[WebAssembly] Add more details to llvm-readobj for wasm files

[dschuff]

Code looks good. Maybe also add a test to test/MC/WebAssembly/reloc-data.ll or one of those others too?

[sbc100]

• rebase and update test

[dschuff]

So trivial.obj.wasm already has the updated linking section or this patch just depends on updating it?

[sbc100]

Yes this patch depends on the one that just landed that updated the binary.

This patch itself only changes the information output about the binary, no the binary itself.

[dschuff]

Cool, LGTM

test/tools/llvm-readobj/sections.test

 WASM-NEXT:     Offset: 228
 WASM-NEXT:     Name: reloc.CODE
 WASM-NEXT:   }
 WASM-NEXT:   Section {
 WASM-NEXT:     Type: CUSTOM (0x0)
 WASM-NEXT:     Size: 22
 WASM-NEXT:     Offset: 257
 WASM-NEXT:     Name: linking
+WASM-NEXT:     DataSize: 13
+WASM-NEXT:     DataAlignment: 1
 WASM-NEXT:   }
 WASM-NEXT: ]

tools/llvm-readobj/WasmDumper.cpp

for (const SectionRef &Section : Obj->sections()) {
     const WasmSection &WasmSec = Obj->getWasmSection(Section);
     DictScope SectionD(W, "Section");
     W.printEnum("Type", WasmSec.Type, makeArrayRef(WasmSectionTypes));
     W.printNumber("Size", (uint64_t)WasmSec.Content.size());
     W.printNumber("Offset", WasmSec.Offset);
     switch (WasmSec.Type) {
     case wasm::WASM_SEC_CUSTOM:
       W.printString("Name", WasmSec.Name);
+      if (WasmSec.Name == "linking") {
+        const wasm::WasmLinkingData &LinkingData = Obj->linkingData();
+        W.printNumber("DataSize", LinkingData.DataSize);
+        if (LinkingData.DataAlignment)
+          W.printNumber("DataAlignment", LinkingData.DataAlignment);
+      }
       break;
     case wasm::WASM_SEC_MEMORY:
       ListScope Group(W, "Memories");
       for (const wasm::WasmLimits &Memory : Obj->memories()) {
         DictScope Group(W, "Memory");
         W.printNumber("InitialPages", Memory.Initial);
         if (Memory.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) {
           W.printNumber("MaxPages", WasmSec.Offset);