Expose ignored error snapshot

Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.10)
 # 1.0.0 replaced the consumer-sized __AKERR_ERROR_NAMES array with private
 # storage. 2.0.0 makes the library thread safe, which is a second ABI break in
-# the same places: __akerr_last_ignored became thread-local storage, and
+# the same places: akerr_last_ignored became thread-local storage, and
 # ENSURE_ERROR_READY no longer takes the pool reference that akerr_next_error()
 # now takes for it. Consumer code compiled against a 1.x header would
 # double-count every reference. Hence the major bump and the SOVERSION, so a

README.md

@@ -170,7 +170,7 @@ the exit code was the status truncated to a byte, and every consumer status
 starts at 256. Use `akerr_exit()` instead of `exit()` — see
 [docs/exit-status.md](docs/exit-status.md). No ABI break.
 
-2.0.0 makes the library thread safe. That is an ABI break — `__akerr_last_ignored`
+2.0.0 makes the library thread safe. That is an ABI break — `akerr_last_ignored`
 became thread-local storage and the pool now takes its own reference — so
 everything built against a 1.x header must be rebuilt. 1.0.0 replaced the
 consumer-sized status-name array with a private, ownership-enforced registry.

UPGRADING.md

@@ -52,7 +52,7 @@ accident.
 
 What moved at the ABI:
 
-* `__akerr_last_ignored` is thread-local storage. An ignored error is a fact
+* `akerr_last_ignored` is thread-local storage. An ignored error is a fact
   about the thread that ignored it, and one shared slot had two threads
   overwriting each other's. The `IGNORE` macro expands at *your* call site, so
   your objects reference the symbol under whichever storage model your header

docs/thread-safety.md

@@ -15,7 +15,7 @@ What that covers:
   cannot both win — exactly one gets `NULL` and the other gets
   `AKERR_STATUS_RANGE_OVERLAP` naming the winner.
 * **Per-thread state.** `IGNORE` copies the swallowed context into its
-  thread-local `__akerr_last_ignored` snapshot before releasing the pool slot.
+  thread-local `akerr_last_ignored` snapshot before releasing the pool slot.
   The snapshot remains valid until that thread ignores another error, so a
   later pool checkout cannot overwrite it. The snapshot and the last-ditch
   context used to report `akerr_release_error(NULL)` are thread-local, so

include/akerror.tmpl.h

@@ -15,7 +15,7 @@
  * scripts/generrno.sh stamps this value in at build time from the AKERR_THREADS
  * build option, the same way it stamps AKERR_LAST_ERRNO_VALUE. It is generated
  * rather than defined by the consumer on purpose: whether the library
- * serializes its global state and whether __akerr_last_ignored is a
+ * serializes its global state and whether akerr_last_ignored is a
  * thread-local are the same decision, and a consumer that disagreed with the
  * library about it would link against a differently shaped symbol.
  *
@@ -173,12 +173,12 @@ extern akerr_ErrorContext AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR];
 extern akerr_ErrorUnhandledErrorHandler akerr_handler_unhandled_error;
 extern akerr_ErrorLogFunction akerr_log_method;
 /*
- * IGNORE()'s per-thread snapshot. IGNORE() copies the swallowed error here
+ * IGNORE()'s public per-thread snapshot. IGNORE() copies the swallowed error here
  * before releasing its pool context, so this remains a useful debugging aid
  * after the pool slot is reused. The snapshot is read-only and is replaced by
  * the next ignored error. Thread local only when AKERR_THREAD_SAFE is 1.
  */
-static AKERR_THREAD_LOCAL akerr_ErrorContext __akerr_last_ignored;
+static AKERR_THREAD_LOCAL akerr_ErrorContext akerr_last_ignored;
 
 /*
  * Drop one reference, returning NULL once the last one is gone so the caller can
@@ -438,12 +438,12 @@ akerr_ErrorContext AKERR_NOIGNORE *__akerr_copy_string(char *destination, int ca
     do {								\
 	akerr_ErrorContext *__akerr_ignored = __stmt;				\
 	if ( __akerr_ignored != NULL ) {				\
-	    memcpy(&__akerr_last_ignored, __akerr_ignored,	\
-		   sizeof(__akerr_last_ignored));			\
-	    __akerr_last_ignored.stacktracebufptr =		\
-		(char *)&__akerr_last_ignored.stacktracebuf;		\
+	    memcpy(&akerr_last_ignored, __akerr_ignored,	\
+		   sizeof(akerr_last_ignored));			\
+	    akerr_last_ignored.stacktracebufptr =		\
+		(char *)&akerr_last_ignored.stacktracebuf;	\
 	    akerr_ErrorContext *__akerr_ignored_snapshot =	\
-		&__akerr_last_ignored;					\
+		&akerr_last_ignored;					\
 	    LOG_ERROR_WITH_MESSAGE(__akerr_ignored_snapshot,	\
 				   "** IGNORED ERROR **");		\
 	    RELEASE_ERROR(__akerr_ignored);				\

tests/MUTATION.md

@@ -107,7 +107,7 @@ The remaining survivors are dominated by:
 
 * **Equivalent mutants** in `akerr_init`: deleting the `memset`/`NULL` setup of
   file-scope statics (`AKERR_ARRAY_ERROR`, `__akerr_last_ditch`,
-  `__akerr_last_ignored`) changes nothing, because C already zero-initializes
+  `akerr_last_ignored`) changes nothing, because C already zero-initializes
   objects with static storage duration. `int oldid = 0;` → `1` is likewise
   dead: it is overwritten before use, and so is clearing `akerr_initializing`
   at the end of initialization — nothing reads that flag once the once-routine

tests/err_ignore.c

@@ -24,8 +24,8 @@ int main(void)
      * iteration. */
     for ( int i = 0; i < AKERR_MAX_ARRAY_ERROR + 1; i++ ) {
 	IGNORE(boom());
-	AKERR_CHECK(__akerr_last_ignored.status == AKERR_VALUE);
-	AKERR_CHECK(strcmp(__akerr_last_ignored.message,
+	AKERR_CHECK(akerr_last_ignored.status == AKERR_VALUE);
+	AKERR_CHECK(strcmp(akerr_last_ignored.message,
 			  "this error is ignored on purpose") == 0);
 	AKERR_CHECK(akerr_slots_in_use() == 0);
     }

tests/err_threads_pool.c

@@ -103,8 +103,8 @@ static void *pool_body(void *raw)
     /* IGNORE's snapshot is thread-local while logging and remains valid after
      * release. Concurrent ignored errors must all return their pool slots. */
     IGNORE(ignorable(arg));
-    AKERR_TCHECK(arg, __akerr_last_ignored.status == AKERR_IO);
-    AKERR_TCHECK(arg, strcmp(__akerr_last_ignored.message, expected) == 0);
+    AKERR_TCHECK(arg, akerr_last_ignored.status == AKERR_IO);
+    AKERR_TCHECK(arg, strcmp(akerr_last_ignored.message, expected) == 0);
 
     /* Reuse a slot after IGNORE and prove that the copied snapshot did not
      * become an alias for the newly acquired context. */
@@ -113,8 +113,8 @@ static void *pool_body(void *raw)
     if ( reused != NULL ) {
 	RELEASE_ERROR(reused);
     }
-    AKERR_TCHECK(arg, __akerr_last_ignored.status == AKERR_IO);
-    AKERR_TCHECK(arg, strcmp(__akerr_last_ignored.message, expected) == 0);
+    AKERR_TCHECK(arg, akerr_last_ignored.status == AKERR_IO);
+    AKERR_TCHECK(arg, strcmp(akerr_last_ignored.message, expected) == 0);
 
     return NULL;
 }