Avoid useless malloc/free traffic around getFormattedTypeName().

Coverity complained that one caller of getFormattedTypeName() failed
to free the returned string.  Which is true, but rather than fixing
that one, let's get rid of this tedious and error-prone requirement.
Now that getFormattedTypeName() caches its result, strdup'ing that
result and expecting the caller to free it accomplishes little except
to waste cycles.  We do create a leak in the case where getTypes didn't
make a TypeInfo for the type, but that basically shouldn't ever happen.

Back-patch, as commit 6c450a861 was.  This isn't a particularly
interesting bug fix, but the API change seems like a hazard for
future back-patching activity if we don't back-patch it.

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 2c4763d9eabc857bfed018e1fb94c54638ddd08d..c0617076f24a332a5f5ae6aded779c38ababce42 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -251,7 +251,7 @@ static char *getFormattedOperatorName(Archive *fout, const char *oproid);
 static char *convertTSFunction(Archive *fout, Oid funcOid);
 static Oid     findLastBuiltinOid_V71(Archive *fout, const char *);
 static Oid     findLastBuiltinOid_V70(Archive *fout);
-static char *getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts);
+static const char *getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts);
 static char *myFormatType(const char *typname, int32 typmod);
 static void getBlobs(Archive *fout);
 static void dumpBlob(Archive *fout, BlobInfo *binfo);
@@ -10488,13 +10488,9 @@ dumpBaseType(Archive *fout, TypeInfo *tyinfo)
        }
 
        if (OidIsValid(tyinfo->typelem))
-       {
-               char       *elemType;
-
-               elemType = getFormattedTypeName(fout, tyinfo->typelem, zeroAsOpaque);
-               appendPQExpBuffer(q, ",\n    ELEMENT = %s", elemType);
-               free(elemType);
-       }
+               appendPQExpBuffer(q, ",\n    ELEMENT = %s",
+                                                 getFormattedTypeName(fout, tyinfo->typelem,
+                                                                                          zeroAsOpaque));
 
        if (strcmp(typcategory, "U") != 0)
        {
@@ -11296,7 +11292,7 @@ format_function_arguments_old(Archive *fout,
        for (j = 0; j < nallargs; j++)
        {
                Oid                     typid;
-               char       *typname;
+               const char *typname;
                const char *argmode;
                const char *argname;
 
@@ -11335,7 +11331,6 @@ format_function_arguments_old(Archive *fout,
                                                  argname ? fmtId(argname) : "",
                                                  argname ? " " : "",
                                                  typname);
-               free(typname);
        }
        appendPQExpBufferChar(&fn, ')');
        return fn.data;
@@ -11364,15 +11359,12 @@ format_function_signature(Archive *fout, FuncInfo *finfo, bool honor_quotes)
                appendPQExpBuffer(&fn, "%s(", finfo->dobj.name);
        for (j = 0; j < finfo->nargs; j++)
        {
-               char       *typname;
-
                if (j > 0)
                        appendPQExpBufferStr(&fn, ", ");
 
-               typname = getFormattedTypeName(fout, finfo->argtypes[j],
-                                                                          zeroAsOpaque);
-               appendPQExpBufferStr(&fn, typname);
-               free(typname);
+               appendPQExpBufferStr(&fn,
+                                                        getFormattedTypeName(fout, finfo->argtypes[j],
+                                                                                                 zeroAsOpaque));
        }
        appendPQExpBufferChar(&fn, ')');
        return fn.data;
@@ -11415,7 +11407,6 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
        char       *prorows;
        char       *proparallel;
        char       *lanname;
-       char       *rettypename;
        int                     nallargs;
        char      **allargtypes = NULL;
        char      **argmodes = NULL;
@@ -11774,14 +11765,10 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
        if (funcresult)
                appendPQExpBuffer(q, "RETURNS %s", funcresult);
        else
-       {
-               rettypename = getFormattedTypeName(fout, finfo->prorettype,
-                                                                                  zeroAsOpaque);
                appendPQExpBuffer(q, "RETURNS %s%s",
                                                  (proretset[0] == 't') ? "SETOF " : "",
-                                                 rettypename);
-               free(rettypename);
-       }
+                                                 getFormattedTypeName(fout, finfo->prorettype,
+                                                                                          zeroAsOpaque));
 
        appendPQExpBuffer(q, "\n    LANGUAGE %s", fmtId(lanname));
 
@@ -11983,8 +11970,8 @@ dumpCast(Archive *fout, CastInfo *cast)
        PQExpBuffer labelq;
        PQExpBuffer castargs;
        FuncInfo   *funcInfo = NULL;
-       char       *sourceType;
-       char       *targetType;
+       const char *sourceType;
+       const char *targetType;
 
        /* Skip if not to be dumped */
        if (!cast->dobj.dump || dopt->dataOnly)
@@ -12071,9 +12058,6 @@ dumpCast(Archive *fout, CastInfo *cast)
                                        NULL, "",
                                        cast->dobj.catId, 0, cast->dobj.dumpId);
 
-       free(sourceType);
-       free(targetType);
-
        destroyPQExpBuffer(defqry);
        destroyPQExpBuffer(delqry);
        destroyPQExpBuffer(labelq);
@@ -12094,7 +12078,7 @@ dumpTransform(Archive *fout, TransformInfo *transform)
        FuncInfo   *fromsqlFuncInfo = NULL;
        FuncInfo   *tosqlFuncInfo = NULL;
        char       *lanname;
-       char       *transformType;
+       const char *transformType;
 
        /* Skip if not to be dumped */
        if (!transform->dobj.dump || dopt->dataOnly)
@@ -12200,7 +12184,6 @@ dumpTransform(Archive *fout, TransformInfo *transform)
                                        transform->dobj.catId, 0, transform->dobj.dumpId);
 
        free(lanname);
-       free(transformType);
        destroyPQExpBuffer(defqry);
        destroyPQExpBuffer(delqry);
        destroyPQExpBuffer(labelq);
@@ -13480,17 +13463,11 @@ format_aggregate_signature(AggInfo *agginfo, Archive *fout, bool honor_quotes)
        {
                appendPQExpBufferChar(&buf, '(');
                for (j = 0; j < agginfo->aggfn.nargs; j++)
-               {
-                       char       *typname;
-
-                       typname = getFormattedTypeName(fout, agginfo->aggfn.argtypes[j],
-                                                                                  zeroAsOpaque);
-
                        appendPQExpBuffer(&buf, "%s%s",
                                                          (j > 0) ? ", " : "",
-                                                         typname);
-                       free(typname);
-               }
+                                                         getFormattedTypeName(fout,
+                                                                                                  agginfo->aggfn.argtypes[j],
+                                                                                                  zeroAsOpaque));
                appendPQExpBufferChar(&buf, ')');
        }
        return buf.data;
@@ -17891,8 +17868,10 @@ findDumpableDependencies(ArchiveHandle *AH, DumpableObject *dobj,
  *
  * This does not guarantee to schema-qualify the output, so it should not
  * be used to create the target object name for CREATE or ALTER commands.
+ *
+ * Note that the result is cached and must not be freed by the caller.
  */
-static char *
+static const char *
 getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts)
 {
        TypeInfo   *typeInfo;
@@ -17903,19 +17882,19 @@ getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts)
        if (oid == 0)
        {
                if ((opts & zeroAsOpaque) != 0)
-                       return pg_strdup(g_opaque_type);
+                       return g_opaque_type;
                else if ((opts & zeroAsAny) != 0)
-                       return pg_strdup("'any'");
+                       return "'any'";
                else if ((opts & zeroAsStar) != 0)
-                       return pg_strdup("*");
+                       return "*";
                else if ((opts & zeroAsNone) != 0)
-                       return pg_strdup("NONE");
+                       return "NONE";
        }
 
        /* see if we have the result cached in the type's TypeInfo record */
        typeInfo = findTypeByOid(oid);
        if (typeInfo && typeInfo->ftypname)
-               return pg_strdup(typeInfo->ftypname);
+               return typeInfo->ftypname;
 
        query = createPQExpBuffer();
        if (fout->remoteVersion >= 70300)
@@ -17952,9 +17931,14 @@ getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts)
        PQclear(res);
        destroyPQExpBuffer(query);
 
-       /* cache a copy for later requests */
+       /*
+        * Cache the result for re-use in later requests, if possible.  If we
+        * don't have a TypeInfo for the type, the string will be leaked once the
+        * caller is done with it ... but that case really should not happen, so
+        * leaking if it does seems acceptable.
+        */
        if (typeInfo)
-               typeInfo->ftypname = pg_strdup(result);
+               typeInfo->ftypname = result;
 
        return result;
 }