feat: S14.06 flip the SD vtable to SolidSyslogSdElement

Core/Interface/SolidSyslogStructuredData.h

@@ -5,13 +5,10 @@
 
 EXTERN_C_BEGIN
 
-    struct SolidSyslogFormatter;
+    struct SolidSyslogSdElement;
     struct SolidSyslogStructuredData;
 
-    void SolidSyslogStructuredData_Format(
-        struct SolidSyslogStructuredData * sd,
-        struct SolidSyslogFormatter * formatter
-    );
+    void SolidSyslogStructuredData_Format(struct SolidSyslogStructuredData * sd, struct SolidSyslogSdElement * element);
 
 EXTERN_C_END
 

Core/Interface/SolidSyslogStructuredDataDefinition.h

@@ -5,11 +5,11 @@
 
 EXTERN_C_BEGIN
 
-    struct SolidSyslogFormatter;
+    struct SolidSyslogSdElement;
 
     struct SolidSyslogStructuredData
     {
-        void (*Format)(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter);
+        void (*Format)(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element);
     };
 
 EXTERN_C_END

Core/Source/SolidSyslogMessageFormatter.c

@@ -7,6 +7,7 @@
 #include "SolidSyslog.h"
 #include "SolidSyslogFormatter.h"
 #include "SolidSyslogPrival.h"
+#include "SolidSyslogSdElementPrivate.h"
 #include "SolidSyslogStringFunction.h"
 #include "SolidSyslogStructuredData.h"
 #include "SolidSyslogTimestamp.h"
@@ -168,10 +169,12 @@ static inline void MessageFormatter_FormatStructuredData(
 )
 {
     size_t lengthBefore = SolidSyslogFormatter_Length(f);
+    struct SolidSyslogSdElement element;
 
+    SolidSyslogSdElement_FromFormatter(&element, f);
     for (size_t i = 0; i < sdCount; i++)
     {
-        SolidSyslogStructuredData_Format(sd[i], f);
+        SolidSyslogStructuredData_Format(sd[i], &element);
     }
 
     if (SolidSyslogFormatter_Length(f) == lengthBefore)

Core/Source/SolidSyslogMetaSd.c

@@ -7,15 +7,13 @@
 #include "SolidSyslogMetaSdErrors.h"
 #include "SolidSyslogMetaSdPrivate.h"
 #include "SolidSyslogNullSd.h"
-#include "SolidSyslogSdElementPrivate.h"
+#include "SolidSyslogSdElement.h"
 #include "SolidSyslogSdValue.h"
 #include "SolidSyslogStructuredDataDefinition.h"
 
 const struct SolidSyslogErrorSource MetaSdErrorSource = {"MetaSd"};
 
-struct SolidSyslogFormatter;
-
-static void MetaSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter);
+static void MetaSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element);
 
 static inline struct SolidSyslogMetaSd* MetaSd_SelfFromBase(struct SolidSyslogStructuredData* base);
 
@@ -37,26 +35,24 @@ void MetaSd_Cleanup(struct SolidSyslogStructuredData* base)
     *base = *SolidSyslogNullSd_Get();
 }
 
-static void MetaSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter)
+static void MetaSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element)
 {
     struct SolidSyslogMetaSd* self = MetaSd_SelfFromBase(base);
-    struct SolidSyslogSdElement element;
 
-    SolidSyslogSdElement_FromFormatter(&element, formatter);
-    SolidSyslogSdElement_Begin(&element, "meta", 0U);
+    SolidSyslogSdElement_Begin(element, "meta", 0U);
     SolidSyslogSdValue_Uint32(
-        SolidSyslogSdElement_Param(&element, "sequenceId"),
+        SolidSyslogSdElement_Param(element, "sequenceId"),
         SolidSyslogAtomicCounter_Increment(self->Counter)
     );
     if (self->GetSysUpTime != NULL)
     {
-        SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(&element, "sysUpTime"), self->GetSysUpTime());
+        SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(element, "sysUpTime"), self->GetSysUpTime());
     }
     if (self->GetLanguage != NULL)
     {
-        self->GetLanguage(SolidSyslogSdElement_Param(&element, "language"), self->LanguageContext);
+        self->GetLanguage(SolidSyslogSdElement_Param(element, "language"), self->LanguageContext);
     }
-    SolidSyslogSdElement_End(&element);
+    SolidSyslogSdElement_End(element);
 }
 
 static inline struct SolidSyslogMetaSd* MetaSd_SelfFromBase(struct SolidSyslogStructuredData* base)

Core/Source/SolidSyslogNullSd.c

@@ -2,18 +2,18 @@
 
 #include "SolidSyslogStructuredDataDefinition.h"
 
-struct SolidSyslogFormatter;
+struct SolidSyslogSdElement;
 
-static void NullSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter);
+static void NullSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element);
 
 struct SolidSyslogStructuredData* SolidSyslogNullSd_Get(void)
 {
     static struct SolidSyslogStructuredData instance = {.Format = NullSd_Format};
     return &instance;
 }
 
-static void NullSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter)
+static void NullSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element)
 {
     (void) base;
-    (void) formatter;
+    (void) element;
 }

Core/Source/SolidSyslogOriginSd.c

@@ -6,15 +6,13 @@
 #include "SolidSyslogNullSd.h"
 #include "SolidSyslogOriginSdErrors.h"
 #include "SolidSyslogOriginSdPrivate.h"
-#include "SolidSyslogSdElementPrivate.h"
+#include "SolidSyslogSdElement.h"
 #include "SolidSyslogSdValue.h"
 #include "SolidSyslogStructuredDataDefinition.h"
 
 const struct SolidSyslogErrorSource OriginSdErrorSource = {"OriginSd"};
 
-struct SolidSyslogFormatter;
-
-static void OriginSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter);
+static void OriginSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element);
 
 static inline struct SolidSyslogOriginSd* OriginSd_SelfFromBase(struct SolidSyslogStructuredData* base);
 static inline void OriginSd_EmitSoftware(struct SolidSyslogSdElement* element, const char* software);
@@ -42,18 +40,16 @@ void OriginSd_Cleanup(struct SolidSyslogStructuredData* base)
     *base = *SolidSyslogNullSd_Get();
 }
 
-static void OriginSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter)
+static void OriginSd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element)
 {
     struct SolidSyslogOriginSd* self = OriginSd_SelfFromBase(base);
-    struct SolidSyslogSdElement element;
 
-    SolidSyslogSdElement_FromFormatter(&element, formatter);
-    SolidSyslogSdElement_Begin(&element, "origin", 0U);
-    OriginSd_EmitSoftware(&element, self->Software);
-    OriginSd_EmitSwVersion(&element, self->SwVersion);
-    OriginSd_EmitEnterpriseId(&element, self->EnterpriseId);
-    OriginSd_EmitIps(&element, self);
-    SolidSyslogSdElement_End(&element);
+    SolidSyslogSdElement_Begin(element, "origin", 0U);
+    OriginSd_EmitSoftware(element, self->Software);
+    OriginSd_EmitSwVersion(element, self->SwVersion);
+    OriginSd_EmitEnterpriseId(element, self->EnterpriseId);
+    OriginSd_EmitIps(element, self);
+    SolidSyslogSdElement_End(element);
 }
 
 static inline struct SolidSyslogOriginSd* OriginSd_SelfFromBase(struct SolidSyslogStructuredData* base)

Core/Source/SolidSyslogStructuredData.c

@@ -1,9 +1,9 @@
 #include "SolidSyslogStructuredDataDefinition.h"
 #include "SolidSyslogStructuredData.h"
 
-struct SolidSyslogFormatter;
+struct SolidSyslogSdElement;
 
-void SolidSyslogStructuredData_Format(struct SolidSyslogStructuredData* sd, struct SolidSyslogFormatter* formatter)
+void SolidSyslogStructuredData_Format(struct SolidSyslogStructuredData* sd, struct SolidSyslogSdElement* element)
 {
-    sd->Format(sd, formatter);
+    sd->Format(sd, element);
 }

Core/Source/SolidSyslogTimeQualitySd.c

@@ -5,17 +5,15 @@
 
 #include "SolidSyslogError.h"
 #include "SolidSyslogNullSd.h"
-#include "SolidSyslogSdElementPrivate.h"
+#include "SolidSyslogSdElement.h"
 #include "SolidSyslogSdValue.h"
 #include "SolidSyslogStructuredDataDefinition.h"
 #include "SolidSyslogTimeQualitySdErrors.h"
 #include "SolidSyslogTimeQualitySdPrivate.h"
 
 const struct SolidSyslogErrorSource TimeQualitySdErrorSource = {"TimeQualitySd"};
 
-struct SolidSyslogFormatter;
-
-static void TimeQualitySd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter);
+static void TimeQualitySd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element);
 
 static inline struct SolidSyslogTimeQualitySd* TimeQualitySd_SelfFromBase(struct SolidSyslogStructuredData* base);
 
@@ -34,23 +32,21 @@ void TimeQualitySd_Cleanup(struct SolidSyslogStructuredData* base)
     *base = *SolidSyslogNullSd_Get();
 }
 
-static void TimeQualitySd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogFormatter* formatter)
+static void TimeQualitySd_Format(struct SolidSyslogStructuredData* base, struct SolidSyslogSdElement* element)
 {
     struct SolidSyslogTimeQualitySd* self = TimeQualitySd_SelfFromBase(base);
     struct SolidSyslogTimeQuality q = {0};
-    struct SolidSyslogSdElement element;
 
     self->GetTimeQuality(&q);
 
-    SolidSyslogSdElement_FromFormatter(&element, formatter);
-    SolidSyslogSdElement_Begin(&element, "timeQuality", 0U);
-    SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(&element, "tzKnown"), q.TzKnown ? 1U : 0U);
-    SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(&element, "isSynced"), q.IsSynced ? 1U : 0U);
+    SolidSyslogSdElement_Begin(element, "timeQuality", 0U);
+    SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(element, "tzKnown"), q.TzKnown ? 1U : 0U);
+    SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(element, "isSynced"), q.IsSynced ? 1U : 0U);
     if (q.SyncAccuracyMicroseconds != SOLIDSYSLOG_SYNC_ACCURACY_OMIT)
     {
-        SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(&element, "syncAccuracy"), q.SyncAccuracyMicroseconds);
+        SolidSyslogSdValue_Uint32(SolidSyslogSdElement_Param(element, "syncAccuracy"), q.SyncAccuracyMicroseconds);
     }
-    SolidSyslogSdElement_End(&element);
+    SolidSyslogSdElement_End(element);
 }
 
 static inline struct SolidSyslogTimeQualitySd* TimeQualitySd_SelfFromBase(struct SolidSyslogStructuredData* base)

DEVLOG.md

@@ -14520,3 +14520,34 @@ MISRA rule — different category, doesn't set precedent.
 
 ### Open questions
 - None outstanding.
+
+## 2026-06-06 — S14.06: flip the SD vtable to SolidSyslogSdElement
+
+### Decisions
+- **Flipped the SD extension point.** `struct SolidSyslogStructuredData.Format` and the
+  `SolidSyslogStructuredData_Format` dispatch wrapper now take a
+  `struct SolidSyslogSdElement*` instead of a raw `struct SolidSyslogFormatter*`. A
+  custom-SD author's `Format` can no longer reach a formatter — the footgun is closed at
+  the vtable itself, the payoff of the S14.03–05 migrations.
+- **One element per message.** Moved the `SolidSyslogSdElement_FromFormatter` wrap up into
+  `MessageFormatter_FormatStructuredData`: build the element once, pass it to each SD in
+  the existing order. `SolidSyslogSdElement_Begin` resets the element's per-SD state, so a
+  single instance hosts every configured SD sequentially (`[meta…][origin…]`).
+- **SDs slimmed.** MetaSd / OriginSd / TimeQualitySd drop their local `element` +
+  `_FromFormatter` and emit straight onto the handed element; they now include the public
+  `SolidSyslogSdElement.h` rather than the private header. NullSd's no-op signature
+  follows. Byte-for-byte identical output (existing tests stand). SD test doubles' `Format`
+  signatures updated; the `[spy]`/`[spy2]` spies now emit via `_Begin`/`_End`; each SD
+  unit test's `format()` helper and `SolidSyslogNullSdTest` build the element from the
+  formatter via the private `_FromFormatter`.
+- Checks: debug green (1459 tests), BddTargetTests 66/66; clang-format applied;
+  cppcheck-MISRA exit 0 (anchors moved: MetaSd 11.3 64→60, OriginSd 11.3 61→57,
+  TimeQualitySd 11.3 58→54, MessageFormatter 11.8 ×5 +1 and 5.7 19→20).
+
+### Deferred
+- Header-field callbacks still take a formatter until S14.07; moving
+  `SolidSyslogFormatter.h` out of the public interface is S14.08 (along with the CLAUDE.md
+  header-table revision).
+
+### Open questions
+- None outstanding.

Tests/SolidSyslogMetaSdTest.cpp

@@ -9,6 +9,7 @@
 #include "SolidSyslogMetaSd.h"
 #include "SolidSyslogMetaSdErrors.h"
 #include "SolidSyslogPrival.h"
+#include "SolidSyslogSdElementPrivate.h"
 #include "SolidSyslogSdValue.h"
 #include "SolidSyslogStructuredData.h"
 #include "SolidSyslogTunables.h"
@@ -120,7 +121,9 @@ TEST_GROUP(SolidSyslogMetaSd)
 
     void format() const
     {
-        SolidSyslogStructuredData_Format(sd, formatter);
+        struct SolidSyslogSdElement element{};
+        SolidSyslogSdElement_FromFormatter(&element, formatter);
+        SolidSyslogStructuredData_Format(sd, &element);
     }
 
     void resetFormatter()
@@ -178,7 +181,7 @@ TEST(SolidSyslogMetaSd, UseAfterDestroyIsCrashSafeViaNullSdVtable)
      * Format through the stale handle is a safe no-op rather than a NULL-fn-pointer
      * crash. NullSd.Format writes nothing into the Formatter. */
     SolidSyslogMetaSd_Destroy(sd);
-    SolidSyslogStructuredData_Format(sd, formatter);
+    format();
     LONGS_EQUAL(0, SolidSyslogFormatter_Length(formatter));
     sd = SolidSyslogMetaSd_Create(&config); // for teardown
 }

Tests/SolidSyslogNullSdTest.cpp

@@ -1,6 +1,7 @@
 #include "CppUTest/TestHarness.h"
 #include "SolidSyslogFormatter.h"
 #include "SolidSyslogNullSd.h"
+#include "SolidSyslogSdElementPrivate.h"
 #include "SolidSyslogStructuredData.h"
 
 // clang-format off
@@ -21,6 +22,8 @@ TEST_GROUP(SolidSyslogNullSd)
 
 TEST(SolidSyslogNullSd, FormatWritesNothing)
 {
-    SolidSyslogStructuredData_Format(sd, formatter);
+    struct SolidSyslogSdElement element{};
+    SolidSyslogSdElement_FromFormatter(&element, formatter);
+    SolidSyslogStructuredData_Format(sd, &element);
     LONGS_EQUAL(0, SolidSyslogFormatter_Length(formatter));
 }

Tests/SolidSyslogOriginSdTest.cpp

@@ -9,6 +9,7 @@
 #include "SolidSyslogOriginSd.h"
 #include "SolidSyslogOriginSdErrors.h"
 #include "SolidSyslogPrival.h"
+#include "SolidSyslogSdElementPrivate.h"
 #include "SolidSyslogSdValue.h"
 #include "SolidSyslogStructuredData.h"
 #include "SolidSyslogTunables.h"
@@ -139,7 +140,9 @@ TEST_GROUP(SolidSyslogOriginSd)
 
     void format() const
     {
-        SolidSyslogStructuredData_Format(sd, formatter);
+        struct SolidSyslogSdElement element{};
+        SolidSyslogSdElement_FromFormatter(&element, formatter);
+        SolidSyslogStructuredData_Format(sd, &element);
     }
 
     void resetFormatter()
@@ -161,7 +164,7 @@ TEST(SolidSyslogOriginSd, UseAfterDestroyIsCrashSafeViaNullSdVtable)
      * Format through the stale handle is a safe no-op rather than a NULL-fn-pointer
      * crash. NullSd.Format writes nothing into the Formatter. */
     SolidSyslogOriginSd_Destroy(sd);
-    SolidSyslogStructuredData_Format(sd, formatter);
+    format();
     LONGS_EQUAL(0, SolidSyslogFormatter_Length(formatter));
     sd = SolidSyslogOriginSd_Create(&config); // for teardown
 }

Tests/SolidSyslogTest.cpp

@@ -19,6 +19,7 @@
 #include "SolidSyslogNullStore.h"
 #include "SolidSyslogPassthroughBuffer.h"
 #include "SolidSyslogPrival.h"
+#include "SolidSyslogSdElement.h"
 #include "SolidSyslogStore.h"
 #include "SolidSyslogStructuredDataDefinition.h"
 #include "SolidSyslogTimeQuality.h"
@@ -58,24 +59,23 @@ static const char * const TEST_MSG       = "hello world";
 
 #define CHECK_PROCID(expected) STRCMP_EQUAL(expected, SyslogField(lastMessage(), SYSLOG_FIELD_PROCID).c_str())
 
-static const char SD_SPY_TEXT[] = "[spy]";
-static const char SD_SPY2_TEXT[] = "[spy2]";
-
-static void SdSpyFormat(struct SolidSyslogStructuredData* /* self */, struct SolidSyslogFormatter* formatter)
+static void SdSpyFormat(struct SolidSyslogStructuredData* /* self */, struct SolidSyslogSdElement* element)
 {
-    SolidSyslogFormatter_BoundedString(formatter, SD_SPY_TEXT, sizeof(SD_SPY_TEXT) - 1);
+    SolidSyslogSdElement_Begin(element, "spy", 0U);
+    SolidSyslogSdElement_End(element);
 }
 
 static struct SolidSyslogStructuredData sdSpy = {SdSpyFormat};
 
-static void SdSpyFormat2(struct SolidSyslogStructuredData* /* self */, struct SolidSyslogFormatter* formatter)
+static void SdSpyFormat2(struct SolidSyslogStructuredData* /* self */, struct SolidSyslogSdElement* element)
 {
-    SolidSyslogFormatter_BoundedString(formatter, SD_SPY2_TEXT, sizeof(SD_SPY2_TEXT) - 1);
+    SolidSyslogSdElement_Begin(element, "spy2", 0U);
+    SolidSyslogSdElement_End(element);
 }
 
 static struct SolidSyslogStructuredData sdSpy2 = {SdSpyFormat2};
 
-static void SdFailFormat(struct SolidSyslogStructuredData* /* self */, struct SolidSyslogFormatter* /* formatter */)
+static void SdFailFormat(struct SolidSyslogStructuredData* /* self */, struct SolidSyslogSdElement* /* element */)
 {
 }