[WebAssembly] Expose the offset of each data segment
Summary:
This allows tools like lld that process relocations
to apply data relocation correctly. This information
is required because relocation are stored as section
offset.
Subscribers: jfb, dschuff, jgravelle-google, aheejin
Differential Revision: https://reviews.llvm.org/D35234
llvm-svn: 307741
diff --git a/llvm/include/llvm/BinaryFormat/Wasm.h b/llvm/include/llvm/BinaryFormat/Wasm.h
index 4cb373a..23e30b7 100644
--- a/llvm/include/llvm/BinaryFormat/Wasm.h
+++ b/llvm/include/llvm/BinaryFormat/Wasm.h
@@ -94,7 +94,7 @@
};
struct WasmDataSegment {
- uint32_t Index;
+ uint32_t MemoryIndex;
WasmInitExpr Offset;
ArrayRef<uint8_t> Content;
};
diff --git a/llvm/include/llvm/Object/Wasm.h b/llvm/include/llvm/Object/Wasm.h
index f1c140c..07ee4a4 100644
--- a/llvm/include/llvm/Object/Wasm.h
+++ b/llvm/include/llvm/Object/Wasm.h
@@ -69,8 +69,7 @@
#endif
};
-class WasmSection {
-public:
+struct WasmSection {
WasmSection() = default;
uint32_t Type = 0; // Section type (See below)
@@ -80,6 +79,11 @@
std::vector<wasm::WasmRelocation> Relocations; // Relocations for this section
};
+struct WasmSegment {
+ uint32_t SectionOffset;
+ wasm::WasmDataSegment Data;
+};
+
class WasmObjectFile : public ObjectFile {
public:
@@ -110,7 +114,7 @@
return ElemSegments;
}
- const std::vector<wasm::WasmDataSegment>& dataSegments() const {
+ const std::vector<WasmSegment>& dataSegments() const {
return DataSegments;
}
@@ -210,7 +214,7 @@
std::vector<wasm::WasmImport> Imports;
std::vector<wasm::WasmExport> Exports;
std::vector<wasm::WasmElemSegment> ElemSegments;
- std::vector<wasm::WasmDataSegment> DataSegments;
+ std::vector<WasmSegment> DataSegments;
std::vector<wasm::WasmFunction> Functions;
std::vector<WasmSymbol> Symbols;
ArrayRef<uint8_t> CodeSection;
diff --git a/llvm/include/llvm/ObjectYAML/WasmYAML.h b/llvm/include/llvm/ObjectYAML/WasmYAML.h
index 6bf08d3..709ad8e 100644
--- a/llvm/include/llvm/ObjectYAML/WasmYAML.h
+++ b/llvm/include/llvm/ObjectYAML/WasmYAML.h
@@ -98,7 +98,8 @@
};
struct DataSegment {
- uint32_t Index;
+ uint32_t MemoryIndex;
+ uint32_t SectionOffset;
wasm::WasmInitExpr Offset;
yaml::BinaryRef Content;
};
diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 3c675aa..7f80bf0 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -675,15 +675,17 @@
}
Error WasmObjectFile::parseDataSection(const uint8_t *Ptr, const uint8_t *End) {
+ const uint8_t *Start = Ptr;
uint32_t Count = readVaruint32(Ptr);
DataSegments.reserve(Count);
while (Count--) {
- wasm::WasmDataSegment Segment;
- Segment.Index = readVaruint32(Ptr);
- if (Error Err = readInitExpr(Segment.Offset, Ptr))
+ WasmSegment Segment;
+ Segment.Data.MemoryIndex = readVaruint32(Ptr);
+ if (Error Err = readInitExpr(Segment.Data.Offset, Ptr))
return Err;
uint32_t Size = readVaruint32(Ptr);
- Segment.Content = ArrayRef<uint8_t>(Ptr, Size);
+ Segment.Data.Content = ArrayRef<uint8_t>(Ptr, Size);
+ Segment.SectionOffset = Ptr - Start;
Ptr += Size;
DataSegments.push_back(Segment);
}
diff --git a/llvm/lib/ObjectYAML/WasmYAML.cpp b/llvm/lib/ObjectYAML/WasmYAML.cpp
index 2040efd..6a68cd2 100644
--- a/llvm/lib/ObjectYAML/WasmYAML.cpp
+++ b/llvm/lib/ObjectYAML/WasmYAML.cpp
@@ -345,7 +345,8 @@
void MappingTraits<WasmYAML::DataSegment>::mapping(
IO &IO, WasmYAML::DataSegment &Segment) {
- IO.mapRequired("Index", Segment.Index);
+ IO.mapOptional("SectionOffset", Segment.SectionOffset);
+ IO.mapRequired("MemoryIndex", Segment.MemoryIndex);
IO.mapRequired("Offset", Segment.Offset);
IO.mapRequired("Content", Segment.Content);
}
diff --git a/llvm/test/MC/WebAssembly/external-data.ll b/llvm/test/MC/WebAssembly/external-data.ll
index 6914736..b8c9745 100644
--- a/llvm/test/MC/WebAssembly/external-data.ll
+++ b/llvm/test/MC/WebAssembly/external-data.ll
@@ -13,7 +13,8 @@
; CHECK: Index: 0
; CHECK: Offset: 0x0000000E
; CHECK: Segments:
-; CHECK: - Index: 0
+; CHECK: - SectionOffset: 6
+; CHECK: MemoryIndex: 0
; CHECK: Offset:
; CHECK: Opcode: I32_CONST
; CHECK: Value: 0
diff --git a/llvm/test/MC/WebAssembly/unnamed-data.ll b/llvm/test/MC/WebAssembly/unnamed-data.ll
index fd98508..fa0ff96 100644
--- a/llvm/test/MC/WebAssembly/unnamed-data.ll
+++ b/llvm/test/MC/WebAssembly/unnamed-data.ll
@@ -46,7 +46,8 @@
; CHECK-NEXT: Index: 1
; CHECK-NEXT: Offset: 0x0000001E
; CHECK-NEXT: Segments:
-; CHECK-NEXT: - Index: 0
+; CHECK-NEXT: - SectionOffset: 6
+; CHECK-NEXT: MemoryIndex: 0
; CHECK-NEXT: Offset:
; CHECK-NEXT: Opcode: I32_CONST
; CHECK-NEXT: Value: 0
diff --git a/llvm/test/ObjectYAML/wasm/data_section.yaml b/llvm/test/ObjectYAML/wasm/data_section.yaml
index b8c65ab..521aa54 100644
--- a/llvm/test/ObjectYAML/wasm/data_section.yaml
+++ b/llvm/test/ObjectYAML/wasm/data_section.yaml
@@ -8,7 +8,7 @@
- Initial: 0x00000003
- Type: DATA
Segments:
- - Index: 0
+ - MemoryIndex: 0
Offset:
Opcode: I32_CONST
Value: 4
@@ -38,7 +38,8 @@
# CHECK-NEXT: Offset: 0x00000006
# CHECK-NEXT: Addend: -6
# CHECK-NEXT: Segments:
-# CHECK-NEXT: - Index: 0
+# CHECK-NEXT: - SectionOffset: 6
+# CHECK-NEXT: MemoryIndex: 0
# CHECK-NEXT: Offset:
# CHECK-NEXT: Opcode: I32_CONST
# CHECK-NEXT: Value: 4
diff --git a/llvm/tools/obj2yaml/wasm2yaml.cpp b/llvm/tools/obj2yaml/wasm2yaml.cpp
index 1df6afc..a1da4b6 100644
--- a/llvm/tools/obj2yaml/wasm2yaml.cpp
+++ b/llvm/tools/obj2yaml/wasm2yaml.cpp
@@ -236,9 +236,10 @@
auto DataSec = make_unique<WasmYAML::DataSection>();
for (auto &Segment : Obj.dataSegments()) {
WasmYAML::DataSegment Seg;
- Seg.Index = Segment.Index;
- Seg.Offset = Segment.Offset;
- Seg.Content = yaml::BinaryRef(Segment.Content);
+ Seg.SectionOffset = Segment.SectionOffset;
+ Seg.MemoryIndex = Segment.Data.MemoryIndex;
+ Seg.Offset = Segment.Data.Offset;
+ Seg.Content = yaml::BinaryRef(Segment.Data.Content);
DataSec->Segments.push_back(Seg);
}
S = std::move(DataSec);
diff --git a/llvm/tools/yaml2obj/yaml2wasm.cpp b/llvm/tools/yaml2obj/yaml2wasm.cpp
index 110700d..059ec5f 100644
--- a/llvm/tools/yaml2obj/yaml2wasm.cpp
+++ b/llvm/tools/yaml2obj/yaml2wasm.cpp
@@ -338,7 +338,7 @@
WasmYAML::DataSection &Section) {
encodeULEB128(Section.Segments.size(), OS);
for (auto &Segment : Section.Segments) {
- encodeULEB128(Segment.Index, OS);
+ encodeULEB128(Segment.MemoryIndex, OS);
writeInitExpr(Segment.Offset, OS);
encodeULEB128(Segment.Content.binary_size(), OS);
Segment.Content.writeAsBinary(OS);