main: improve version string

Initialize a build variable to the date on which the binary was
generated. Include the date in the build info string which is output
when running aerc -v and in the crash logs.

Do not rely on parsing the build flags via some obscure base64 voodoo to
determine if notmuch support is available or not. Instead, use the
symbols from the linked library directly if available.

Before:

 $ aerc -v
 0.16.0-183-g4cc2e6be3a01 +notmuch (go1.21.6 amd64 linux)

After:

 $ aerc -v
 aerc 0.16.0-183-g4cc2e6be3a01 +notmuch-5.6.0 (go1.21.6 amd64 linux 2024-01-31)

Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Ciarán Ainsworth <cda@sporiff.dev>

3 files changed, 29 insertions, 0 deletions

diff --git a/lib/notmuch/notmuch.go b/lib/notmuch/notmuch.go
index 9b13878b..27c0bdfa 100644
--- a/lib/notmuch/notmuch.go
+++ b/lib/notmuch/notmuch.go
@@ -15,6 +15,17 @@ package notmuch
 
 */
 import "C"
+import "fmt"
+
+const (
+	MAJOR_VERSION = C.LIBNOTMUCH_MAJOR_VERSION
+	MINOR_VERSION = C.LIBNOTMUCH_MINOR_VERSION
+	MICRO_VERSION = C.LIBNOTMUCH_MICRO_VERSION
+)
+
+func Version() string {
+	return fmt.Sprintf("%d.%d.%d", MAJOR_VERSION, MINOR_VERSION, MICRO_VERSION)
+}
 
 // NOTE: Any CGO call which passes a reference to a pointer (**object) will fail
 // gocritic:dupSubExpr. All of these calls are set to be ignored by the linter
diff --git a/lib/notmuch_version.go b/lib/notmuch_version.go
new file mode 100644
index 00000000..c2025bda
--- /dev/null
+++ b/lib/notmuch_version.go
@@ -0,0 +1,10 @@
+//go:build notmuch
+// +build notmuch
+
+package lib
+
+import "git.sr.ht/~rjarry/aerc/lib/notmuch"
+
+func NotmuchVersion() (string, bool) {
+	return notmuch.Version(), true
+}
diff --git a/lib/notmuch_version_dummy.go b/lib/notmuch_version_dummy.go
new file mode 100644
index 00000000..f04905e1
--- /dev/null
+++ b/lib/notmuch_version_dummy.go
@@ -0,0 +1,8 @@
+//go:build !notmuch
+// +build !notmuch
+
+package lib
+
+func NotmuchVersion() (string, bool) {
+	return "", false
+}