From 46cf461c83489859531d548d57e1751f8c5cb68c Mon Sep 17 00:00:00 2001 From: Per Bothner Date: Sat, 14 Nov 1998 09:22:22 -0800 Subject: [PATCH] Allow uses of interface types to verify. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit � Allow uses of interface types to verify. This is not really type-safe, but it matches what Sun does, and is OK as long as there are appropriate run-time checks. * verify.c (merge_types): If merging two interface types, just set the result to java.lang.Object. * expr.c (pop_type): Any interface is matches by java.lang.Object. From-SVN: r23656 --- gcc/java/expr.c | 6 ++++++ gcc/java/verify.c | 26 ++++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/gcc/java/expr.c b/gcc/java/expr.c index 0df6106bcaa..9bd1ca7430c 100644 --- a/gcc/java/expr.c +++ b/gcc/java/expr.c @@ -268,6 +268,12 @@ pop_type (type) return type; else if (can_widen_reference_to (t, type)) return t; + /* This is a kludge, but matches what Sun's verifier does. + It can be tricked, but is safe as long as type errors + (i.e. interface method calls) are caught at run-time. */ + else if (CLASS_INTERFACE (TYPE_NAME (TREE_TYPE (type))) + && t == object_ptr_type_node) + return t; } error ("unexpected type on stack"); return t; diff --git a/gcc/java/verify.c b/gcc/java/verify.c index d73c52af6a6..9554a81d523 100644 --- a/gcc/java/verify.c +++ b/gcc/java/verify.c @@ -150,6 +150,32 @@ merge_types (type1, type2) } return object_ptr_type_node; } + + if (CLASS_INTERFACE (TYPE_NAME (tt1))) + { + if (CLASS_INTERFACE (TYPE_NAME (tt2))) + { + /* This is a kludge, but matches what Sun's verifier does. + It can be tricked, but is safe as long as type errors + (i.e. interface method calls) are caught at run-time. */ + return object_ptr_type_node; + } + else + { + if (can_widen_reference_to (tt2, tt1)) + return type1; + else + return TYPE_UNKNOWN; + } + } + else if (CLASS_INTERFACE (TYPE_NAME (tt2))) + { + if (can_widen_reference_to (tt1, tt2)) + return type2; + else + return TYPE_UNKNOWN; + } + type1 = tt1; type2 = tt2; -- 2.30.2