Test init reservation failure

.gitea/workflows/ci.yaml

@@ -37,23 +37,6 @@ jobs:
           fail_on_failure: 'true'
       - run: echo "🍏 This job's status is ${{ job.status }}."
 
-  sanitizer:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check out repository code
-        uses: actions/checkout@v4
-      - name: dependencies
-        run: |
-          sudo apt-get update -y
-          sudo apt-get install -y cmake gcc moreutils
-      - name: build with AddressSanitizer and UBSan
-        run: |
-          cmake -S . -B build/asan -DAKERR_SANITIZE=address,undefined
-          cmake --build build/asan
-      - name: test with AddressSanitizer and UBSan
-        run: ctest --test-dir build/asan --output-on-failure
-      - run: echo "🍏 This job's status is ${{ job.status }}."
-
   coverage:
     runs-on: ubuntu-latest
     steps:

CMakeLists.txt

@@ -158,10 +158,18 @@ add_custom_command(
   VERBATIM
 )
 
+# More than one library target consumes the generated sources below. Route
+# them through one explicit prerequisite so parallel Make builds cannot invoke
+# the same generator twice and interleave writes to errno.c.
+add_custom_target(akerror_generated
+  DEPENDS ${GENERATED_ERRNO_C} ${GENERATED_AKERROR_H}
+)
+
 add_library(akerror SHARED
   src/error.c
   ${GENERATED_ERRNO_C}
 )
+add_dependencies(akerror akerror_generated)
 
 target_include_directories(akerror PUBLIC
   $<BUILD_INTERFACE:${GENERATED_DIR}/include>
@@ -200,6 +208,32 @@ set_target_properties(akerror PROPERTIES
 akerr_instrument_for_coverage(akerror)
 akerr_instrument_for_sanitizers(akerror)
 
+# akerr_init() must terminate if it cannot reserve the library-owned status
+# band. The production table sizes are deliberately PRIVATE, so exercise that
+# otherwise unreachable startup failure with a second library target whose
+# private registries cannot accept even the first reservation. Keeping this a
+# distinct target is the test: no compile definition leaks into consumers or
+# weakens the production library.
+add_library(akerror_init_failure SHARED
+  src/error.c
+  ${GENERATED_ERRNO_C}
+)
+add_dependencies(akerror_init_failure akerror_generated)
+target_include_directories(akerror_init_failure PUBLIC
+  ${GENERATED_DIR}/include
+)
+target_compile_definitions(akerror_init_failure
+  PUBLIC AKERR_USE_STDLIB=${AKERR_USE_STDLIB}
+  PRIVATE AKERR_STATUS_NAME_SLOTS=8
+  PRIVATE AKERR_MAX_RESERVED_STATUS_RANGES=0
+  PRIVATE ${AKERR_THREADS_DEFINE}
+)
+if(AKERR_THREAD_SAFE)
+    target_link_libraries(akerror_init_failure PRIVATE Threads::Threads)
+endif()
+akerr_instrument_for_coverage(akerror_init_failure)
+akerr_instrument_for_sanitizers(akerror_init_failure)
+
 # Each test is one source file in tests/ built into test_<name> and registered
 # as CTest <name>. Tests expected to abort (unhandled error / contract
 # violation) go in AKERR_WILL_FAIL_TESTS; all others must exit 0.
@@ -227,6 +261,7 @@ set(AKERR_TESTS
     err_registry_init_order
     err_status_exception
     err_copy_string
+    err_init_reservation_fatal
     err_library_status_fatal
     err_refcount_double_fail
     err_stacktrace_bounds
@@ -254,13 +289,18 @@ endif()
 set(AKERR_WILL_FAIL_TESTS
     err_trace
     err_improper_closure
+    err_init_reservation_fatal
     err_library_status_fatal
 )
 
 foreach(_test IN LISTS AKERR_TESTS)
     add_executable(test_${_test} tests/${_test}.c)
     target_include_directories(test_${_test} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/tests)
+    if(_test STREQUAL "err_init_reservation_fatal")
+        target_link_libraries(test_${_test} PRIVATE akerror_init_failure)
+    else()
         target_link_libraries(test_${_test} PRIVATE akerror)
+    endif()
     if(AKERR_THREAD_SAFE)
         target_link_libraries(test_${_test} PRIVATE Threads::Threads)
     endif()
@@ -282,22 +322,6 @@ foreach(_test IN LISTS AKERR_TESTS)
     endif()
 endforeach()
 
-# The ignored-error slot is declared in the public header but must have one
-# library definition. Compare its address from two translation units, and
-# compile the consumer-facing test with all ordinary warnings enabled: a
-# header-local TLS definition would both duplicate storage and warn when unused.
-add_executable(test_err_ignore_multitu
-               tests/err_ignore_multitu.c
-               tests/err_ignore_multitu_helper.c)
-target_include_directories(test_err_ignore_multitu
-                           PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/tests)
-target_link_libraries(test_err_ignore_multitu PRIVATE akerror)
-target_compile_options(test_err_ignore_multitu PRIVATE -Wall -Wextra -Werror)
-if(AKERR_THREAD_SAFE)
-    target_link_libraries(test_err_ignore_multitu PRIVATE Threads::Threads)
-endif()
-add_test(NAME err_ignore_multitu COMMAND test_err_ignore_multitu)
-
 # HANDLE_GROUP deliberately enters the next case label. Keep that public macro
 # compiling with the warning enabled, so a future macro edit cannot restore the
 # warning for consumers which adopt -Wextra.

scripts/mutation_test.py

@@ -25,8 +25,6 @@ Usage:
     --work DIR          scratch dir for the mutated copy (default: a temp dir)
     --timeout SECONDS   per-suite ctest timeout (default: 120)
     --threshold PCT     exit non-zero if mutation score < PCT (default: 0 = off)
-    --cmake-arg ARG     pass an additional argument to the mutant CMake configure;
-                        repeat for multiple arguments (e.g. -DAKERR_SANITIZE=thread)
     --list              only list the mutants that would be run, then exit
     --keep              keep the scratch working copy on exit (for debugging)
     -j N                (reserved) currently runs sequentially
@@ -201,11 +199,10 @@ def generate_mutants(root, rel_target):
 # --------------------------------------------------------------------------- #
 
 class Runner:
-    def __init__(self, work, timeout, cmake_args):
+    def __init__(self, work, timeout):
         self.work = work
         self.build = os.path.join(work, "build")
         self.timeout = timeout
-        self.cmake_args = cmake_args
 
     def _run(self, cmd, timeout=None):
         return subprocess.run(
@@ -214,8 +211,7 @@ class Runner:
         )
 
     def configure(self):
-        r = self._run(["cmake", "-S", ".", "-B", "build", *self.cmake_args],
+        r = self._run(["cmake", "-S", ".", "-B", "build"], timeout=self.timeout)
-                      timeout=self.timeout)
         return r.returncode == 0, r.stdout
 
     def build_and_test(self):
@@ -311,8 +307,6 @@ def main():
     ap.add_argument("--work", default=None)
     ap.add_argument("--timeout", type=int, default=120)
     ap.add_argument("--threshold", type=float, default=0.0)
-    ap.add_argument("--cmake-arg", action="append", default=[],
-                    help="pass an argument to the mutant CMake configure; repeatable")
     ap.add_argument("--junit", default=None,
                     help="write a JUnit XML report to this path")
     ap.add_argument("--max-mutants", type=int, default=0,
@@ -360,7 +354,7 @@ def main():
     print(f"\nCopying sources to scratch dir: {work}")
     copy_tree(root, work)
 
-    runner = Runner(work, args.timeout, args.cmake_arg)
+    runner = Runner(work, args.timeout)
 
     print("Configuring baseline ...")
     ok, out = runner.configure()

src/error.c

@@ -88,7 +88,10 @@ typedef struct
 
 static akerr_StatusName akerr_status_names[AKERR_STATUS_NAME_SLOTS];
 static int akerr_status_name_count;
-static akerr_StatusRange akerr_status_ranges[AKERR_MAX_RESERVED_STATUS_RANGES];
+/* C has no portable zero-length arrays. Keep one unused physical slot when a
+ * test build sets the logical capacity to zero to drive init's fatal path. */
+static akerr_StatusRange akerr_status_ranges[
+    AKERR_MAX_RESERVED_STATUS_RANGES > 0 ? AKERR_MAX_RESERVED_STATUS_RANGES : 1];
 static int akerr_status_range_count;
 
 akerr_ErrorContext AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR];
@@ -664,7 +667,7 @@ static akerr_ErrorContext AKERR_NOIGNORE *akerr_reserve_status_range_locked(int
 			"must not overflow int)",
 			count, first_status, owner == NULL ? "(null)" : owner,
 			AKERR_MAX_STATUS_RANGE_OWNER_LENGTH);
-    last_status = first_status + (count - 1);
+    last_status = first_status + count - 1;
 
     for ( int i = 0; i < akerr_status_range_count; i++ ) {
 	if ( first_status <= akerr_status_ranges[i].last &&

tests/MUTATION.md

@@ -32,9 +32,6 @@ scripts/mutation_test.py --target src/error.c --list
 
 # Gate CI: exit non-zero if the score drops below 90%
 scripts/mutation_test.py --threshold 90
-
-# Check concurrency mutants under ThreadSanitizer
-scripts/mutation_test.py --cmake-arg=-DAKERR_SANITIZE=thread
 ```
 
 Via CMake (configures a build first if needed):
@@ -43,10 +40,8 @@ Via CMake (configures a build first if needed):
 cmake --build build --target mutation
 ```
 
-Useful flags: `--cmake-arg ARG` (pass a CMake configure argument to every
+Useful flags: `--timeout SECONDS` (per-suite build+test cap; a mutant that
-mutant build; repeat it for multiple arguments), `--timeout SECONDS` (per-suite
+hangs is counted as killed), `--keep` (retain the scratch copy for debugging),
-build+test cap; a mutant that hangs is counted as killed), `--keep` (retain the
-scratch copy for debugging),
 `--work DIR` (use a specific scratch directory), `--junit FILE` (write a JUnit
 XML report — surviving mutants appear as failing test cases).
 

tests/err_ignore_multitu.c

@@ -1,18 +0,0 @@
-#include "akerror.h"
-#include "err_ignore_multitu.h"
-#include <stdio.h>
-
-int main(void)
-{
-    akerr_ErrorContext **main_address = &__akerr_last_ignored;
-    akerr_ErrorContext **helper_address = akerr_multitu_snapshot_address();
-
-    if ( main_address != helper_address ) {
-	fprintf(stderr,
-		"CHECK FAILED: ignored-error storage differs between translation units\n");
-	return 1;
-    }
-
-    fprintf(stderr, "err_ignore_multitu ok\n");
-    return 0;
-}

tests/err_ignore_multitu.h

@@ -1,8 +0,0 @@
-#ifndef AKERR_TEST_IGNORE_MULTITU_H
-#define AKERR_TEST_IGNORE_MULTITU_H
-
-#include "akerror.h"
-
-akerr_ErrorContext **akerr_multitu_snapshot_address(void);
-
-#endif

tests/err_ignore_multitu_helper.c

@@ -1,6 +0,0 @@
-#include "err_ignore_multitu.h"
-
-akerr_ErrorContext **akerr_multitu_snapshot_address(void)
-{
-    return &__akerr_last_ignored;
-}

tests/err_init_reservation_fatal.c

@@ -0,0 +1,20 @@
+#include "akerror.h"
+
+#include <stdio.h>
+
+/*
+ * This executable links to akerror_init_failure, a test-only library target
+ * with no status-range slots. The first reservation in akerr_init() must be
+ * terminal: continuing would leave every library status unowned and make all
+ * subsequent name registrations invalid.
+ *
+ * CTest marks this WILL_FAIL. Reaching the message and returning zero means
+ * initialization swallowed its own reservation failure.
+ */
+int main(void)
+{
+    akerr_init();
+
+    fprintf(stderr, "err_init_reservation_fatal: akerr_init did not terminate\n");
+    return 0;
+}