Commits on Sep 19, 2023

1. Don't call MethodByName with a variable arg …

   Go 1.22 goes somewhat toward addressing the issue using reflect
   MethodByName disabling linker deadcode elimination (DCE) and the
   resultant large increase in binary size because the linker cannot
   prune unused code because it might be reached via reflection.
   
   Go Issue golang/go#62257 reduces the number of incidences of this
   problem by leveraging a compiler assist to avoid marking functions
   containing calls to MethodByName as ReflectMethods as long as the
   arguments are constants.
   
   An analysis of Uber Technologies code base however shows that a number
   of transitive imports still contain calls to MethodByName with a
   variable argument, including GORM.
   
   In the case of GORM, the solution we are proposing is because the
   number of possible methods is finite, we will "unroll" this. This
   demonstrably shows that GORM is not longer a problem for DCE.
   
   Before
   ```
   % go version
   go version devel go1.22-2f3458a8ce Sat Sep 16 16:26:48 2023 -0700 darwin/arm64
   % go  test ./... -ldflags=-dumpdep   2>  >(grep -i -e  '->.*<reflectmethod>')
   gorm.io/gorm.(*Statement).BuildCondition -> gorm.io/gorm/schema.ParseWithSpecialTableName <ReflectMethod>
   type:reflect.Value <UsedInIface> -> reflect.(*Value).Method <ReflectMethod>
   type:reflect.Value <UsedInIface> -> reflect.(*Value).MethodByName <ReflectMethod>
   ok  	gorm.io/gorm	(cached)
   ok  	gorm.io/gorm/callbacks	(cached)
   gorm.io/gorm/clause_test.BenchmarkComplexSelect -> gorm.io/gorm/schema.ParseWithSpecialTableName <ReflectMethod>
   type:reflect.Value <UsedInIface> -> reflect.(*Value).Method <ReflectMethod>
   type:reflect.Value <UsedInIface> -> reflect.(*Value).MethodByName <ReflectMethod>
   ?   	gorm.io/gorm/migrator	[no test files]
   ok  	gorm.io/gorm/clause	(cached)
   ok  	gorm.io/gorm/logger	(cached)
   gorm.io/gorm/schema_test.TestAdvancedDataTypeValuerAndSetter -> gorm.io/gorm/schema.ParseWithSpecialTableName <ReflectMethod>
   type:reflect.Value <UsedInIface> -> reflect.(*Value).Method <ReflectMethod>
   type:reflect.Value <UsedInIface> -> reflect.(*Value).MethodByName <ReflectMethod>
   ?   	gorm.io/gorm/utils/tests	[no test files]
   ok  	gorm.io/gorm/schema	(cached)
   ok  	gorm.io/gorm/utils	(cached)
   ```
   
   After
   
   ```
   %go version
   go version devel go1.22-2f3458a8ce Sat Sep 16 16:26:48 2023 -0700 darwin/arm64
   %go  test ./... -ldflags=-dumpdep   2>  >(grep -i -e  '->.*<reflectmethod>')
   ok  	gorm.io/gorm	(cached)
   ok  	gorm.io/gorm/callbacks	(cached)
   ?   	gorm.io/gorm/migrator	[no test files]
   ?   	gorm.io/gorm/utils/tests	[no test files]
   ok  	gorm.io/gorm/clause	(cached)
   ok  	gorm.io/gorm/logger	(cached)
   ok  	gorm.io/gorm/schema	(cached)
   ok  	gorm.io/gorm/utils	(cached)
   ```

   

   jquirke committed Sep 19, 2023
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