Rollup merge of rust-lang#72937 - AdrianCX:master, r=nikomatsakis

Fortanix SGX target libunwind build process changes

Ticket: fortanix/rust-sgx#174
LLVM related changes (merged): rust-lang/llvm-project#57

Description: libunwind changes needed to run code in sgx environment via rust-sgx.

Target that uses this in rust: x86_64-fortanix-unknown-sgx.

Without this change, rust std for this toolchain is forced to use a precompiled library loaded via environment variable.

With this change we act the same as musl target.

src/bootstrap/compile.rs

@@ -131,26 +131,13 @@ fn copy_third_party_objects(
     compiler: &Compiler,
     target: Interned<String>,
 ) -> Vec<(PathBuf, DependencyType)> {
-    let libdir = builder.sysroot_libdir(*compiler, target);
     let mut target_deps = vec![];
 
-    // Copies libunwind.a compiled to be linked with x86_64-fortanix-unknown-sgx.
-    //
-    // This target needs to be linked to Fortanix's port of llvm's libunwind.
-    // libunwind requires support for rwlock and printing to stderr,
-    // which is provided by std for this target.
+    // FIXME: remove this in 2021
     if target == "x86_64-fortanix-unknown-sgx" {
-        let src_path_env = "X86_FORTANIX_SGX_LIBS";
-        let src =
-            env::var(src_path_env).unwrap_or_else(|_| panic!("{} not found in env", src_path_env));
-        copy_and_stamp(
-            builder,
-            &*libdir,
-            Path::new(&src),
-            "libunwind.a",
-            &mut target_deps,
-            DependencyType::Target,
-        );
+        if env::var_os("X86_FORTANIX_SGX_LIBS").is_some() {
+            builder.info("Warning: X86_FORTANIX_SGX_LIBS environment variable is ignored, libunwind is now compiled as part of rustbuild");
+        }
     }
 
     if builder.config.sanitizers && compiler.stage != 0 {

src/ci/docker/dist-various-2/Dockerfile

@@ -71,9 +71,7 @@ RUN /tmp/build-solaris-toolchain.sh sparcv9 sparcv9 solaris-sparc
 COPY dist-various-2/build-x86_64-fortanix-unknown-sgx-toolchain.sh /tmp/
 COPY dist-various-2/x86_64-fortanix-unknown-sgx-clang-wrap.sh /usr/bin/x86_64-fortanix-unknown-sgx-clang-11
 RUN ln -s /usr/bin/x86_64-fortanix-unknown-sgx-clang-11 /usr/bin/x86_64-fortanix-unknown-sgx-clang++-11
-# We pass the commit id of the port of LLVM's libunwind to the build script.
-# Any update to the commit id here, should cause the container image to be re-built from this point on.
-RUN /tmp/build-x86_64-fortanix-unknown-sgx-toolchain.sh "800f95131fe6acd20b96b6f4723ca3c820f3d379"
+RUN /tmp/build-x86_64-fortanix-unknown-sgx-toolchain.sh
 
 COPY dist-various-2/build-wasi-toolchain.sh /tmp/
 RUN /tmp/build-wasi-toolchain.sh
@@ -105,8 +103,6 @@ ENV TARGETS=$TARGETS,nvptx64-nvidia-cuda
 ENV TARGETS=$TARGETS,armv7-unknown-linux-gnueabi
 ENV TARGETS=$TARGETS,armv7-unknown-linux-musleabi
 
-ENV X86_FORTANIX_SGX_LIBS="/x86_64-fortanix-unknown-sgx/lib/"
-
 # As per https://bugs.launchpad.net/ubuntu/+source/gcc-defaults/+bug/1300211
 # we need asm in the search path for gcc-7 (for gnux32) but not in the search path of the
 # cross compilers.

src/ci/docker/dist-various-2/build-x86_64-fortanix-unknown-sgx-toolchain.sh

@@ -3,14 +3,7 @@
 set -eu
 source shared.sh
 
-if [ -z "$1" ]; then
-    echo "Usage: ${0} <commit_id>"
-    exit -1
-fi
-
 target="x86_64-fortanix-unknown-sgx"
-url="https://github.com/fortanix/llvm-project/archive/${1}.tar.gz"
-repo_name="llvm-project"
 
 install_prereq() {
     curl https://apt.llvm.org/llvm-snapshot.gpg.key|apt-key add -
@@ -24,39 +17,4 @@ install_prereq() {
             clang-11
 }
 
-build_unwind() {
-    set -x
-    dir_name="${target}_temp"
-    rm -rf ${dir_name}
-    mkdir -p ${dir_name}
-    pushd ${dir_name}
-
-    # Clone Fortanix's fork of llvm-project which has a port of libunwind
-    fetch_github_commit_archive "$repo_name" "$url"
-    cd "${repo_name}/libunwind"
-
-    # Build libunwind
-    mkdir -p build
-    cd build
-    target_CC="CC_${target//-/_}"
-    target_CXX="CXX_${target//-/_}"
-    target_CFLAGS="CFLAGS_${target//-/_}"
-    target_CXXFLAGS="CXXFLAGS_${target//-/_}"
-    cmake -DCMAKE_BUILD_TYPE="RELEASE" -DRUST_SGX=1 -G "Unix Makefiles" \
-        -DCMAKE_C_COMPILER="${!target_CC}" -DCMAKE_CXX_COMPILER="${!target_CXX}" \
-        -DCMAKE_C_FLAGS="${!target_CFLAGS}" -DCMAKE_CXX_FLAGS="${!target_CXXFLAGS}" \
-        -DCMAKE_C_COMPILER_TARGET=$target -DCMAKE_CXX_COMPILER_TARGET=$target \
-        -DLLVM_ENABLE_WARNINGS=1 -DLIBUNWIND_ENABLE_WERROR=1 -DLIBUNWIND_ENABLE_PEDANTIC=0 \
-        -DLLVM_PATH=../../llvm/ ../
-    make unwind_static
-    install -D "lib/libunwind.a" "/${target}/lib/libunwind.a"
-
-    popd
-    rm -rf ${dir_name}
-
-    { set +x; } 2>/dev/null
-}
-
-set -x
 hide_output install_prereq
-build_unwind

src/librustc_target/spec/x86_64_fortanix_unknown_sgx.rs

@@ -48,8 +48,10 @@ pub fn target() -> Result<Target, String> {
         "ENCLAVE_SIZE",
         "CFGDATA_BASE",
         "DEBUG",
-        "EH_FRM_HDR_BASE",
-        "EH_FRM_HDR_SIZE",
+        "EH_FRM_HDR_OFFSET",
+        "EH_FRM_HDR_LEN",
+        "EH_FRM_OFFSET",
+        "EH_FRM_LEN",
         "TEXT_BASE",
         "TEXT_SIZE",
     ];

src/libstd/sys/sgx/abi/entry.S

@@ -11,7 +11,7 @@ IMAGE_BASE:
     .long 1                    /* type = NT_VERSION */
 0:  .asciz "toolchain-version" /* name */
 1:  .align 4
-2:  .long 0                    /* desc - toolchain version number, 32-bit LE */
+2:  .long 1                    /* desc - toolchain version number, 32-bit LE */
 3:  .align 4
 
 .section .rodata
@@ -60,10 +60,14 @@ IMAGE_BASE:
     globvar TEXT_BASE 8
     /*  The size in bytes of enclacve text section */
     globvar TEXT_SIZE 8
-    /*  The base address (relative to enclave start) of the enclave EH_FRM_HDR section */
-    globvar EH_FRM_HDR_BASE 8
-    /*  The size in bytes of enclacve EH_FRM_HDR section */
-    globvar EH_FRM_HDR_SIZE 8
+    /*  The base address (relative to enclave start) of the enclave .eh_frame_hdr section */
+    globvar EH_FRM_HDR_OFFSET 8
+    /*  The size in bytes of enclave .eh_frame_hdr section */
+    globvar EH_FRM_HDR_LEN 8
+    /*  The base address (relative to enclave start) of the enclave .eh_frame section */
+    globvar EH_FRM_OFFSET 8
+    /*  The size in bytes of enclacve .eh_frame section */
+    globvar EH_FRM_LEN 8
 
 .org .Lxsave_clear+512
 .Lxsave_header:

src/libunwind/build.rs

@@ -9,6 +9,8 @@ fn main() {
     {
         // Build the unwinding from libunwind C/C++ source code.
         llvm_libunwind::compile();
+    } else if target.contains("x86_64-fortanix-unknown-sgx") {
+        llvm_libunwind::compile();
     } else if target.contains("linux") {
         if target.contains("musl") {
             // linking for musl is handled in lib.rs
@@ -55,6 +57,7 @@ mod llvm_libunwind {
 
     /// Compile the libunwind C/C++ source code.
     pub fn compile() {
+        let target = env::var("TARGET").expect("TARGET was not set");
         let target_env = env::var("CARGO_CFG_TARGET_ENV").unwrap();
         let target_vendor = env::var("CARGO_CFG_TARGET_VENDOR").unwrap();
         let target_endian_little = env::var("CARGO_CFG_TARGET_ENDIAN").unwrap() != "big";
@@ -75,6 +78,35 @@ mod llvm_libunwind {
             cfg.flag("/EHsc");
             cfg.define("_CRT_SECURE_NO_WARNINGS", None);
             cfg.define("_LIBUNWIND_DISABLE_VISIBILITY_ANNOTATIONS", None);
+        } else if target.contains("x86_64-fortanix-unknown-sgx") {
+            cfg.cpp(false);
+
+            cfg.static_flag(true);
+            cfg.opt_level(3);
+
+            cfg.flag("-nostdinc++");
+            cfg.flag("-fno-exceptions");
+            cfg.flag("-fno-rtti");
+            cfg.flag("-fstrict-aliasing");
+            cfg.flag("-funwind-tables");
+            cfg.flag("-fvisibility=hidden");
+            cfg.flag("-fno-stack-protector");
+            cfg.flag("-ffreestanding");
+            cfg.flag("-fexceptions");
+
+            // easiest way to undefine since no API available in cc::Build to undefine
+            cfg.flag("-U_FORTIFY_SOURCE");
+            cfg.define("_FORTIFY_SOURCE", "0");
+
+            cfg.flag_if_supported("-fvisibility-global-new-delete-hidden");
+
+            cfg.define("_LIBUNWIND_DISABLE_VISIBILITY_ANNOTATIONS", None);
+            cfg.define("RUST_SGX", "1");
+            cfg.define("__NO_STRING_INLINES", None);
+            cfg.define("__NO_MATH_INLINES", None);
+            cfg.define("_LIBUNWIND_IS_BAREMETAL", None);
+            cfg.define("__LIBUNWIND_IS_NATIVE_ONLY", None);
+            cfg.define("NDEBUG", None);
         } else {
             cfg.flag("-std=c99");
             cfg.flag("-std=c++11");
@@ -103,6 +135,10 @@ mod llvm_libunwind {
             unwind_sources.push("Unwind_AppleExtras.cpp");
         }
 
+        if target.contains("x86_64-fortanix-unknown-sgx") {
+            unwind_sources.push("UnwindRustSgx.c");
+        }
+
         let root = Path::new("../llvm-project/libunwind");
         cfg.include(root.join("include"));
         for src in unwind_sources {