proper error handling for dump edgecases

src/cdump.c

@@ -4,6 +4,7 @@
 #include "cmem.h"
 #include "cobj.h"
 #include "cvalue.h"
+#include "cvm.h"
 
 typedef struct
 {
@@ -13,7 +14,12 @@ typedef struct
     int writerStatus;
 } DumpState;
 
-static void writeCValue(DumpState *dstate, CValue val);
+static bool writeCValue(DumpState *dstate, CValue val);
+
+#define check(e)                                                                                   \
+    if (!e) {                                                                                      \
+        return false;                                                                              \
+    }
 
 static void initDumpState(CState *state, DumpState *dstate, cosmo_Writer writer,
                           const void *userData)
@@ -24,82 +30,92 @@ static void initDumpState(CState *state, DumpState *dstate, cosmo_Writer writer,
     dstate->writerStatus = 0;
 }
 
-static void writeBlock(DumpState *dstate, const void *data, size_t size)
+static bool writeBlock(DumpState *dstate, const void *data, size_t size)
 {
     if (dstate->writerStatus == 0) {
         dstate->writerStatus = dstate->writer(dstate->state, data, size, dstate->userData);
     }
+
+    return dstate->writerStatus == 0;
 }
 
-static void writeu8(DumpState *dstate, uint8_t d)
+static bool writeu8(DumpState *dstate, uint8_t d)
 {
-    writeBlock(dstate, &d, sizeof(uint8_t));
+    return writeBlock(dstate, &d, sizeof(uint8_t));
 }
 
-static void writeu32(DumpState *dstate, uint32_t d)
+static bool writeu32(DumpState *dstate, uint32_t d)
 {
-    writeBlock(dstate, &d, sizeof(uint32_t));
+    return writeBlock(dstate, &d, sizeof(uint32_t));
 }
 
-static void writeSize(DumpState *dstate, size_t d)
+static bool writeSize(DumpState *dstate, size_t d)
 {
-    writeBlock(dstate, &d, sizeof(size_t));
+    return writeBlock(dstate, &d, sizeof(size_t));
 }
 
-static void writeVector(DumpState *dstate, const void *data, size_t size, size_t count)
+static bool writeVector(DumpState *dstate, const void *data, size_t size, size_t count)
 {
-    writeSize(dstate, count);
+    check(writeSize(dstate, count));
-    writeBlock(dstate, data, size * count);
+    check(writeBlock(dstate, data, size * count));
+
+    return true;
 }
 
-static void writeHeader(DumpState *dstate)
+static bool writeHeader(DumpState *dstate)
 {
-    writeBlock(dstate, COSMO_MAGIC, COSMO_MAGIC_LEN);
+    check(writeBlock(dstate, COSMO_MAGIC, COSMO_MAGIC_LEN));
 
     /* after the magic, we write some platform information */
-    writeu8(dstate, cosmoD_isBigEndian());
+    check(writeu8(dstate, cosmoD_isBigEndian()));
-    writeu8(dstate, sizeof(cosmo_Number));
+    check(writeu8(dstate, sizeof(cosmo_Number)));
-    writeu8(dstate, sizeof(size_t));
+    check(writeu8(dstate, sizeof(size_t)));
-    writeu8(dstate, sizeof(int));
+    check(writeu8(dstate, sizeof(int)));
+
+    return true;
 }
 
-static void writeCObjString(DumpState *dstate, CObjString *obj)
+static bool writeCObjString(DumpState *dstate, CObjString *obj)
 {
     if (obj == NULL) { /* this is in case cobjfunction's name or module strings are null */
-        writeu32(dstate, 0);
+        check(writeu32(dstate, 0));
-        return;
+        return true;
     }
 
     /* write string length */
-    writeu32(dstate, obj->length);
+    check(writeu32(dstate, obj->length));
 
     /* write string data */
-    writeBlock(dstate, obj->str, obj->length);
+    check(writeBlock(dstate, obj->str, obj->length));
+
+    return true;
 }
 
-static void writeCObjFunction(DumpState *dstate, CObjFunction *obj)
+static bool writeCObjFunction(DumpState *dstate, CObjFunction *obj)
 {
-    writeCObjString(dstate, obj->name);
+    check(writeCObjString(dstate, obj->name));
-    writeCObjString(dstate, obj->module);
+    check(writeCObjString(dstate, obj->module));
 
-    writeu32(dstate, obj->args);
+    check(writeu32(dstate, obj->args));
-    writeu32(dstate, obj->upvals);
+    check(writeu32(dstate, obj->upvals));
-    writeu8(dstate, obj->variadic);
+    check(writeu8(dstate, obj->variadic));
 
     /* write chunk info */
-    writeVector(dstate, obj->chunk.buf, sizeof(uint8_t), obj->chunk.count);
+    check(writeVector(dstate, obj->chunk.buf, sizeof(uint8_t), obj->chunk.count));
 
     /* write line info */
-    writeVector(dstate, obj->chunk.lineInfo, sizeof(int), obj->chunk.count);
+    check(writeVector(dstate, obj->chunk.lineInfo, sizeof(int), obj->chunk.count));
 
     /* write constants */
-    writeSize(dstate, obj->chunk.constants.count);
+    check(writeSize(dstate, obj->chunk.constants.count));
     for (int i = 0; i < obj->chunk.constants.count; i++) {
-        writeCValue(dstate, obj->chunk.constants.values[i]);
+        check(writeCValue(dstate, obj->chunk.constants.values[i]));
     }
+
+    return true;
 }
 
-static void writeCObj(DumpState *dstate, CObj *obj)
+static bool writeCObj(DumpState *dstate, CObj *obj)
 {
     /*
         we can kind of cheat here since our parser only emits a few very limited CObjs...
@@ -117,24 +133,27 @@ static void writeCObj(DumpState *dstate, CObj *obj)
     /* write object payload/body */
     switch (t) {
     case COBJ_STRING:
-        writeCObjString(dstate, (CObjString *)obj);
+        check(writeCObjString(dstate, (CObjString *)obj));
         break;
     case COBJ_FUNCTION:
-        writeCObjFunction(dstate, (CObjFunction *)obj);
+        check(writeCObjFunction(dstate, (CObjFunction *)obj));
         break;
     default:
-        break;
+        cosmoV_error(dstate->state, "invalid cobj type: %d", t);
+        return false;
     }
+
+    return true;
 }
 
 #define WRITE_VAR(dstate, type, expression)                                                        \
     {                                                                                              \
         type _tmp = expression;                                                                    \
-        writeBlock(dstate, &_tmp, sizeof(_tmp));                                                   \
+        check(writeBlock(dstate, &_tmp, sizeof(_tmp)));                                            \
         break;                                                                                     \
     }
 
-static void writeCValue(DumpState *dstate, CValue val)
+static bool writeCValue(DumpState *dstate, CValue val)
 {
     CosmoType t = GET_TYPE(val);
 
@@ -148,12 +167,16 @@ static void writeCValue(DumpState *dstate, CValue val)
     case COSMO_TBOOLEAN:
         WRITE_VAR(dstate, bool, cosmoV_readBoolean(val))
     case COSMO_TREF:
-        writeCObj(dstate, cosmoV_readRef(val));
+        check(writeCObj(dstate, cosmoV_readRef(val)));
+        break;
+    case COSMO_TNIL: /* no body */
         break;
-    case COSMO_TNIL: /* fallthrough, no body */
     default:
-        break;
+        cosmoV_error(dstate->state, "invalid value type: %d", t);
+        return false;
     }
+
+    return true;
 }
 
 #undef WRITE_VAR
@@ -174,8 +197,8 @@ int cosmoD_dump(CState *state, CObjFunction *func, cosmo_Writer writer, const vo
     DumpState dstate;
     initDumpState(state, &dstate, writer, userData);
 
-    writeHeader(&dstate);
+    check(writeHeader(&dstate));
-    writeCObjFunction(&dstate, func);
+    check(writeCObjFunction(&dstate, func));
 
     return dstate.writerStatus;
 }

src/cundump.c

@@ -172,10 +172,10 @@ static bool readCObj(UndumpState *udstate, CObj **obj)
 
 static bool readCValue(UndumpState *udstate, CValue *val)
 {
-    uint8_t type;
+    uint8_t t;
-    check(readu8(udstate, &type));
+    check(readu8(udstate, &t));
 
-    switch (type) {
+    switch (t) {
     case COSMO_TNUMBER:
         READ_VAR(udstate, val, cosmo_Number, cosmoV_newNumber)
     case COSMO_TBOOLEAN:
@@ -190,7 +190,8 @@ static bool readCValue(UndumpState *udstate, CValue *val)
         *val = cosmoV_newNil();
         break;
     default:
-        break;
+        cosmoV_error(udstate->state, "invalid value type: %d", t);
+        return false;
     }
 
     return true;