build: install musl toolchains in the dockerfile

Dockerfile

@@ -30,4 +30,9 @@ RUN apt update && apt install -y \
     wget \
     xz-utils
 
+# Install musl-based toolchains.
+ENV MUSL_INSTALL_DIR="/opt/musl-cross"
+COPY src/compilation/install_musl_toolchains.sh .
+RUN ./install_musl_toolchains.sh
+
 WORKDIR /app/gdb

src/compilation/install_musl_toolchains.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+set -e
+
+# Define architectures and their respective musl toolchain URLs.
+ARCHS=("x86_64" "arm" "aarch64" "powerpc" "mips" "mipsel")
+BASE_URL="https://musl.cc"
+
+if [[ -z "$MUSL_INSTALL_DIR" ]]; then
+    echo "MUSL_INSTALL_DIR variable has not been set!"
+    exit 1
+fi
+
+# Create install directory.
+mkdir -p "$MUSL_INSTALL_DIR"
+cd "$MUSL_INSTALL_DIR"
+
+# Download and extract each toolchain.
+for ARCH in "${ARCHS[@]}"; do
+    TOOLCHAIN_TAR="${ARCH}-linux-musl-cross.tgz"
+
+    # Arm has a non-generic special toolchain name :(.
+    if [[ "$ARCH" == "arm" ]]; then
+        TOOLCHAIN_TAR="arm-linux-musleabi-cross.tgz"
+    fi
+
+    URL="$BASE_URL/$TOOLCHAIN_TAR"
+
+    echo "Downloading $URL..."
+    wget -q --show-progress "$URL"
+
+    echo "Extracting $TOOLCHAIN_TAR..."
+    tar -xzf "$TOOLCHAIN_TAR"
+    rm "$TOOLCHAIN_TAR"
+done
+
+# Add the installed toolchains to the PATH.
+echo "Updating PATH..."
+MUSL_PATHS=""
+for dir in /opt/musl-cross/*/bin; do
+    MUSL_PATHS="$dir:$MUSL_PATHS"
+done
+
+echo "PATH=$MUSL_PATHS:$PATH" >> ~/.bashrc