Support R 4.2

configure.win

@@ -25,6 +25,10 @@ case $ret in
     exit $ret
 esac
 
+# To address the change of the toolchain on R 4.2
+BEFORE_CARGO_BUILD="${BEFORE_CARGO_BUILD}"' export CARGO_TARGET_X86_64_PC_WINDOWS_GNU_LINKER="$(CARGO_LINKER)" \&\&'
+BEFORE_CARGO_BUILD="${BEFORE_CARGO_BUILD}"' export LIBRARY_PATH="$${LIBRARY_PATH};$(CURDIR)/$(LIBDIR)/libgcc_mock" \&\&'
+
 # If it's on CRAN, a package is not allowed to write in any other place than the
 # temporary directory on installation. So, we need to tweak Makevars to make the
 # compilation happen only within the package directory (i.e. `$(PWD)`).

src/.gitignore

@@ -2,3 +2,5 @@
 *.so
 *.dll
 target
+
+/rust/.vscode/settings.json

src/Makevars.ucrt

@@ -0,0 +1,10 @@
+# Use GNU toolchain for R >= 4.2
+TOOLCHAIN = stable-gnu
+
+
+# Rtools42 doesn't have the linker in the location that cargo expects, so we
+# need to overwrite it via configuration.
+CARGO_LINKER = x86_64-w64-mingw32.static.posix-gcc.exe
+
+
+include Makevars.win

src/Makevars.win.in

@@ -2,7 +2,8 @@
 # available when configure.win is used. So, R_ARCH is chosen here.
 TARGET = $(subst /x64,x86_64,$(subst /i386,i686,$(R_ARCH)))-pc-windows-gnu
 
-TOOLCHAIN = stable-gnu
+# This is provided in Makevars.ucrt for R >= 4.2
+TOOLCHAIN ?= stable-msvc
 
 LIBDIR = ./rust/target/$(TARGET)/release
 
@@ -16,6 +17,13 @@ all: C_clean
 $(SHLIB): $(STATLIB)
 
 $(STATLIB):
+	mkdir -p $(LIBDIR)/libgcc_mock
+	cd $(LIBDIR)/libgcc_mock && \
+		touch gcc_mock.c && \
+		gcc -c gcc_mock.c -o gcc_mock.o && \
+		ar -r libgcc_eh.a gcc_mock.o && \
+		cp libgcc_eh.a libgcc_s.a
+
 	@BEFORE_CARGO_BUILD@ cargo +$(TOOLCHAIN) build --target=$(TARGET) --lib --release --manifest-path=./rust/Cargo.toml
 	@AFTER_CARGO_BUILD@
 

src/rust/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["staticlib"]
 
 [dependencies]
-extendr-api = { git = "https://github.com/yutannihilation/extendr", branch = "feature/graphics-feature-gate", features = ["graphics"] }
+extendr-api = { git = "https://github.com/extendr/extendr", features = ["graphics"] }
 
 wgpu = { git = "https://github.com/gfx-rs/wgpu/" }
 # bytemuck converts Rust data into Plain Old Data, which can be passed to WebGPU