1 files changed, 29 insertions, 3 deletions
diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go
index 866c46a83d..56f2a00d76 100644
--- a/src/runtime/symtab.go
+++ b/src/runtime/symtab.go
@@ -647,8 +647,15 @@ func moduledataverify1(datap *moduledata) {
 
 	min := datap.textAddr(datap.ftab[0].entryoff)
 	max := datap.textAddr(datap.ftab[nftab].entryoff)
-	if datap.minpc != min || datap.maxpc != max {
-		println("minpc=", hex(datap.minpc), "min=", hex(min), "maxpc=", hex(datap.maxpc), "max=", hex(max))
+	minpc := datap.minpc
+	maxpc := datap.maxpc
+	if GOARCH == "wasm" {
+		// On Wasm, the func table contains the function index, whereas
+		// the "PC" is function index << 16 + block index.
+		maxpc = alignUp(maxpc, 1<<16) // round up for end PC
+	}
+	if minpc != min || maxpc != max {
+		println("minpc=", hex(minpc), "min=", hex(min), "maxpc=", hex(maxpc), "max=", hex(max))
 		throw("minpc or maxpc invalid")
 	}
 
@@ -694,6 +701,11 @@ func (md *moduledata) textAddr(off32 uint32) uintptr {
 			throw("runtime: text offset out of range")
 		}
 	}
+	if GOARCH == "wasm" {
+		// On Wasm, a text offset (e.g. in the method table) is function index, whereas
+		// the "PC" is function index << 16 + block index.
+		res <<= 16
+	}
 	return res
 }
 
@@ -704,8 +716,17 @@ func (md *moduledata) textAddr(off32 uint32) uintptr {
 //
 //go:nosplit
 func (md *moduledata) textOff(pc uintptr) (uint32, bool) {
-	res := uint32(pc - md.text)
+	off := pc - md.text
+	if GOARCH == "wasm" {
+		// On Wasm, the func table contains the function index, whereas
+		// the "PC" is function index << 16 + block index.
+		off >>= 16
+	}
+	res := uint32(off)
 	if len(md.textsectmap) > 1 {
+		if GOARCH == "wasm" {
+			fatal("unexpected multiple text sections on Wasm")
+		}
 		for i, sect := range md.textsectmap {
 			if sect.baseaddr > pc {
 				// pc is not in any section.
@@ -904,6 +925,11 @@ func findfunc(pc uintptr) funcInfo {
 	}
 
 	x := uintptr(pcOff) + datap.text - datap.minpc // TODO: are datap.text and datap.minpc always equal?
+	if GOARCH == "wasm" {
+		// On Wasm, pcOff is the function index, whereas
+		// the "PC" is function index << 16 + block index.
+		x = uintptr(pcOff)<<16 + datap.text - datap.minpc
+	}
 	b := x / abi.FuncTabBucketSize
 	i := x % abi.FuncTabBucketSize / (abi.FuncTabBucketSize / nsub)