aya-bpf-macros: More consistent flow

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>

aya-bpf-macros/src/cgroup_sock.rs

@@ -12,6 +12,9 @@ pub(crate) struct CgroupSock {
 
 impl CgroupSock {
     pub(crate) fn parse(attrs: TokenStream, item: TokenStream) -> Result<CgroupSock> {
+        if attrs.is_empty() {
+            abort!(attrs, "missing attach type")
+        }
         let item: ItemFn = syn::parse2(item)?;
         let attach_type: Ident = syn::parse2(attrs)?;
         match attach_type.to_string().as_str() {

aya-bpf-macros/src/cgroup_sock_addr.rs

@@ -15,6 +15,7 @@ impl CgroupSockAddr {
         if attrs.is_empty() {
             abort!(attrs, "missing attach type")
         }
+        let item = syn::parse2(item)?;
         let attach_type: Ident = syn::parse2(attrs)?;
         match attach_type.to_string().as_str() {
             "connect4" | "connect6" | "bind4" | "bind6" | "getpeername4" | "getpeername6"
@@ -22,7 +23,6 @@ impl CgroupSockAddr {
             | "recvmsg6" => (),
             _ => abort!(attach_type, "invalid attach type"),
         }
-        let item = syn::parse2(item)?;
         Ok(CgroupSockAddr {
             item,
             attach_type: attach_type.to_string(),

aya-bpf-macros/src/cgroup_sockopt.rs

@@ -15,12 +15,12 @@ impl CgroupSockopt {
         if attrs.is_empty() {
             abort!(attrs, "expected attach type");
         }
+        let item = syn::parse2(item)?;
         let attach_type: Ident = syn::parse2(attrs)?;
         match attach_type.to_string().as_str() {
             "getsockopt" | "setsockopt" => (),
             _ => abort!(attach_type, "invalid attach type"),
         }
-        let item = syn::parse2(item)?;
         Ok(CgroupSockopt {
             item,
             attach_type: attach_type.to_string(),

aya-bpf-macros/src/kprobe.rs

@@ -33,12 +33,12 @@ pub(crate) struct KProbe {
 
 impl KProbe {
     pub(crate) fn parse(kind: KProbeKind, attrs: TokenStream, item: TokenStream) -> Result<KProbe> {
+        let item = syn::parse2(item)?;
         let mut args = syn::parse2(attrs)?;
         let function = pop_string_arg(&mut args, "function");
         let offset = pop_string_arg(&mut args, "offset").map(|v| v.parse::<u64>().unwrap());
         err_on_unknown_args(&args)?;
 
-        let item = syn::parse2(item)?;
         Ok(KProbe {
             kind,
             item,

aya-bpf-macros/src/map.rs

@@ -14,8 +14,8 @@ pub(crate) struct Map {
 
 impl Map {
     pub(crate) fn parse(attrs: TokenStream, item: TokenStream) -> Result<Map> {
-        let mut args = syn::parse2(attrs)?;
         let item: ItemStatic = syn::parse2(item)?;
+        let mut args = syn::parse2(attrs)?;
         let name = name_arg(&mut args).unwrap_or_else(|| item.ident.to_string());
         Ok(Map { item, name })
     }

aya-bpf-macros/src/tracepoint.rs

@@ -15,8 +15,8 @@ pub(crate) struct TracePoint {
 
 impl TracePoint {
     pub(crate) fn parse(attrs: TokenStream, item: TokenStream) -> Result<TracePoint> {
-        let mut args = syn::parse2(attrs)?;
         let item = syn::parse2(item)?;
+        let mut args = syn::parse2(attrs)?;
         let name = pop_string_arg(&mut args, "name");
         let category = pop_string_arg(&mut args, "category");
         err_on_unknown_args(&args)?;

aya-bpf-macros/src/uprobe.rs

@@ -35,14 +35,13 @@ pub(crate) struct UProbe {
 
 impl UProbe {
     pub(crate) fn parse(kind: UProbeKind, attrs: TokenStream, item: TokenStream) -> Result<UProbe> {
+        let item = syn::parse2(item)?;
         let mut args = syn::parse2(attrs)?;
         let path = pop_string_arg(&mut args, "path");
         let function = pop_string_arg(&mut args, "function");
         let offset = pop_string_arg(&mut args, "offset").map(|v| v.parse::<u64>().unwrap());
         let sleepable = pop_bool_arg(&mut args, "sleepable");
         err_on_unknown_args(&args)?;
-
-        let item = syn::parse2(item)?;
         Ok(UProbe {
             kind,
             item,