lib9p: idl.gen: Fix c_ver_cond() compiling with versions disabled

2 files changed, 68 insertions, 22 deletions

diff --git a/lib9p/9p.generated.c b/lib9p/9p.generated.c
index 67644e4..df00f7b 100644
--- a/lib9p/9p.generated.c
+++ b/lib9p/9p.generated.c
@@ -11,6 +11,31 @@
 
 #include "internal.h"
 
+/* utilities ******************************************************************/
+
+/**
+ * is_ver(ctx, ver) is essentially `(ctx->ctx->version == LIB9P_VER_##ver)`,
+ * but compiles correctly (to `false`) even if `LIB9P_VER_##ver` isn't defined
+ * (because `!CONFIG_9P_ENABLE_##ver`).  This is useful when `||`ing
+ * several version checks together.
+ */
+#define is_ver(ctx, ver) _is_ver_##ver(ctx->ctx->version)
+#if CONFIG_9P_ENABLE_9P2000
+	#define _is_ver_9P2000(v) (v == LIB9P_VER_9P2000)
+#else
+	#define _is_ver_9P2000(v) false
+#endif
+#if CONFIG_9P_ENABLE_9P2000_e
+	#define _is_ver_9P2000_e(v) (v == LIB9P_VER_9P2000_e)
+#else
+	#define _is_ver_9P2000_e(v) false
+#endif
+#if CONFIG_9P_ENABLE_9P2000_u
+	#define _is_ver_9P2000_u(v) (v == LIB9P_VER_9P2000_u)
+#else
+	#define _is_ver_9P2000_u(v) false
+#endif
+
 /* strings ********************************************************************/
 
 static const char *version_strs[LIB9P_VER_NUM] = {
@@ -493,7 +518,7 @@ LM_FLATTEN static bool validate_Rerror(struct _validate_ctx *ctx) {
 	    || validate_tag(ctx)
 	    || validate_s(ctx)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_4(ctx) )
+	    || ( is_ver(ctx, 9P2000_u) && validate_4(ctx) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint32_t exp = ctx->net_offset - _size_offset; (((uint32_t)size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "size value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)size, exp); })
@@ -585,7 +610,7 @@ LM_FLATTEN static bool validate_Tauth(struct _validate_ctx *ctx) {
 	    || validate_s(ctx)
 	    || validate_s(ctx)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_nuid(ctx) )
+	    || ( is_ver(ctx, 9P2000_u) && validate_nuid(ctx) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint32_t exp = ctx->net_offset - _size_offset; (((uint32_t)size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "size value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)size, exp); })
@@ -607,7 +632,7 @@ LM_FLATTEN static bool validate_Tattach(struct _validate_ctx *ctx) {
 	    || validate_s(ctx)
 	    || validate_s(ctx)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_nuid(ctx) )
+	    || ( is_ver(ctx, 9P2000_u) && validate_nuid(ctx) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint32_t exp = ctx->net_offset - _size_offset; (((uint32_t)size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "size value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)size, exp); })
@@ -669,10 +694,10 @@ LM_ALWAYS_INLINE static bool validate_stat(struct _validate_ctx *ctx) {
 	    || validate_s(ctx)
 	    || validate_s(ctx)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_s(ctx) )
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_nuid(ctx) )
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_nuid(ctx) )
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_nuid(ctx) )
+	    || ( is_ver(ctx, 9P2000_u) && validate_s(ctx) )
+	    || ( is_ver(ctx, 9P2000_u) && validate_nuid(ctx) )
+	    || ( is_ver(ctx, 9P2000_u) && validate_nuid(ctx) )
+	    || ( is_ver(ctx, 9P2000_u) && validate_nuid(ctx) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint16_t exp = ctx->net_offset - _kern_type_offset; (((uint16_t)stat_size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "stat_size value is wrong (actual:%"PRIu16" != correct:%"PRIu16")", (uint16_t)stat_size, exp); })
@@ -1040,7 +1065,7 @@ LM_FLATTEN static void unmarshal_Rerror(struct _unmarshal_ctx *ctx, struct lib9p
 	unmarshal_tag(ctx, &out->tag);
 	unmarshal_s(ctx, &out->ename);
 #if CONFIG_9P_ENABLE_9P2000_u
-	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_4(ctx, &out->errno);
+	if ( is_ver(ctx, 9P2000_u) ) unmarshal_4(ctx, &out->errno);
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
@@ -1105,7 +1130,7 @@ LM_FLATTEN static void unmarshal_Tauth(struct _unmarshal_ctx *ctx, struct lib9p_
 	unmarshal_s(ctx, &out->uname);
 	unmarshal_s(ctx, &out->aname);
 #if CONFIG_9P_ENABLE_9P2000_u
-	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_nuid(ctx, &out->n_uid);
+	if ( is_ver(ctx, 9P2000_u) ) unmarshal_nuid(ctx, &out->n_uid);
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
@@ -1119,7 +1144,7 @@ LM_FLATTEN static void unmarshal_Tattach(struct _unmarshal_ctx *ctx, struct lib9
 	unmarshal_s(ctx, &out->uname);
 	unmarshal_s(ctx, &out->aname);
 #if CONFIG_9P_ENABLE_9P2000_u
-	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_nuid(ctx, &out->n_uid);
+	if ( is_ver(ctx, 9P2000_u) ) unmarshal_nuid(ctx, &out->n_uid);
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
@@ -1158,10 +1183,10 @@ LM_ALWAYS_INLINE static void unmarshal_stat(struct _unmarshal_ctx *ctx, struct l
 	unmarshal_s(ctx, &out->file_owner_gid);
 	unmarshal_s(ctx, &out->file_last_modified_uid);
 #if CONFIG_9P_ENABLE_9P2000_u
-	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_s(ctx, &out->file_extension);
-	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_nuid(ctx, &out->file_owner_n_uid);
-	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_nuid(ctx, &out->file_owner_n_gid);
-	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_nuid(ctx, &out->file_last_modified_n_uid);
+	if ( is_ver(ctx, 9P2000_u) ) unmarshal_s(ctx, &out->file_extension);
+	if ( is_ver(ctx, 9P2000_u) ) unmarshal_nuid(ctx, &out->file_owner_n_uid);
+	if ( is_ver(ctx, 9P2000_u) ) unmarshal_nuid(ctx, &out->file_owner_n_gid);
+	if ( is_ver(ctx, 9P2000_u) ) unmarshal_nuid(ctx, &out->file_last_modified_n_uid);
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
@@ -1577,7 +1602,7 @@ LM_FLATTEN static bool marshal_Rerror(struct _marshal_ctx *ctx, struct lib9p_msg
 	    || marshal_tag(ctx, &val->tag)
 	    || marshal_s(ctx, &val->ename)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->errno) )
+	    || ( is_ver(ctx, 9P2000_u) && marshal_4(ctx, &val->errno) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u32le(ctx->net_offset - _size_offset, &ctx->net_bytes[_size_offset]); false; })
 	    || ({ encode_u8le(107, &ctx->net_bytes[_typ_offset]); false; })
@@ -1663,7 +1688,7 @@ LM_FLATTEN static bool marshal_Tauth(struct _marshal_ctx *ctx, struct lib9p_msg_
 	    || marshal_s(ctx, &val->uname)
 	    || marshal_s(ctx, &val->aname)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_nuid(ctx, &val->n_uid) )
+	    || ( is_ver(ctx, 9P2000_u) && marshal_nuid(ctx, &val->n_uid) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u32le(ctx->net_offset - _size_offset, &ctx->net_bytes[_size_offset]); false; })
 	    || ({ encode_u8le(102, &ctx->net_bytes[_typ_offset]); false; })
@@ -1682,7 +1707,7 @@ LM_FLATTEN static bool marshal_Tattach(struct _marshal_ctx *ctx, struct lib9p_ms
 	    || marshal_s(ctx, &val->uname)
 	    || marshal_s(ctx, &val->aname)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_nuid(ctx, &val->n_uid) )
+	    || ( is_ver(ctx, 9P2000_u) && marshal_nuid(ctx, &val->n_uid) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u32le(ctx->net_offset - _size_offset, &ctx->net_bytes[_size_offset]); false; })
 	    || ({ encode_u8le(104, &ctx->net_bytes[_typ_offset]); false; })
@@ -1736,10 +1761,10 @@ LM_ALWAYS_INLINE static bool marshal_stat(struct _marshal_ctx *ctx, struct lib9p
 	    || marshal_s(ctx, &val->file_owner_gid)
 	    || marshal_s(ctx, &val->file_last_modified_uid)
 #if CONFIG_9P_ENABLE_9P2000_u
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_s(ctx, &val->file_extension) )
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_nuid(ctx, &val->file_owner_n_uid) )
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_nuid(ctx, &val->file_owner_n_gid) )
-	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_nuid(ctx, &val->file_last_modified_n_uid) )
+	    || ( is_ver(ctx, 9P2000_u) && marshal_s(ctx, &val->file_extension) )
+	    || ( is_ver(ctx, 9P2000_u) && marshal_nuid(ctx, &val->file_owner_n_uid) )
+	    || ( is_ver(ctx, 9P2000_u) && marshal_nuid(ctx, &val->file_owner_n_gid) )
+	    || ( is_ver(ctx, 9P2000_u) && marshal_nuid(ctx, &val->file_last_modified_n_uid) )
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u16le(ctx->net_offset - _kern_type_offset, &ctx->net_bytes[_stat_size_offset]); false; })
 	    ;
diff --git a/lib9p/idl.gen b/lib9p/idl.gen
index 31f6527..47ca49a 100755
--- a/lib9p/idl.gen
+++ b/lib9p/idl.gen
@@ -62,7 +62,8 @@ def c_ver_ifdef(versions: set[str]) -> str:
 
 def c_ver_cond(versions: set[str]) -> str:
     if len(versions) == 1:
-        return f"(ctx->ctx->version=={c_ver_enum(next(v for v in versions))})"
+        v = next(v for v in versions)
+        return f"is_ver(ctx, {v.replace('.', '_')})"
     return "( " + (" || ".join(c_ver_cond({v}) for v in sorted(versions))) + " )"
 
 
@@ -318,12 +319,32 @@ def gen_c(versions: set[str], typs: list[idl.Type]) -> str:
 #include "internal.h"
 """
 
+    # utilities ################################################################
+    ret += f"""
+/* utilities ******************************************************************/
+"""
+
     def used(arg: str) -> str:
         return arg
 
     def unused(arg: str) -> str:
         return f"LM_UNUSED({arg})"
 
+    ret += "\n"
+    ret += "/**\n"
+    ret += f" * is_ver(ctx, ver) is essentially `(ctx->ctx->version == {idprefix.upper()}VER_##ver)`,\n"
+    ret += f" * but compiles correctly (to `false`) even if `{idprefix.upper()}VER_##ver` isn't defined\n"
+    ret += " * (because `!CONFIG_9P_ENABLE_##ver`).  This is useful when `||`ing\n"
+    ret += " * several version checks together.\n"
+    ret += " */\n"
+    ret += "#define is_ver(ctx, ver) _is_ver_##ver(ctx->ctx->version)\n"
+    for v in sorted(versions):
+        ret += f"#if CONFIG_9P_ENABLE_{v.replace('.', '_')}\n"
+        ret += f"\t#define _is_ver_{v.replace('.', '_')}(v) (v == {c_ver_enum(v)})\n"
+        ret += "#else\n"
+        ret += f"\t#define _is_ver_{v.replace('.', '_')}(v) false\n"
+        ret += "#endif\n"
+
     # strings ##################################################################
     ret += f"""
 /* strings ********************************************************************/