Auto merge of #67759 - nikic:llvm-10, r=<try>

Update to LLVM 10

LLVM 10 is going to be branched soon, so it's a good time to start finding all those tasty new miscompiles and performance regressions ;)

Status:

 * Preparation split off into #67900.
 * Optimization regressions:
   * [x] https://bugs.llvm.org/show_bug.cgi?id=44419 => https://reviews.llvm.org/D72048 has landed.
   * [x] https://bugs.llvm.org/show_bug.cgi?id=44423 => https://reviews.llvm.org/D72060 has landed.
   * [ ] https://reviews.llvm.org/D72169 submitted.
   * [ ] https://bugs.llvm.org/show_bug.cgi?id=44461 reported. https://reviews.llvm.org/D72420 submitted, but unlikely eligible for LLVM 10.
 * Compile-time regressions:
   * [x] GlobalOpt regression identified. ~~fhahn proposed https://reviews.llvm.org/D72214.~~ fhahn has [reverted](llvm/llvm-project@192cce1) the patch.
   * [ ] Even with the revert, there are [large regressions](https://perf.rust-lang.org/compare.html?start=760ce94c69ca510d44087291c311296f6d9ccdf5&end=4e84f97d76e694bb9f59039f5bdeb6d8bca46d14).
 * Assertion failures / infinite loops:
   * [x] https://bugs.llvm.org/show_bug.cgi?id=44600 => https://reviews.llvm.org/D73135, https://reviews.llvm.org/D73854 and https://reviews.llvm.org/D73908 have landed and been cherry-picked to the 10.x branch.
   * [x] https://bugs.llvm.org/show_bug.cgi?id=44835 => https://reviews.llvm.org/D74278 has landed and been cherry-picked.

r? @ghost

.gitmodules

@@ -40,7 +40,7 @@
 [submodule "src/llvm-project"]
 	path = src/llvm-project
 	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/9.0-2019-12-19
+	branch = rustc/10.0-2020-02-05
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book
 	url = https://github.com/rust-embedded/book.git

src/bootstrap/test.rs

@@ -1140,6 +1140,8 @@ impl Step for Compiletest {
             let llvm_config = builder.ensure(native::Llvm { target: builder.config.build });
             if !builder.config.dry_run {
                 let llvm_version = output(Command::new(&llvm_config).arg("--version"));
+                // Remove trailing newline from llvm-config output.
+                let llvm_version = llvm_version.trim_end();
                 cmd.arg("--llvm-version").arg(llvm_version);
             }
             if !builder.is_rust_llvm(target) {

src/rustllvm/PassWrapper.cpp

@@ -59,7 +59,11 @@ extern "C" void LLVMInitializePasses() {
 }
 
 extern "C" void LLVMTimeTraceProfilerInitialize() {
-#if LLVM_VERSION_GE(9, 0)
+#if LLVM_VERSION_GE(10, 0)
+  timeTraceProfilerInitialize(
+      /* TimeTraceGranularity */ 0,
+      /* ProcName */ "rustc");
+#elif LLVM_VERSION_GE(9, 0)
   timeTraceProfilerInitialize();
 #endif
 }

src/test/run-make-fulldeps/target-specs/my-awesome-platform.json

@@ -1,5 +1,5 @@
 {
-    "data-layout": "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128",
+    "data-layout": "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128",
     "linker-flavor": "gcc",
     "llvm-target": "i686-unknown-linux-gnu",
     "target-endian": "little",

src/test/run-make-fulldeps/target-specs/my-x86_64-unknown-linux-gnu-platform.json

@@ -1,6 +1,6 @@
 {
     "pre-link-args": {"gcc": ["-m64"]},
-    "data-layout": "e-m:e-i64:64-f80:128-n8:16:32:64-S128",
+    "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
     "linker-flavor": "gcc",
     "llvm-target": "x86_64-unknown-linux-gnu",
     "target-endian": "little",

src/tools/compiletest/src/header.rs

@@ -191,6 +191,7 @@ impl EarlyProps {
                 return true;
             }
             if let Some(ref actual_version) = config.llvm_version {
+                let actual_version = version_to_int(actual_version);
                 if line.starts_with("min-llvm-version") {
                     let min_version = line
                         .trim_end()
@@ -199,7 +200,7 @@ impl EarlyProps {
                         .expect("Malformed llvm version directive");
                     // Ignore if actual version is smaller the minimum required
                     // version
-                    &actual_version[..] < min_version
+                    actual_version < version_to_int(min_version)
                 } else if line.starts_with("min-system-llvm-version") {
                     let min_version = line
                         .trim_end()
@@ -208,7 +209,7 @@ impl EarlyProps {
                         .expect("Malformed llvm version directive");
                     // Ignore if using system LLVM and actual version
                     // is smaller the minimum required version
-                    config.system_llvm && &actual_version[..] < min_version
+                    config.system_llvm && actual_version < version_to_int(min_version)
                 } else if line.starts_with("ignore-llvm-version") {
                     // Syntax is: "ignore-llvm-version <version1> [- <version2>]"
                     let range_components = line
@@ -219,15 +220,15 @@ impl EarlyProps {
                         .take(3) // 3 or more = invalid, so take at most 3.
                         .collect::<Vec<&str>>();
                     match range_components.len() {
-                        1 => &actual_version[..] == range_components[0],
+                        1 => actual_version == version_to_int(range_components[0]),
                         2 => {
-                            let v_min = range_components[0];
-                            let v_max = range_components[1];
+                            let v_min = version_to_int(range_components[0]);
+                            let v_max = version_to_int(range_components[1]);
                             if v_max < v_min {
                                 panic!("Malformed LLVM version range: max < min")
                             }
                             // Ignore if version lies inside of range.
-                            &actual_version[..] >= v_min && &actual_version[..] <= v_max
+                            actual_version >= v_min && actual_version <= v_max
                         }
                         _ => panic!("Malformed LLVM version directive"),
                     }
@@ -238,6 +239,20 @@ impl EarlyProps {
                 false
             }
         }
+
+        fn version_to_int(version: &str) -> u32 {
+            let version_without_suffix = version.split('-').next().unwrap();
+            let components: Vec<u32> = version_without_suffix
+                .split('.')
+                .map(|s| s.parse().expect("Malformed version component"))
+                .collect();
+            match components.len() {
+                1 => components[0] * 10000,
+                2 => components[0] * 10000 + components[1] * 100,
+                3 => components[0] * 10000 + components[1] * 100 + components[2],
+                _ => panic!("Malformed version"),
+            }
+        }
     }
 }