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[lld][WebAssembly] Add missing relocation types to the --compress-relocations path #144578

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6e1ccf9
Add missing relocation types to the --compress-relocs path
SingleAccretion Jun 17, 2025
34e2f30
Better error handling
SingleAccretion Jun 18, 2025
fc8ef56
Add testing for all handled relocs
SingleAccretion Jun 18, 2025
cd95cf8
Rename test function, remove newlines
SingleAccretion Jun 18, 2025
f60da1b
Make missing reloc cases warn
SingleAccretion Jun 18, 2025
8b910b0
Formatting fix
SingleAccretion Jun 19, 2025
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26 changes: 0 additions & 26 deletions lld/test/wasm/compress-relocs.ll
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129 changes: 129 additions & 0 deletions lld/test/wasm/compress-relocs.s
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# RUN: llvm-mc -mattr=+reference-types,+exception-handling -filetype=obj -triple=wasm32-unknown-unknown %s -o %t.o
# RUN: wasm-ld --export-dynamic -o %t.wasm %t.o
# RUN: llvm-objdump -d %t.wasm | FileCheck %s
# RUN: wasm-ld --export-dynamic -O2 -o %t-opt.wasm %t.o
# RUN: llvm-objdump -d %t-opt.wasm | FileCheck %s
# RUN: not wasm-ld --compress-relocations -o %t-compressed.wasm %t.o 2>&1 | FileCheck %s -check-prefix=ERROR
# RUN: wasm-ld --export-dynamic --strip-debug --compress-relocations -o %t-compressed.wasm %t.o
# RUN: llvm-objdump -d %t-compressed.wasm | FileCheck %s -check-prefix=COMPRESS

.globl _start
_start:
.functype _start () -> ()
end_function

.globl func_ret_i64
func_ret_i64:
.functype func_ret_i64 () -> (i64)
i64.const 1
end_function

.globl func_ret_i32
func_ret_i32:
.functype func_ret_i32 () -> (i32)
i32.const 2
end_function

i32_global:
.globaltype i32_global, i32

i32_tag:
.tagtype i32_tag i32

.globl test_memory_and_indirect_call_relocs
test_memory_and_indirect_call_relocs:
.functype test_memory_and_indirect_call_relocs () -> ()
i32.const indirect_func_ret_i64 # R_WASM_MEMORY_ADDR_SLEB
i32.load 0
call_indirect () -> (i64) # R_WASM_TYPE_INDEX_LEB, R_WASM_TABLE_NUMBER_LEB
drop
i32.const 0
i32.load indirect_func_ret_i32 # R_WASM_MEMORY_ADDR_LEB
call_indirect () -> (i32)
drop
i32.const func_ret_i64 # R_WASM_TABLE_INDEX_SLEB
call_indirect () -> (i64)
drop
end_function

# CHECK: test_memory_and_indirect_call_relocs
# CHECK: 41 90 88 80 80 00 i32.const 1040
# CHECK: 11 80 80 80 80 00 80 80 80 80 00 call_indirect 0
# CHECK: 28 02 94 88 80 80 00 i32.load 1044
# CHECK: 11 81 80 80 80 00 80 80 80 80 00 call_indirect 1
# CHECK: 41 81 80 80 80 00 i32.const 1
# CHECK: 11 80 80 80 80 00 80 80 80 80 00 call_indirect 0
# COMPRESS: test_memory_and_indirect_call_relocs
# COMPRESS: 41 90 08 i32.const 1040
# COMPRESS: 11 00 00 call_indirect 0
# COMPRESS: 28 02 94 08 i32.load 1044
# COMPRESS: 11 01 00 call_indirect 1
# COMPRESS: 41 01 i32.const 1
# COMPRESS: 11 00 00 call_indirect 0

.globl test_simple_index_relocs
test_simple_index_relocs:
.functype test_simple_index_relocs () -> ()
call func_ret_i32 # R_WASM_FUNCTION_INDEX_LEB
global.set i32_global # R_WASM_GLOBAL_INDEX_LEB
i32.const 0
throw i32_tag # R_WASM_TAG_INDEX_LEB
end_function

# CHECK: test_simple_index_relocs
# CHECK: 10 82 80 80 80 00 call 2
# CHECK: 24 81 80 80 80 00 global.set 1
# CHECK: 08 80 80 80 80 00 throw 0
# COMPRESS: test_simple_index_relocs
# COMPRESS: 10 02 call 2
# COMPRESS: 24 01 global.set 1
# COMPRESS: 08 00 throw 0

.globl test_relative_relocs
test_relative_relocs:
.functype test_relative_relocs () -> ()
i32.const indirect_func_ret_i64@MBREL # R_WASM_MEMORY_ADDR_REL_SLEB
drop
i32.const func_ret_i32@TBREL # R_WASM_TABLE_INDEX_REL_SLEB
drop
i32.const i32_tls_data@TLSREL # R_WASM_MEMORY_ADDR_TLS_SLEB
drop
end_function

# CHECK: test_relative_relocs
# CHECK: 41 90 88 80 80 00 i32.const 1040
# CHECK: 41 81 80 80 80 00 i32.const 1
# CHECK: 41 83 80 80 80 00 i32.const 3
# COMPRESS: test_relative_relocs
# COMPRESS: 41 90 08 i32.const 1040
# COMPRESS: 41 01 i32.const 1
# COMPRESS: 41 03 i32.const 3

# ERROR: wasm-ld: error: --compress-relocations is incompatible with output debug information. Please pass --strip-debug or --strip-all

.section .tdata,"T",@
.int8 0
.int8 0
.int8 0
i32_tls_data:
.int32 65
.size i32_tls_data, 4

.section .data,"",@
.p2align 4
indirect_func_ret_i64:
.int32 func_ret_i64
.size indirect_func_ret_i64, 4

indirect_func_ret_i32:
.int32 func_ret_i32
.size indirect_func_ret_i32, 4

.section .custom_section.target_features,"",@
.int8 2
.int8 43
.int8 7
.ascii "atomics"
.int8 43
.int8 11
.ascii "bulk-memory"
92 changes: 92 additions & 0 deletions lld/test/wasm/compress-relocs64.s
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# RUN: llvm-mc -filetype=obj -triple=wasm64-unknown-unknown %s -o %t.o
# RUN: wasm-ld -mwasm64 --export-dynamic -o %t.wasm %t.o
# RUN: llvm-objdump -d %t.wasm | FileCheck %s
# RUN: wasm-ld -mwasm64 --export-dynamic -O2 -o %t-opt.wasm %t.o
# RUN: llvm-objdump -d %t-opt.wasm | FileCheck %s
# RUN: wasm-ld -mwasm64 --export-dynamic --strip-debug --compress-relocations -o %t-compressed.wasm %t.o
# RUN: llvm-objdump -d %t-compressed.wasm | FileCheck %s -check-prefix=COMPRESS

.globl _start
_start:
.functype _start () -> ()
end_function

.globl func_ret_i64
func_ret_i64:
.functype func_ret_i64 () -> (i64)
i64.const 1
end_function

.globl func_ret_i32
func_ret_i32:
.functype func_ret_i32 () -> (i32)
i32.const 2
end_function

.globl test_memory_and_indirect_call_relocs
test_memory_and_indirect_call_relocs:
.functype test_memory_and_indirect_call_relocs () -> ()
i64.const indirect_func_ret_i64 # R_WASM_MEMORY_ADDR_SLEB64
drop
i64.const 0
i64.load indirect_func_ret_i32 # R_WASM_MEMORY_ADDR_LEB64
drop
i64.const func_ret_i64 # R_WASM_TABLE_INDEX_SLEB64
drop
end_function

# CHECK: test_memory_and_indirect_call_relocs
# CHECK: 42 90 88 80 80 80 80 80 80 80 00 i64.const 1040
# CHECK: 29 03 98 88 80 80 80 80 80 80 80 00 i64.load 1048
# CHECK: 42 81 80 80 80 80 80 80 80 80 00 i64.const 1
# COMPRESS: test_memory_and_indirect_call_relocs
# COMPRESS: 42 90 08 i64.const 1040
# COMPRESS: 29 03 98 08 i64.load 1048
# COMPRESS: 42 01 i64.const 1

.globl test_relative_relocs
test_relative_relocs:
.functype test_relative_relocs () -> ()
i64.const indirect_func_ret_i64@MBREL # R_WASM_MEMORY_ADDR_REL_SLEB64
drop
i64.const func_ret_i32@TBREL # R_WASM_TABLE_INDEX_REL_SLEB64
drop
i64.const i32_tls_data@TLSREL # R_WASM_MEMORY_ADDR_TLS_SLEB64
drop
end_function

# CHECK: test_relative_relocs
# CHECK: 42 90 88 80 80 80 80 80 80 80 00 i64.const 1040
# CHECK: 42 81 80 80 80 80 80 80 80 80 00 i64.const 1
# CHECK: 42 83 80 80 80 80 80 80 80 80 00 i64.const 3
# COMPRESS: test_relative_relocs
# COMPRESS: 42 90 08 i64.const 1040
# COMPRESS: 42 01 i64.const 1
# COMPRESS: 42 03 i64.const 3

.section .tdata,"T",@
.int8 0
.int8 0
.int8 0
i32_tls_data:
.int32 65
.size i32_tls_data, 4

.section .data,"",@
.p2align 4
indirect_func_ret_i64:
.int64 func_ret_i64
.size indirect_func_ret_i64, 8

indirect_func_ret_i32:
.int64 func_ret_i32
.size indirect_func_ret_i32, 8

.section .custom_section.target_features,"",@
.int8 2
.int8 43
.int8 7
.ascii "atomics"
.int8 43
.int8 11
.ascii "bulk-memory"
46 changes: 40 additions & 6 deletions lld/wasm/InputChunks.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -228,7 +228,7 @@ void InputFunction::setTableIndex(uint32_t index) {
// witten.
static unsigned writeCompressedReloc(uint8_t *buf, const WasmRelocation &rel,
uint64_t value) {
switch (rel.Type) {
switch (rel.getType()) {
case R_WASM_TYPE_INDEX_LEB:
case R_WASM_FUNCTION_INDEX_LEB:
case R_WASM_GLOBAL_INDEX_LEB:
Expand All @@ -239,32 +239,66 @@ static unsigned writeCompressedReloc(uint8_t *buf, const WasmRelocation &rel,
return encodeULEB128(value, buf);
case R_WASM_TABLE_INDEX_SLEB:
case R_WASM_TABLE_INDEX_SLEB64:
case R_WASM_TABLE_INDEX_REL_SLEB64:
case R_WASM_MEMORY_ADDR_SLEB:
case R_WASM_MEMORY_ADDR_SLEB64:
case R_WASM_MEMORY_ADDR_REL_SLEB:
case R_WASM_MEMORY_ADDR_REL_SLEB64:
case R_WASM_MEMORY_ADDR_TLS_SLEB:
case R_WASM_MEMORY_ADDR_TLS_SLEB64:
case R_WASM_TABLE_INDEX_REL_SLEB:
return encodeSLEB128(static_cast<int64_t>(value), buf);
default:
llvm_unreachable("unexpected relocation type");
case R_WASM_TABLE_INDEX_I32:
case R_WASM_MEMORY_ADDR_I32:
case R_WASM_FUNCTION_OFFSET_I32:
case R_WASM_SECTION_OFFSET_I32:
case R_WASM_GLOBAL_INDEX_I32:
case R_WASM_MEMORY_ADDR_I64:
case R_WASM_TABLE_INDEX_I64:
case R_WASM_FUNCTION_OFFSET_I64:
case R_WASM_MEMORY_ADDR_LOCREL_I32:
case R_WASM_FUNCTION_INDEX_I32:
fatal("relocation compression not supported for " +
relocTypeToString(rel.Type));
}
llvm_unreachable("unhandled relocation type");
}

static unsigned getRelocWidthPadded(const WasmRelocation &rel) {
switch (rel.Type) {
switch (rel.getType()) {
case R_WASM_TYPE_INDEX_LEB:
case R_WASM_FUNCTION_INDEX_LEB:
case R_WASM_GLOBAL_INDEX_LEB:
case R_WASM_TAG_INDEX_LEB:
case R_WASM_MEMORY_ADDR_LEB:
case R_WASM_TABLE_NUMBER_LEB:
case R_WASM_TABLE_INDEX_SLEB:
case R_WASM_TABLE_INDEX_REL_SLEB:
case R_WASM_MEMORY_ADDR_SLEB:
case R_WASM_MEMORY_ADDR_REL_SLEB:
case R_WASM_MEMORY_ADDR_TLS_SLEB:
return 5;
case R_WASM_TABLE_INDEX_SLEB64:
case R_WASM_TABLE_INDEX_REL_SLEB64:
case R_WASM_MEMORY_ADDR_LEB64:
case R_WASM_MEMORY_ADDR_SLEB64:
case R_WASM_MEMORY_ADDR_REL_SLEB64:
case R_WASM_MEMORY_ADDR_TLS_SLEB64:
return 10;
default:
llvm_unreachable("unexpected relocation type");
case R_WASM_TABLE_INDEX_I32:
case R_WASM_MEMORY_ADDR_I32:
case R_WASM_FUNCTION_OFFSET_I32:
case R_WASM_SECTION_OFFSET_I32:
case R_WASM_GLOBAL_INDEX_I32:
case R_WASM_MEMORY_ADDR_I64:
case R_WASM_TABLE_INDEX_I64:
case R_WASM_FUNCTION_OFFSET_I64:
case R_WASM_MEMORY_ADDR_LOCREL_I32:
case R_WASM_FUNCTION_INDEX_I32:
fatal("relocation compression not supported for " +
relocTypeToString(rel.Type));
}
llvm_unreachable("unhandled relocation type");
}

static unsigned getRelocWidth(const WasmRelocation &rel, uint64_t value) {
Expand Down
4 changes: 3 additions & 1 deletion llvm/include/llvm/BinaryFormat/Wasm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -253,7 +253,7 @@ const unsigned WASM_SYMBOL_ABSOLUTE = 0x200;

#define WASM_RELOC(name, value) name = value,

enum : unsigned {
enum WasmRelocType : unsigned {
#include "WasmRelocs.def"
};

Expand Down Expand Up @@ -452,6 +452,8 @@ struct WasmRelocation {
uint32_t Index; // Index into either symbol or type index space.
uint64_t Offset; // Offset from the start of the section.
int64_t Addend; // A value to add to the symbol.

WasmRelocType getType() const { return static_cast<WasmRelocType>(Type); }
};

struct WasmInitFunc {
Expand Down