[WebAssembly] Improve logging and comments around relocations. NFC.

Differential Revision: https://reviews.llvm.org/D44350

llvm-svn: 327232

2 files changed, 16 insertions, 8 deletions

diff --git a/lld/wasm/InputChunks.cpp b/lld/wasm/InputChunks.cpp
index f5df6eb0eb1..585d1163147 100644
--- a/lld/wasm/InputChunks.cpp
+++ b/lld/wasm/InputChunks.cpp
@@ -23,6 +23,15 @@ using namespace llvm::support::endian;
 using namespace lld;
 using namespace lld::wasm;
 
+StringRef ReloctTypeToString(uint8_t RelocType) {
+  switch (RelocType) {
+#define WASM_RELOC(NAME, REL) case REL: return #NAME;
+#include "llvm/BinaryFormat/WasmRelocs.def"
+#undef WASM_RELOC
+  }
+  llvm_unreachable("unknown reloc type");
+}
+
 std::string lld::toString(const InputChunk *C) {
   return (toString(C->File) + ":(" + C->getName() + ")").str();
 }
@@ -46,14 +55,14 @@ void InputChunk::writeTo(uint8_t *Buf) const {
   if (Relocations.empty())
     return;
 
-  DEBUG(dbgs() << "applyRelocations: count=" << Relocations.size() << "\n");
+  DEBUG(dbgs() << "applying relocations: count=" << Relocations.size() << "\n");
   int32_t Off = OutputOffset - getInputSectionOffset();
 
   for (const WasmRelocation &Rel : Relocations) {
     uint8_t *Loc = Buf + Rel.Offset + Off;
-    uint64_t Value = File->calcNewValue(Rel);
-
-    DEBUG(dbgs() << "write reloc: type=" << Rel.Type << " index=" << Rel.Index
+    uint32_t Value = File->calcNewValue(Rel);
+    DEBUG(dbgs() << "apply reloc: type=" << ReloctTypeToString(Rel.Type)
+                 << " addend=" << Rel.Addend << " index=" << Rel.Index
                  << " value=" << Value << " offset=" << Rel.Offset << "\n");
 
     switch (Rel.Type) {
diff --git a/lld/wasm/InputFiles.cpp b/lld/wasm/InputFiles.cpp
index 12ee9ec6f8c..5b69070b3de 100644
--- a/lld/wasm/InputFiles.cpp
+++ b/lld/wasm/InputFiles.cpp
@@ -49,10 +49,9 @@ void ObjFile::dumpInfo() const {
       "\n       Global Imports : " + Twine(WasmObj->getNumImportedGlobals()));
 }
 
-// Relocations contain an index into the function, global or table index
-// space of the input file.  This function takes a relocation and returns the
-// relocated index (i.e. translates from the input index space to the output
-// index space).
+// Relocations contain either symbol or type indices.  This function takes a
+// relocation and returns relocated index (i.e. translates from the input
+// sybmol/type space to the output symbol/type space).
 uint32_t ObjFile::calcNewIndex(const WasmRelocation &Reloc) const {
   if (Reloc.Type == R_WEBASSEMBLY_TYPE_INDEX_LEB) {
     assert(TypeIsUsed[Reloc.Index]);