llvm-6502/test/Linker/Inputs/alias.ll

@zed = global i32 42
@foo = alias i32* @zed
@foo2 = alias bitcast (i32* @zed to i16*)
Fix most of PR10367. This patch changes the design of GlobalAlias so that it doesn't take a ConstantExpr anymore. It now points directly to a GlobalObject, but its type is independent of the aliasee type. To avoid changing all alias related tests in this patches, I kept the common syntax @foo = alias i32* @bar to mean the same as now. The cases that used to use cast now use the more general syntax @foo = alias i16, i32* @bar. Note that GlobalAlias now behaves a bit more like GlobalVariable. We know that its type is always a pointer, so we omit the '*'. For the bitcode, a nice surprise is that we were writing both identical types already, so the format change is minimal. Auto upgrade is handled by looking through the casts and no new fields are needed for now. New bitcode will simply have different types for Alias and Aliasee. One last interesting point in the patch is that replaceAllUsesWith becomes smart enough to avoid putting a ConstantExpr in the aliasee. This seems better than checking and updating every caller. A followup patch will delete getAliasedGlobal now that it is redundant. Another patch will add support for an explicit offset. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209007 91177308-0d34-0410-b5e6-96231b3b80d8 2014-05-16 19:35:39 +00:00			`@zed = global i32 42`
			`@foo = alias i32* @zed`
Allow alias to point to an arbitrary ConstantExpr. This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is up to MC (or the system assembler) to decide if that expression is valid or not. This reduces our ability to diagnose invalid uses and how early we can spot them, but it also lets us do things like @test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32), i32 ptrtoint (i32* @bar to i32)) to i32) An important implication of this patch is that the notion of aliased global doesn't exist any more. The alias has to encode the information needed to access it in its metadata (linkage, visibility, type, etc). Another consequence to notice is that getSection has to return a "const char ". It could return a NullTerminatedStringRef if there was such a thing, but when that was proposed the decision was to just uses "const char*" for that. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210062 91177308-0d34-0410-b5e6-96231b3b80d8 2014-06-03 02:41:57 +00:00			`@foo2 = alias bitcast (i32* @zed to i16*)`