rust: initial merge of most of meta-rust

In the meta-rust repo at commit:
   448047c Upgrade to 1.54.0 (#359)

Make the required directories:
  mkdir ../oe-core/meta/recipes-devtools/rust
  mkdir ../oe-core/meta/recipes-devtools/cargo
  mkdir ../oe-core/meta/recipes-example
and then:
  cp recipes-devtools/rust/* ../oe-core/meta/recipes-devtools/rust
  cp recipes-devtools/cargo/* ../oe-core/meta/recipes-devtools/cargo
  cp lib/crate.py ../oe-core/meta/lib
  cp recipes-example/* ../oe-core/meta/recipes-example
  cp conf/distro/include/rust_* ../oe-core/meta/conf/distro/include/
  cp classes/* ../oe-core/meta/classes/
  cp recipes-core/packagegroups/packagegroup-rust-cross-canadian.bb ../oe-core/meta/recipes-core/packagegroups

(From OE-Core rev: 3ed57578cca93ff1ba4e0bf3f25566e10659a2f9)

Signed-off-by: Randy MacLeod <Randy.MacLeod@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 174 insertions, 0 deletions

diff --git a/meta/classes/rust-common.bbclass b/meta/classes/rust-common.bbclass
new file mode 100644
index 0000000000..2093654ac6
--- /dev/null
+++ b/meta/classes/rust-common.bbclass
@@ -0,0 +1,174 @@
+# Common variables used by all Rust builds
+export rustlibdir = "${libdir}/rust"
+FILES:${PN} += "${rustlibdir}/*.so"
+FILES:${PN}-dev += "${rustlibdir}/*.rlib ${rustlibdir}/*.rmeta"
+FILES:${PN}-dbg += "${rustlibdir}/.debug"
+
+RUSTLIB = "-L ${STAGING_LIBDIR}/rust"
+RUST_DEBUG_REMAP = "--remap-path-prefix=${WORKDIR}=/usr/src/debug/${PN}/${EXTENDPE}${PV}-${PR}"
+RUSTFLAGS += "${RUSTLIB} ${RUST_DEBUG_REMAP}"
+RUSTLIB_DEP ?= "libstd-rs"
+RUST_TARGET_PATH = "${STAGING_LIBDIR_NATIVE}/rustlib"
+RUST_PANIC_STRATEGY ?= "unwind"
+
+# Native builds are not effected by TCLIBC. Without this, rust-native
+# thinks it's "target" (i.e. x86_64-linux) is a musl target.
+RUST_LIBC = "${TCLIBC}"
+RUST_LIBC:class-native = "glibc"
+
+def determine_libc(d, thing):
+    '''Determine which libc something should target'''
+
+    # BUILD is never musl, TARGET may be musl or glibc,
+    # HOST could be musl, but only if a compiler is built to be run on
+    # target in which case HOST_SYS != BUILD_SYS.
+    if thing == 'TARGET':
+        libc = d.getVar('RUST_LIBC')
+    elif thing == 'BUILD' and (d.getVar('HOST_SYS') != d.getVar('BUILD_SYS')):
+        libc = d.getVar('RUST_LIBC')
+    else:
+        libc = d.getVar('RUST_LIBC:class-native')
+
+    return libc
+
+def target_is_armv7(d):
+    '''Determine if target is armv7'''
+    # TUNE_FEATURES may include arm* even if the target is not arm
+    # in the case of *-native packages
+    if d.getVar('TARGET_ARCH') != 'arm':
+        return False
+
+    feat = d.getVar('TUNE_FEATURES')
+    feat = frozenset(feat.split())
+    mach_overrides = d.getVar('MACHINEOVERRIDES')
+    mach_overrides = frozenset(mach_overrides.split(':'))
+
+    v7=frozenset(['armv7a', 'armv7r', 'armv7m', 'armv7ve'])
+    if mach_overrides.isdisjoint(v7) and feat.isdisjoint(v7):
+        return False
+    else:
+        return True
+
+# Responsible for taking Yocto triples and converting it to Rust triples
+def rust_base_triple(d, thing):
+    '''
+    Mangle bitbake's *_SYS into something that rust might support (see
+    rust/mk/cfg/* for a list)
+
+    Note that os is assumed to be some linux form
+    '''
+
+    # The llvm-target for armv7 is armv7-unknown-linux-gnueabihf
+    if thing == "TARGET" and target_is_armv7(d):
+        arch = "armv7"
+    else:
+        arch = d.getVar('{}_ARCH'.format(thing))
+
+    # All the Yocto targets are Linux and are 'unknown'
+    vendor = "-unknown"
+    os = d.getVar('{}_OS'.format(thing))
+    libc = determine_libc(d, thing)
+
+    # Prefix with a dash and convert glibc -> gnu
+    if libc == "glibc":
+        libc = "-gnu"
+    elif libc == "musl":
+        libc = "-musl"
+
+    # Don't double up musl (only appears to be the case on aarch64)
+    if os == "linux-musl":
+        if libc != "-musl":
+            bb.fatal("{}_OS was '{}' but TCLIBC was not 'musl'".format(thing, os))
+        os = "linux"
+
+    # This catches ARM targets and appends the necessary hard float bits
+    if os == "linux-gnueabi" or os == "linux-musleabi":
+        libc = bb.utils.contains('TUNE_FEATURES', 'callconvention-hard', 'hf', '', d)
+    return arch + vendor + '-' + os + libc
+
+# Naming explanation
+# Yocto
+# - BUILD_SYS - Yocto triple of the build environment
+# - HOST_SYS - What we're building for in Yocto
+# - TARGET_SYS - What we're building for in Yocto
+#
+# So when building '-native' packages BUILD_SYS == HOST_SYS == TARGET_SYS
+# When building packages for the image HOST_SYS == TARGET_SYS
+# This is a gross over simplification as there are other modes but
+# currently this is all that's supported.
+#
+# Rust
+# - TARGET - the system where the binary will run
+# - HOST - the system where the binary is being built
+#
+# Rust additionally will use two additional cases:
+# - undecorated (e.g. CC) - equivalent to TARGET
+# - triple suffix (e.g. CC:x86_64_unknown_linux_gnu) - both
+#   see: https://github.com/alexcrichton/gcc-rs
+# The way that Rust's internal triples and Yocto triples are mapped together
+# its likely best to not use the triple suffix due to potential confusion.
+
+RUST_BUILD_SYS = "${@rust_base_triple(d, 'BUILD')}"
+RUST_HOST_SYS = "${@rust_base_triple(d, 'HOST')}"
+RUST_TARGET_SYS = "${@rust_base_triple(d, 'TARGET')}"
+
+# wrappers to get around the fact that Rust needs a single
+# binary but Yocto's compiler and linker commands have
+# arguments. Technically the archiver is always one command but
+# this is necessary for builds that determine the prefix and then
+# use those commands based on the prefix.
+WRAPPER_DIR = "${WORKDIR}/wrapper"
+RUST_BUILD_CC = "${WRAPPER_DIR}/build-rust-cc"
+RUST_BUILD_CXX = "${WRAPPER_DIR}/build-rust-cxx"
+RUST_BUILD_CCLD = "${WRAPPER_DIR}/build-rust-ccld"
+RUST_BUILD_AR = "${WRAPPER_DIR}/build-rust-ar"
+RUST_TARGET_CC = "${WRAPPER_DIR}/target-rust-cc"
+RUST_TARGET_CXX = "${WRAPPER_DIR}/target-rust-cxx"
+RUST_TARGET_CCLD = "${WRAPPER_DIR}/target-rust-ccld"
+RUST_TARGET_AR = "${WRAPPER_DIR}/target-rust-ar"
+
+create_wrapper () {
+        file="$1"
+        shift
+
+        cat <<- EOF > "${file}"
+        #!/bin/sh
+        exec $@ "\$@"
+        EOF
+        chmod +x "${file}"
+}
+
+export WRAPPER_TARGET_CC = "${CC}"
+export WRAPPER_TARGET_CXX = "${CXX}"
+export WRAPPER_TARGET_CCLD = "${CCLD}"
+export WRAPPER_TARGET_LDFLAGS = "${LDFLAGS}"
+export WRAPPER_TARGET_AR = "${AR}"
+
+# compiler is used by gcc-rs
+# linker is used by rustc/cargo
+# archiver is used by the build of libstd-rs
+do_rust_create_wrappers () {
+        mkdir -p "${WRAPPER_DIR}"
+
+        # Yocto Build / Rust Host C compiler
+        create_wrapper "${RUST_BUILD_CC}" "${BUILD_CC}"
+        # Yocto Build / Rust Host C++ compiler
+        create_wrapper "${RUST_BUILD_CXX}" "${BUILD_CXX}"
+        # Yocto Build / Rust Host linker
+        create_wrapper "${RUST_BUILD_CCLD}" "${BUILD_CCLD}" "${BUILD_LDFLAGS}"
+        # Yocto Build / Rust Host archiver
+        create_wrapper "${RUST_BUILD_AR}" "${BUILD_AR}"
+
+        # Yocto Target / Rust Target C compiler
+        create_wrapper "${RUST_TARGET_CC}" "${WRAPPER_TARGET_CC}"
+        # Yocto Target / Rust Target C++ compiler
+        create_wrapper "${RUST_TARGET_CXX}" "${WRAPPER_TARGET_CXX}"
+        # Yocto Target / Rust Target linker
+        create_wrapper "${RUST_TARGET_CCLD}" "${WRAPPER_TARGET_CCLD}" "${WRAPPER_TARGET_LDFLAGS}"
+        # Yocto Target / Rust Target archiver
+        create_wrapper "${RUST_TARGET_AR}" "${WRAPPER_TARGET_AR}"
+
+}
+
+addtask rust_create_wrappers before do_configure after do_patch
+do_rust_create_wrappers[dirs] += "${WRAPPER_DIR}"