Commit Graph

128 Commits

Author SHA1 Message Date
Alexey Samsonov af023adb86 Be more careful in parsing Module::ModFlagBehavior value
to make sure we don't do invalid load of an enum. Share the
conversion code between llvm::Module implementation and the
verifier.

This bug was reported by UBSan.

llvm-svn: 217395
2014-09-08 19:16:28 +00:00
Reid Kleckner 329d4a2b29 Verifier: Don't reject varargs callee cleanup functions
We've rejected these kinds of functions since r28405 in 2006 because
it's impossible to lower the return of a callee cleanup varargs
function. However there are lots of legal ways to leave such a function
without returning, such as aborting. Today we can leave a function with
a musttail call to another function with the correct prototype, and
everything works out.

I'm removing the verifier check declaring that a normal return from such
a function is UB.

Reviewed By: nlewycky

Differential Revision: http://reviews.llvm.org/D5059

llvm-svn: 216779
2014-08-29 21:25:28 +00:00
Craig Topper 71b7b68b74 Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size.
llvm-svn: 216158
2014-08-21 05:55:13 +00:00
Craig Topper 6230691c91 Revert "Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size."
Getting a weird buildbot failure that I need to investigate.

llvm-svn: 215870
2014-08-18 00:24:38 +00:00
Craig Topper 5229cfd163 Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size.
llvm-svn: 215868
2014-08-17 23:47:00 +00:00
Duncan P. N. Exon Smith 6c99015fe2 Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."
This reverts commit r213474 (and r213475), which causes a miscompile on
a stage2 LTO build.  I'll reply on the list in a moment.

llvm-svn: 213562
2014-07-21 17:06:51 +00:00
Manuel Jacob d11beffef4 [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges.
Summary: This patch introduces two new iterator ranges and updates existing code to use it.  No functional change intended.

Test Plan: All tests (make check-all) still pass.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4481

llvm-svn: 213474
2014-07-20 09:10:11 +00:00
Reid Kleckner 15fe7a530d Document the maximum LLVM IR alignment, which is 1 << 29 or 0.5 GiB
Add verifier checks.  We already check these in the assembly parser, but
a frontend producing IR in memory wouldn't hit those checks.

llvm-svn: 213027
2014-07-15 01:16:09 +00:00
David Majnemer ebc741168b IR: Allow comdats to be applied to globals with internal linkage
Our verifier check for checking if a global has local linkage was too
strict.  Forbid private linkage but permit local linkage.

Object file formats permit this and forbidding it prevents elimination
of unused, internal, vftables under the MSVC ABI.

llvm-svn: 212900
2014-07-13 04:56:11 +00:00
David Majnemer 329b5602d7 Verifier: Update assert message to reflect LangRef
No functionality change, just correcting the assertion message.

llvm-svn: 211977
2014-06-28 06:24:49 +00:00
David Majnemer dad0a645a7 IR: Add COMDATs to the IR
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

llvm-svn: 211920
2014-06-27 18:19:56 +00:00
Jingyue Wu 37fcb5919d [ValueTracking] Extend range metadata to call/invoke
Summary:
With this patch, range metadata can be added to call/invoke including
IntrinsicInst. Previously, it could only be added to load.

Rename computeKnownBitsLoad to computeKnownBitsFromRangeMetadata because
range metadata is not only used by load.

Update the language reference to reflect this change.

Test Plan:
Add several tests in range-2.ll to confirm the verifier is happy with
having range metadata on call/invoke.

Add two tests in AddOverFlow.ll to confirm annotating range metadata to
call/invoke can benefit InstCombine.

Reviewers: meheff, nlewycky, reames, hfinkel, eliben

Reviewed By: eliben

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4187

llvm-svn: 211281
2014-06-19 16:50:16 +00:00
Bob Wilson 2f7cc01895 Fix verifier for GlobalAliases to avoid recursing into global initializers.
The verifier follows GlobalAlias operands so that it can detect cycles of
alias definitions. It was doing this in a way that caused it to also recurse
through initializers for the GlobalValue aliasees, and it would fail when
an initializer refers to a global that is a declaration and not a definition.
This patch causes it to stop recursing when it hits a global definition.
<rdar://problem/17277451>

llvm-svn: 210734
2014-06-12 01:46:54 +00:00
Rafael Espindola 42a4c9f9e0 Allow aliases to be unnamed_addr.
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.

It seems natural to allow unnamed_addr in aliases:

* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.

This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.

llvm-svn: 210302
2014-06-06 01:20:28 +00:00
Tom Roeder 44cb65fff1 Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.
It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.

This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.

llvm-svn: 210280
2014-06-05 19:29:43 +00:00
Rafael Espindola 4dc5dfc56b Clauses in a landingpad are always Constant. Use a stricter type.
llvm-svn: 210203
2014-06-04 18:51:31 +00:00
Rafael Espindola 64c1e18033 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.

llvm-svn: 210062
2014-06-03 02:41:57 +00:00
Rafael Espindola 19913ee160 Use existing helper function.
No functionality change.

llvm-svn: 209639
2014-05-26 19:57:55 +00:00
Reid Kleckner fceb76f5f9 Add comdat key field to llvm.global_ctors and llvm.global_dtors
This allows us to put dynamic initializers for weak data into the same
comdat group as the data being initialized.  This is necessary for MSVC
ABI compatibility.  Once we have comdats for guard variables, we can use
the combination to help GlobalOpt fire more often for weak data with
guarded initialization on other platforms.

Reviewers: nlewycky

Differential Revision: http://reviews.llvm.org/D3499

llvm-svn: 209015
2014-05-16 20:39:27 +00:00
Rafael Espindola 6b238633b7 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.

llvm-svn: 209007
2014-05-16 19:35:39 +00:00
Reid Kleckner d20c970aac musttail: Fix the verification of alignment attributes
Previously this would fail with an assertion failure when trying to add
an alignment attribute without a value.

llvm-svn: 208935
2014-05-15 23:58:57 +00:00
Reid Kleckner 7941856445 Allow sret on the second parameter as well as the first
MSVC always places the implicit sret parameter after the implicit this
parameter of instance methods.  We used to handle this for
x86_thiscallcc by allocating the sret parameter on the stack and leaving
the this pointer in ecx, but that doesn't handle alternative calling
conventions like cdecl, stdcall, fastcall, or the win64 convention.

Instead, change the verifier to allow sret on the second parameter.

This also requires changing the Mips and X86 backends to return the
argument with the sret parameter, instead of assuming that the sret
parameter comes first.

The Sparc backend also returns sret parameters in a register, but I
wasn't able to update it to handle secondary sret parameters.  It
currently calls report_fatal_error if you feed it an sret in the second
parameter.

Reviewers: rafael.espindola, majnemer

Differential Revision: http://reviews.llvm.org/D3617

llvm-svn: 208453
2014-05-09 22:32:13 +00:00
Rafael Espindola 8d8f100c57 Special case aliases in GlobalValue::getSection.
This is similar to the getAlignment patch, but is done just for
completeness. It looks like we never call getSection on an alias. All the
tests still pass if the if is replaced with an assert.

llvm-svn: 208139
2014-05-06 22:44:30 +00:00
Rafael Espindola 52dc5d828f Special case aliases in GlobalValue::getAlignment.
An alias has the address of what it points to, so it also has the same
alignment.

This allows a few optimizations to see past aliases for free.

llvm-svn: 208103
2014-05-06 16:48:58 +00:00
Rafael Espindola bf8bf54bfc Aliases are always definitions. Delete dead code.
llvm-svn: 207869
2014-05-02 21:10:48 +00:00
David Majnemer 91db08bfe4 IR: Conservatively verify inalloca arguments
Summary: Try to spot obvious mismatches with inalloca use.

Reviewers: rnk

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3572

llvm-svn: 207676
2014-04-30 17:22:00 +00:00
Reid Kleckner 5772b77789 Add 'musttail' marker to call instructions
This is similar to the 'tail' marker, except that it guarantees that
tail call optimization will occur.  It also comes with convervative IR
verification rules that ensure that tail call optimization is possible.

Reviewers: nicholas

Differential Revision: http://llvm-reviews.chandlerc.com/D3240

llvm-svn: 207143
2014-04-24 20:14:34 +00:00
Duncan P. N. Exon Smith 0d640014ff verify-di: Add back braces for MSVC compatability
Fixup after r206300.

<rdar://problem/15500563>

llvm-svn: 206305
2014-04-15 17:28:26 +00:00
Duncan P. N. Exon Smith 6ef5f284d6 verify-di: Implement DebugInfoVerifier
Implement DebugInfoVerifier, which steals verification relying on
DebugInfoFinder from Verifier.

  - Adds LegacyDebugInfoVerifierPassPass, a ModulePass which wraps
    DebugInfoVerifier.  Uses -verify-di command-line flag.

  - Change verifyModule() to invoke DebugInfoVerifier as well as
    Verifier.

  - Add a call to createDebugInfoVerifierPass() wherever there was a
    call to createVerifierPass().

This implementation as a module pass should sidestep efficiency issues,
allowing us to turn debug info verification back on.

<rdar://problem/15500563>

llvm-svn: 206300
2014-04-15 16:27:38 +00:00
Duncan P. N. Exon Smith 67b44da0dd verify-di: split out VerifierSupport
Split out assertion and output helpers from Verifier in preparation for
writing the DebugInfoVerifier.

<rdar://problem/15500563>

llvm-svn: 206299
2014-04-15 16:27:32 +00:00
Craig Topper c620761ca5 [C++11] More 'nullptr' conversion or in some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 205831
2014-04-09 06:08:46 +00:00
Duncan P. N. Exon Smith 2541d4e525 Verifier: Give the right message for bad atomic loads
Talk about load (not store) on an invalid atomic load.

<rdar://problem/16287567>

llvm-svn: 205777
2014-04-08 17:07:44 +00:00
Eric Christopher 484182779d Invert the option to enable debug info verification. No functional
change outside of the command line to enable it.

llvm-svn: 205713
2014-04-07 13:55:21 +00:00
Tim Northover 4516de3412 Intrinsics: add LLVMHalfElementsVectorType constraint
This is like the LLVMMatchType, except the verifier checks that the
second argument is a vector with the same base type and half the
number of elements.

This will be used by the ARM64 backend.

llvm-svn: 205079
2014-03-29 07:04:54 +00:00
Tim Northover aa3cf1e691 Intrinsics: expand semantics of LLVMExtendedVectorType (& trunc)
These are used in the ARM backends to aid type-checking on patterns involving
intrinsics. By making sure one argument is an extended/truncated version of
another.

However, there's no reason to limit them to just vectors types. For example
AArch64 has the instruction "uqshrn sD, dN, #imm" which would naturally use an
intrinsic taking an i64 and returning an i32.

llvm-svn: 205003
2014-03-28 12:31:39 +00:00
Rafael Espindola 24a669d225 Prevent alias from pointing to weak aliases.
This adds back r204781.

Original message:

Aliases are just another name for a position in a file. As such, the
regular symbol resolutions are not applied. For example, given

define void @my_func() {
  ret void
}
@my_alias = alias weak void ()* @my_func
@my_alias2 = alias void ()* @my_alias

We produce without this patch:

        .weak   my_alias
my_alias = my_func
        .globl  my_alias2
my_alias2 = my_alias

That is, in the resulting ELF file my_alias, my_func and my_alias are
just 3 names pointing to offset 0 of .text. That is *not* the
semantics of IR linking. For example, linking in a

@my_alias = alias void ()* @other_func

would require the strong my_alias to override the weak one and
my_alias2 would end up pointing to other_func.

There is no way to represent that with aliases being just another
name, so the best solution seems to be to just disallow it, converting
a miscompile into an error.

llvm-svn: 204934
2014-03-27 15:26:56 +00:00
Rafael Espindola 65481d7b97 Revert "Prevent alias from pointing to weak aliases."
This reverts commit r204781.

I will follow up to with msan folks to see what is what they
were trying to do with aliases to weak aliases.

llvm-svn: 204784
2014-03-26 06:14:40 +00:00
Rafael Espindola 3b712a84a9 Prevent alias from pointing to weak aliases.
Aliases are just another name for a position in a file. As such, the
regular symbol resolutions are not applied. For example, given

define void @my_func() {
  ret void
}
@my_alias = alias weak void ()* @my_func
@my_alias2 = alias void ()* @my_alias

We produce without this patch:

        .weak   my_alias
my_alias = my_func
        .globl  my_alias2
my_alias2 = my_alias

That is, in the resulting ELF file my_alias, my_func and my_alias are
just 3 names pointing to offset 0 of .text. That is *not* the
semantics of IR linking. For example, linking in a

@my_alias = alias void ()* @other_func

would require the strong my_alias to override the weak one and
my_alias2 would end up pointing to other_func.

There is no way to represent that with aliases being just another
name, so the best solution seems to be to just disallow it, converting
a miscompile into an error.

llvm-svn: 204781
2014-03-26 04:48:47 +00:00
Alon Mishne ad312155a6 [C++11] Change DebugInfoFinder to use range-based loops
Also changes the iterators to return actual DI type over MDNode.

llvm-svn: 204130
2014-03-18 09:41:07 +00:00
Rafael Espindola f3336bc1d5 Reject alias to undefined symbols in the verifier.
On ELF and COFF an alias is just another name for a position in the file.
There is no way to refer to a position in another file, so an alias to
undefined is meaningless.

MachO currently doesn't support aliases. The spec has a N_INDR, which when
implemented will have a different set of restrictions. Adding support for
it shouldn't be harder than any other IR extension.

For now, having the IR represent what is actually possible with current
tools makes it easier to fix the design of GlobalAlias.

llvm-svn: 203705
2014-03-12 20:15:49 +00:00
Rafael Espindola 2e43aff460 Avoid repeated calls to CE->getOperand(0). No functionality change.
llvm-svn: 203686
2014-03-12 18:08:14 +00:00
Tim Northover e94a518a22 IR: add a second ordering operand to cmpxhg for failure
The syntax for "cmpxchg" should now look something like:

	cmpxchg i32* %addr, i32 42, i32 3 acquire monotonic

where the second ordering argument gives the required semantics in the case
that no exchange takes place. It should be no stronger than the first ordering
constraint and cannot be either "release" or "acq_rel" (since no store will
have taken place).

rdar://problem/15996804

llvm-svn: 203559
2014-03-11 10:48:52 +00:00
Justin Bogner 28e1cf6061 IR: Slightly more verbose error in Verifier
Extend the error message generated by the Verifier when an intrinsic
name does not match the expected mangling to include the expected
name.  Simplifies debugging.

Patch by Philip Reames!

llvm-svn: 203490
2014-03-10 21:22:44 +00:00
Ahmed Charles 821b66669c [C++11] Fix break due to MSVC bug.
MSVC (2012, 2013, 2013 Nov CTP) fail on the following code:

int main() {
  int arr[] = {1, 2};
  for (int i : arr)
    do {} while (0);
}

The fix is to put {} around the for loop. I've reported this to the MSVC
team.

llvm-svn: 203371
2014-03-09 04:57:09 +00:00
Chandler Carruth cdf4788401 [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
2014-03-09 03:16:01 +00:00
Chandler Carruth 7da14f1ab9 [Layering] Move InstVisitor.h into the IR library as it is pretty
obviously coupled to the IR.

llvm-svn: 203064
2014-03-06 03:23:41 +00:00
Chandler Carruth 9a4c9e597b [Layering] Move DebugInfo.h into the IR library where its implementation
already lives.

llvm-svn: 203046
2014-03-06 00:46:21 +00:00
Craig Topper f398d7c6bf [C++11] Add 'override' keyword to IR library.
llvm-svn: 202939
2014-03-05 06:35:38 +00:00
Chandler Carruth 8cd041ef19 [Modules] Move the ConstantRange class into the IR library. This is
a bit surprising, as the class is almost entirely abstracted away from
any particular IR, however it encodes the comparsion predicates which
mutate ranges as ICmp predicate codes. This is reasonable as they're
used for both instructions and constants. Thus, it belongs in the IR
library with instructions and constants.

llvm-svn: 202838
2014-03-04 12:24:34 +00:00
Chandler Carruth 1305dc3351 [Modules] Move CFG.h to the IR library as it defines graph traits over
IR types.

llvm-svn: 202827
2014-03-04 11:45:46 +00:00