Windows: use libsodium from Rtools if available

.github/workflows/R-CMD-check.yaml

@@ -23,6 +23,7 @@ jobs:
           - {os: windows-latest,  r: '4.1'}
           - {os: windows-latest,  r: '4.2'}
           - {os: windows-latest,  r: 'release'}
+          - {os: windows-latest,  r: 'devel'}
           - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-latest,   r: 'release'}
           - {os: ubuntu-latest,   r: 'oldrel-1'}

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: sodium
 Type: Package
 Title: A Modern and Easy-to-Use Crypto Library
-Version: 1.3.2
+Version: 1.4.0
 Authors@R: person("Jeroen", "Ooms", role = c("aut", "cre"), email = "jeroenooms@gmail.com",
     comment = c(ORCID = "0000-0002-4035-0289"))
 Description: Bindings to 'libsodium' <https://doc.libsodium.org/>: a modern, 

NEWS

@@ -1,3 +1,6 @@
+1.4.0
+ - Windows: use libsodium from Rtools if available
+
 1.3.1
  - Fix shell script error for cross compiling
 

src/Makevars.win

@@ -1,14 +1,20 @@
+PKG_CONFIG ?= $(BINPREF)pkg-config
+PKG_LIBS := $(shell $(PKG_CONFIG) --libs libsodium)
+
+ifneq ($(PKG_LIBS),)
+$(info using Sodium from Rtools)
+PKG_CPPFLAGS := $(shell $(PKG_CONFIG) --cflags libsodium)
+else
 RWINLIB = ../windows/sodium
 PKG_CPPFLAGS = -I$(RWINLIB)/include
+PKG_LIBS = -L$(RWINLIB)/lib$(R_ARCH) -L${RWINLIB}/lib -lsodium
+endif
 
-PKG_LIBS = \
-	-L$(RWINLIB)/lib$(R_ARCH) \
-	-L${RWINLIB}/lib \
-	-lsodium
+all: $(SHLIB)
 
-all: clean winlibs
+$(OBJECTS): $(RWINLIB)
 
-winlibs:
+$(RWINLIB):
 	"${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" "../tools/winlibs.R"
 
 clean: