Expose parameter clause context to sqlc plugins

Surface the AST clause context (SET, WHERE, LIMIT, OFFSET, etc.) for
each query parameter through the plugin proto. The compiler already
dispatches on parent node type to resolve parameters — this commit tags
each Parameter with that context so plugins can distinguish e.g. WHERE
params from SET params without reparsing query text.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mrmeku

internal/cmd/shim.go

@@ -236,8 +236,9 @@ func pluginQueryColumn(c *compiler.Column) *plugin.Column {
 
 func pluginQueryParam(p compiler.Parameter) *plugin.Parameter {
 	return &plugin.Parameter{
-		Number: int32(p.Number),
-		Column: pluginQueryColumn(p.Column),
+		Number:  int32(p.Number),
+		Column:  pluginQueryColumn(p.Column),
+		Context: plugin.ParameterContext(p.Context),
 	}
 }
 

internal/compiler/query.go

@@ -61,7 +61,21 @@ type Query struct {
 	RawStmt *ast.RawStmt
 }
 
+type ParameterContext int
+
+const (
+	ParameterContextUnspecified ParameterContext = iota
+	ParameterContextSet
+	ParameterContextValues
+	ParameterContextWhere
+	ParameterContextHaving
+	ParameterContextFunctionArg
+	ParameterContextLimit
+	ParameterContextOffset
+)
+
 type Parameter struct {
-	Number int
-	Column *Column
+	Number  int
+	Column  *Column
+	Context ParameterContext
 }

internal/compiler/resolve.go

@@ -126,6 +126,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 					NotNull:      p.NotNull(),
 					IsNamedParam: isNamed,
 				},
+				Context: ParameterContextOffset,
 			})
 
 		case *limitCount:
@@ -139,6 +140,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 					NotNull:      p.NotNull(),
 					IsNamedParam: isNamed,
 				},
+				Context: ParameterContextLimit,
 			})
 
 		case *ast.A_Expr:
@@ -173,6 +175,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 						NotNull:      p.NotNull(),
 						IsSqlcSlice:  p.IsSqlcSlice(),
 					},
+					Context: ParameterContextWhere,
 				})
 				continue
 			}
@@ -246,6 +249,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 								IsNamedParam: isNamed,
 								IsSqlcSlice:  p.IsSqlcSlice(),
 							},
+							Context: ParameterContextWhere,
 						})
 					}
 				}
@@ -311,6 +315,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 							IsNamedParam: isNamed,
 							IsSqlcSlice:  p.IsSqlcSlice(),
 						},
+						Context: ParameterContextWhere,
 					})
 				}
 			}
@@ -383,6 +388,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 							NotNull:      p.NotNull(),
 							IsSqlcSlice:  p.IsSqlcSlice(),
 						},
+						Context: ParameterContextFunctionArg,
 					})
 					continue
 				}
@@ -425,6 +431,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 						IsNamedParam: isNamed,
 						IsSqlcSlice:  p.IsSqlcSlice(),
 					},
+					Context: ParameterContextFunctionArg,
 				})
 			}
 
@@ -498,6 +505,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 						IsNamedParam: isNamed,
 						IsSqlcSlice:  p.IsSqlcSlice(),
 					},
+					Context: ParameterContextSet,
 				})
 			} else {
 				return nil, &sqlerr.Error{
@@ -608,6 +616,7 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 								IsNamedParam: isNamed,
 								IsSqlcSlice:  p.IsSqlcSlice(),
 							},
+							Context: ParameterContextWhere,
 						})
 					}
 				}

internal/endtoend/testdata/codegen_json/gen/codegen.json

@@ -65074,7 +65074,8 @@
             "original_name": "id",
             "unsigned": false,
             "array_dims": 0
-          }
+          },
+          "context": "PARAMETER_CONTEXT_WHERE"
         }
       ],
       "comments": [],
@@ -65286,7 +65287,8 @@
             "original_name": "name",
             "unsigned": false,
             "array_dims": 0
-          }
+          },
+          "context": "PARAMETER_CONTEXT_SET"
         },
         {
           "number": 2,
@@ -65315,7 +65317,8 @@
             "original_name": "bio",
             "unsigned": false,
             "array_dims": 0
-          }
+          },
+          "context": "PARAMETER_CONTEXT_SET"
         }
       ],
       "comments": [],
@@ -65361,7 +65364,8 @@
             "original_name": "bio",
             "unsigned": false,
             "array_dims": 0
-          }
+          },
+          "context": "PARAMETER_CONTEXT_SET"
         },
         {
           "number": 2,
@@ -65390,7 +65394,8 @@
             "original_name": "id",
             "unsigned": false,
             "array_dims": 0
-          }
+          },
+          "context": "PARAMETER_CONTEXT_WHERE"
         }
       ],
       "comments": [],
@@ -65436,7 +65441,8 @@
             "original_name": "id",
             "unsigned": false,
             "array_dims": 0
-          }
+          },
+          "context": "PARAMETER_CONTEXT_WHERE"
         }
       ],
       "comments": [],