Merge pull request #72760 from gottesmm/pr-9f0fef6eb535d1e5860df021c272806b2a8494f8

[silgen] Emit the location of the original function def if SILGen is erroring on a duplicate symbol definition.

Author: gottesmm

include/swift/AST/DiagnosticsSIL.def

@@ -46,6 +46,9 @@ ERROR(bridging_objcbridgeable_broken,none,
 ERROR(sil_function_redefinition,none,
       "multiple definitions of symbol '%0'",
       (StringRef))
+NOTE(sil_function_redefinition_note,none,
+      "other definition here",
+      ())
 
 ERROR(invalid_sil_builtin,none,
       "INTERNAL ERROR: invalid use of builtin: %0",

lib/SILGen/SILGen.cpp

@@ -813,6 +813,8 @@ void SILGenModule::emitFunctionDefinition(SILDeclRef constant, SILFunction *f) {
   if (!f->empty()) {
     diagnose(constant.getAsRegularLocation(), diag::sil_function_redefinition,
              f->getName());
+    if (f->hasLocation())
+      diagnose(f->getLocation(), diag::sil_function_redefinition_note);
     return;
   }
 

test/SILGen/diagnose_duplicate_functions.swift

@@ -1,7 +1,7 @@
 // RUN: %target-swift-emit-silgen %s -o /dev/null -verify
 
 @_silgen_name("foo")
-func a(_ x: Int) -> Int {
+func a(_ x: Int) -> Int { // expected-note {{other definition here}}
   return x
 }
 
@@ -11,7 +11,7 @@ func b(_ x: Int) -> Int { // expected-error {{multiple definitions of symbol 'fo
 }
 
 @_cdecl("bar")
-func c(_ x: Int) -> Int {
+func c(_ x: Int) -> Int { // expected-note {{other definition here}}
   return x
 }