[WebAssembly] Fix null pointer in createInitTLSFunction

[quantum]

Summary

createSyntheticSymbols, which creates WasmSym::InitTLS, is only called
when !config->relocatable, but this condition is not checked when calling
createInitTLSFunction.

This diff checks !config->relocatable before calling createInitTLSFunction.

Fixes https://github.com/emscripten-core/emscripten/issues/9155.

[tlively]

Oops it would be good to have a test, too ;)

[quantum]

Add test to check --relocatable with --shared-memory.

lld/test/wasm/relocatable.ll

 ; RUN: llc -filetype=obj %p/Inputs/hello.ll -o %t.hello.o
 ; RUN: llc -filetype=obj %s -o %t.o
 ; RUN: wasm-ld -r -o %t.wasm %t.hello.o %t.o
-; RUN: obj2yaml %t.wasm | FileCheck %s
+; RUN: obj2yaml %t.wasm | FileCheck %s --check-prefixes CHECK,NORMAL
+
+; RUN: llc -filetype=obj %p/Inputs/hello.ll -o %t.hello.bm.o -mattr=+bulk-memory
+; RUN: llc -filetype=obj %s -o %t.bm.o -mattr=+bulk-memory
+; RUN: wasm-ld -r -o %t.mt.wasm %t.hello.bm.o %t.bm.o --shared-memory --max-memory=131072
+; RUN: obj2yaml %t.mt.wasm | FileCheck %s --check-prefixes CHECK,SHARED
 
 target triple = "wasm32-unknown-unknown"
 
 ; Function Attrs: nounwind
 define hidden i32 @my_func() local_unnamed_addr {
 entry:
   %call = tail call i32 @foo_import()
   %call2 = tail call i32 @bar_import()

 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        FUNCREF
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
 ; CHECK-NEXT:           Initial:         0x00000004
 ; CHECK-NEXT:           Maximum:         0x00000004
 ; CHECK-NEXT:   - Type:            MEMORY
 ; CHECK-NEXT:     Memories:
-; CHECK-NEXT:       - Initial:         0x00000001
+; NORMAL-NEXT:      - Initial:         0x00000001
+; SHARED-NEXT:      - Flags:           [ HAS_MAX, IS_SHARED ]
+; SHARED-NEXT:        Initial:         0x00000001
+; SHARED-NEXT:        Maximum:         0x00000002
 ; CHECK-NEXT:   - Type:            ELEM
 ; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1
 ; CHECK-NEXT:         Functions:       [ 4, 1, 2 ]
+; SHARED-NEXT:  - Type:            DATACOUNT
+; SHARED-NEXT:    Count:           6
 ; CHECK-NEXT:   - Type:            CODE
 ; CHECK-NEXT:     Relocations:
 ; CHECK-NEXT:       - Type:            R_WASM_MEMORY_ADDR_SLEB
 ; CHECK-NEXT:         Index:           1
 ; CHECK-NEXT:         Offset:          0x00000004
 ; CHECK-NEXT:       - Type:            R_WASM_FUNCTION_INDEX_LEB
 ; CHECK-NEXT:         Index:           2
 ; CHECK-NEXT:         Offset:          0x0000000A

 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:          4180808080001080808080000B
 ; CHECK-NEXT:       - Index:         4
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:          1081808080001A1082808080001A41010B
 ; CHECK-NEXT:       - Index:         5
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:          419C808080000B
-; CHECK-NEXT:   - Type:            DATA
-; CHECK-NEXT:     Relocations:
-; CHECK-NEXT:       - Type:            R_WASM_TABLE_INDEX_I32
-; CHECK-NEXT:         Index:           3
-; CHECK-NEXT:         Offset:          0x00000012
-; CHECK-NEXT:       - Type:            R_WASM_TABLE_INDEX_I32
-; CHECK-NEXT:         Index:           4
-; CHECK-NEXT:         Offset:          0x0000001B
-; CHECK-NEXT:       - Type:            R_WASM_TABLE_INDEX_I32
-; CHECK-NEXT:         Index:           5
-; CHECK-NEXT:         Offset:          0x00000024
-; CHECK-NEXT:       - Type:            R_WASM_MEMORY_ADDR_I32
-; CHECK-NEXT:         Index:           12
-; CHECK-NEXT:         Offset:          0x0000002D
-; CHECK-NEXT:     Segments:
-; CHECK-NEXT:       - SectionOffset:   6
-; CHECK-NEXT:         InitFlags:       0
-; CHECK-NEXT:         Offset:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           0
-; CHECK-NEXT:         Content:         68656C6C6F0A00
-; CHECK-NEXT:       - SectionOffset:   18
-; CHECK-NEXT:         InitFlags:       0
-; CHECK-NEXT:         Offset:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           8
-; CHECK-NEXT:         Content:         '01000000'
-; CHECK-NEXT:       - SectionOffset:   27
-; CHECK-NEXT:         InitFlags:       0
-; CHECK-NEXT:         Offset:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           12
-; CHECK-NEXT:         Content:         '02000000'
-; CHECK-NEXT:       - SectionOffset:   36
-; CHECK-NEXT:         InitFlags:       0
-; CHECK-NEXT:         Offset:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           16
-; CHECK-NEXT:         Content:         '03000000'
-; CHECK-NEXT:       - SectionOffset:   45
-; CHECK-NEXT:         InitFlags:       0
-; CHECK-NEXT:         Offset:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           24
-; CHECK-NEXT:         Content:         '00000000'
-; CHECK-NEXT:       - SectionOffset:   54
-; CHECK-NEXT:         InitFlags:       0
-; CHECK-NEXT:         Offset:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           28
-; CHECK-NEXT:         Content:         '616263'
-; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     Version:         2
-; CHECK-NEXT:     SymbolTable:
-; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Name:            hello
-; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
-; CHECK-NEXT:         Function:        3
-; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         Kind:            DATA
-; CHECK-NEXT:         Name:            hello_str
-; CHECK-NEXT:         Flags:           [  ]
-; CHECK-NEXT:         Segment:         0
-; CHECK-NEXT:         Size:            7
-; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Name:            puts
-; CHECK-NEXT:         Flags:           [ UNDEFINED ]
-; CHECK-NEXT:         Function:        0
-; CHECK-NEXT:       - Index:           3
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Name:            my_func
-; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
-; CHECK-NEXT:         Function:        4
-; CHECK-NEXT:       - Index:           4
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Name:            foo_import
-; CHECK-NEXT:         Flags:           [ UNDEFINED ]
-; CHECK-NEXT:         Function:        1
-; CHECK-NEXT:       - Index:           5
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Name:            bar_import
-; CHECK-NEXT:         Flags:           [ BINDING_WEAK, UNDEFINED ]
-; CHECK-NEXT:         Function:        2
-; CHECK-NEXT:       - Index:           6
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Name:            func_comdat
-; CHECK-NEXT:         Flags:           [ BINDING_WEAK ]
-; CHECK-NEXT:         Function:        5
-; CHECK-NEXT:       - Index:           7
-; CHECK-NEXT:         Kind:            DATA
-; CHECK-NEXT:         Name:            data_comdat
-; CHECK-NEXT:         Flags:           [ BINDING_WEAK ]
-; CHECK-NEXT:         Segment:         5
-; CHECK-NEXT:         Size:            3
-; CHECK-NEXT:       - Index:           8
-; CHECK-NEXT:         Kind:            DATA
-; CHECK-NEXT:         Name:            func_addr1
-; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
-; CHECK-NEXT:         Segment:         1
-; CHECK-NEXT:         Size:            4
-; CHECK-NEXT:       - Index:           9
-; CHECK-NEXT:         Kind:            DATA
-; CHECK-NEXT:         Name:            func_addr2
-; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
-; CHECK-NEXT:         Segment:         2
-; CHECK-NEXT:         Size:            4
-; CHECK-NEXT:       - Index:           10
-; CHECK-NEXT:         Kind:            DATA
-; CHECK-NEXT:         Name:            func_addr3
-; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
-; CHECK-NEXT:         Segment:         3
-; CHECK-NEXT:         Size:            4
-; CHECK-NEXT:       - Index:           11
-; CHECK-NEXT:         Kind:            DATA
-; CHECK-NEXT:         Name:            data_addr1
-; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
-; CHECK-NEXT:         Segment:         4
-; CHECK-NEXT:         Size:            4
-; CHECK-NEXT:       - Index:           12
-; CHECK-NEXT:         Kind:            DATA
-; CHECK-NEXT:         Name:            data_import
-; CHECK-NEXT:         Flags:           [ UNDEFINED ]
-; CHECK-NEXT:     SegmentInfo:
-; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         Name:            .rodata.hello_str
-; CHECK-NEXT:         Alignment:       0
-; CHECK-NEXT:         Flags:           [  ]
-; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         Name:            .data.func_addr1
-; CHECK-NEXT:         Alignment:       2
-; CHECK-NEXT:         Flags:           [  ]
-; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         Name:            .data.func_addr2
-; CHECK-NEXT:         Alignment:       2
-; CHECK-NEXT:         Flags:           [  ]
-; CHECK-NEXT:       - Index:           3
-; CHECK-NEXT:         Name:            .data.func_addr3
-; CHECK-NEXT:         Alignment:       2
-; CHECK-NEXT:         Flags:           [  ]
-; CHECK-NEXT:       - Index:           4
-; CHECK-NEXT:         Name:            .data.data_addr1
-; CHECK-NEXT:         Alignment:       3
-; CHECK-NEXT:         Flags:           [  ]
-; CHECK-NEXT:       - Index:           5
-; CHECK-NEXT:         Name:            .rodata.data_comdat
-; CHECK-NEXT:         Alignment:       0
-; CHECK-NEXT:         Flags:           [  ]
-; CHECK-NEXT:     Comdats:
-; CHECK-NEXT:       - Name:            func_comdat
-; CHECK-NEXT:         Entries:
-; CHECK-NEXT:           - Kind:            FUNCTION
-; CHECK-NEXT:             Index:           5
-; CHECK-NEXT:           - Kind:            DATA
-; CHECK-NEXT:             Index:           5
-; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            name
-; CHECK-NEXT:     FunctionNames:
-; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         Name:            puts
-; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         Name:            foo_import
-; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         Name:            bar_import
-; CHECK-NEXT:       - Index:           3
-; CHECK-NEXT:         Name:            hello
-; CHECK-NEXT:       - Index:           4
-; CHECK-NEXT:         Name:            my_func
-; CHECK-NEXT:       - Index:           5
-; CHECK-NEXT:         Name:            func_comdat
-; CHECK-NEXT: ...
+; NORMAL-NEXT:  - Type:            DATA
+; NORMAL-NEXT:    Relocations:
+; NORMAL-NEXT:      - Type:            R_WASM_TABLE_INDEX_I32
+; NORMAL-NEXT:        Index:           3
+; NORMAL-NEXT:        Offset:          0x00000012
+; NORMAL-NEXT:      - Type:            R_WASM_TABLE_INDEX_I32
+; NORMAL-NEXT:        Index:           4
+; NORMAL-NEXT:        Offset:          0x0000001B
+; NORMAL-NEXT:      - Type:            R_WASM_TABLE_INDEX_I32
+; NORMAL-NEXT:        Index:           5
+; NORMAL-NEXT:        Offset:          0x00000024
+; NORMAL-NEXT:      - Type:            R_WASM_MEMORY_ADDR_I32
+; NORMAL-NEXT:        Index:           12
+; NORMAL-NEXT:        Offset:          0x0000002D
+; NORMAL-NEXT:    Segments:
+; NORMAL-NEXT:      - SectionOffset:   6
+; NORMAL-NEXT:        InitFlags:       0
+; NORMAL-NEXT:        Offset:
+; NORMAL-NEXT:          Opcode:          I32_CONST
+; NORMAL-NEXT:          Value:           0
+; NORMAL-NEXT:        Content:         68656C6C6F0A00
+; NORMAL-NEXT:      - SectionOffset:   18
+; NORMAL-NEXT:        InitFlags:       0
+; NORMAL-NEXT:        Offset:
+; NORMAL-NEXT:          Opcode:          I32_CONST
+; NORMAL-NEXT:          Value:           8
+; NORMAL-NEXT:        Content:         '01000000'
+; NORMAL-NEXT:      - SectionOffset:   27
+; NORMAL-NEXT:        InitFlags:       0
+; NORMAL-NEXT:        Offset:
+; NORMAL-NEXT:          Opcode:          I32_CONST
+; NORMAL-NEXT:          Value:           12
+; NORMAL-NEXT:        Content:         '02000000'
+; NORMAL-NEXT:      - SectionOffset:   36
+; NORMAL-NEXT:        InitFlags:       0
+; NORMAL-NEXT:        Offset:
+; NORMAL-NEXT:          Opcode:          I32_CONST
+; NORMAL-NEXT:          Value:           16
+; NORMAL-NEXT:        Content:         '03000000'
+; NORMAL-NEXT:      - SectionOffset:   45
+; NORMAL-NEXT:        InitFlags:       0
+; NORMAL-NEXT:        Offset:
+; NORMAL-NEXT:          Opcode:          I32_CONST
+; NORMAL-NEXT:          Value:           24
+; NORMAL-NEXT:        Content:         '00000000'
+; NORMAL-NEXT:      - SectionOffset:   54
+; NORMAL-NEXT:        InitFlags:       0
+; NORMAL-NEXT:        Offset:
+; NORMAL-NEXT:          Opcode:          I32_CONST
+; NORMAL-NEXT:          Value:           28
+; NORMAL-NEXT:        Content:         '616263'
+; NORMAL-NEXT:  - Type:            CUSTOM
+; NORMAL-NEXT:    Name:            linking
+; NORMAL-NEXT:    Version:         2
+; NORMAL-NEXT:    SymbolTable:
+; NORMAL-NEXT:      - Index:           0
+; NORMAL-NEXT:        Kind:            FUNCTION
+; NORMAL-NEXT:        Name:            hello
+; NORMAL-NEXT:        Flags:           [ VISIBILITY_HIDDEN ]
+; NORMAL-NEXT:        Function:        3
+; NORMAL-NEXT:      - Index:           1
+; NORMAL-NEXT:        Kind:            DATA
+; NORMAL-NEXT:        Name:            hello_str
+; NORMAL-NEXT:        Flags:           [  ]
+; NORMAL-NEXT:        Segment:         0
+; NORMAL-NEXT:        Size:            7
+; NORMAL-NEXT:      - Index:           2
+; NORMAL-NEXT:        Kind:            FUNCTION
+; NORMAL-NEXT:        Name:            puts
+; NORMAL-NEXT:        Flags:           [ UNDEFINED ]
+; NORMAL-NEXT:        Function:        0
+; NORMAL-NEXT:      - Index:           3
+; NORMAL-NEXT:        Kind:            FUNCTION
+; NORMAL-NEXT:        Name:            my_func
+; NORMAL-NEXT:        Flags:           [ VISIBILITY_HIDDEN ]
+; NORMAL-NEXT:        Function:        4
+; NORMAL-NEXT:      - Index:           4
+; NORMAL-NEXT:        Kind:            FUNCTION
+; NORMAL-NEXT:        Name:            foo_import
+; NORMAL-NEXT:        Flags:           [ UNDEFINED ]
+; NORMAL-NEXT:        Function:        1
+; NORMAL-NEXT:      - Index:           5
+; NORMAL-NEXT:        Kind:            FUNCTION
+; NORMAL-NEXT:        Name:            bar_import
+; NORMAL-NEXT:        Flags:           [ BINDING_WEAK, UNDEFINED ]
+; NORMAL-NEXT:        Function:        2
+; NORMAL-NEXT:      - Index:           6
+; NORMAL-NEXT:        Kind:            FUNCTION
+; NORMAL-NEXT:        Name:            func_comdat
+; NORMAL-NEXT:        Flags:           [ BINDING_WEAK ]
+; NORMAL-NEXT:        Function:        5
+; NORMAL-NEXT:      - Index:           7
+; NORMAL-NEXT:        Kind:            DATA
+; NORMAL-NEXT:        Name:            data_comdat
+; NORMAL-NEXT:        Flags:           [ BINDING_WEAK ]
+; NORMAL-NEXT:        Segment:         5
+; NORMAL-NEXT:        Size:            3
+; NORMAL-NEXT:      - Index:           8
+; NORMAL-NEXT:        Kind:            DATA
+; NORMAL-NEXT:        Name:            func_addr1
+; NORMAL-NEXT:        Flags:           [ VISIBILITY_HIDDEN ]
+; NORMAL-NEXT:        Segment:         1
+; NORMAL-NEXT:        Size:            4
+; NORMAL-NEXT:      - Index:           9
+; NORMAL-NEXT:        Kind:            DATA
+; NORMAL-NEXT:        Name:            func_addr2
+; NORMAL-NEXT:        Flags:           [ VISIBILITY_HIDDEN ]
+; NORMAL-NEXT:        Segment:         2
+; NORMAL-NEXT:        Size:            4
+; NORMAL-NEXT:      - Index:           10
+; NORMAL-NEXT:        Kind:            DATA
+; NORMAL-NEXT:        Name:            func_addr3
+; NORMAL-NEXT:        Flags:           [ VISIBILITY_HIDDEN ]
+; NORMAL-NEXT:        Segment:         3
+; NORMAL-NEXT:        Size:            4
+; NORMAL-NEXT:      - Index:           11
+; NORMAL-NEXT:        Kind:            DATA
+; NORMAL-NEXT:        Name:            data_addr1
+; NORMAL-NEXT:        Flags:           [ VISIBILITY_HIDDEN ]
+; NORMAL-NEXT:        Segment:         4
+; NORMAL-NEXT:        Size:            4
+; NORMAL-NEXT:      - Index:           12
+; NORMAL-NEXT:        Kind:            DATA
+; NORMAL-NEXT:        Name:            data_import
+; NORMAL-NEXT:        Flags:           [ UNDEFINED ]
+; NORMAL-NEXT:    SegmentInfo:
+; NORMAL-NEXT:      - Index:           0
+; NORMAL-NEXT:        Name:            .rodata.hello_str
+; NORMAL-NEXT:        Alignment:       0
+; NORMAL-NEXT:        Flags:           [  ]
+; NORMAL-NEXT:      - Index:           1
+; NORMAL-NEXT:        Name:            .data.func_addr1
+; NORMAL-NEXT:        Alignment:       2
+; NORMAL-NEXT:        Flags:           [  ]
+; NORMAL-NEXT:      - Index:           2
+; NORMAL-NEXT:        Name:            .data.func_addr2
+; NORMAL-NEXT:        Alignment:       2
+; NORMAL-NEXT:        Flags:           [  ]
+; NORMAL-NEXT:      - Index:           3
+; NORMAL-NEXT:        Name:            .data.func_addr3
+; NORMAL-NEXT:        Alignment:       2
+; NORMAL-NEXT:        Flags:           [  ]
+; NORMAL-NEXT:      - Index:           4
+; NORMAL-NEXT:        Name:            .data.data_addr1
+; NORMAL-NEXT:        Alignment:       3
+; NORMAL-NEXT:        Flags:           [  ]
+; NORMAL-NEXT:      - Index:           5
+; NORMAL-NEXT:        Name:            .rodata.data_comdat
+; NORMAL-NEXT:        Alignment:       0
+; NORMAL-NEXT:        Flags:           [  ]
+; NORMAL-NEXT:    Comdats:
+; NORMAL-NEXT:      - Name:            func_comdat
+; NORMAL-NEXT:        Entries:
+; NORMAL-NEXT:          - Kind:            FUNCTION
+; NORMAL-NEXT:            Index:           5
+; NORMAL-NEXT:          - Kind:            DATA
+; NORMAL-NEXT:            Index:           5
+; NORMAL-NEXT:  - Type:            CUSTOM
+; NORMAL-NEXT:    Name:            name
+; NORMAL-NEXT:    FunctionNames:
+; NORMAL-NEXT:      - Index:           0
+; NORMAL-NEXT:        Name:            puts
+; NORMAL-NEXT:      - Index:           1
+; NORMAL-NEXT:        Name:            foo_import
+; NORMAL-NEXT:      - Index:           2
+; NORMAL-NEXT:        Name:            bar_import
+; NORMAL-NEXT:      - Index:           3
+; NORMAL-NEXT:        Name:            hello
+; NORMAL-NEXT:      - Index:           4
+; NORMAL-NEXT:        Name:            my_func
+; NORMAL-NEXT:      - Index:           5
+; NORMAL-NEXT:        Name:            func_comdat
+; NORMAL-NEXT:...

lld/wasm/Writer.cpp

if (!config->relocatable) {
     // Create linker synthesized functions
     if (config->passiveSegments)
       createInitMemoryFunction();
     if (config->isPic)
       createApplyRelocationsFunction();
     createCallCtorsFunction();
   }
 
-  if (config->sharedMemory && !config->shared)
+  if (!config->relocatable && config->sharedMemory && !config->shared)
     createInitTLSFunction();
 
   if (errorCount())
     return;
 
   log("-- calculateTypes");
   calculateTypes();
   log("-- calculateExports");