diff options
Diffstat (limited to 'src/cmd/compile/internal/gc/bexport.go')
| -rw-r--r-- | src/cmd/compile/internal/gc/bexport.go | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/gc/bexport.go b/src/cmd/compile/internal/gc/bexport.go index 38e035edc8..4c28a68443 100644 --- a/src/cmd/compile/internal/gc/bexport.go +++ b/src/cmd/compile/internal/gc/bexport.go @@ -197,6 +197,9 @@ type exporter struct { written int // bytes written indent int // for p.trace trace bool + + // work-around for issue #16369 only + nesting int // amount of "nesting" of interface types } // export writes the exportlist for localpkg to out and returns the number of bytes written. @@ -790,11 +793,39 @@ func (p *exporter) typ(t *Type) { case TINTER: p.tag(interfaceTag) - // gc doesn't separate between embedded interfaces // and methods declared explicitly with an interface p.int(0) // no embedded interfaces + + // Because the compiler flattens interfaces containing + // embedded interfaces, it is possible to create interface + // types that recur through an unnamed type. + // If trackAllTypes is disabled, such recursion is not + // detected, leading to a stack overflow during export + // (issue #16369). + // As a crude work-around we terminate deep recursion + // through interface types with an empty interface and + // report an error. + // This will catch endless recursion, but is unlikely + // to trigger for valid, deeply nested types given the + // high threshold. + // It would be ok to continue without reporting an error + // since the export format is valid. But a subsequent + // import would import an incorrect type. The textual + // exporter does not report an error but importing the + // resulting package will lead to a syntax error during + // import. + // TODO(gri) remove this once we have a permanent fix + // for the issue. + if p.nesting > 100 { + p.int(0) // 0 methods to indicate empty interface + yyerrorl(t.Lineno, "cannot export unnamed recursive interface") + break + } + + p.nesting++ p.methodList(t) + p.nesting-- case TMAP: p.tag(mapTag) |