diff --git a/src/cmd/link/internal/wasm/asm.go b/src/cmd/link/internal/wasm/asm.go index 2665659fe0..abb4409188 100644 --- a/src/cmd/link/internal/wasm/asm.go +++ b/src/cmd/link/internal/wasm/asm.go @@ -427,8 +427,11 @@ func writeDataSec(ctxt *ld.Link) { // overhead of adding a new segment (same as wasm-opt's memory-packing optimization uses). const segmentOverhead = 8 + // Generate at most this many segments. A higher number of segments gets rejected by some WebAssembly runtimes. + const maxNumSegments = 100000 + var segments []*dataSegment - for _, sec := range sections { + for secIndex, sec := range sections { data := ld.DatblkBytes(ctxt, int64(sec.Vaddr), int64(sec.Length)) offset := int32(sec.Vaddr) @@ -441,21 +444,26 @@ func writeDataSec(ctxt *ld.Link) { for len(data) > 0 { dataLen := int32(len(data)) var segmentEnd, zeroEnd int32 - for { - // look for beginning of zeroes - for segmentEnd < dataLen && data[segmentEnd] != 0 { - segmentEnd++ + if len(segments)+(len(sections)-secIndex) == maxNumSegments { + segmentEnd = dataLen + zeroEnd = dataLen + } else { + for { + // look for beginning of zeroes + for segmentEnd < dataLen && data[segmentEnd] != 0 { + segmentEnd++ + } + // look for end of zeroes + zeroEnd = segmentEnd + for zeroEnd < dataLen && data[zeroEnd] == 0 { + zeroEnd++ + } + // emit segment if omitting zeroes reduces the output size + if zeroEnd-segmentEnd >= segmentOverhead || zeroEnd == dataLen { + break + } + segmentEnd = zeroEnd } - // look for end of zeroes - zeroEnd = segmentEnd - for zeroEnd < dataLen && data[zeroEnd] == 0 { - zeroEnd++ - } - // emit segment if omitting zeroes reduces the output size - if zeroEnd-segmentEnd >= segmentOverhead || zeroEnd == dataLen { - break - } - segmentEnd = zeroEnd } segments = append(segments, &dataSegment{