[WebAssembly] Allow multivalue signatures in object files

[tlively]

Summary

Also changes the wasm YAML format to reflect the possibility of having
multiple return types and to put the returns after the params for
consistency with the binary encoding.

[aheejin]

llvm/test/CodeGen/WebAssembly/multivalue.ll

11

Unrelated question to this CL: Do we treat pair and packed pair in the same way?

[sbc100]

Great!

llvm/lib/Object/WasmObjectFile.cpp

887

Do we want to error out somehow if the feature flags of the object file don't include multi-value?

[tlively]

llvm/lib/Object/WasmObjectFile.cpp

887

That's an interesting idea! I don't think we have a precedent for that kind of validation in the object file parser. It would also be somewhat intrusive, since the target features section is one of the last sections to be parsed, so there would have to be a separate step at the end where feature invariants are checked. The invariants we could check in such a step would also be limited since individual instructions are not exposed in the object file abstraction.

llvm/test/CodeGen/WebAssembly/multivalue.ll

11

Hmm, I guess this isn't a great test because there wouldn't be any padding in this struct anyway, so in this case it literally is the same. I'm not sure what would happen with a packed struct that should contain padding. I'll add a better test in a follow up CL.

lld/test/wasm/Inputs/globals.yaml

 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I64
         ParamTypes:
+        ReturnTypes:
+          - I64
   - Type:            FUNCTION
     FunctionTypes:   [ 0 ]
   - Type:            GLOBAL
     Globals:
       - Index:       0
         Type:        I64
         Mutable:     true
         InitExpr:

lld/test/wasm/Inputs/undefined-globals.yaml

 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I64
         ParamTypes:
+        ReturnTypes:
+          - I64
   - Type:            IMPORT
     Imports:
       - Module:          env
         Field:           unused_undef_global
         Kind:            GLOBAL
         GlobalType:      I64
         GlobalMutable:   true
       - Module:          env

lld/test/wasm/alias.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000001

lld/test/wasm/call-indirect.ll

 
 ; CHECK:      !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I64
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I64
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         ReturnType:      I64
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I64
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I64
 ; CHECK-NEXT:       - Index:           3
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           4
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 3, 1, 3, 4 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000003

lld/test/wasm/event-section.ll

define void @_start() {
   call void @bar(i8* null)
   ret void
 }
 
 ; CHECK:      Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:     []
 
 ; CHECK:        - Type:            EVENT
 ; CHECK-NEXT:     Events:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Attribute:       0
 ; CHECK-NEXT:         SigIndex:        1

lld/test/wasm/function-imports-first.ll

entry:
   ret void
 }
 
 declare i32 @ret32(float) local_unnamed_addr #1
 
 ; CHECK:  - Type:            TYPE
 ; CHECK:    Signatures:
 ; CHECK-NEXT:      - Index:           0
-; CHECK-NEXT:        ReturnType:      NORESULT
-; CHECK-NEXT:        ParamTypes:
+; CHECK-NEXT:        ParamTypes:      []
+; CHECK-NEXT:        ReturnTypes:     []
 ; CHECK-NEXT:      - Index:           1
-; CHECK-NEXT:        ReturnType:      I32
 ; CHECK-NEXT:        ParamTypes:
 ; CHECK-NEXT:          - F32
+; CHECK-NEXT:        ReturnTypes:
+; CHECK-NEXT:          - I32
 ; CHECK:  - Type:            FUNCTION
 ; CHECK-NEXT:    FunctionTypes: [ 0, 1 ]
 ; CHECK:  - Type:            CODE
 ; CHECK-NEXT:    Functions:
 ; CHECK-NEXT:      - Index:           0
 ; CHECK-NEXT:        Locals:
 ; CHECK-NEXT:        Body:            43000000001081808080001A0B
 ; CHECK-NEXT:      - Index:           1

lld/test/wasm/function-imports.ll

 }
 
 declare i32 @ret32(float) local_unnamed_addr #1
 
 ; CHECK:      Sections:
 ; CHECK:       - Type:            TYPE
 ; CHECK-NEXT:    Signatures:
 ; CHECK-NEXT:      - Index:           0
-; CHECK-NEXT:        ReturnType:      I32
 ; CHECK-NEXT:        ParamTypes:
 ; CHECK-NEXT:          - F32
+; CHECK-NEXT:        ReturnTypes:
+; CHECK-NEXT:          - I32
 ; CHECK-NEXT:      - Index:           1
-; CHECK-NEXT:        ReturnType:      NORESULT
 ; CHECK-NEXT:        ParamTypes:
+; CHECK-NEXT:        ReturnTypes:     []
 ; CHECK-NEXT:  - Type:            FUNCTION
 ; CHECK-NEXT:    FunctionTypes:   [ 0, 1 ]
 ; CHECK:       - Type:            CODE
 ; CHECK-NEXT:    Functions:
 ; CHECK:           - Index:       0
 ; CHECK:           - Index:       1
 ; CHECK:         Name:            name
 ; CHECK-NEXT:    FunctionNames:
 ; CHECK-NEXT:      - Index:           0
 ; CHECK-NEXT:        Name:            ret32
 ; CHECK-NEXT:      - Index:           1
 ; CHECK-NEXT:        Name:            _start
 ; CHECK-NEXT: ...

lld/test/wasm/function-index.test

 # RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
 # RUN: llc -filetype=obj %p/Inputs/ret64.ll -o %t.ret64.o
 # RUN: wasm-ld -r -o %t.wasm %t.ret32.o %t.ret64.o
 # RUN: obj2yaml %t.wasm | FileCheck %s
 
 CHECK: Sections:
 CHECK:   - Type:            TYPE
 CHECK:     Signatures:
 CHECK:       - Index:           0
-CHECK:         ReturnType:      I32
 CHECK:         ParamTypes:
 CHECK:           - F32
+CHECK:         ReturnTypes:
+CHECK:           - I32
 CHECK:       - Index:           1
-CHECK:         ReturnType:      I64
 CHECK:         ParamTypes:
 CHECK:           - F64
+CHECK:         ReturnTypes:
+CHECK:           - I64
 CHECK: - Type:            FUNCTION
 CHECK:   FunctionTypes: [ 0, 1 ]

lld/test/wasm/gc-sections.ll

entry:
   ret void
 }
 
 ; RUN: obj2yaml %t1.wasm | FileCheck %s
 
 ; CHECK:        - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         ReturnType:      I64
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I64
 ; CHECK-NEXT:   - Type:            FUNCTION
 
 ; CHECK:        - Type:            GLOBAL
 ; CHECK-NEXT:     Globals:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Type:            I32
 ; CHECK-NEXT:         Mutable:         true
 ; CHECK-NEXT:         InitExpr:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           66576
 ; CHECK-NEXT:       - Index:       1
 ; CHECK-NEXT:         Type:        I64
 ; CHECK-NEXT:         Mutable:     true
 ; CHECK-NEXT:         InitExpr:
 ; CHECK-NEXT:           Opcode:          I64_CONST
 ; CHECK-NEXT:           Value:           456
 
 ; CHECK:        - Type:            DATA
-; CHECK-NEXT:     Segments:        
+; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - SectionOffset:   7
 ; CHECK-NEXT:         InitFlags:       0
 ; CHECK-NEXT:         Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1024
 ; CHECK-NEXT:         Content:         '02000000'
 ; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            used_function
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            use_global
 ; CHECK-NEXT: ...
 
 ; RUN: wasm-ld -print-gc-sections --no-gc-sections -o %t1.no-gc.wasm \
 ; RUN:     %t.o %t_globals.o
 ; RUN: obj2yaml %t1.no-gc.wasm | FileCheck %s -check-prefix=NO-GC
 
 ; NO-GC:        - Type:            TYPE
 ; NO-GC-NEXT:     Signatures:
 ; NO-GC-NEXT:       - Index:           0
-; NO-GC-NEXT:         ReturnType:      NORESULT
-; NO-GC-NEXT:         ParamTypes:
+; NO-GC-NEXT:         ParamTypes:      []
+; NO-GC-NEXT:         ReturnTypes:     []
 ; NO-GC-NEXT:       - Index:           1
-; NO-GC-NEXT:         ReturnType:      I64
 ; NO-GC-NEXT:         ParamTypes:
 ; NO-GC-NEXT:           - I64
+; NO-GC-NEXT:         ReturnTypes:
+; NO-GC-NEXT:           - I64
 ; NO-GC-NEXT:       - Index:           2
-; NO-GC-NEXT:         ReturnType:      I32
-; NO-GC-NEXT:         ParamTypes:
+; NO-GC-NEXT:         ParamTypes:      []
+; NO-GC-NEXT:         ReturnTypes:
+; NO-GC-NEXT:           - I32
 ; NO-GC-NEXT:       - Index:           3
-; NO-GC-NEXT:         ReturnType:      I64
-; NO-GC-NEXT:         ParamTypes:
+; NO-GC-NEXT:         ParamTypes:      []
+; NO-GC-NEXT:         ReturnTypes:
+; NO-GC-NEXT:           - I64
 ; NO-GC-NEXT:   - Type:            FUNCTION
 
 ; NO-GC:        - Type:            GLOBAL
 ; NO-GC-NEXT:     Globals:
 ; NO-GC-NEXT:       - Index:           0
 ; NO-GC-NEXT:         Type:            I32
 ; NO-GC-NEXT:         Mutable:         true
 ; NO-GC-NEXT:         InitExpr:
 ; NO-GC-NEXT:           Opcode:          I32_CONST
 ; NO-GC-NEXT:           Value:           66576
 ; NO-GC-NEXT:       - Index:       1
 ; NO-GC-NEXT:         Type:        I64
 ; NO-GC-NEXT:         Mutable:     true
 ; NO-GC-NEXT:         InitExpr:
 ; NO-GC-NEXT:           Opcode:          I64_CONST
 ; NO-GC-NEXT:           Value:           123
 ; NO-GC-NEXT:       - Index:       2
 ; NO-GC-NEXT:         Type:        I64
 ; NO-GC-NEXT:         Mutable:     true
 ; NO-GC-NEXT:         InitExpr:
 ; NO-GC-NEXT:           Opcode:          I64_CONST
 ; NO-GC-NEXT:           Value:           456
 
 ; NO-GC:        - Type:            DATA
-; NO-GC-NEXT:     Segments:        
+; NO-GC-NEXT:     Segments:
 ; NO-GC-NEXT:       - SectionOffset:   7
 ; NO-GC-NEXT:         InitFlags:       0
 ; NO-GC-NEXT:         Offset:
 ; NO-GC-NEXT:           Opcode:          I32_CONST
 ; NO-GC-NEXT:           Value:           1024
 ; NO-GC-NEXT:         Content:         '010000000000000002000000'
 ; NO-GC-NEXT:   - Type:            CUSTOM
 ; NO-GC-NEXT:     Name:            name

lld/test/wasm/local-symbols.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 1 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000001

lld/test/wasm/locals-duplicate.test

 ; RUN: llc -filetype=obj %p/Inputs/locals-duplicate1.ll -o %t1.o
 ; RUN: llc -filetype=obj %p/Inputs/locals-duplicate2.ll -o %t2.o
 ; RUN: wasm-ld --export-dynamic --no-entry -o %t.wasm %t1.o %t2.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 ; CHECK-NEXT:                        0, 0 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]

 
 ; RELOC:      --- !WASM
 ; RELOC-NEXT: FileHeader:
 ; RELOC-NEXT:   Version:         0x00000001
 ; RELOC-NEXT: Sections:
 ; RELOC-NEXT:   - Type:            TYPE
 ; RELOC-NEXT:     Signatures:
 ; RELOC-NEXT:       - Index:           0
-; RELOC-NEXT:         ReturnType:      I32
-; RELOC-NEXT:         ParamTypes:
+; RELOC-NEXT:         ParamTypes:      []
+; RELOC-NEXT:         ReturnTypes:
+; RELOC-NEXT:           - I32
 ; RELOC-NEXT:   - Type:            FUNCTION
 ; RELOC-NEXT:     FunctionTypes:   [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 ; RELOC-NEXT:                        0, 0 ]
 ; RELOC-NEXT:   - Type:            TABLE
 ; RELOC-NEXT:     Tables:
 ; RELOC-NEXT:       - ElemType:        FUNCREF
 ; RELOC-NEXT:         Limits:
 ; RELOC-NEXT:           Flags:           [ HAS_MAX ]

lld/test/wasm/relocatable.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:   - Type:            IMPORT
 ; CHECK-NEXT:     Imports:
 ; CHECK-NEXT:       - Module:          env
 ; CHECK-NEXT:         Field:           puts
 ; CHECK-NEXT:         Kind:            FUNCTION
 ; CHECK-NEXT:         SigIndex:        0
 ; CHECK-NEXT:       - Module:          env
 ; CHECK-NEXT:         Field:           foo_import

lld/test/wasm/stack-pointer.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            IMPORT
 ; CHECK-NEXT:     Imports:
 ; CHECK-NEXT:       - Module:          env
 ; CHECK-NEXT:         Field:           __stack_pointer
 ; CHECK-NEXT:         Kind:            GLOBAL
 ; CHECK-NEXT:         GlobalType:      I32
 ; CHECK-NEXT:         GlobalMutable:   true
 ; CHECK-NEXT:   - Type:            FUNCTION

lld/test/wasm/undefined-weak-call.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 0, 1, 2 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000001

lld/test/wasm/weak-alias-overide.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 1, 0, 0, 0, 0, 0 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000003

lld/test/wasm/weak-alias.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      I32
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 1, 1, 1, 1, 1 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000002

 
 ; RELOC:      --- !WASM
 ; RELOC-NEXT: FileHeader:
 ; RELOC-NEXT:   Version:         0x00000001
 ; RELOC-NEXT: Sections:
 ; RELOC-NEXT:   - Type:            TYPE
 ; RELOC-NEXT:     Signatures:
 ; RELOC-NEXT:       - Index:           0
-; RELOC-NEXT:         ReturnType:      NORESULT
-; RELOC-NEXT:         ParamTypes:
+; RELOC-NEXT:         ParamTypes:      []
+; RELOC-NEXT:         ReturnTypes:     []
 ; RELOC-NEXT:       - Index:           1
-; RELOC-NEXT:         ReturnType:      I32
-; RELOC-NEXT:         ParamTypes:
+; RELOC-NEXT:         ParamTypes:      []
+; RELOC-NEXT:         ReturnTypes:
+; RELOC-NEXT:           - I32
 ; RELOC-NEXT:   - Type:            IMPORT
 ; RELOC-NEXT:     Imports:
 ; RELOC-NEXT:       - Module:          env
 ; RELOC-NEXT:         Field:           __stack_pointer
 ; RELOC-NEXT:         Kind:            GLOBAL
 ; RELOC-NEXT:         GlobalType:      I32
 ; RELOC-NEXT:         GlobalMutable:   true
 ; RELOC-NEXT:   - Type:            FUNCTION

lld/test/wasm/weak-symbols.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      I32
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 1, 1, 1 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000002

lld/test/wasm/weak-undefined.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:   - Type:            FUNCTION
 ; CHECK-NEXT:     FunctionTypes:   [ 0, 0, 1 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000001

llvm/include/llvm/ObjectYAML/WasmYAML.h

struct SegmentInfo {
   uint32_t Alignment;
   SegmentFlags Flags;
 };
 
 struct Signature {
   uint32_t Index;
   SignatureForm Form = wasm::WASM_TYPE_FUNC;
   std::vector<ValueType> ParamTypes;
-  ValueType ReturnType;
+  std::vector<ValueType> ReturnTypes;
 };
 
 struct SymbolInfo {
   uint32_t Index;
   StringRef Name;
   SymbolKind Kind;
   SymbolFlags Flags;
   union {

llvm/lib/Object/WasmObjectFile.cpp

while (Count--) {
     }
     uint32_t ParamCount = readVaruint32(Ctx);
     Sig.Params.reserve(ParamCount);
     while (ParamCount--) {
       uint32_t ParamType = readUint8(Ctx);
       Sig.Params.push_back(wasm::ValType(ParamType));
     }
     uint32_t ReturnCount = readVaruint32(Ctx);
-    if (ReturnCount) {
-      if (ReturnCount != 1) {
-        return make_error<GenericBinaryError>(
-            "Multiple return types not supported", object_error::parse_failed);
-      }
-      Sig.Returns.push_back(wasm::ValType(readUint8(Ctx)));
+    while (ReturnCount--) {
+      uint32_t ReturnType = readUint8(Ctx);
+      Sig.Returns.push_back(wasm::ValType(ReturnType));
     }
     Signatures.push_back(std::move(Sig));
   }
   if (Ctx.Ptr != Ctx.End)
     return make_error<GenericBinaryError>("Type section ended prematurely",
                                           object_error::parse_failed);
   return Error::success();
 }

llvm/lib/ObjectYAML/WasmEmitter.cpp

if (Sig.Index != ExpectedIndex) {
       reportError("unexpected type index: " + Twine(Sig.Index));
       return;
     }
     ++ExpectedIndex;
     writeUint8(OS, Sig.Form);
     encodeULEB128(Sig.ParamTypes.size(), OS);
     for (auto ParamType : Sig.ParamTypes)
       writeUint8(OS, ParamType);
-    if (Sig.ReturnType == wasm::WASM_TYPE_NORESULT) {
-      encodeULEB128(0, OS);
-    } else {
-      encodeULEB128(1, OS);
-      writeUint8(OS, Sig.ReturnType);
-    }
+    encodeULEB128(Sig.ReturnTypes.size(), OS);
+    for (auto ReturnType : Sig.ReturnTypes)
+      writeUint8(OS, ReturnType);
   }
 }
 
 void WasmWriter::writeSectionContent(raw_ostream &OS,
                                     WasmYAML::ImportSection &Section) {
   encodeULEB128(Section.Imports.size(), OS);
   for (const WasmYAML::Import &Import : Section.Imports) {
     writeStringRef(Import.Module, OS);

llvm/lib/ObjectYAML/WasmYAML.cpp

#define ECase(X) IO.enumCase(Type, #X, wasm::WASM_SEC_##X);
   ECase(DATA);
   ECase(DATACOUNT);
 #undef ECase
 }
 
 void MappingTraits<WasmYAML::Signature>::mapping(
     IO &IO, WasmYAML::Signature &Signature) {
   IO.mapRequired("Index", Signature.Index);
-  IO.mapRequired("ReturnType", Signature.ReturnType);
   IO.mapRequired("ParamTypes", Signature.ParamTypes);
+  IO.mapRequired("ReturnTypes", Signature.ReturnTypes);
 }
 
 void MappingTraits<WasmYAML::Table>::mapping(IO &IO, WasmYAML::Table &Table) {
   IO.mapRequired("ElemType", Table.ElemType);
   IO.mapRequired("Limits", Table.TableLimits);
 }
 
 void MappingTraits<WasmYAML::Function>::mapping(IO &IO,

 #define ECase(X) IO.enumCase(Type, #X, wasm::WASM_TYPE_##X);
   ECase(I32);
   ECase(I64);
   ECase(F32);
   ECase(F64);
   ECase(V128);
   ECase(FUNCREF);
   ECase(FUNC);
-  ECase(NORESULT);
 #undef ECase
 }
 
 void ScalarEnumerationTraits<WasmYAML::ExportKind>::enumeration(
     IO &IO, WasmYAML::ExportKind &Kind) {
 #define ECase(X) IO.enumCase(Kind, #X, wasm::WASM_EXTERNAL_##X);
   ECase(FUNCTION);
   ECase(TABLE);

llvm/test/CodeGen/WebAssembly/multivalue.ll

 ; RUN: llc < %s -asm-verbose=false -verify-machineinstrs -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -mattr=+multivalue | FileCheck %s
+; RUN: llc < %s --filetype=obj -mattr=+multivalue | obj2yaml | FileCheck %s --check-prefix OBJ
 
 ; Test that the multivalue returns, function types, and block types
 ; work as expected.
 
 target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
 %pair = type { i32, i32 }
 %packed_pair = type <{ i32, i32 }>
 
 ; CHECK-LABEL: pair_ident:
 ; CHECK-NEXT: .functype pair_ident (i32, i32) -> (i32, i32)
 ; CHECK-NEXT: return $0, $1{{$}}
 define %pair @pair_ident(%pair %p) {
   ret %pair %p
 }
 
loop:
   br label %loop
 }
 
 ; CHECK-LABEL: .section .custom_section.target_features
 ; CHECK-NEXT: .int8 1
 ; CHECK-NEXT: .int8 43
 ; CHECK-NEXT: .int8 10
 ; CHECK-NEXT: .ascii "multivalue"
+
+; OBJ-LABEL:  - Type:            TYPE
+; OBJ-NEXT:     Signatures:
+; OBJ-NEXT:       - Index:           0
+; OBJ-NEXT:         ParamTypes:
+; OBJ-NEXT:           - I32
+; OBJ-NEXT:           - I32
+; OBJ-NEXT:         ReturnTypes:
+; OBJ-NEXT:           - I32
+; OBJ-NEXT:           - I32
+; OBJ-NEXT:       - Index:           1
+; OBJ-NEXT:         ParamTypes:
+; OBJ-NEXT:           - I32
+; OBJ-NEXT:         ReturnTypes:
+; OBJ-NEXT:           - I32
+; OBJ-NEXT:           - I64

llvm/test/CodeGen/WebAssembly/tailcall.ll

 }
 
 
 
 ; Check that the signatures generated for external indirectly
 ; return-called functions include the proper return types
 
 ; YAML-LABEL: - Index:           8
-; YAML-NEXT:    ReturnType:      I32
 ; YAML-NEXT:    ParamTypes:
 ; YAML-NEXT:      - I32
 ; YAML-NEXT:      - F32
 ; YAML-NEXT:      - I64
 ; YAML-NEXT:      - F64
+; YAML-NEXT:    ReturnTypes:
+; YAML-NEXT:      - I32
 define i32 @unique_caller(i32 (i32, float, i64, double)** %p) {
   %f = load i32 (i32, float, i64, double)*, i32 (i32, float, i64, double)** %p
   %v = tail call i32 %f(i32 0, float 0., i64 0, double 0.)
   ret i32 %v
 }
 
 ; CHECK-LABEL: .section .custom_section.target_features
 ; CHECK-NEXT: .int8 1
 ; CHECK-NEXT: .int8 43
 ; CHECK-NEXT: .int8 9
 ; CHECK-NEXT: .ascii "tail-call"

llvm/test/MC/WebAssembly/assembler-binary.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:   - Type:            IMPORT
 ; CHECK-NEXT:     Imports:
 ; CHECK-NEXT:       - Module:          env
 ; CHECK-NEXT:         Field:           __linear_memory
 ; CHECK-NEXT:         Kind:            MEMORY
 ; CHECK-NEXT:         Memory:
 ; CHECK-NEXT:           Initial:         0x00000000
 ; CHECK-NEXT:       - Module:          env

llvm/test/MC/WebAssembly/comdat.ll

 define linkonce_odr i32 @sharedFn() #1 comdat($sharedComdat) {
   ret i32 0
 }
 
 ; CHECK:      Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
-; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ParamTypes:      []
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            IMPORT
 ; CHECK-NEXT:     Imports:
 ; CHECK-NEXT:       - Module:          env
 ; CHECK-NEXT:         Field:           __linear_memory
 ; CHECK-NEXT:         Kind:            MEMORY
 ; CHECK-NEXT:         Memory:
 ; CHECK-NEXT:           Initial:         0x00000001
 ; CHECK-NEXT:       - Module:          env

llvm/test/MC/WebAssembly/data-section.s

 
 # BIN:      --- !WASM
 # BIN-NEXT: FileHeader:
 # BIN-NEXT:   Version:         0x00000001
 # BIN-NEXT: Sections:
 # BIN-NEXT:   - Type:            TYPE
 # BIN-NEXT:     Signatures:
 # BIN-NEXT:       - Index:           0
-# BIN-NEXT:         ReturnType:      I32
 # BIN-NEXT:         ParamTypes:      []
+# BIN-NEXT:         ReturnTypes:
+# BIN-NEXT:           - I32
 # BIN-NEXT:   - Type:            IMPORT
 # BIN-NEXT:     Imports:
 # BIN-NEXT:       - Module:          env
 # BIN-NEXT:         Field:           __linear_memory
 # BIN-NEXT:         Kind:            MEMORY
 # BIN-NEXT:         Memory:
 # BIN-NEXT:           Initial:         0x00000001
 # BIN-NEXT:       - Module:          env

llvm/test/MC/WebAssembly/event-section.ll

define i32 @test_throw1(i8* %p) {
   call void @llvm.wasm.throw(i32 0, i8* %p)
   ret i32 1
 }
 
 ; CHECK:      Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:      []
 
 ; CHECK:        - Type:            EVENT
 ; CHECK-NEXT:     Events:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Attribute:       0
 ; CHECK-NEXT:         SigIndex:        1
 
 ; CHECK-NEXT:   - Type:            CODE

llvm/test/MC/WebAssembly/external-func-address.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK:        - Type:            IMPORT
 ; CHECK-NEXT:     Imports:
 ; CHECK:            - Module:          env
 ; CHECK-NEXT:         Field:           __linear_memory
 ; CHECK:            - Module:          env
 ; CHECK-NEXT:         Field:           __indirect_function_table
 ; CHECK:            - Module:          env
 ; CHECK-NEXT:         Field:           varargs

llvm/test/MC/WebAssembly/libcall.ll

 
 ; CHECK:      --- !WASM
 ; CHECK-NEXT: FileHeader:
 ; CHECK-NEXT:   Version:         0x00000001
 ; CHECK-NEXT: Sections:
 ; CHECK-NEXT:   - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:     []
 ; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            IMPORT

llvm/test/MC/WebAssembly/reloc-pic.s

 
 # CHECK:      --- !WASM
 # CHECK-NEXT: FileHeader:
 # CHECK-NEXT:   Version:         0x00000001
 # CHECK-NEXT: Sections:
 # CHECK-NEXT:   - Type:            TYPE
 # CHECK-NEXT:     Signatures:
 # CHECK-NEXT:       - Index:           0
-# CHECK-NEXT:         ReturnType:      I32
 # CHECK-NEXT:         ParamTypes:      []
+# CHECK-NEXT:         ReturnTypes:
+# CHECK-NEXT:           - I32
 # CHECK-NEXT:   - Type:            IMPORT
 # CHECK-NEXT:     Imports:
 # CHECK-NEXT:       - Module:          env
 # CHECK-NEXT:         Field:           __linear_memory
 # CHECK-NEXT:         Kind:            MEMORY
 # CHECK-NEXT:         Memory:
 # CHECK-NEXT:           Initial:         0x00000001
 # CHECK-NEXT:       - Module:          env

llvm/test/MC/WebAssembly/type-index.s

 
 # BIN:      --- !WASM
 # BIN-NEXT: FileHeader:
 # BIN-NEXT:   Version:         0x00000001
 # BIN-NEXT: Sections:
 # BIN-NEXT:   - Type:            TYPE
 # BIN-NEXT:     Signatures:
 # BIN-NEXT:       - Index:           0
-# BIN-NEXT:         ReturnType:      I32
 # BIN-NEXT:         ParamTypes:
 # BIN-NEXT:           - I32
+# BIN-NEXT:         ReturnTypes:
+# BIN-NEXT:           - I32
 # BIN-NEXT:       - Index:           1
-# BIN-NEXT:         ReturnType:      F64
 # BIN-NEXT:         ParamTypes:
 # BIN-NEXT:           - F64
+# BIN-NEXT:         ReturnTypes:
+# BIN-NEXT:           - F64
 # BIN-NEXT:   - Type:            IMPORT
 # BIN-NEXT:     Imports:
 # BIN-NEXT:       - Module:          env
 # BIN-NEXT:         Field:           __linear_memory
 # BIN-NEXT:         Kind:            MEMORY
 # BIN-NEXT:         Memory:
 # BIN-NEXT:           Initial:         0x00000000
 # BIN-NEXT:       - Module:          env

 # BIN-NEXT:     Version:         2
 # BIN-NEXT:     SymbolTable:
 # BIN-NEXT:       - Index:           0
 # BIN-NEXT:         Kind:            FUNCTION
 # BIN-NEXT:         Name:            test0
 # BIN-NEXT:         Flags:           [ BINDING_LOCAL ]
 # BIN-NEXT:         Function:        0
 # BIN-NEXT: ...
-

llvm/test/MC/WebAssembly/types.ll

 
 define void @vararg(i32, i32, ...) {
   ret void
 }
 
 ; CHECK-LABEL: - Type: TYPE
 ; CHECK-NEXT:    Signatures:
 ; CHECK-NEXT:       - Index: 0
-; CHECK-NEXT:         ReturnType: NORESULT
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes: []
 ; CHECK-NEXT:       - Index: 1
-; CHECK-NEXT:         ReturnType: I32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:       - Index: 2
-; CHECK-NEXT:         ReturnType: I64
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I64
 ; CHECK-NEXT:       - Index: 3
-; CHECK-NEXT:         ReturnType: F32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - F32
 ; CHECK-NEXT:       - Index: 4
-; CHECK-NEXT:         ReturnType: F64
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - F64
 ; CHECK-NEXT:       - Index: 5
-; CHECK-NEXT:         ReturnType: V128
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - V128
 ; CHECK-NEXT:       - Index: 6
-; CHECK-NEXT:         ReturnType: NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes: []
 ; CHECK-NEXT:       - Index: 7
-; CHECK-NEXT:         ReturnType: NORESULT
 ; CHECK-NEXT:         ParamTypes:
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:           - I32
+; CHECK-NEXT:         ReturnTypes: []
 ; should be no additional types
-; CHECK-NOT: ReturnType
+; CHECK-NOT: ReturnTypes

llvm/test/MC/WebAssembly/weak-alias.ll

entry:
   %0 = load i32 ()*, i32 ()** @alias_address, align 8
   %call = call i32 %0()
   ret i32 %call
 }
 
 ; CHECK:        - Type:            TYPE
 ; CHECK-NEXT:     Signatures:
 ; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:         ReturnTypes:
+; CHECK-NEXT:           - I32
 ; CHECK-NEXT:   - Type:            IMPORT
 ; CHECK-NEXT:     Imports:
 ; CHECK-NEXT:       - Module:          env
 ; CHECK-NEXT:         Field:           __linear_memory
 ; CHECK-NEXT:         Kind:            MEMORY
 ; CHECK-NEXT:         Memory:
 ; CHECK-NEXT:           Initial:         0x00000001
 ; CHECK-NEXT:       - Module:          env

llvm/test/ObjectYAML/wasm/code_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      F32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - F32
       - Index:           1
-        ReturnType:      NORESULT
         ParamTypes:
           - I32
           - I64
+        ReturnTypes:     []
   - Type:            FUNCTION
     FunctionTypes:
       - 0
       - 1
   - Type:            CODE
     Relocations:
       - Type:            R_WASM_TABLE_INDEX_SLEB
         Index:           0

 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
 # CHECK:   Version:           0x00000001
 # CHECK: Sections:
 # CHECK:  - Type:            TYPE
 # CHECK:    Signatures:
 # CHECK:      - Index:           0
-# CHECK:        ReturnType:      F32
 # CHECK:        ParamTypes:
 # CHECK:          - I32
+# CHECK:        ReturnTypes:
+# CHECK:          - F32
 # CHECK:      - Index:           1
-# CHECK:        ReturnType:      NORESULT
 # CHECK:        ParamTypes:
 # CHECK:          - I32
 # CHECK:          - I64
+# CHECK:        ReturnTypes:     []
 # CHECK:  - Type:            CODE
 # CHECK:    Relocations:
 # CHECK:      - Type:            R_WASM_TABLE_INDEX_SLEB
 # CHECK:        Index:           0
 # CHECK:        Offset:          0x00000006
 # CHECK:      - Type:            R_WASM_FUNCTION_INDEX_LEB
 # CHECK:        Index:           1
 # CHECK:        Offset:          0x00000025

llvm/test/ObjectYAML/wasm/event_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
       - Index:           1
-        ReturnType:      NORESULT
         ParamTypes:
           - I32
+        ReturnTypes:      []
   - Type:            FUNCTION
     FunctionTypes:   [ 0 ]
   - Type:            EVENT
     Events:
       - Index:           0
         Attribute:       0
         SigIndex:        1
   - Type:            CODE

 
 # CHECK:      --- !WASM
 # CHECK-NEXT: FileHeader:
 # CHECK-NEXT:   Version:         0x00000001
 # CHECK-NEXT: Sections:
 # CHECK-NEXT:   - Type:            TYPE
 # CHECK-NEXT:     Signatures:
 # CHECK-NEXT:       - Index:           0
-# CHECK-NEXT:         ReturnType:      I32
 # CHECK-NEXT:         ParamTypes:
 # CHECK-NEXT:           - I32
+# CHECK-NEXT:         ReturnTypes:
+# CHECK-NEXT:           - I32
 # CHECK-NEXT:       - Index:           1
-# CHECK-NEXT:         ReturnType:      NORESULT
 # CHECK-NEXT:         ParamTypes:
 # CHECK-NEXT:           - I32
+# CHECK-NEXT:         ReturnTypes:     []
 # CHECK-NEXT:   - Type:            FUNCTION
 # CHECK-NEXT:     FunctionTypes:   [ 0 ]
 # CHECK-NEXT:   - Type:            EVENT
 # CHECK-NEXT:     Events:
 # CHECK-NEXT:       - Index:           0
 # CHECK-NEXT:         Attribute:       0
 # CHECK-NEXT:         SigIndex:        1
 # CHECK-NEXT:   - Type:            CODE

llvm/test/ObjectYAML/wasm/export_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      NORESULT
         ParamTypes:
+        ReturnTypes:     []
   - Type:            FUNCTION
     FunctionTypes: [ 0, 0 ]
   - Type:            GLOBAL
     Globals:
       - Index:       0
         Type:        I32
         Mutable:     false
         InitExpr:
           Opcode:          I64_CONST
           Value:           32
       - Index:       1
         Type:        I32
         Mutable:     false
         InitExpr:
           Opcode:          I64_CONST
           Value:           64
   - Type:            EXPORT
-    Exports:         
+    Exports:
       - Name:            function_export
         Kind:            FUNCTION
         Index:           1
       - Name:            global_export
         Kind:            GLOBAL
         Index:           1
       - Name:            memory_export
         Kind:            MEMORY
Functions:
         Locals:
         Body:            0B
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
 # CHECK:   Version:           0x00000001
 # CHECK: Sections:
 # CHECK:   - Type:            EXPORT
-# CHECK:     Exports:         
+# CHECK:     Exports:
 # CHECK:       - Name:            function_export
 # CHECK:         Kind:            FUNCTION
 # CHECK:         Index:           1
 # CHECK:       - Name:            global_export
 # CHECK:         Kind:            GLOBAL
 # CHECK:         Index:           1
 # CHECK:       - Name:            memory_export
 # CHECK:         Kind:            MEMORY
 # CHECK:         Index:           0
 # CHECK:       - Name:            table_export
 # CHECK:         Kind:            TABLE
 # CHECK:         Index:           0
 # CHECK: ...

llvm/test/ObjectYAML/wasm/function_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      NORESULT
         ParamTypes:
+        ReturnTypes:     []
       - Index:           1
-        ReturnType:      NORESULT
         ParamTypes:
           - I32
+        ReturnTypes:     []
   - Type:            FUNCTION
     FunctionTypes: [ 1, 0 ]
   - Type:            CODE
     Functions:
       - Index:           0
         Locals:
         Body:            0B
       - Index:           1

llvm/test/ObjectYAML/wasm/import_memory_shared.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
   - Type:            IMPORT
     Imports:
       - Module:          foo
         Field:           imported_memory
         Kind:            MEMORY
         Memory:
           Flags:           [ HAS_MAX, IS_SHARED ]
           Initial:         0x00000010
           Maximum:         0x00000011
 
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
 # CHECK:   Version:           0x00000001
 # CHECK: Sections:
 # CHECK:   - Type:            IMPORT
-# CHECK:     Imports:         
+# CHECK:     Imports:
 # CHECK:       - Module:          foo
 # CHECK:         Field:           imported_memory
 # CHECK:         Kind:            MEMORY
 # CHECK:         Memory:
 # CHECK:           Flags:           [ HAS_MAX, IS_SHARED ]
 # CHECK:           Initial:         0x00000010
 # CHECK:           Maximum:         0x00000011
 # CHECK: ...

llvm/test/ObjectYAML/wasm/import_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
   - Type:            IMPORT
     Imports:
       - Module:          foo
         Field:           imported_function
         Kind:            FUNCTION
         SigIndex:        0
       - Module:          fiz
         Field:           imported_global
Imports:
             Initial:         0x00000020
             Maximum:         0x00000022
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
 # CHECK:   Version:           0x00000001
 # CHECK: Sections:
 # CHECK:   - Type:            IMPORT
-# CHECK:     Imports:         
+# CHECK:     Imports:
 # CHECK:       - Module:          foo
 # CHECK:         Field:           imported_function
 # CHECK:         Kind:            FUNCTION
 # CHECK:         SigIndex:        0
 # CHECK:       - Module:          fiz
 # CHECK:         Field:           imported_global
 # CHECK:         Kind:            GLOBAL
 # CHECK:         GlobalType:      I32

llvm/test/ObjectYAML/wasm/invalid_section_order.yaml

 # RUN: not yaml2obj %s -o /dev/null 2>&1 | FileCheck %s
 
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      NORESULT
         ParamTypes:      []
+        ReturnTypes:     []
   - Type:            CODE
     Functions:
       - Index:           0
         Locals:          []
         Body:            0B
   # CHECK: yaml2obj: error: out of order section type: 3
   - Type:            FUNCTION
     FunctionTypes:   [ 0 ]
 ...

llvm/test/ObjectYAML/wasm/linking_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
   - Type:            IMPORT
     Imports:
       - Module:          foo
         Field:           bar
         Kind:            FUNCTION
         SigIndex:        0
   - Type:            DATA
     Segments:

llvm/test/ObjectYAML/wasm/name_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
   - Type:            IMPORT
     Imports:
       - Module:          foo
         Field:           a
         Kind:            FUNCTION
         SigIndex:        0
       - Module:          foo
         Field:           b

llvm/test/ObjectYAML/wasm/start_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      NORESULT
-        ParamTypes:
+        ParamTypes:      []
+        ReturnTypes:     []
   - Type:            FUNCTION
     FunctionTypes: [ 0, 0, 0 ]
   - Type:            START
     StartFunction:   1
   - Type:            CODE
     Functions:
       - Index:           0
         Locals:

llvm/test/ObjectYAML/wasm/type_section.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - F32
           - F32
+        ReturnTypes:
+          - I32
       - Index:           1
-        ReturnType:      I64
         ParamTypes:
           - F64
           - F64
+        ReturnTypes:
+          - I64
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
 # CHECK:   Version:           0x00000001
 # CHECK: Sections:
 # CHECK:  - Type:            TYPE
 # CHECK:    Signatures:
 # CHECK:      - Index:           0
-# CHECK:        ReturnType:      I32
 # CHECK:        ParamTypes:
 # CHECK:          - F32
 # CHECK:          - F32
+# CHECK:        ReturnTypes:
+# CHECK:          - I32
 # CHECK:      - Index:           1
-# CHECK:        ReturnType:      I64
 # CHECK:        ParamTypes:
 # CHECK:          - F64
 # CHECK:          - F64
+# CHECK:        ReturnTypes:
+# CHECK:          - I64
 # CHECK: ...

llvm/test/ObjectYAML/wasm/weak_symbols.yaml

 # RUN: yaml2obj %s | obj2yaml | FileCheck %s
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
-        ParamTypes:
+        ParamTypes:      []
+        ReturnTypes:
+          - I32
   - Type:            FUNCTION
     FunctionTypes:   [ 0, 0 ]
   - Type:            GLOBAL
-    Globals:         
+    Globals:
       - Index:       0
         Type:        I32
         Mutable:     false
         InitExpr:
           Opcode:          I32_CONST
           Value:           1
   - Type:            EXPORT
-    Exports:         
+    Exports:
       - Name:            function_export
         Kind:            FUNCTION
         Index:           1
       - Name:            global_export
         Kind:            GLOBAL
         Index:           0
   - Type:            CODE
     Functions:
SymbolTable:
         Flags:           [ BINDING_WEAK ]
         Global:          0
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
 # CHECK:   Version:           0x00000001
 # CHECK: Sections:
 # CHECK:   - Type:            EXPORT
-# CHECK:     Exports:         
+# CHECK:     Exports:
 # CHECK:       - Name:            function_export
 # CHECK:         Kind:            FUNCTION
 # CHECK:         Index:           1
 # CHECK:       - Name:            global_export
 # CHECK:         Kind:            GLOBAL
 # CHECK:         Index:           0
 # CHECK:   - Type:            CUSTOM
 # CHECK:     Name:            linking

llvm/test/tools/llvm-nm/wasm/exports.yaml

 # RUN: yaml2obj < %s | llvm-nm - | FileCheck -strict-whitespace %s
 
 # Check that wasm exports of functions/globals/data are displayed correctly
 
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
   - Type:            FUNCTION
     FunctionTypes: [ 0 ]
   - Type:            GLOBAL
     Globals:
       - Index:       0
         Type:        I32
         Mutable:     false
         InitExpr:

llvm/test/tools/llvm-nm/wasm/imports.yaml

 # RUN: yaml2obj < %s | llvm-nm - | FileCheck -strict-whitespace %s
 
 # Check that wasm import of functions/globals/data are displayed correctly
 
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
   - Type:            IMPORT
     Imports:
       - Module:          env
         Field:           fimport
         Kind:            FUNCTION
         SigIndex:        0
       - Module:          env
         Field:           gimport

llvm/test/tools/llvm-nm/wasm/weak-symbols.yaml

 # RUN: yaml2obj < %s | llvm-nm - | FileCheck -strict-whitespace %s
 
 # Check that wasm weak function/global/data symbols are displayed correctly
 
 --- !WASM
 FileHeader:
   Version:         0x00000001
 Sections:
   - Type:            TYPE
     Signatures:
       - Index:           0
-        ReturnType:      I32
         ParamTypes:
           - I32
+        ReturnTypes:
+          - I32
   - Type:            IMPORT
     Imports:
       - Module:          env
         Field:           weak_import_func
         Kind:            FUNCTION
         SigIndex:        0
   - Type:            FUNCTION
     FunctionTypes: [ 0 ]

llvm/tools/obj2yaml/wasm2yaml.cpp

case wasm::WASM_SEC_CUSTOM: {
       break;
     }
     case wasm::WASM_SEC_TYPE: {
       auto TypeSec = std::make_unique<WasmYAML::TypeSection>();
       uint32_t Index = 0;
       for (const auto &FunctionSig : Obj.types()) {
         WasmYAML::Signature Sig;
         Sig.Index = Index++;
-        Sig.ReturnType = wasm::WASM_TYPE_NORESULT;
-        assert(FunctionSig.Returns.size() <= 1 &&
-               "Functions with multiple returns are not supported");
-        if (FunctionSig.Returns.size())
-          Sig.ReturnType = static_cast<uint32_t>(FunctionSig.Returns[0]);
         for (const auto &ParamType : FunctionSig.Params)
           Sig.ParamTypes.emplace_back(static_cast<uint32_t>(ParamType));
+        for (const auto &ReturnType : FunctionSig.Returns)
+          Sig.ReturnTypes.emplace_back(static_cast<uint32_t>(ReturnType));
         TypeSec->Signatures.push_back(Sig);
       }
       S = std::move(TypeSec);
       break;
     }
     case wasm::WASM_SEC_IMPORT: {
       auto ImportSec = std::make_unique<WasmYAML::ImportSection>();
       for (auto &Import : Obj.imports()) {