Adds support for DWARF based stack traces (#881)

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>

internal/wasmdebug/dwarf_test.go

@@ -0,0 +1,51 @@
+package wasmdebug_test
+
+import (
+	"math"
+	"testing"
+
+	"github.com/tetratelabs/wazero/api"
+	"github.com/tetratelabs/wazero/internal/testing/dwarftestdata"
+	"github.com/tetratelabs/wazero/internal/testing/require"
+	"github.com/tetratelabs/wazero/internal/wasm"
+	"github.com/tetratelabs/wazero/internal/wasm/binary"
+	"github.com/tetratelabs/wazero/internal/wasmdebug"
+)
+
+func TestGetSourceInfo(t *testing.T) {
+	mod, err := binary.DecodeModule(dwarftestdata.DWARFWasm, api.CoreFeaturesV2, wasm.MemoryLimitPages, false, true, false)
+	require.NoError(t, err)
+	require.NotNil(t, mod.DWARF)
+
+	// Get the offsets of functions named "a", "b" and "c" in dwarftestdata.DWARFWasm.
+	var a, b, c uint64
+	for _, exp := range mod.ExportSection {
+		switch exp.Name {
+		case "a":
+			a = mod.CodeSection[exp.Index-mod.ImportFuncCount()].BodyOffsetInCodeSection
+		case "b":
+			b = mod.CodeSection[exp.Index-mod.ImportFuncCount()].BodyOffsetInCodeSection
+		case "c":
+			c = mod.CodeSection[exp.Index-mod.ImportFuncCount()].BodyOffsetInCodeSection
+		}
+	}
+
+	tests := []struct {
+		offset uint64
+		exp    string
+	}{
+		// Unknown offset returns empty string.
+		{offset: math.MaxUint64, exp: ""},
+		// The first instruction should point to the first line of each function in internal/testing/dwarftestdata/testdata/main.go
+		{offset: a, exp: "wazero/internal/testing/dwarftestdata/testdata/main.go:9:3"},
+		{offset: b, exp: "wazero/internal/testing/dwarftestdata/testdata/main.go:14:3"},
+		{offset: c, exp: "wazero/internal/testing/dwarftestdata/testdata/main.go:19:7"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.exp, func(t *testing.T) {
+			actual := wasmdebug.GetSourceInfo(mod.DWARF, tc.offset)
+			require.Contains(t, actual, tc.exp)
+		})
+	}
+}