[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
This commit is contained in:
Chandler Carruth
2014-03-09 03:16:01 +00:00
parent c980afc578
commit cdf4788401
100 changed files with 920 additions and 1075 deletions

View File

@@ -128,8 +128,8 @@ Function* PartialInliner::unswitchFunction(Function* F) {
InlineFunctionInfo IFI;
// Inline the top-level if test into all callers.
std::vector<User*> Users(duplicateFunction->use_begin(),
duplicateFunction->use_end());
std::vector<User *> Users(duplicateFunction->user_begin(),
duplicateFunction->user_end());
for (std::vector<User*>::iterator UI = Users.begin(), UE = Users.end();
UI != UE; ++UI)
if (CallInst *CI = dyn_cast<CallInst>(*UI))
@@ -162,9 +162,8 @@ bool PartialInliner::runOnModule(Module& M) {
if (currFunc->use_empty()) continue;
bool recursive = false;
for (Function::use_iterator UI = currFunc->use_begin(),
UE = currFunc->use_end(); UI != UE; ++UI)
if (Instruction* I = dyn_cast<Instruction>(*UI))
for (User *U : currFunc->users())
if (Instruction* I = dyn_cast<Instruction>(U))
if (I->getParent()->getParent() == currFunc) {
recursive = true;
break;