[pve-devel] [PATCH proxmox-backup-qemu 1/3] include debian version and git rev in header file

[Stefan Reiter <s.reiter@proxmox.com>]

...so we can get the library version a binary is currently running with.

Details are retrieved in build.rs by calling dpkg-parsechangelog and
git, then appended using 'with_after_include' to appear within the
include guard.

The version string in current-api.h is inconsequential, so ignore it in
diff. This way we only have to re-commit that file whenever the *actual*
API changes, not the version.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
---
 Makefile      |  4 ++--
 build.rs      | 26 ++++++++++++++++++++++++++
 current-api.h |  2 ++
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 8761298..bc5f1f0 100644
--- a/Makefile
+++ b/Makefile
@@ -20,7 +20,7 @@ endif
 all:
 ifneq ($(BUILD_MODE), skip)
 	cargo build $(CARGO_BUILD_ARGS)
-	diff -up current-api.h proxmox-backup-qemu.h
+	diff -I 'PROXMOX_BACKUP_QEMU_VERSION' -up current-api.h proxmox-backup-qemu.h
 endif
 
 # always re-create this dir
@@ -29,7 +29,7 @@ endif
 build:
 	rm -rf build
 	cargo build --release
-	diff -up current-api.h proxmox-backup-qemu.h
+	diff -I 'PROXMOX_BACKUP_QEMU_VERSION' -up current-api.h proxmox-backup-qemu.h
 	rsync -a debian Makefile Cargo.toml Cargo.lock build.rs proxmox-backup-qemu.h src target current-api.h build/
 
 .PHONY: install
diff --git a/build.rs b/build.rs
index 46dbb7a..c49b2ab 100644
--- a/build.rs
+++ b/build.rs
@@ -2,16 +2,42 @@
 extern crate cbindgen;
 
 use std::env;
+use std::process::Command;
+
+fn capture_stdout(cmd: &str) -> String {
+    let args: Vec<&str> = cmd.split(' ').collect();
+    let (exe, args) = (args[0], &args[1..]);
+
+    let stdout = Command::new(exe)
+        .args(args)
+        .output()
+        .expect(&format!("failed to run program: {}", exe))
+        .stdout;
+
+    String::from_utf8(stdout)
+        .expect(&format!("program {} produced invalid UTF-8 output", exe))
+        .trim()
+        .to_owned()
+}
 
 fn main() {
     let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
     let header = std::fs::read_to_string("header-preamble.c").unwrap();
 
+    let debver = capture_stdout("dpkg-parsechangelog -l debian/changelog -SVersion");
+    let gitver = capture_stdout("git rev-parse --short=8 HEAD");
+    let version_define = format!(
+        "\n#define PROXMOX_BACKUP_QEMU_VERSION \"{} ({})\"",
+        debver,
+        gitver,
+    );
+
     cbindgen::Builder::new()
         .with_language(cbindgen::Language::C)
         .with_crate(&crate_dir)
         .with_header(header)
         .with_include_guard("PROXMOX_BACKUP_QEMU_H")
+        .with_after_include(version_define)
         .generate()
         .unwrap()
         .write_to_file("proxmox-backup-qemu.h");
diff --git a/current-api.h b/current-api.h
index 77e8c4b..97c185f 100644
--- a/current-api.h
+++ b/current-api.h
@@ -32,6 +32,8 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#define PROXMOX_BACKUP_QEMU_VERSION "0.7.1-1 (296da586)"
+
 #define PROXMOX_BACKUP_DEFAULT_CHUNK_SIZE ((1024 * 1024) * 4)
 
 /**
-- 
2.20.1