64-gnu-llvm-5.0 RUST_BACKTRACE=1
       if: type = pull_request OR branch = auto
 
     - env: IMAGE=dist-x86_64-linux DEPLOY=1

src/bootstrap/native.rs

@@ -256,12 +256,12 @@ fn check_llvm_version(builder: &Builder, llvm_config: &Path) {
     let version = output(cmd.arg("--version"));
     let mut parts = version.split('.').take(2)
         .filter_map(|s| s.parse::<u32>().ok());
-    if let (Some(major), Some(minor)) = (parts.next(), parts.next()) {
-        if major > 3 || (major == 3 && minor >= 9) {
+    if let (Some(major), Some(_minor)) = (parts.next(), parts.next()) {
+        if major >= 5 {
             return
         }
     }
-    panic!("\n\nbad LLVM version: {}, need >=3.9\n\n", version)
+    panic!("\n\nbad LLVM version: {}, need >=5.0\n\n", version)
 }
 
 fn configure_cmake(builder: &Builder,

src/ci/docker/x86_64-gnu-llvm-3.9/Dockerfile renamed to src/ci/docker/x86_64-gnu-llvm-5.0/Dockerfile

@@ -11,7 +11,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   cmake \
   sudo \
   gdb \
-  llvm-3.9-tools \
+  llvm-5.0-tools \
   libedit-dev \
   zlib1g-dev \
   xz-utils
@@ -22,6 +22,6 @@ RUN sh /scripts/sccache.sh
 # using llvm-link-shared due to libffi issues -- see #34486
 ENV RUST_CONFIGURE_ARGS \
       --build=x86_64-unknown-linux-gnu \
-      --llvm-root=/usr/lib/llvm-3.9 \
+      --llvm-root=/usr/lib/llvm-5.0 \
       --enable-llvm-link-shared
 ENV RUST_CHECK_TARGET check

src/librustc_codegen_llvm/abi.rs

@@ -666,11 +666,7 @@ impl<'a, 'tcx> FnTypeExt<'a, 'tcx> for FnType<'tcx, Ty<'tcx>> {
                 layout::Int(..) if !scalar.is_bool() => {
                     let range = scalar.valid_range_exclusive(bx.cx);
                     if range.start != range.end {
-                        // FIXME(nox): This causes very weird type errors about
-                        // SHL operators in constants in stage 2 with LLVM 3.9.
-                        if unsafe { llvm::LLVMRustVersionMajor() >= 4 } {
-                            bx.range_metadata(callsite, range);
-                        }
+                        bx.range_metadata(callsite, range);
                     }
                 }
                 _ => {}

src/librustc_codegen_llvm/mir/mod.rs

@@ -22,7 +22,7 @@ use builder::Builder;
 use common::{CodegenCx, Funclet};
 use debuginfo::{self, declare_local, VariableAccess, VariableKind, FunctionDebugContext};
 use monomorphize::Instance;
-use abi::{ArgAttribute, ArgTypeExt, FnType, FnTypeExt, PassMode};
+use abi::{ArgTypeExt, FnType, FnTypeExt, PassMode};
 use type_::Type;
 
 use syntax_pos::{DUMMY_SP, NO_EXPANSION, BytePos, Span};
@@ -430,10 +430,6 @@ fn arg_local_refs<'a, 'tcx>(bx: &Builder<'a, 'tcx>,
         None
     };
 
-    let deref_op = unsafe {
-        [llvm::LLVMRustDIBuilderCreateOpDeref()]
-    };
-
     mir.args_iter().enumerate().map(|(arg_index, local)| {
         let arg_decl = &mir.local_decls[local];
 
@@ -543,21 +539,11 @@ fn arg_local_refs<'a, 'tcx>(bx: &Builder<'a, 'tcx>,
             if arg_index > 0 || mir.upvar_decls.is_empty() {
                 // The Rust ABI passes indirect variables using a pointer and a manual copy, so we
                 // need to insert a deref here, but the C ABI uses a pointer and a copy using the
-                // byval attribute, for which LLVM does the deref itself, so we must not add it.
-                // Starting with D31439 in LLVM 5, it *always* does the deref itself.
-                let mut variable_access = VariableAccess::DirectVariable {
+                // byval attribute, for which LLVM always does the deref itself,
+                // so we must not add it.
+                let variable_access = VariableAccess::DirectVariable {
                     alloca: place.llval
                 };
-                if unsafe { llvm::LLVMRustVersionMajor() < 5 } {
-                    if let PassMode::Indirect(ref attrs) = arg.mode {
-                        if !attrs.contains(ArgAttribute::ByVal) {
-                            variable_access = VariableAccess::IndirectVariable {
-                                alloca: place.llval,
-                                address_operations: &deref_op,
-                            };
-                        }
-                    }
-                }
 
                 declare_local(
                     bx,