compiler-rt: add bare metal ARM runtimes and picolibc

compiler-rt.be0

@@ -1,6 +1,6 @@
 #!/usr/bin/env beesh
 
-# BEE_VERSION compiler-rt-23.1.3-0
+# BEE_VERSION compiler-rt-23.1.3-1
 
 #SRCURL[0]="https://github.com/llvm/llvm-project/releases/download/llvmorg-${PKGVERSION}/llvm-project-${PKGVERSION}.src.tar.xz"
 SRCURL[0]="https://beehive.molgen.mpg.de/d7e227fe471d80d5e2d411127a0123b1/llvm-project-23.1.3.src.tar.xz"
@@ -11,6 +11,19 @@ SRCURL[0]="https://beehive.molgen.mpg.de/d7e227fe471d80d5e2d411127a0123b1/llvm-p
 
 sourcesubdir_append compiler-rt
 
+# Bare-metal Arm builtins, one build per multilib variant: the directory below
+# ${LIBDIR}/clang-runtimes, the target, and the flags. multilib.yaml, written
+# in mee_install(), lets clang pick a variant from -mcpu/-mfloat-abi/-mfpu.
+# picolibc.be0 installs the C library into the same directories.
+BAREMETAL_VARIANTS=(
+    "arm-none-eabi/armv6m_soft_nofp         thumbv6m-none-eabi        -mfloat-abi=soft"
+    "arm-none-eabi/armv7m_soft_nofp         thumbv7m-none-eabi        -mfloat-abi=soft"
+    "arm-none-eabi/armv7em_soft_fpv4_sp_d16 thumbv7em-none-eabi       -mfloat-abi=softfp -mfpu=fpv4-sp-d16"
+    "arm-none-eabi/armv7em_hard_fpv4_sp_d16 thumbv7em-none-eabihf     -mfloat-abi=hard -mfpu=fpv4-sp-d16"
+    "arm-none-eabi/armv8m.main_soft_fp      thumbv8m.main-none-eabi   -mfloat-abi=softfp -mfpu=fpv5-sp-d16"
+    "arm-none-eabi/armv8m.main_hard_fp      thumbv8m.main-none-eabihf -mfloat-abi=hard -mfpu=fpv5-sp-d16"
+)
+
 #mee_extract() {
 #    bee_extract "${@}"
 #}
@@ -33,12 +46,102 @@ mee_configure() {
         -DCMAKE_CXX_COMPILER=clang++ \
         -Wno-dev \
         -G Ninja
+
+    local dir target flags
+    for variant in "${BAREMETAL_VARIANTS[@]}" ; do
+        read -r dir target flags <<< "${variant}"
+        start_cmd cmake \
+            -S ${S}/lib/builtins \
+            -B ${B}/baremetal/${dir} \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DCMAKE_SYSTEM_NAME=Generic \
+            -DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY \
+            -DCMAKE_C_COMPILER=clang \
+            -DCMAKE_ASM_COMPILER=clang \
+            -DCMAKE_C_COMPILER_TARGET=${target} \
+            -DCMAKE_ASM_COMPILER_TARGET=${target} \
+            -DCMAKE_C_FLAGS="${flags}" \
+            -DCMAKE_ASM_FLAGS="${flags}" \
+            -DCMAKE_AR=$(command -v llvm-ar) \
+            -DCMAKE_RANLIB=$(command -v llvm-ranlib) \
+            -DCOMPILER_RT_STANDALONE_BUILD=ON \
+            -DCOMPILER_RT_BAREMETAL_BUILD=ON \
+            -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON \
+            -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON \
+            -DCOMPILER_RT_INSTALL_LIBRARY_DIR=${LIBDIR}/clang-runtimes/${dir}/lib \
+            -DLLVM_CMAKE_DIR=$(llvm-config --cmakedir) \
+            -Wno-dev \
+            -G Ninja
+    done
 }
 
 mee_build() {
     start_cmd ninja -v -C ${B} ${BEE_NINJAFLAGS} "${@}"
+
+    local dir target flags
+    for variant in "${BAREMETAL_VARIANTS[@]}" ; do
+        read -r dir target flags <<< "${variant}"
+        start_cmd ninja -v -C ${B}/baremetal/${dir} ${BEE_NINJAFLAGS} "${@}"
+    done
 }
 
 mee_install() {
     DESTDIR=${D} start_cmd ninja -C ${B} install "${@}"
+
+    local dir target flags
+    for variant in "${BAREMETAL_VARIANTS[@]}" ; do
+        read -r dir target flags <<< "${variant}"
+        DESTDIR=${D} start_cmd ninja -C ${B}/baremetal/${dir} install "${@}"
+
+        # compiler-rt appends the normalized target to the library
+        # directory, but clang only searches the variant's lib directory.
+        local libdir=${D}${LIBDIR}/clang-runtimes/${dir}/lib
+        start_cmd mv ${libdir}/*/libclang_rt.builtins.a ${libdir}/
+        start_cmd rmdir ${libdir}/*/
+    done
+
+    # A variant matches if clang's flags (see -print-multi-flags-experimental)
+    # contain all of its flags, and of the matching variants the last one
+    # wins. The mappings let compatible cores use them: a library runs on any
+    # core of the same or a later architecture, and an FPv5 unit executes
+    # FPv4 code. The variants without FPU require -mfpu=none, as their crt0
+    # does not enable the FPU, which code built with -mfloat-abi=softfp for
+    # a core with FPU uses.
+    cat > ${D}${LIBDIR}/clang-runtimes/multilib.yaml <<-'EOF'
+	MultilibVersion: 1.0
+
+	Groups:
+	- Name: stdlibs
+	  Type: Exclusive
+
+	Variants:
+	- Dir: arm-none-eabi/armv6m_soft_nofp
+	  Flags: [--target=thumbv6m-unknown-none-eabi, -mfpu=none]
+	  Group: stdlibs
+	- Dir: arm-none-eabi/armv7m_soft_nofp
+	  Flags: [--target=thumbv7m-unknown-none-eabi, -mfpu=none]
+	  Group: stdlibs
+	- Dir: arm-none-eabi/armv7em_soft_fpv4_sp_d16
+	  Flags: [--target=thumbv7em-unknown-none-eabi, -mfpu=fpv4-sp-d16]
+	  Group: stdlibs
+	- Dir: arm-none-eabi/armv7em_hard_fpv4_sp_d16
+	  Flags: [--target=thumbv7em-unknown-none-eabihf, -mfpu=fpv4-sp-d16]
+	  Group: stdlibs
+	- Dir: arm-none-eabi/armv8m.main_soft_fp
+	  Flags: [--target=thumbv8m.main-unknown-none-eabi, -mfpu=fpv5-sp-d16]
+	  Group: stdlibs
+	- Dir: arm-none-eabi/armv8m.main_hard_fp
+	  Flags: [--target=thumbv8m.main-unknown-none-eabihf, -mfpu=fpv5-sp-d16]
+	  Group: stdlibs
+
+	Mappings:
+	- Match: --target=thumbv8m\.base-unknown-none-eabi
+	  Flags: [--target=thumbv6m-unknown-none-eabi]
+	- Match: --target=thumbv(7em|8m\.main|8\.1m\.main)-unknown-none-eabi
+	  Flags: [--target=thumbv7m-unknown-none-eabi]
+	- Match: -mfpu=fpv5-(sp-)?d16
+	  Flags: [-mfpu=fpv4-sp-d16]
+	- Match: -mfpu=fpv5-d16
+	  Flags: [-mfpu=fpv5-sp-d16]
+	EOF
 }

picolibc.be0

@@ -0,0 +1,91 @@
+#!/usr/bin/env beesh
+
+# BEE_VERSION picolibc-1.8.12-0
+
+# SRCURL[0]="https://github.com/picolibc/picolibc/releases/download/${PKGVERSION}/picolibc-${PKGVERSION}.tar.xz"
+SRCURL[0]="https://beehive.molgen.mpg.de/7219ddf0193c83528f22b7b8fbc1fff4/picolibc-1.8.12.tar.xz"
+
+# PATCHURL+=()
+
+# build_in_sourcedir
+
+# sourcesubdir_append src
+
+# Bare-metal Arm C library, one build per multilib variant: the directory
+# below ${LIBDIR}/clang-runtimes, the target, and the flags. Keep the list in
+# sync with compiler-rt.be0, which builds the builtins for these variants and
+# installs the multilib.yaml that lets clang pick one.
+BAREMETAL_VARIANTS=(
+    "arm-none-eabi/armv6m_soft_nofp         thumbv6m-none-eabi        -mfloat-abi=soft"
+    "arm-none-eabi/armv7m_soft_nofp         thumbv7m-none-eabi        -mfloat-abi=soft"
+    "arm-none-eabi/armv7em_soft_fpv4_sp_d16 thumbv7em-none-eabi       -mfloat-abi=softfp -mfpu=fpv4-sp-d16"
+    "arm-none-eabi/armv7em_hard_fpv4_sp_d16 thumbv7em-none-eabihf     -mfloat-abi=hard -mfpu=fpv4-sp-d16"
+    "arm-none-eabi/armv8m.main_soft_fp      thumbv8m.main-none-eabi   -mfloat-abi=softfp -mfpu=fpv5-sp-d16"
+    "arm-none-eabi/armv8m.main_hard_fp      thumbv8m.main-none-eabihf -mfloat-abi=hard -mfpu=fpv5-sp-d16"
+)
+
+#mee_extract() {
+#    bee_extract "${@}"
+#}
+
+#mee_patch() {
+#    bee_patch "${@}"
+#}
+
+mee_configure() {
+    local dir target flags
+    for variant in "${BAREMETAL_VARIANTS[@]}" ; do
+        read -r dir target flags <<< "${variant}"
+
+        # -nostdlibinc keeps the headers of an installed picolibc out of
+        # the build, -nostdlib the libraries. clang's bare-metal driver
+        # defaults to GNU ld, which on MarIuX only knows x86.
+        mkdir -p ${B}/cross/${dir%/*}
+        cat > ${B}/cross/${dir}.txt <<-EOF
+		[binaries]
+		c = ['clang', '--target=${target}', $(printf "'%s', " ${flags})'-nostdlibinc', '-nostdlib']
+		c_ld = 'lld'
+		ar = 'llvm-ar'
+		nm = 'llvm-nm'
+		strip = 'llvm-strip'
+
+		[host_machine]
+		system = 'none'
+		cpu_family = 'arm'
+		cpu = 'arm'
+		endian = 'little'
+
+		[properties]
+		skip_sanity_check = true
+		EOF
+
+        # Without -Dspecsdir=none the GCC specs file would be installed
+        # into clang's install directory, /usr/bin.
+        start_cmd meson setup \
+            --cross-file ${B}/cross/${dir}.txt \
+            --prefix=${LIBDIR}/clang-runtimes/${dir} \
+            --includedir=include \
+            --libdir=lib \
+            --wrap-mode=nofallback \
+            -Dmultilib=false \
+            -Dspecsdir=none \
+            ${B}/${dir} \
+            ${S}
+    done
+}
+
+mee_build() {
+    local dir target flags
+    for variant in "${BAREMETAL_VARIANTS[@]}" ; do
+        read -r dir target flags <<< "${variant}"
+        start_cmd ninja -v -C ${B}/${dir} ${BEE_NINJAFLAGS} "${@}"
+    done
+}
+
+mee_install() {
+    local dir target flags
+    for variant in "${BAREMETAL_VARIANTS[@]}" ; do
+        read -r dir target flags <<< "${variant}"
+        DESTDIR=${D} start_cmd ninja -C ${B}/${dir} install "${@}"
+    done
+}