Revert "build.rs: Obtain version from macro; simplify"

.github/workflows/ci.yml

@@ -101,8 +101,6 @@ jobs:
           - stable
           - nightly
     runs-on: ubuntu-latest
-    env:
-      QEMU_RUN_IGNORE_VERSION: 1
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1

Cargo.toml

@@ -35,10 +35,6 @@ bitflags = "1"
 rustc_version = "0.4"
 trybuild = "1.0.42"
 
-[build-dependencies]
-git-version = "0.3"
-semver = "1.0"
-
 [workspace]
 members = [
   ".",
@@ -62,7 +58,10 @@ lto = "fat"
 opt-level = 3
 overflow-checks = false
 
+[build-dependencies]
+semver = "1.0"
+
 [package.metadata.docs.rs]
 features = ["alloc"]
-rustdoc-args = ["--cfg=docsrs"]
+rustdoc-args = [ "--cfg=docsrs" ]
 targets = ["thumbv6m-none-eabi", "thumbv7em-none-eabihf"]

build.rs

@@ -1,50 +1,56 @@
-use std::{env, error::Error, fs, path::PathBuf};
-
-use git_version::git_version;
+use semver::Version;
+use std::{env, error::Error, fs, path::Path, path::PathBuf, process::Command};
 
 fn main() -> Result<(), Box<dyn Error>> {
-    // `--match v*` matches defmt tags, e.g. `v0.2.3`, but ignores related crates, e.g. `defmt-decoder-v0.2.2`
-    const GIT_DESCRIBE: &str = git_version!(args = ["--long", "--match", "v*"], cargo_prefix = "");
-
-    let version = match semver::Version::parse(GIT_DESCRIBE) {
-        // if parsing fails it is a git version
-        Err(_) => extract_git_hash(GIT_DESCRIBE).to_string(),
-        // if success it is semver
-        Ok(semver) => match semver.major {
+    // Put the linker script somewhere the linker can find it
+    let out = &PathBuf::from(env::var("OUT_DIR")?);
+    let mut linker_script = fs::read_to_string("defmt.x.in")?;
+    let hash = Command::new("git")
+        .args(&["rev-parse", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|output| {
+            if output.status.success() {
+                String::from_utf8(output.stdout).ok()
+            } else {
+                None
+            }
+        });
+    let version = if let Some(hash) = hash {
+        hash
+    } else {
+        assert!(
+            !Path::new(".git").exists(),
+            "you need to install the `git` command line tool to use the git version of `defmt`"
+        );
+
+        // no git info -> assume crates.io
+        let semver = Version::parse(&std::env::var("CARGO_PKG_VERSION")?)?;
+        if semver.major == 0 {
             // minor is breaking when major = 0
-            0 => format!("{}.{}", semver.major, semver.minor),
+            format!("{}.{}", semver.major, semver.minor)
+        } else {
             // ignore minor, patch, pre and build
-            _ => semver.major.to_string(),
-        },
+            semver.major.to_string()
+        }
     };
-
-    // Load linker-script and insert version
-    let mut linker_script = fs::read_to_string("defmt.x.in")?;
     linker_script = linker_script.replace("$DEFMT_VERSION", version.trim());
-
-    // Put the linker script somewhere the linker can find it
-    let out = &PathBuf::from(env::var("OUT_DIR")?);
     fs::write(out.join("defmt.x"), linker_script)?;
     println!("cargo:rustc-link-search={}", out.display());
+    let target = env::var("TARGET")?;
 
     // `"atomic-cas": false` in `--print target-spec-json`
     // last updated: rust 1.48.0
-    if matches!(
-        &*env::var("TARGET")?,
+    match &target[..] {
         "avr-gnu-base"
-            | "msp430-none-elf"
-            | "riscv32i-unknown-none-elf"
-            | "riscv32imc-unknown-none-elf"
-            | "thumbv4t-none-eabi"
-            | "thumbv6m-none-eabi"
-    ) {
-        println!("cargo:rustc-cfg=no_cas");
+        | "msp430-none-elf"
+        | "riscv32i-unknown-none-elf"
+        | "riscv32imc-unknown-none-elf"
+        | "thumbv4t-none-eabi"
+        | "thumbv6m-none-eabi" => {
+            println!("cargo:rustc-cfg=no_cas");
+        }
+        _ => {}
     }
-
     Ok(())
 }
-
-/// Extract git hash from a `git describe` statement
-fn extract_git_hash(git_describe: &str) -> &str {
-    git_describe.split("-").nth(2).unwrap()
-}