[PATCH] D63696: [WebAssembly] Fix list of relocations with addends in lld

[Keno Fischer via Phabricator via llvm-commits]

loladiro created this revision.
loladiro added a reviewer: sbc100.
Herald added subscribers: llvm-commits, sunfish, aheejin, hiraditya, jgravelle-google, dschuff.
Herald added a project: LLVM.

The list of relocations with addend in lld was missing `R_WASM_MEMORY_ADDR_REL_SLEB`,
causing `wasm-ld` to generate corrupted output. This fixes that problem and while
we're at it pulls the list of such relocations into the Wasm.h header, to avoid
duplicating it in multiple places.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D63696

Files:
  lld/wasm/InputChunks.cpp
  llvm/include/llvm/BinaryFormat/Wasm.h
  llvm/lib/MC/WasmObjectWriter.cpp


Index: llvm/lib/MC/WasmObjectWriter.cpp
===================================================================
--- llvm/lib/MC/WasmObjectWriter.cpp
+++ llvm/lib/MC/WasmObjectWriter.cpp
@@ -147,19 +147,7 @@
       : Offset(Offset), Symbol(Symbol), Addend(Addend), Type(Type),
         FixupSection(FixupSection) {}
 
-  bool hasAddend() const {
-    switch (Type) {
-    case wasm::R_WASM_MEMORY_ADDR_LEB:
-    case wasm::R_WASM_MEMORY_ADDR_SLEB:
-    case wasm::R_WASM_MEMORY_ADDR_REL_SLEB:
-    case wasm::R_WASM_MEMORY_ADDR_I32:
-    case wasm::R_WASM_FUNCTION_OFFSET_I32:
-    case wasm::R_WASM_SECTION_OFFSET_I32:
-      return true;
-    default:
-      return false;
-    }
-  }
+  bool hasAddend() const { return wasm::WasmRelocation::hasAddend(Type); }
 
   void print(raw_ostream &Out) const {
     Out << wasm::relocTypetoString(Type) << " Off=" << Offset
Index: llvm/include/llvm/BinaryFormat/Wasm.h
===================================================================
--- llvm/include/llvm/BinaryFormat/Wasm.h
+++ llvm/include/llvm/BinaryFormat/Wasm.h
@@ -165,6 +165,8 @@
   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.
+  static bool hasAddend(unsigned Type);
+  inline bool hasAddend() const { return hasAddend(Type); };
 };
 
 struct WasmInitFunc {
@@ -322,6 +324,20 @@
 
 #undef WASM_RELOC
 
+inline bool WasmRelocation::hasAddend(unsigned Type) {
+  switch (Type) {
+  case R_WASM_MEMORY_ADDR_LEB:
+  case R_WASM_MEMORY_ADDR_SLEB:
+  case R_WASM_MEMORY_ADDR_REL_SLEB:
+  case R_WASM_MEMORY_ADDR_I32:
+  case R_WASM_FUNCTION_OFFSET_I32:
+  case R_WASM_SECTION_OFFSET_I32:
+    return true;
+  default:
+    return false;
+  }
+}
+
 // Subset of types that a value can have
 enum class ValType {
   I32 = WASM_TYPE_I32,
Index: lld/wasm/InputChunks.cpp
===================================================================
--- lld/wasm/InputChunks.cpp
+++ lld/wasm/InputChunks.cpp
@@ -154,15 +154,8 @@
     writeUleb128(OS, Rel.Offset + Off, "reloc offset");
     writeUleb128(OS, File->calcNewIndex(Rel), "reloc index");
 
-    switch (Rel.Type) {
-    case R_WASM_MEMORY_ADDR_LEB:
-    case R_WASM_MEMORY_ADDR_SLEB:
-    case R_WASM_MEMORY_ADDR_I32:
-    case R_WASM_FUNCTION_OFFSET_I32:
-    case R_WASM_SECTION_OFFSET_I32:
+    if (Rel.hasAddend())
       writeSleb128(OS, File->calcNewAddend(Rel), "reloc addend");
-      break;
-    }
   }
 }
 


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