refactor(compiler): replace panic with error returns in toColumn

  Convert toColumn function from using panic() to returning errors,
  improving error handling for invalid SQL type names. This allows
  callers to handle errors gracefully instead of crashing.

  Changes:
  - toColumn now returns (*Column, error) instead of *Column
  - Updated 3 call sites in resolve.go and output_columns.go

Author: Ray0907

internal/compiler/output_columns.go

@@ -201,7 +201,10 @@ func (c *Compiler) outputColumns(qc *QueryCatalog, node ast.Node) ([]*Column, er
 					name = *res.Name
 				}
 				// TODO Validate column names
-				col := toColumn(tc.TypeName)
+				col, err := toColumn(tc.TypeName)
+				if err != nil {
+					return nil, err
+				}
 				col.Name = name
 				cols = append(cols, col)
 			} else if aconst, ok := n.Defresult.(*ast.A_Const); ok {
@@ -358,7 +361,10 @@ func (c *Compiler) outputColumns(qc *QueryCatalog, node ast.Node) ([]*Column, er
 				name = *res.Name
 			}
 			// TODO Validate column names
-			col := toColumn(n.TypeName)
+			col, err := toColumn(n.TypeName)
+			if err != nil {
+				return nil, err
+			}
 			col.Name = name
 			// TODO Add correct, real type inference
 			if constant, ok := n.Arg.(*ast.A_Const); ok {

internal/compiler/resolve.go

@@ -511,7 +511,10 @@ func (comp *Compiler) resolveCatalogRefs(qc *QueryCatalog, rvs []*ast.RangeVar,
 			if n.TypeName == nil {
 				return nil, fmt.Errorf("*ast.TypeCast has nil type name")
 			}
-			col := toColumn(n.TypeName)
+			col, err := toColumn(n.TypeName)
+			if err != nil {
+				return nil, err
+			}
 			defaultP := named.NewInferredParam(col.Name, col.NotNull)
 			p, _ := params.FetchMerge(ref.ref.Number, defaultP)
 

internal/compiler/to_column.go

@@ -1,6 +1,7 @@
 package compiler
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/sqlc-dev/sqlc/internal/sql/ast"
@@ -14,13 +15,13 @@ func arrayDims(n *ast.TypeName) int {
 	return len(n.ArrayBounds.Items)
 }
 
-func toColumn(n *ast.TypeName) *Column {
+func toColumn(n *ast.TypeName) (*Column, error) {
 	if n == nil {
-		panic("can't build column for nil type name")
+		return nil, fmt.Errorf("can't build column for nil type name")
 	}
 	typ, err := ParseTypeName(n)
 	if err != nil {
-		panic("toColumn: " + err.Error())
+		return nil, fmt.Errorf("toColumn: %w", err)
 	}
 	arrayDims := arrayDims(n)
 	return &Column{
@@ -29,5 +30,5 @@ func toColumn(n *ast.TypeName) *Column {
 		NotNull:   true, // XXX: How do we know if this should be null?
 		IsArray:   arrayDims > 0,
 		ArrayDims: arrayDims,
-	}
+	}, nil
 }