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09d8d110a6
Replace some bogus "x[1]" declarations with "x[FLEXIBLE_ARRAY_MEMBER]". Aside from being more self-documenting, this should help prevent bogus warnings from static code analyzers and perhaps compiler misoptimizations. This patch is just a down payment on eliminating the whole problem, but it gets rid of a lot of easy-to-fix cases. Note that the main problem with doing this is that one must no longer rely on computing sizeof(the containing struct), since the result would be compiler-dependent. Instead use offsetof(struct, lastfield). Autoconf also warns against spelling that offsetof(struct, lastfield[0]). Michael Paquier, review and additional fixes by me.
106 lines
3.7 KiB
C
106 lines
3.7 KiB
C
/*-------------------------------------------------------------------------
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*
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* params.h
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* Support for finding the values associated with Param nodes.
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*
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*
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* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/nodes/params.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef PARAMS_H
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#define PARAMS_H
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/* To avoid including a pile of parser headers, reference ParseState thus: */
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struct ParseState;
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/* ----------------
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* ParamListInfo
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*
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* ParamListInfo arrays are used to pass parameters into the executor
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* for parameterized plans. Each entry in the array defines the value
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* to be substituted for a PARAM_EXTERN parameter. The "paramid"
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* of a PARAM_EXTERN Param can range from 1 to numParams.
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*
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* Although parameter numbers are normally consecutive, we allow
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* ptype == InvalidOid to signal an unused array entry.
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*
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* pflags is a flags field. Currently the only used bit is:
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* PARAM_FLAG_CONST signals the planner that it may treat this parameter
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* as a constant (i.e., generate a plan that works only for this value
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* of the parameter).
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*
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* There are two hook functions that can be associated with a ParamListInfo
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* array to support dynamic parameter handling. First, if paramFetch
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* isn't null and the executor requires a value for an invalid parameter
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* (one with ptype == InvalidOid), the paramFetch hook is called to give
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* it a chance to fill in the parameter value. Second, a parserSetup
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* hook can be supplied to re-instantiate the original parsing hooks if
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* a query needs to be re-parsed/planned (as a substitute for supposing
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* that the current ptype values represent a fixed set of parameter types).
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* Although the data structure is really an array, not a list, we keep
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* the old typedef name to avoid unnecessary code changes.
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* ----------------
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*/
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#define PARAM_FLAG_CONST 0x0001 /* parameter is constant */
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typedef struct ParamExternData
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{
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Datum value; /* parameter value */
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bool isnull; /* is it NULL? */
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uint16 pflags; /* flag bits, see above */
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Oid ptype; /* parameter's datatype, or 0 */
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} ParamExternData;
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typedef struct ParamListInfoData *ParamListInfo;
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typedef void (*ParamFetchHook) (ParamListInfo params, int paramid);
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typedef void (*ParserSetupHook) (struct ParseState *pstate, void *arg);
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typedef struct ParamListInfoData
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{
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ParamFetchHook paramFetch; /* parameter fetch hook */
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void *paramFetchArg;
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ParserSetupHook parserSetup; /* parser setup hook */
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void *parserSetupArg;
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int numParams; /* number of ParamExternDatas following */
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ParamExternData params[FLEXIBLE_ARRAY_MEMBER];
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} ParamListInfoData;
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/* ----------------
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* ParamExecData
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*
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* ParamExecData entries are used for executor internal parameters
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* (that is, values being passed into or out of a sub-query). The
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* paramid of a PARAM_EXEC Param is a (zero-based) index into an
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* array of ParamExecData records, which is referenced through
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* es_param_exec_vals or ecxt_param_exec_vals.
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*
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* If execPlan is not NULL, it points to a SubPlanState node that needs
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* to be executed to produce the value. (This is done so that we can have
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* lazy evaluation of InitPlans: they aren't executed until/unless a
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* result value is needed.) Otherwise the value is assumed to be valid
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* when needed.
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* ----------------
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*/
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typedef struct ParamExecData
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{
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void *execPlan; /* should be "SubPlanState *" */
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Datum value;
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bool isnull;
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} ParamExecData;
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/* Functions found in src/backend/nodes/params.c */
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extern ParamListInfo copyParamList(ParamListInfo from);
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#endif /* PARAMS_H */
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