Swift Calling Convention: Parameters are allowed after the

swift_error/swift_context parameter

We need to be able to decelare witness functions which append the self type and
the self witness tables at the end of the parameter list.

rdar://28720996

llvm-svn: 283933

3 files changed, 8 insertions, 20 deletions

diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index b0f18fd1bdc..0f2ec79ba38 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -2400,28 +2400,16 @@ static void checkExtParameterInfos(Sema &S, ArrayRef<QualType> paramTypes,
       }
       continue;
 
-    // swift_context parameters must be the last parameter except for
-    // a possible swift_error parameter.
     case ParameterABI::SwiftContext:
       checkForSwiftCC(paramIndex);
-      if (!(paramIndex == numParams - 1 ||
-            (paramIndex == numParams - 2 &&
-             EPI.ExtParameterInfos[numParams - 1].getABI()
-               == ParameterABI::SwiftErrorResult))) {
-        S.Diag(getParamLoc(paramIndex),
-               diag::err_swift_context_not_before_swift_error_result);
-      }
       continue;
 
-    // swift_error parameters must be the last parameter.
+    // swift_error parameters must be preceded by a swift_context parameter.
     case ParameterABI::SwiftErrorResult:
       checkForSwiftCC(paramIndex);
-      if (paramIndex != numParams - 1) {
-        S.Diag(getParamLoc(paramIndex),
-               diag::err_swift_error_result_not_last);
-      } else if (paramIndex == 0 ||
-                 EPI.ExtParameterInfos[paramIndex - 1].getABI()
-                   != ParameterABI::SwiftContext) {
+      if (paramIndex == 0 ||
+          EPI.ExtParameterInfos[paramIndex - 1].getABI() !=
+              ParameterABI::SwiftContext) {
         S.Diag(getParamLoc(paramIndex),
                diag::err_swift_error_result_not_after_swift_context);
       }
diff --git a/clang/test/Sema/attr-swiftcall.c b/clang/test/Sema/attr-swiftcall.c
index 3458167cf2e..1720612290f 100644
--- a/clang/test/Sema/attr-swiftcall.c
+++ b/clang/test/Sema/attr-swiftcall.c
@@ -18,13 +18,13 @@ void indirect_result_single(INDIRECT_RESULT void *out) SWIFTCALL;
 void indirect_result_multiple(INDIRECT_RESULT void *out1, INDIRECT_RESULT void *out2) SWIFTCALL;
 
 void error_result_nonswift(ERROR_RESULT void **error); // expected-error {{'swift_error_result' parameter can only be used with swiftcall calling convention}} expected-error{{'swift_error_result' parameter must follow 'swift_context' parameter}}
-void error_result_bad_position(ERROR_RESULT void **error, int last) SWIFTCALL; // expected-error {{'swift_error_result' parameter must be last parameter of function}}
 void error_result_bad_position2(int first, ERROR_RESULT void **error) SWIFTCALL; // expected-error {{'swift_error_result' parameter must follow 'swift_context' parameter}}
 void error_result_bad_type(CONTEXT void *context, ERROR_RESULT int error) SWIFTCALL; // expected-error {{'swift_error_result' parameter must have pointer to unqualified pointer type; type here is 'int'}}
 void error_result_bad_type2(CONTEXT void *context, ERROR_RESULT int *error) SWIFTCALL; // expected-error {{'swift_error_result' parameter must have pointer to unqualified pointer type; type here is 'int *'}}
 void error_result_okay(int a, int b, CONTEXT void *context, ERROR_RESULT void **error) SWIFTCALL;
+void error_result_okay2(CONTEXT void *context, ERROR_RESULT void **error, void *selfType, char **selfWitnessTable) SWIFTCALL;
 
 void context_nonswift(CONTEXT void *context); // expected-error {{'swift_context' parameter can only be used with swiftcall calling convention}}
-void context_bad_position(CONTEXT void *context, int x) SWIFTCALL; // expected-error {{'swift_context' parameter can only be followed by 'swift_error_result' parameter}}
 void context_bad_type(CONTEXT int context) SWIFTCALL; // expected-error {{'swift_context' parameter must have pointer type; type here is 'int'}}
 void context_okay(CONTEXT void *context) SWIFTCALL;
+void context_okay2(CONTEXT void *context, void *selfType, char **selfWitnessTable) SWIFTCALL;
diff --git a/clang/test/SemaCXX/attr-swiftcall.cpp b/clang/test/SemaCXX/attr-swiftcall.cpp
index fd17aae1852..eb9538e3104 100644
--- a/clang/test/SemaCXX/attr-swiftcall.cpp
+++ b/clang/test/SemaCXX/attr-swiftcall.cpp
@@ -17,16 +17,16 @@ void indirect_result_single(INDIRECT_RESULT void *out) SWIFTCALL;
 void indirect_result_multiple(INDIRECT_RESULT void *out1, INDIRECT_RESULT void *out2) SWIFTCALL;
 
 void error_result_nonswift(ERROR_RESULT void **error); // expected-error {{'swift_error_result' parameter can only be used with swiftcall calling convention}} expected-error{{'swift_error_result' parameter must follow 'swift_context' parameter}}
-void error_result_bad_position(ERROR_RESULT void **error, int last) SWIFTCALL; // expected-error {{'swift_error_result' parameter must be last parameter of function}}
 void error_result_bad_position2(int first, ERROR_RESULT void **error) SWIFTCALL; // expected-error {{'swift_error_result' parameter must follow 'swift_context' parameter}}
 void error_result_bad_type(CONTEXT void *context, ERROR_RESULT int error) SWIFTCALL; // expected-error {{'swift_error_result' parameter must have pointer to unqualified pointer type; type here is 'int'}}
 void error_result_bad_type2(CONTEXT void *context, ERROR_RESULT int *error) SWIFTCALL; // expected-error {{'swift_error_result' parameter must have pointer to unqualified pointer type; type here is 'int *'}}
 void error_result_okay(int a, int b, CONTEXT void *context, ERROR_RESULT void **error) SWIFTCALL;
+void error_result_okay(CONTEXT void *context, ERROR_RESULT void **error, void *selfType, char **selfWitnessTable) SWIFTCALL;
 
 void context_nonswift(CONTEXT void *context); // expected-error {{'swift_context' parameter can only be used with swiftcall calling convention}}
-void context_bad_position(CONTEXT void *context, int x) SWIFTCALL; // expected-error {{'swift_context' parameter can only be followed by 'swift_error_result' parameter}}
 void context_bad_type(CONTEXT int context) SWIFTCALL; // expected-error {{'swift_context' parameter must have pointer type; type here is 'int'}}
 void context_okay(CONTEXT void *context) SWIFTCALL;
+void context_okay(CONTEXT void *context, void *selfType, char **selfWitnessTable) SWIFTCALL;
 
 template <class T> void indirect_result_temp_okay1(INDIRECT_RESULT T *out) SWIFTCALL;
 template <class T> void indirect_result_temp_okay2(INDIRECT_RESULT T out) SWIFTCALL; // expected-note {{candidate template ignored: substitution failure [with T = int]: 'swift_indirect_result' parameter must have pointer type; type here is 'int'}}