Hi Chris,
> Okay, do you have a testcase that demonstrates this?
I will synthesize one for you.
> Also, the code for handling "large arrays" isn't needed. This code
> is only called for fixed size structures that are small.
Hey, you are the one who used getInt64 to get the array length! :)
Another point to consider is that this call could barf:
unsigned EltSizeBits = TREE_INT_CST_LOW(TYPE_SIZE(TREE_TYPE(type)));
This can happen if the array is a zero length array with an element
type of variable size (meaning the array has length zero). I reckon the
best thing to do is to bail out early if the type has zero size.
I've attached a new patch.
Ciao,
Duncan.
Index: gcc.llvm.master/gcc/llvm-types.cpp
===================================================================
--- gcc.llvm.master.orig/gcc/llvm-types.cpp 2007-06-01 21:56:34.000000000 +0200
+++ gcc.llvm.master/gcc/llvm-types.cpp 2007-06-01 21:58:19.000000000 +0200
@@ -526,12 +526,20 @@
type = TYPE_MAIN_VARIANT(type);
// If the type does not overlap, don't bother checking below.
- if (TYPE_SIZE(type) == 0 ||
- PadStartBits >= int(TREE_INT_CST_LOW(TYPE_SIZE(type))) ||
+
+ if (!TYPE_SIZE(type))
+ return false;
+
+ if (!isInt64(TYPE_SIZE(type), false))
+ // Variable sized or huge - be conservative.
+ return true;
+
+ if (!getInt64(TYPE_SIZE(type), false) ||
+ PadStartBits >= (int64_t)getInt64(TYPE_SIZE(type), false) ||
PadStartBits+PadSizeBits <= 0)
return false;
-
+
switch (TREE_CODE(type)) {
default:
fprintf(stderr, "Unknown type to compare:\n");
@@ -574,7 +582,7 @@
return GCCTypeOverlapsWithPadding(TREE_TYPE(Field),
PadStartBits, PadSizeBits);
}
-
+
// See if any elements overlap.
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field)) {
if (TREE_CODE(Field) != FIELD_DECL) continue;
@@ -587,16 +595,16 @@
return false;
}
-
- case RECORD_TYPE:
+
+ case RECORD_TYPE:
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field)) {
if (TREE_CODE(Field) != FIELD_DECL) continue;
-
+
if (TREE_CODE(DECL_FIELD_OFFSET(Field)) != INTEGER_CST)
return true;
-
+
unsigned FieldBitOffset = getFieldOffsetInBits(Field);
- if (GCCTypeOverlapsWithPadding(TREE_TYPE(Field),
+ if (GCCTypeOverlapsWithPadding(TREE_TYPE(Field),
PadStartBits-FieldBitOffset, PadSizeBits))
return true;
}
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