ci: Test on development snapshots of GCC and Clang

.cirrus.yml

@@ -62,12 +62,12 @@ linux_container_snippet: &LINUX_CONTAINER
     # Gives us more CPUs for free if they're available.
     greedy: true
     # More than enough for our scripts.
-    memory: 1G
+    memory: 2G
 
 task:
   name: "x86_64: Linux (Debian stable)"
   << : *LINUX_CONTAINER
-  matrix: &ENV_MATRIX
+  matrix:
     - env: {WIDEMUL:  int64,  RECOVERY: yes}
     - env: {WIDEMUL:  int64,                 ECDH: yes, SCHNORRSIG: yes, ELLSWIFT: yes}
     - env: {WIDEMUL: int128}
@@ -88,6 +88,10 @@ task:
         CC: gcc
     - env:
         CC: clang
+    - env:
+        CC: gcc-snapshot
+    - env:
+        CC: clang-snapshot
   test_script:
     - ./ci/cirrus.sh
   << : *CAT_LOGS
@@ -118,17 +122,20 @@ task:
     HOMEBREW_NO_INSTALL_CLEANUP: 1
     # Cirrus gives us a fixed number of 4 virtual CPUs. Not that we even have that many jobs at the moment...
     MAKEFLAGS: -j5
-  matrix:
-    << : *ENV_MATRIX
   env:
     ASM: no
     WITH_VALGRIND: no
     CTIMETESTS: no
+    CC: clang
   matrix:
-    - env:
-        CC: gcc
-    - env:
-        CC: clang
+    - env: {WIDEMUL:  int64,  RECOVERY: yes, ECDH: yes, SCHNORRSIG: yes, ELLSWIFT: yes}
+    - env: {WIDEMUL:  int64,  RECOVERY: yes, ECDH: yes, SCHNORRSIG: yes, ELLSWIFT: yes, CC: gcc}
+    - env: {WIDEMUL: int128_struct, ECMULTGENPRECISION: 2, ECMULTWINDOW: 4}
+    - env: {WIDEMUL: int128,                 ECDH: yes, SCHNORRSIG: yes, ELLSWIFT: yes}
+    - env: {WIDEMUL: int128,  RECOVERY: yes,            SCHNORRSIG: yes}
+    - env: {WIDEMUL: int128,  RECOVERY: yes, ECDH: yes, SCHNORRSIG: yes, ELLSWIFT: yes, CC: gcc}
+    - env: {WIDEMUL: int128,  RECOVERY: yes, ECDH: yes, SCHNORRSIG: yes, ELLSWIFT: yes, CPPFLAGS: -DVERIFY}
+    - env: {BUILD: distcheck}
   brew_script:
     - brew install automake libtool gcc
   test_script:

ci/linux-debian.Dockerfile

@@ -1,5 +1,7 @@
 FROM debian:stable
 
+SHELL ["/bin/bash", "-c"]
+
 RUN dpkg --add-architecture i386 && \
     dpkg --add-architecture s390x && \
     dpkg --add-architecture armhf && \
@@ -9,7 +11,7 @@ RUN dpkg --add-architecture i386 && \
 # dkpg-dev: to make pkg-config work in cross-builds
 # llvm: for llvm-symbolizer, which is used by clang's UBSan for symbolized stack traces
 RUN apt-get update && apt-get install --no-install-recommends -y \
-        git ca-certificates \
+        git ca-certificates wget \
         make automake libtool pkg-config dpkg-dev valgrind qemu-user \
         gcc clang llvm libclang-rt-dev libc6-dbg \
         g++ \
@@ -23,7 +25,39 @@ RUN apt-get update && apt-get install --no-install-recommends -y \
         sagemath
 
 WORKDIR /root
-# The "wine" package provides a convience wrapper that we need
+
+# Build and install gcc snapshot
+ARG GCC_SNAPSHOT_MAJOR=14
+RUN wget --progress=dot:giga --https-only --recursive --accept '*.tar.xz' --level 1 --no-directories "https://gcc.gnu.org/pub/gcc/snapshots/LATEST-${GCC_SNAPSHOT_MAJOR}" && \
+    wget "https://gcc.gnu.org/pub/gcc/snapshots/LATEST-${GCC_SNAPSHOT_MAJOR}/sha512.sum" && \
+    sha512sum --check --ignore-missing sha512.sum && \
+    # We should have downloaded exactly one tar.xz file
+    ls && \
+    [[ $(ls *.tar.xz | wc -l) -eq "1" ]] && \
+    tar xf *.tar.xz && \
+    mkdir gcc-build && cd gcc-build && \
+    apt-get update && apt-get install --no-install-recommends -y libgmp-dev libmpfr-dev libmpc-dev flex && \
+    ../*/configure --prefix=/opt/gcc-snapshot --enable-languages=c --disable-bootstrap --disable-multilib --without-isl && \
+    make -j $(nproc) && \
+    make install && \
+    ln -s /opt/gcc-snapshot/bin/gcc /usr/bin/gcc-snapshot
+
+# Install clang snapshot
+RUN wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc && \
+    # Add repository for this Debian release
+    . /etc/os-release && echo "deb http://apt.llvm.org/${VERSION_CODENAME} llvm-toolchain-${VERSION_CODENAME} main" >> /etc/apt/sources.list && \
+    # Install clang snapshot
+    apt-get update && apt-get install --no-install-recommends -y clang && \
+    # Remove just the "clang" symlink again
+    apt-get remove -y clang && \
+    # We should have exactly two clang versions now
+    ls /usr/bin/clang* && \
+    [[    $(ls /usr/bin/clang-?? | sort | wc -l) -eq "2" ]] && \
+    # Create symlinks for them
+    ln -s $(ls /usr/bin/clang-?? | sort | tail -1) /usr/bin/clang-snapshot && \
+    ln -s $(ls /usr/bin/clang-?? | sort | head -1) /usr/bin/clang
+
+# The "wine" package provides a convenience wrapper that we need
 RUN apt-get update && apt-get install --no-install-recommends -y \
         git ca-certificates wine64 wine python3-simplejson python3-six msitools winbind procps && \
 # Workaround for `wine` package failure to employ the Debian alternatives system properly.