From 05ca3f9a8776676d7d113b1f0dcf1f1fb815e41e Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Fri, 29 Sep 2023 13:22:15 +0900 Subject: [PATCH v25 1/5] Add soft error handling to some expression nodes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This adjusts the CoerceViaIO and CoerceToDomain expression evaluation code to handle errors softly. For CoerceViaIo, this adds a new ExprEvalStep opcode EEOP_IOCOERCE_SAFE, which is implemented in new function ExecEvalCoerceViaIOSafe(). The only difference from EEOP_IOCOERCE's inline implementation is that the input function receives an ErrorSaveContext via the function's FunctionCallInfo.context, which it can use to handle errors softly. For CoerceToDomain, this simply entails replacing the ereport() in ExecEvalConstraintCheck() by errsave() using the ErrorSaveContext passed in the expression's ExprEvalStep. In both cases, the ErrorSaveContext to be used is passed by setting ExprState.escontext to point to it before calling ExecInitExprRec() on the expression tree whose errors are to be suppressed. Note that no call site of ExecInitExprRec() has been changed in this commit, so there's no functional change. This is intended for implementing new SQL/JSON expression nodes in future commits that will use to it suppress errors that may occur during type coercions. Reviewed-by: Álvaro Herrera Reviewed-by: Andres Freund Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com --- src/backend/executor/execExpr.c | 8 ++- src/backend/executor/execExprInterp.c | 72 ++++++++++++++++++++++++++- src/backend/jit/llvm/llvmjit_expr.c | 6 +++ src/backend/jit/llvm/llvmjit_types.c | 1 + src/include/executor/execExpr.h | 4 ++ src/include/nodes/execnodes.h | 7 +++ 6 files changed, 96 insertions(+), 2 deletions(-) diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c index 2c62b0c9c8..34bd2102b5 100644 --- a/src/backend/executor/execExpr.c +++ b/src/backend/executor/execExpr.c @@ -1563,7 +1563,10 @@ ExecInitExprRec(Expr *node, ExprState *state, * We don't check permissions here as a type's input/output * function are assumed to be executable by everyone. */ - scratch.opcode = EEOP_IOCOERCE; + if (state->escontext == NULL) + scratch.opcode = EEOP_IOCOERCE; + else + scratch.opcode = EEOP_IOCOERCE_SAFE; /* lookup the source type's output function */ scratch.d.iocoerce.finfo_out = palloc0(sizeof(FmgrInfo)); @@ -1599,6 +1602,8 @@ ExecInitExprRec(Expr *node, ExprState *state, fcinfo_in->args[2].value = Int32GetDatum(-1); fcinfo_in->args[2].isnull = false; + fcinfo_in->context = (Node *) state->escontext; + ExprEvalPushStep(state, &scratch); break; } @@ -3306,6 +3311,7 @@ ExecInitCoerceToDomain(ExprEvalStep *scratch, CoerceToDomain *ctest, /* we'll allocate workspace only if needed */ scratch->d.domaincheck.checkvalue = NULL; scratch->d.domaincheck.checknull = NULL; + scratch->d.domaincheck.escontext = state->escontext; /* * Evaluate argument - it's fine to directly store it into resv/resnull, diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c index 24c2b60c62..4e152fdfe3 100644 --- a/src/backend/executor/execExprInterp.c +++ b/src/backend/executor/execExprInterp.c @@ -63,6 +63,7 @@ #include "executor/nodeSubplan.h" #include "funcapi.h" #include "miscadmin.h" +#include "nodes/miscnodes.h" #include "nodes/nodeFuncs.h" #include "parser/parsetree.h" #include "pgstat.h" @@ -452,6 +453,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull) &&CASE_EEOP_CASE_TESTVAL, &&CASE_EEOP_MAKE_READONLY, &&CASE_EEOP_IOCOERCE, + &&CASE_EEOP_IOCOERCE_SAFE, &&CASE_EEOP_DISTINCT, &&CASE_EEOP_NOT_DISTINCT, &&CASE_EEOP_NULLIF, @@ -1205,6 +1207,12 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull) EEO_NEXT(); } + EEO_CASE(EEOP_IOCOERCE_SAFE) + { + ExecEvalCoerceViaIOSafe(state, op); + EEO_NEXT(); + } + EEO_CASE(EEOP_DISTINCT) { /* @@ -2510,6 +2518,68 @@ ExecEvalParamExtern(ExprState *state, ExprEvalStep *op, ExprContext *econtext) errmsg("no value found for parameter %d", paramId))); } +/* + * Evaluate a CoerceViaIO node in soft-error mode. + * + * The source value is in op's result variable. + */ +void +ExecEvalCoerceViaIOSafe(ExprState *state, ExprEvalStep *op) +{ + char *str; + + /* call output function (similar to OutputFunctionCall) */ + if (*op->resnull) + { + /* output functions are not called on nulls */ + str = NULL; + } + else + { + FunctionCallInfo fcinfo_out; + + fcinfo_out = op->d.iocoerce.fcinfo_data_out; + fcinfo_out->args[0].value = *op->resvalue; + fcinfo_out->args[0].isnull = false; + + fcinfo_out->isnull = false; + str = DatumGetCString(FunctionCallInvoke(fcinfo_out)); + + /* OutputFunctionCall assumes result isn't null */ + Assert(!fcinfo_out->isnull); + } + + /* call input function (similar to InputFunctionCall) */ + if (!op->d.iocoerce.finfo_in->fn_strict || str != NULL) + { + FunctionCallInfo fcinfo_in; + + fcinfo_in = op->d.iocoerce.fcinfo_data_in; + fcinfo_in->args[0].value = PointerGetDatum(str); + fcinfo_in->args[0].isnull = *op->resnull; + /* second and third arguments are already set up */ + + /* ErrorSaveContext must be present. */ + Assert(IsA(fcinfo_in->context, ErrorSaveContext)); + + fcinfo_in->isnull = false; + *op->resvalue = FunctionCallInvoke(fcinfo_in); + + if (SOFT_ERROR_OCCURRED(fcinfo_in->context)) + { + *op->resnull = true; + *op->resvalue = (Datum) 0; + return; + } + + /* Should get null result if and only if str is NULL */ + if (str == NULL) + Assert(*op->resnull); + else + Assert(!*op->resnull); + } +} + /* * Evaluate a SQLValueFunction expression. */ @@ -3745,7 +3815,7 @@ ExecEvalConstraintCheck(ExprState *state, ExprEvalStep *op) { if (!*op->d.domaincheck.checknull && !DatumGetBool(*op->d.domaincheck.checkvalue)) - ereport(ERROR, + errsave((Node *) op->d.domaincheck.escontext, (errcode(ERRCODE_CHECK_VIOLATION), errmsg("value for domain %s violates check constraint \"%s\"", format_type_be(op->d.domaincheck.resulttype), diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c index a3a0876bff..81856a9dc7 100644 --- a/src/backend/jit/llvm/llvmjit_expr.c +++ b/src/backend/jit/llvm/llvmjit_expr.c @@ -1431,6 +1431,12 @@ llvm_compile_expr(ExprState *state) break; } + case EEOP_IOCOERCE_SAFE: + build_EvalXFunc(b, mod, "ExecEvalCoerceViaIOSafe", + v_state, op); + LLVMBuildBr(b, opblocks[opno + 1]); + break; + case EEOP_DISTINCT: case EEOP_NOT_DISTINCT: { diff --git a/src/backend/jit/llvm/llvmjit_types.c b/src/backend/jit/llvm/llvmjit_types.c index 791902ff1f..3a4be09e50 100644 --- a/src/backend/jit/llvm/llvmjit_types.c +++ b/src/backend/jit/llvm/llvmjit_types.c @@ -162,6 +162,7 @@ void *referenced_functions[] = ExecEvalRow, ExecEvalRowNotNull, ExecEvalRowNull, + ExecEvalCoerceViaIOSafe, ExecEvalSQLValueFunction, ExecEvalScalarArrayOp, ExecEvalHashedScalarArrayOp, diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h index 048573c2bc..c4fd933154 100644 --- a/src/include/executor/execExpr.h +++ b/src/include/executor/execExpr.h @@ -16,6 +16,7 @@ #include "executor/nodeAgg.h" #include "nodes/execnodes.h" +#include "nodes/miscnodes.h" /* forward references to avoid circularity */ struct ExprEvalStep; @@ -168,6 +169,7 @@ typedef enum ExprEvalOp /* evaluate assorted special-purpose expression types */ EEOP_IOCOERCE, + EEOP_IOCOERCE_SAFE, EEOP_DISTINCT, EEOP_NOT_DISTINCT, EEOP_NULLIF, @@ -547,6 +549,7 @@ typedef struct ExprEvalStep bool *checknull; /* OID of domain type */ Oid resulttype; + ErrorSaveContext *escontext; } domaincheck; /* for EEOP_CONVERT_ROWTYPE */ @@ -776,6 +779,7 @@ extern void ExecEvalParamExec(ExprState *state, ExprEvalStep *op, ExprContext *econtext); extern void ExecEvalParamExtern(ExprState *state, ExprEvalStep *op, ExprContext *econtext); +extern void ExecEvalCoerceViaIOSafe(ExprState *state, ExprEvalStep *op); extern void ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op); extern void ExecEvalCurrentOfExpr(ExprState *state, ExprEvalStep *op); extern void ExecEvalNextValueExpr(ExprState *state, ExprEvalStep *op); diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 5d7f17dee0..6a7118d300 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -34,6 +34,7 @@ #include "fmgr.h" #include "lib/ilist.h" #include "lib/pairingheap.h" +#include "nodes/miscnodes.h" #include "nodes/params.h" #include "nodes/plannodes.h" #include "nodes/tidbitmap.h" @@ -129,6 +130,12 @@ typedef struct ExprState Datum *innermost_domainval; bool *innermost_domainnull; + + /* + * For expression nodes that support soft errors. Should be set to NULL + * before calling ExecInitExprRec() if the caller wants errors thrown. + */ + ErrorSaveContext *escontext; } ExprState; -- 2.35.3