diff options
| -rwxr-xr-x | compiler/semexprs.nim | 7 | ||||
| -rwxr-xr-x | compiler/semstmts.nim | 11 |
2 files changed, 13 insertions, 5 deletions
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim index 59089d01c..2c98d9de6 100755 --- a/compiler/semexprs.nim +++ b/compiler/semexprs.nim @@ -723,9 +723,6 @@ proc buildEchoStmt(c: PContext, n: PNode): PNode = addSon(result, semExpr(c, arg)) proc discardCheck(result: PNode) = - proc ImplicitelyDiscardable(n: PNode): bool {.inline.} = - result = isCallExpr(n) and n.sons[0].kind == nkSym and - sfDiscardable in n.sons[0].sym.flags if result.typ != nil and result.typ.kind notin {tyStmt, tyEmpty}: if result.kind == nkNilLit: # XXX too much work and fixing would break bootstrapping: @@ -1105,7 +1102,9 @@ proc semProcBody(c: PContext, n: PNode): PNode = # ``result``: if result.kind == nkSym and result.sym == c.p.resultSym: nil - elif result.kind == nkNilLit: + elif result.kind == nkNilLit or ImplicitelyDiscardable(result): + # intended semantic: if it's 'discardable' and the context allows for it, + # discard it. This is bad for chaining but nicer for C wrappers. # ambiguous :-( result.typ = nil else: diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim index 5c0060e20..2d36015a7 100755 --- a/compiler/semstmts.nim +++ b/compiler/semstmts.nim @@ -1088,6 +1088,10 @@ proc insertDestructors(c: PContext, varSection: PNode): return +proc ImplicitelyDiscardable(n: PNode): bool = + result = isCallExpr(n) and n.sons[0].kind == nkSym and + sfDiscardable in n.sons[0].sym.flags + proc semStmtList(c: PContext, n: PNode): PNode = # these must be last statements in a block: const @@ -1134,7 +1138,12 @@ proc semStmtList(c: PContext, n: PNode): PNode = # a statement list (s; e) has the type 'e': if result.kind == nkStmtList and result.len > 0: - result.typ = lastSon(result).typ + var lastStmt = lastSon(result) + if not ImplicitelyDiscardable(lastStmt): + result.typ = lastStmt.typ + #localError(lastStmt.info, errGenerated, + # "Last expression must be explicitly returned if it " & + # "is discardable or discarded") proc SemStmt(c: PContext, n: PNode): PNode = # now: simply an alias: |