capi: switch to cargo-c

It seems cargo-c is the "recommended" way of building distro-friendly
.so's for Rust crates and so switch to that.

The lack of fine-grained SONAME control might be an issue in the future
(when we do a 1.0 release, we probably don't want to do a full SONAME
API breakage -- but maybe we can do a 1.0 release when pathrs is ready
for packaging anyway). It also seems that the ability to do Version.map
stuff is limited with cargo-c, but we can cross that bridge when we get
to it (for the most part there aren't many cargo-c-specific changes).

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

.github/workflows/bindings.yml

@@ -33,6 +33,9 @@ jobs:
       - uses: actions/checkout@v4
       # Build and install libpathrs.so.
       - uses: dtolnay/rust-toolchain@stable
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-c
       - name: build libpathrs
         run: make release
       - name: install libpathrs
@@ -50,6 +53,9 @@ jobs:
       - uses: actions/checkout@v4
       # Build and install libpathrs.so.
       - uses: dtolnay/rust-toolchain@stable
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-c
       - name: build libpathrs
         run: make release
       - name: install libpathrs
@@ -73,6 +79,9 @@ jobs:
       - uses: actions/checkout@v4
       # Build and install libpathrs.so.
       - uses: dtolnay/rust-toolchain@stable
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-c
       - name: build libpathrs
         run: make release
       - name: install libpathrs

Cargo.toml

@@ -33,7 +33,20 @@ rust-version = "1.63"
 maintenance = { status = "experimental" }
 
 [lib]
-crate-type = ["rlib", "cdylib", "staticlib"]
+crate-type = ["rlib"]
+
+[package.metadata.capi.header]
+subdirectory = false
+
+[package.metadata.capi.library]
+name = "pathrs"
+# TODO: In order to avoid breaking dependencies when we do our 1.0 release, we
+#       might need to fake the so version...
+#version = "1.0.0"
+#version_suffix_components = 1
+# Since we are cdylib, panic!s will cause aborts once they hit the FFI barrier
+# anyway. We might as well reduce our code size if we're doing it.
+rustflags = "-Cpanic=abort"
 
 [features]
 capi = ["dep:rand"]
@@ -43,9 +56,6 @@ _test_as_root = []
 [profile.release]
 # Enable link-time optimisations.
 lto = true
-# Since we are cdylib, panic!s will cause aborts once they hit the FFI barrier
-# anyway. We might as well reduce our code size if we're doing it.
-panic = "abort"
 
 [dependencies]
 bitflags = "^2"

Makefile

@@ -18,19 +18,19 @@ CARGO ?= cargo
 CARGO_NIGHTLY ?= cargo +nightly
 
 SRC_FILES = $(shell find . -name '*.rs')
-CAPI_FEATURES = --features=capi
+DESTDIR ?= /
 
 .PHONY: debug
 debug: target/debug
 
 target/debug: $(SRC_FILES)
-	$(CARGO) build $(CAPI_FEATURES)
+	$(CARGO) cbuild
 
 .PHONY: release
 release: target/release
 
 target/release: $(SRC_FILES)
-	$(CARGO) build $(CAPI_FEATURES) --release
+	$(CARGO) cbuild --release
 
 .PHONY: smoke-test
 smoke-test:
@@ -83,7 +83,7 @@ docs:
 
 .PHONY: install
 install: release
-	@echo "If you want to configure the install paths, use ./install.sh directly."
+	@echo "If you want to configure the install paths, use 'cargo cinstall' directly."
 	@echo "[Sleeping for 3 seconds.]"
 	@sleep 3s
-	./install.sh
+	cargo cinstall --release --destdir=$(DESTDIR) --prefix=/usr