ART: Avoid uninitialized padding in LinkerPatch.
Bug: 26956807
Change-Id: I0cb54a4443109de9bc95728d96bd1f80810e68a3
diff --git a/compiler/compiled_method.h b/compiler/compiled_method.h
index 7a93613..5887620 100644
--- a/compiler/compiled_method.h
+++ b/compiler/compiled_method.h
@@ -283,11 +283,13 @@
static_assert(sizeof(element_offset_) == sizeof(cmp1_), "needed by relational operators");
};
union {
- uint32_t cmp2_; // Used for relational operators.
+ // Note: To avoid uninitialized padding on 64-bit systems, we use `size_t` for `cmp2_`.
+ // This allows a hashing function to treat an array of linker patches as raw memory.
+ size_t cmp2_; // Used for relational operators.
// Literal offset of the insn loading PC (same as literal_offset if it's the same insn,
// may be different if the PC-relative addressing needs multiple insns).
uint32_t pc_insn_offset_;
- static_assert(sizeof(pc_insn_offset_) == sizeof(cmp2_), "needed by relational operators");
+ static_assert(sizeof(pc_insn_offset_) <= sizeof(cmp2_), "needed by relational operators");
};
friend bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs);
