[WebAssembly] Add some tests for wasm MC layer

[sbc100]

Summary

Also, modify readobj such that addends are only emitted for
relevant relocation types.

[sbc100]

• Add sections test

[dschuff]

test/MC/WebAssembly/reloc-code.ll

1 ↗

(On Diff #96819)

Is there any particular reason this needs to be O0?

30 ↗

(On Diff #96819)

Can we add a test with a non-0 addend? I guess negative too now that we have support for that.

[sbc100]

• Merge remote-tracking branch 'origin/master' into add_tests
• Only emit addends for relevant relocations

[sbc100]

test/MC/WebAssembly/reloc-code.ll

30 ↗

(On Diff #96819)

I have trouble getting llvm to produce non-zero data relocations in the text section. I think when I add the tests for the data sections relocations it will be possible. Perhaps @sunfish knows more about this, but I'd like to land this soon to get some minimal testing in.

[dschuff]

That's fine, this is obviously an improvement, i just noticed that they were all 0 in the tests.

llvm/trunk/test/MC/WebAssembly/reloc-code.ll

+; RUN: llc -mtriple wasm32-unknown-unknown-wasm -filetype=obj %s -o - | llvm-readobj -r -expand-relocs | FileCheck %s
+
+; Pointers to functions of two different types
+@a = global i64 ()* inttoptr (i64 5 to i64 ()*), align 8
+@b = global i32 ()* inttoptr (i32 7 to i32 ()*), align 8
+
+; External functions
+declare i32 @c()
+declare i32 @d()
+
+define i32 @f1() {
+entry:
+    %aa = load i64 ()*, i64 ()** @a, align 8
+    %bb = load i32 ()*, i32 ()** @b, align 8
+    %tmp1 = call i64 %aa()
+    %tmp2 = call i32 %bb()
+    %tmp3 = call i32 @c()
+    %tmp4 = call i32 @d()
+    ret i32 %tmp2
+}
+
+
+; CHECK: Format: WASM
+; CHECK: Relocations [
+; CHECK-NEXT:   Section (8) CODE {
+; CHECK-NEXT:     Relocation {
+; CHECK-NEXT:       Type: R_WEBASSEMBLY_GLOBAL_ADDR_LEB (3)
+; CHECK-NEXT:       Offset: 0x9
+; CHECK-NEXT:       Index: 0x0
+; CHECK-NEXT:       Addend: 0
+; CHECK-NEXT:     }
+; CHECK-NEXT:     Relocation {
+; CHECK-NEXT:       Type: R_WEBASSEMBLY_GLOBAL_ADDR_LEB (3)
+; CHECK-NEXT:       Offset: 0x14
+; CHECK-NEXT:       Index: 0x1
+; CHECK-NEXT:       Addend: 0
+; CHECK-NEXT:     }
+; CHECK-NEXT:     Relocation {
+; CHECK-NEXT:       Type: R_WEBASSEMBLY_FUNCTION_INDEX_LEB (0)
+; CHECK-NEXT:       Offset: 0x2D
+; CHECK-NEXT:       Index: 0x0
+; CHECK-NEXT:     }
+; CHECK-NEXT:     Relocation {
+; CHECK-NEXT:       Type: R_WEBASSEMBLY_FUNCTION_INDEX_LEB (0)
+; CHECK-NEXT:       Offset: 0x34
+; CHECK-NEXT:       Index: 0x1
+; CHECK-NEXT:     }
+; CHECK-NEXT:     Relocation {
+; CHECK-NEXT:       Type: R_WEBASSEMBLY_TYPE_INDEX_LEB (6)
+; CHECK-NEXT:       Offset: 0x1A
+; CHECK-NEXT:       Index: 0x1
+; CHECK-NEXT:     }
+; CHECK-NEXT:     Relocation {
+; CHECK-NEXT:       Type: R_WEBASSEMBLY_TYPE_INDEX_LEB (6)
+; CHECK-NEXT:       Offset: 0x24
+; CHECK-NEXT:       Index: 0x0
+; CHECK-NEXT:     }
+; CHECK-NEXT:   }
+; CHECK-NEXT: ]

llvm/trunk/test/MC/WebAssembly/sections.ll

+; RUN: llc -mtriple wasm32-unknown-unknown-wasm -filetype=obj %s -o - | llvm-readobj -s | FileCheck %s
+
+; external function
+declare i32 @a()
+
+; global data
+@b = global i32 3, align 4
+
+; local function
+define i32 @f1() {
+entry:
+    %tmp1 = call i32 @a()
+    ret i32 %tmp1
+}
+
+
+; CHECK: Format: WASM
+; CHECK: Arch: wasm32
+; CHECK: AddressSize: 32bit
+; CHECK: Sections [
+; CHECK:   Section {
+; CHECK:     Type: TYPE (0x1)
+; CHECK:   }
+; CHECK:  Section {
+; CHECK:    Type: IMPORT (0x2)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: FUNCTION (0x3)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: TABLE (0x4)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: MEMORY (0x5)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: GLOBAL (0x6)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: EXPORT (0x7)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: CODE (0xA)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: DATA (0xB)
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: CUSTOM (0x0)
+; CHECK:    Name: name
+; CHECK:  }
+; CHECK:  Section {
+; CHECK:    Type: CUSTOM (0x0)
+; CHECK:    Name: reloc.CODE
+; CHECK:  }
+; CHECK:]
+

llvm/trunk/test/tools/llvm-readobj/relocations.test

 MACHO-ARM-NEXT:  ]
 
 WASM:      Relocations [
 WASM-NEXT:   Section (8) CODE {
 WASM-NEXT:     Relocation {
 WASM-NEXT:       Type: R_WEBASSEMBLY_TABLE_INDEX_SLEB (1)
 WASM-NEXT:       Offset: 0x6
 WASM-NEXT:       Index: 0x0
-WASM-NEXT:       Addend: 0x0
 WASM-NEXT:     }
 WASM-NEXT:     Relocation {
 WASM-NEXT:       Type: R_WEBASSEMBLY_GLOBAL_ADDR_LEB (3)
 WASM-NEXT:       Offset: 0x15
 WASM-NEXT:       Index: 0x0
-WASM-NEXT:       Addend: 0x0
+WASM-NEXT:       Addend: 0
 WASM-NEXT:     }
 WASM-NEXT:     Relocation {
 WASM-NEXT:       Type: R_WEBASSEMBLY_GLOBAL_ADDR_LEB (3)
 WASM-NEXT:       Offset: 0x24
 WASM-NEXT:       Index: 0x1
-WASM-NEXT:       Addend: 0x0
+WASM-NEXT:       Addend: 0
 WASM-NEXT:     }
 WASM-NEXT:   }
 WASM-NEXT: ]

llvm/trunk/tools/llvm-readobj/WasmDumper.cpp

 
 void WasmDumper::printRelocation(const SectionRef &Section,
                                  const RelocationRef &Reloc) {
   SmallString<64> RelocTypeName;
   uint64_t RelocType = Reloc.getType();
   Reloc.getTypeName(RelocTypeName);
   const wasm::WasmRelocation &WasmReloc = Obj->getWasmRelocation(Reloc);
 
+  bool HasAddend = false;
+  switch (RelocType) {
+  case wasm::R_WEBASSEMBLY_GLOBAL_ADDR_LEB:
+  case wasm::R_WEBASSEMBLY_GLOBAL_ADDR_SLEB:
+  case wasm::R_WEBASSEMBLY_GLOBAL_ADDR_I32:
+    HasAddend = true;
+    break;
+  default:
+    break;
+  }
   if (opts::ExpandRelocs) {
     DictScope Group(W, "Relocation");
     W.printNumber("Type", RelocTypeName, RelocType);
     W.printHex("Offset", Reloc.getOffset());
     W.printHex("Index", WasmReloc.Index);
-    W.printHex("Addend", WasmReloc.Addend);
+    if (HasAddend)
+      W.printNumber("Addend", WasmReloc.Addend);
   } else {
     raw_ostream& OS = W.startLine();
     OS << W.hex(Reloc.getOffset())
-       << " " << RelocTypeName << "[" << WasmReloc.Index << "]"
-       << " " << W.hex(WasmReloc.Addend) << "\n";
+       << " " << RelocTypeName << "[" << WasmReloc.Index << "]";
+    if (HasAddend)
+      OS << " " << WasmReloc.Addend;
+    OS << "\n";
   }
 }
 
 void WasmDumper::printRelocations() {
   ListScope D(W, "Relocations");
 
   int SectionNumber = 0;
   for (const SectionRef &Section : Obj->sections()) {