Simplify build.rs

Merges: #79

Cargo.toml

@@ -3,7 +3,7 @@ name = "riot-wrappers"
 version = "0.8.2"
 authors = ["Christian Amsüss <chrysn@fsfe.org>"]
 edition = "2021"
-rust-version = "1.65"
+rust-version = "1.75"
 
 description = "Rust API wrappers for the RIOT operating system"
 documentation = "https://rustdoc.etonomy.org/riot_wrappers/"

README.md

@@ -44,8 +44,7 @@ Supported RIOT & Rust versions
 Currently, this crate targets the latest development version of RIOT.
 Support for the latest release is maintained on a best-effort basis.
 
-This crate works on stable Rust 1.64,
-unless particular features are enabled.
+This crate has no MSRV, it may start depending on the latest stable as soon as RIOT's build infrastructure has it.
 
 When a released version of RIOT is used with anything but the riot-sys / riot-wrappers / nightly-compiler combination it was released with,
 it is likely that all these must be upgraded together.
@@ -62,7 +61,7 @@ On item presence and modules
 
 This crate makes some of its modules' presence conditional on whether the
 corresponding RIOT module is active in the build configuration; that
-information is obtained through the riot-sys crate. For example,
+information is obtained by inspecting the `riotbuild.h file`. For example,
 `riot_wrappers::saul` is only present if `USEMODULE += saul` is (directly or
 indirectly) set in the Makefile.
 

build.rs

@@ -3,78 +3,56 @@ extern crate shlex;
 use std::env;
 
 fn main() {
- let cflags = env::var("DEP_RIOT_SYS_CFLAGS")
- .expect("DEP_RIOT_SYS_CFLAGS is not set, check whether riot-sys exports it.");
- let cflags = shlex::split(&cflags).expect("Odd shell escaping in CFLAGS");
-
- println!("cargo:rerun-if-env-changed=DEP_RIOT_SYS_CFLAGS");
+ println!("cargo:rerun-if-env-changed=RIOTBUILD_CONFIG_HEADER_C");
+ let riotbuildh = env::var("RIOTBUILD_CONFIG_HEADER_C")
+ .expect("riotbuild.h is expected to be indicated in the RIOTBUILD_CONFIG_HEADER_C environment variable, or another source of enabled modules provided.");
+ println!("cargo:rerun-if-changed={riotbuildh}");
+
+ let mut defines = std::collections::HashMap::new();
+
+ use std::io::BufRead;
+ for line in std::io::BufReader::new(
+ std::fs::File::open(riotbuildh)
+ .expect("Failed to read riotbuild.h (RIOTBUILD_CONFIG_HEADER_C)"),
+ )
+ .lines()
+ {
+ let line = line.expect("Error reading line from riotbuild.h (RIOTBUILD_CONFIG_HEADER_C)");
+ if let Some(name) = line.strip_prefix("#undef ") {
+ defines.remove(name.trim());
+ }
+ if let Some((name, val)) = line
+ .strip_prefix("#define ")
+ .and_then(|nv| nv.split_once(" "))
+ {
+ defines.insert(name.trim().to_owned(), val.trim().to_owned());
+ }
+ }
 
- for flag in cflags.iter() {
- if flag.starts_with("-DMODULE_") {
+ const BOOLEAN_FLAGS: &[&str] = &[
+ // This decides whether or not some fields are populated ... and unlike with other
+ // structs, the zeroed default is not a good solution here. (It'd kind of work, but
+ // it'd produce incorrect debug output).
+ "CONFIG_AUTO_INIT_ENABLE_DEBUG",
+ ];
+
+ for (def, val) in defines {
+ if val != "1" {
+ // So far, only processing boolean flags
+ continue;
+ }
+ if let Some(module) = def.strip_prefix("MODULE_") {
  // Some modules like cmsis-dsp_StatisticsFunctions have funny characters
  println!(
  "cargo:rustc-cfg=riot_module_{}",
- flag[9..].to_lowercase().replace("-", "_")
+ module.to_lowercase().replace("-", "_")
  );
  }
-
- if flag == "-DDEVELHELP" {
+ if def == "DEVELHELP" {
  println!("cargo:rustc-cfg=riot_develhelp");
  }
- }
-
- let mut bindgen_output_file = None;
-
- for (key, value) in env::vars() {
- if let Some(marker) = key.strip_prefix("DEP_RIOT_SYS_MARKER_") {
- println!("cargo:rerun-if-env-changed={}", key);
- // It appears that they get uppercased in Cargo -- but should be lower-case as in the
- // original riot-sys build.rs, especially to not make the cfg statements look weird.
- println!("cargo:rustc-cfg=marker_{}", marker.to_lowercase());
- }
- if key == "DEP_RIOT_SYS_BINDGEN_OUTPUT_FILE" {
- bindgen_output_file = Some(value);
- }
- }
-
- if let Some(bindgen_output_file) = bindgen_output_file {
- let bindgen_output = std::fs::read_to_string(bindgen_output_file)
- .expect("Failed to read BINDGEN_OUTPUT_FILE");
-
- const BOOLEAN_FLAGS: &[&str] = &[
- // This decides whether or not some fields are populated ... and unlike with other
- // structs, the zeroed default is not a good solution here. (It'd kind of work, but
- // it'd produce incorrect debug output).
- "CONFIG_AUTO_INIT_ENABLE_DEBUG",
- ];
-
- let parsed = syn::parse_file(&bindgen_output).expect("Failed to parse bindgen output");
- for item in &parsed.items {
- if let syn::Item::Const(const_) = item {
- // It's the easiest way to get something we can `contains`...
- let ident = const_.ident.to_string();
- if BOOLEAN_FLAGS.contains(&ident.as_str()) {
- if let syn::Expr::Lit(syn::ExprLit {
- lit: syn::Lit::Int(litint),
- ..
- }) = &*const_.expr
- {
- let value: usize = litint
- .base10_parse()
- .expect("Identifier is integer literal but not parsable");
- if value != 0 {
- println!("cargo:rustc-cfg=marker_{}", ident.to_lowercase());
- }
- continue;
- }
- panic!(
- "Found {} but it's not the literal const it was expected to be",
- ident
- );
- }
- }
+ if BOOLEAN_FLAGS.contains(&def.as_str()) {
+ println!("cargo:rustc-cfg=marker_{}", def.to_lowercase());
  }
- } else {
- println!("cargo:warning=Old riot-sys did not provide BINDGEN_OUTPUT_FILE, assuming it's an old RIOT version");
  }
 }

src/gcoap.rs

@@ -7,11 +7,6 @@ use riot_sys::{coap_optpos_t, coap_pkt_t, gcoap_listener_t};
 
 use riot_sys::coap_resource_t;
 
-#[cfg(marker_coap_request_ctx_t)]
-type HandlerArg4 = riot_sys::coap_request_ctx_t;
-#[cfg(not(marker_coap_request_ctx_t))]
-type HandlerArg4 = libc::c_void;
-
 /// Give the caller a way of registering Gcoap handlers into the global Gcoap registry inside a
 /// callback. When the callback terminates, the registered handlers are deregistered again,
 /// theoretically allowing the registration of non-'static handlers.
@@ -177,14 +172,11 @@ where
  pkt: *mut coap_pkt_t,
  buf: *mut u8,
  len: u32,
- context: *mut HandlerArg4,
+ context: *mut riot_sys::coap_request_ctx_t,
  ) -> i32 {
- #[cfg(marker_coap_request_ctx_t)]
  /* The remaining information in the request_ctx is inaccessible through the CoAP handler
  * API as it is now */
  let h = riot_sys::coap_request_ctx_get_context(context) as *mut H;
- #[cfg(not(marker_coap_request_ctx_t))]
- let h = context as *mut H;
 
  let h = &mut *h;
  let mut pb = PacketBuffer {