[bootstrap] pipe wget into tar instead of using temporary files (openthread#12833)

Using `/tmp` to store large download files will fail when the system
is under memory pressure. `/tmp` is backed by `tmpfs` in many Linux
distributions.

Author: enkiusz

script/bootstrap

@@ -74,11 +74,9 @@ install_packages_apt()
         sudo apt-get --no-install-recommends install -y binutils-arm-none-eabi gcc-arm-none-eabi gdb-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib
     elif [ "$PLATFORM" = "Ubuntu" ]; then
         sudo apt-get --no-install-recommends install -y bzip2 ca-certificates wget
-        (cd /tmp \
-            && wget --tries 4 --no-check-certificate --quiet -c https://developer.arm.com/-/media/Files/downloads/gnu-rm/9-2020q2/gcc-arm-none-eabi-9-2020-q2-update-"$ARCH"-linux.tar.bz2 \
-            && sudo tar xjf gcc-arm-none-eabi-9-2020-q2-update-"$ARCH"-linux.tar.bz2 -C /opt \
-            && rm gcc-arm-none-eabi-9-2020-q2-update-"$ARCH"-linux.tar.bz2 \
-            && sudo ln -s -f /opt/gcc-arm-none-eabi-9-2020-q2-update/bin/* /usr/local/bin/.)
+        (wget --tries 4 --no-check-certificate -O - --quiet https://developer.arm.com/-/media/Files/downloads/gnu-rm/9-2020q2/gcc-arm-none-eabi-9-2020-q2-update-"$ARCH"-linux.tar.bz2 \
+            | sudo tar xj -C /opt) \
+            && sudo ln -s -f /opt/gcc-arm-none-eabi-9-2020-q2-update/bin/* /usr/local/bin/.
     fi
 
     if [ "$PLATFORM" != "Raspbian" ] && [ "${INSTALL_FORMAT_TOOLS}" = "1" ]; then

script/install-llvm.sh

@@ -28,7 +28,7 @@
 #
 # This script downloads and installs a specific version of clang-format and clang-tidy.
 
-set -e
+set -e -o pipefail
 
 LLVM_VERSION="19.1.7"
 ARCH=$(uname -m)
@@ -42,26 +42,15 @@ fi
 LLVM_PACKAGE="LLVM-${LLVM_VERSION}-Linux-X64"
 LLVM_URL="https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VERSION}/${LLVM_PACKAGE}.tar.xz"
 INSTALL_DIR="/opt/llvm-${LLVM_VERSION}"
-TEMP_DIR=$(mktemp -d)
+INSTALL_DIR_tmp="$INSTALL_DIR.tmp"
 
-cleanup()
-{
-    rm -rf "${TEMP_DIR}"
-}
+sudo mkdir -p "${INSTALL_DIR_tmp}"
+trap 'sudo rm -rf "${INSTALL_DIR_tmp}"' EXIT
 
-trap cleanup EXIT
-
-cd "${TEMP_DIR}"
-
-echo "Downloading LLVM from ${LLVM_URL}..."
-wget -O llvm.tar.xz "${LLVM_URL}"
-
-echo "Uncompressing to ${TEMP_DIR}..."
-tar xf llvm.tar.xz
-
-echo "Installing to ${INSTALL_DIR}..."
-sudo mkdir -p /opt
-sudo mv "${LLVM_PACKAGE}" "${INSTALL_DIR}"
+echo "Downloading LLVM from '${LLVM_URL}' into '${INSTALL_DIR}' ..."
+wget -O - "${LLVM_URL}" | sudo tar -f - -C "${INSTALL_DIR_tmp}" --strip-components=1 -xJ
+sudo rm -rf "${INSTALL_DIR}"
+sudo mv "${INSTALL_DIR_tmp}" "${INSTALL_DIR}"
 
 echo "Creating symlinks in /usr/local/bin..."
 sudo ln -sf "${INSTALL_DIR}/bin/clang-format" "/usr/local/bin/clang-format-19"