build, dockerfiles: add support for detecting rustdoc

rustdoc is effectively a custom version of rustc, and it is necessary to
specify it in order to run doctests from Meson.  Add the relevant configure
option and environment variables.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -209,6 +209,8 @@ for opt do
   ;;
   --rustc=*) RUSTC="$optarg"
   ;;
+  --rustdoc=*) RUSTDOC="$optarg"
+  ;;
   --cpu=*) cpu="$optarg"
   ;;
   --extra-cflags=*)
@@ -323,6 +325,7 @@ pkg_config="${PKG_CONFIG-${cross_prefix}pkg-config}"
 sdl2_config="${SDL2_CONFIG-${cross_prefix}sdl2-config}"
 
 rustc="${RUSTC-rustc}"
+rustdoc="${RUSTDOC-rustdoc}"
 
 check_define() {
 cat > $TMPC <<EOF
@@ -660,6 +663,8 @@ for opt do
   ;;
   --rustc=*)
   ;;
+  --rustdoc=*)
+  ;;
   --make=*)
   ;;
   --install=*)
@@ -890,6 +895,7 @@ Advanced options (experts only):
   --cxx=CXX                use C++ compiler CXX [$cxx]
   --objcc=OBJCC            use Objective-C compiler OBJCC [$objcc]
   --rustc=RUSTC            use Rust compiler RUSTC [$rustc]
+  --rustdoc=RUSTDOC        use rustdoc binary RUSTDOC [$rustdoc]
   --extra-cflags=CFLAGS    append extra C compiler flags CFLAGS
   --extra-cxxflags=CXXFLAGS append extra C++ compiler flags CXXFLAGS
   --extra-objcflags=OBJCFLAGS append extra Objective C compiler flags OBJCFLAGS
@@ -1901,8 +1907,10 @@ if test "$skip_meson" = no; then
   if test "$rust" != disabled; then
     if test "$rust_host_triple" != "$rust_target_triple"; then
       echo "rust = [$(meson_quote $rustc --target "$rust_target_triple")]" >> $cross
+      echo "rustdoc = [$(meson_quote $rustdoc --target "$rust_target_triple")]" >> $cross
     else
       echo "rust = [$(meson_quote $rustc)]" >> $cross
+      echo "rustdoc = [$(meson_quote $rustdoc)]" >> $cross
     fi
   fi
   echo "ar = [$(meson_quote $ar)]" >> $cross

meson.build

@@ -106,6 +106,7 @@ if have_rust
 endif
 
 if have_rust
+  rustdoc = find_program('rustdoc', required: get_option('rust'))
   bindgen = find_program('bindgen', required: get_option('rust'))
   if not bindgen.found() or bindgen.version().version_compare('<0.60.0')
     if get_option('rust').enabled()
@@ -4757,6 +4758,7 @@ if have_rust
   summary_info += {'Rust target':     config_host['RUST_TARGET_TRIPLE']}
   summary_info += {'rustc':           ' '.join(rustc.cmd_array())}
   summary_info += {'rustc version':   rustc.version()}
+  summary_info += {'rustdoc':         rustdoc}
   summary_info += {'bindgen':         bindgen.full_path()}
   summary_info += {'bindgen version': bindgen.version()}
 endif

tests/docker/dockerfiles/fedora-rust-nightly.docker

@@ -156,6 +156,7 @@ ENV PYTHON "/usr/bin/python3"
 RUN dnf install -y wget
 ENV RUSTUP_HOME=/usr/local/rustup CARGO_HOME=/usr/local/cargo
 ENV RUSTC=/usr/local/rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/rustc
+ENV RUSTDOC=/usr/local/rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/rustdoc
 ENV CARGO=/usr/local/rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo
 RUN set -eux && \
   rustArch='x86_64-unknown-linux-gnu' && \
@@ -170,6 +171,7 @@ RUN set -eux && \
   /usr/local/cargo/bin/rustup run nightly cargo --version && \
   /usr/local/cargo/bin/rustup run nightly rustc --version && \
   test "$CARGO" = "$(/usr/local/cargo/bin/rustup +nightly which cargo)" && \
+  test "$RUSTDOC" = "$(/usr/local/cargo/bin/rustup +nightly which rustdoc)" && \
   test "$RUSTC" = "$(/usr/local/cargo/bin/rustup +nightly which rustc)"
 ENV PATH=$CARGO_HOME/bin:$PATH
 RUN /usr/local/cargo/bin/rustup run nightly cargo install bindgen-cli

tests/docker/dockerfiles/ubuntu2204.docker

@@ -151,6 +151,7 @@ ENV MAKE "/usr/bin/make"
 ENV NINJA "/usr/bin/ninja"
 ENV PYTHON "/usr/bin/python3"
 ENV RUSTC=/usr/bin/rustc-1.77
+ENV RUSTDOC=/usr/bin/rustdoc-1.77
 ENV CARGO_HOME=/usr/local/cargo
 ENV PATH=$CARGO_HOME/bin:$PATH
 RUN DEBIAN_FRONTEND=noninteractive eatmydata \

tests/lcitool/refresh

@@ -121,6 +121,7 @@ fedora_rustup_nightly_extras = [
     "RUN dnf install -y wget\n",
     "ENV RUSTUP_HOME=/usr/local/rustup CARGO_HOME=/usr/local/cargo\n",
     "ENV RUSTC=/usr/local/rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/rustc\n",
+    "ENV RUSTDOC=/usr/local/rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/rustdoc\n",
     "ENV CARGO=/usr/local/rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo\n",
     "RUN set -eux && \\\n",
     "  rustArch='x86_64-unknown-linux-gnu' && \\\n",
@@ -135,6 +136,7 @@ fedora_rustup_nightly_extras = [
     "  /usr/local/cargo/bin/rustup run nightly cargo --version && \\\n",
     "  /usr/local/cargo/bin/rustup run nightly rustc --version && \\\n",
     '  test "$CARGO" = "$(/usr/local/cargo/bin/rustup +nightly which cargo)" && \\\n',
+    '  test "$RUSTDOC" = "$(/usr/local/cargo/bin/rustup +nightly which rustdoc)" && \\\n',
     '  test "$RUSTC" = "$(/usr/local/cargo/bin/rustup +nightly which rustc)"\n',
     'ENV PATH=$CARGO_HOME/bin:$PATH\n',
     'RUN /usr/local/cargo/bin/rustup run nightly cargo install bindgen-cli\n',
@@ -143,6 +145,7 @@ fedora_rustup_nightly_extras = [
 
 ubuntu2204_rust_extras = [
     "ENV RUSTC=/usr/bin/rustc-1.77\n",
+    "ENV RUSTDOC=/usr/bin/rustdoc-1.77\n",
     "ENV CARGO_HOME=/usr/local/cargo\n",
     'ENV PATH=$CARGO_HOME/bin:$PATH\n',
     "RUN DEBIAN_FRONTEND=noninteractive eatmydata \\\n",