[C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
detail
2) Change it to actually be a *Use* iterator rather than a *User*
iterator.
3) Add an adaptor which is a User iterator that always looks through the
Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
they wanted a use_iterator (and to explicitly dig out the User when
needed), or a user_iterator which makes the Use itself totally
opaque.
Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.
The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.
However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]
llvm-svn: 203364
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index deb708d..f64ebc1 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1974,9 +1974,8 @@
Assert1(BB, "Instruction not embedded in basic block!", &I);
if (!isa<PHINode>(I)) { // Check that non-phi nodes are not self referential
- for (Value::use_iterator UI = I.use_begin(), UE = I.use_end();
- UI != UE; ++UI)
- Assert1(*UI != (User*)&I || !DT.isReachableFromEntry(BB),
+ for (User *U : I.users())
+ Assert1(U != (User*)&I || !DT.isReachableFromEntry(BB),
"Only PHI nodes may reference their own value!", &I);
}
@@ -1999,13 +1998,12 @@
// Check that all uses of the instruction, if they are instructions
// themselves, actually have parent basic blocks. If the use is not an
// instruction, it is an error!
- for (User::use_iterator UI = I.use_begin(), UE = I.use_end();
- UI != UE; ++UI) {
- if (Instruction *Used = dyn_cast<Instruction>(*UI))
+ for (Use &U : I.uses()) {
+ if (Instruction *Used = dyn_cast<Instruction>(U.getUser()))
Assert2(Used->getParent() != 0, "Instruction referencing instruction not"
" embedded in a basic block!", &I, Used);
else {
- CheckFailed("Use of instruction is not an instruction!", *UI);
+ CheckFailed("Use of instruction is not an instruction!", U);
return;
}
}