Commit Graph

497 Commits

Author SHA1 Message Date
Benjamin Kramer 3280a5d9f5 Turn some DenseMaps that are only used for set operations into DenseSets.
DenseSet has better memory efficiency now.

llvm-svn: 223589
2014-12-06 19:22:54 +00:00
Rafael Espindola de567e022b Remove dead code. We are only lazy about functions with bodies.
llvm-svn: 223521
2014-12-05 21:36:06 +00:00
Rafael Espindola 28a2451b35 Simplify the loop linking function bodies. NFC.
llvm-svn: 223512
2014-12-05 21:04:36 +00:00
Rafael Espindola 2bd5b9f558 Remove unused arguments. NFC.
llvm-svn: 223503
2014-12-05 19:35:07 +00:00
Rafael Espindola 26c2951117 Refactor duplicated code. NFC.
llvm-svn: 223486
2014-12-05 17:53:15 +00:00
Rafael Espindola 879aeb776c Small cleanup on how we clear constant variables. NFC.
llvm-svn: 223474
2014-12-05 16:05:19 +00:00
Rafael Espindola ad9d0ca878 Use an early return. NFC.
llvm-svn: 223470
2014-12-05 15:42:30 +00:00
Rafael Espindola 3124ed4b23 linkGlobalVariableProto never returns null. Simplify the caller. NFC.
llvm-svn: 223424
2014-12-05 00:30:47 +00:00
Rafael Espindola 439835a6fe Move merging of alignment to a central location. NFC.
llvm-svn: 223418
2014-12-05 00:09:02 +00:00
Rafael Espindola 31ad468d03 Split the set of identified struct types into opaque and non-opaque ones.
The non-opaque part can be structurally uniqued. To keep this to just
a hash lookup, we don't try to unique cyclic types.

Also change the type mapping algorithm to be optimistic about a type
not being recursive and only create a new type when proven to be wrong.
This is not as strong as trying to speculate that we can keep the source
type, but is simpler (no speculation to revert) and more powerfull
than what we had before (we don't copy non-recursive types at least).

I initially wrote this to try to replace the name based type merging.
It is not strong enough to replace it, but is is a useful addition.

With this patch the number of named struct types is a clang lto bootstrap goes
from 49674 to 15986.

llvm-svn: 223278
2014-12-03 22:36:37 +00:00
Rafael Espindola 2fa1e43a22 Ask the module for its the identified types.
When lazy reading a module, the types used in a function will not be visible to
a TypeFinder until the body is read.

This patch fixes that by asking the module for its identified struct types.
If a materializer is present, the module asks it. If not, it uses a TypeFinder.

This fixes pr21374.

I will be the first to say that this is ugly, but it was the best I could find.

Some of the options I looked at:

* Asking the LLVMContext. This could be made to work for gold, but not currently
  for ld64. ld64 will load multiple modules into a single context before merging
  them. This causes us to see types from future merges. Unfortunately,
  MappedTypes is not just a cache when it comes to opaque types. Once the
  mapping has been made, we have to remember it for as long as the key may
  be used. This would mean moving MappedTypes to the Linker class and having
  to drop the Linker::LinkModules static methods, which are visible from C.

* Adding an option to ignore function bodies in the TypeFinder. This would
  fix the PR by picking the worst result. It would work, but unfortunately
  we are currently quite dependent on the upfront type merging. I will
  try to reduce our dependency, but it is not clear that we will be able
  to get rid of it for now.

The only clean solution I could think of is making the Module own the types.
This would have other advantages, but it is a much bigger change. I will
propose it, but it is nice to have this fixed while that is discussed.

With the gold plugin, this patch takes the number of types in the LTO clang
binary from 52817 to 49669.

llvm-svn: 223215
2014-12-03 07:18:23 +00:00
Peter Collingbourne 51d2de7b9e Prologue support
Patch by Ben Gamari!

This redefines the `prefix` attribute introduced previously and
introduces a `prologue` attribute.  There are a two primary usecases
that these attributes aim to serve,

  1. Function prologue sigils

  2. Function hot-patching: Enable the user to insert `nop` operations
     at the beginning of the function which can later be safely replaced
     with a call to some instrumentation facility

  3. Runtime metadata: Allow a compiler to insert data for use by the
     runtime during execution. GHC is one example of a compiler that
     needs this functionality for its tables-next-to-code functionality.

Previously `prefix` served cases (1) and (2) quite well by allowing the user
to introduce arbitrary data at the entrypoint but before the function
body. Case (3), however, was poorly handled by this approach as it
required that prefix data was valid executable code.

Here we redefine the notion of prefix data to instead be data which
occurs immediately before the function entrypoint (i.e. the symbol
address). Since prefix data now occurs before the function entrypoint,
there is no need for the data to be valid code.

The previous notion of prefix data now goes under the name "prologue
data" to emphasize its duality with the function epilogue.

The intention here is to handle cases (1) and (2) with prologue data and
case (3) with prefix data.

References
----------

This idea arose out of discussions[1] with Reid Kleckner in response to a
proposal to introduce the notion of symbol offsets to enable handling of
case (3).

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html

Test Plan: testsuite

Differential Revision: http://reviews.llvm.org/D6454

llvm-svn: 223189
2014-12-03 02:08:38 +00:00
Rafael Espindola 973b3612e4 Use a continue to reduce indentation and clang-format. NFC.
llvm-svn: 223067
2014-12-01 19:17:46 +00:00
Rafael Espindola 4d4c938770 Use a range loop. NFC.
llvm-svn: 223066
2014-12-01 19:08:07 +00:00
Rafael Espindola dd42b533e9 Drop SrcStructTypesSet. It is redundant.
At the only point in the code it is used, we haven't added any of the src types
to DstStructTypesSet yet.

llvm-svn: 223057
2014-12-01 18:42:18 +00:00
Rafael Espindola a4e85e3db0 Partial revert of r222986.
The explicit set of destination types is not fully redundant when lazy loading
since the TypeFinder will not find types used only in function bodies.

This keeps the logic to drop the name of mapped types since it still helps
with avoiding further renaming.

llvm-svn: 223043
2014-12-01 16:32:20 +00:00
Rafael Espindola 04a74af734 Change how we keep track of which types are in the dest module.
Instead of keeping an explicit set, just drop the names of types we choose
to map to some other type.

This has the advantage that the name of the unused will not cause the context
to rename types on module read.

llvm-svn: 222986
2014-12-01 04:15:59 +00:00
Rafael Espindola a96f235c15 Add back r222727 with a fix.
The original patch would fail when:

* A dst opaque type (%A) is matched with a src type (%A).
* A src opaque (%E) type is then speculatively matched with %A and the
  speculation fails afterward.
* When rolling back the speculation we would cancel the source %A to dest
  %A mapping.

The fix is to keep an explicit list of which resolutions are speculative.

Original message:

Fix overly aggressive type merging.

If we find out that two types are *not* isomorphic, we learn nothing about
opaque sub types in both the source and destination.

llvm-svn: 222923
2014-11-28 16:41:24 +00:00
Rafael Espindola 3d0974105a Add an assert and use a range loop. NFC.
llvm-svn: 222922
2014-11-28 16:26:14 +00:00
Duncan P. N. Exon Smith c586eaa1f1 Revert "Fix overly aggressive type merging."
This reverts commit r222727, which causes LTO bootstrap failures.

Last passing @ r222698:
http://lab.llvm.org:8080/green/job/clang-Rlto_master_build/532/

First failing @ r222843:
http://lab.llvm.org:8080/green/job/clang-Rlto_master_build/533/

Internal bootstraps pointed at a much narrower range: r222725 is
passing, and r222731 is failing.

LTO crashes while handling libclang.dylib:
http://lab.llvm.org:8080/green/job/clang-Rlto_master_build/533/consoleFull#-158682280549ba4694-19c4-4d7e-bec5-911270d8a58c

    GEP is not of right type for indices!
      %InfoObj.i.i = getelementptr inbounds %"class.llvm::OnDiskIterableChainedHashTable"* %.lcssa, i64 0, i32 0, i32 4, !dbg !123627
     %"class.clang::serialization::reader::ASTIdentifierLookupTrait" = type { %"class.clang::ASTReader.31859"*, %"class.clang::serialization::ModuleFile.31870"*, %"class.clang::IdentifierInfo"* }LLVM ERROR: Broken function found, compilation aborted!
    clang: error: linker command failed with exit code 1 (use -v to see invocation)

Looks like the new algorithm doesn't merge types aggressively enough.

llvm-svn: 222895
2014-11-27 17:01:10 +00:00
Rafael Espindola c81c3f554c Set the body of a new struct as soon as it is created.
This changes the order in which different types are passed to get, but
one order is not inherently better than the other.

The main motivation is that this simplifies linkDefinedTypeBodies now that
it is only linking "real" opaque types. It is also means that we only have to
call it once and that we don't need getImpl.

A small change in behavior is that we don't copy type names when resolving
opaque types. This is an improvement IMHO, but it can be added back if
desired. A test is included with the new behavior.

llvm-svn: 222764
2014-11-25 15:33:40 +00:00
Rafael Espindola 290e2cc520 Misc style fixes. NFC.
This just reduces the noise in the next patch.

llvm-svn: 222761
2014-11-25 14:35:53 +00:00
Rafael Espindola 5e7f98071a Remove a bit of duplicated code.
Exactly the same checks are present in areTypesIsomorphic.

This might have been a premature performance optimization. I cannot reproduce
any slowdown with this patch.

llvm-svn: 222758
2014-11-25 13:19:46 +00:00
Rafael Espindola 8f14471e81 Use a range loop. NFC.
llvm-svn: 222730
2014-11-25 06:16:27 +00:00
Rafael Espindola c84f608b08 Style fix: don't indent inside a namemespace.
llvm-svn: 222729
2014-11-25 06:11:24 +00:00
Rafael Espindola f010311166 Remove a nested anonymous namespace.
llvm-svn: 222728
2014-11-25 06:07:51 +00:00
Rafael Espindola 86911440c2 Fix overly aggressive type merging.
If we find out that two types are *not* isomorphic, we learn nothing about
opaque sub types in both the source and destination.

llvm-svn: 222727
2014-11-25 05:59:24 +00:00
Rafael Espindola e96d7eb8bd Link the type of aliases.
They are not more or less "well typed" than GlobalVariables.

llvm-svn: 222725
2014-11-25 04:43:59 +00:00
Rafael Espindola d2a13a2ec6 Don't repeat name in comment or duplicate comment. NFC.
llvm-svn: 222724
2014-11-25 04:28:31 +00:00
Rafael Espindola c8a476ee11 Use range loops. NFC.
llvm-svn: 222723
2014-11-25 04:26:19 +00:00
David Blaikie 70573dcd9f Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

llvm-svn: 222334
2014-11-19 07:49:26 +00:00
David Blaikie 5106ce7897 Remove StringMap::GetOrCreateValue in favor of StringMap::insert
Having two ways to do this doesn't seem terribly helpful and
consistently using the insert version (which we already has) seems like
it'll make the code easier to understand to anyone working with standard
data structures. (I also updated many references to the Entry's
key and value to use first() and second instead of getKey{Data,Length,}
and get/setValue - for similar consistency)

Also removes the GetOrCreateValue functions so there's less surface area
to StringMap to fix/improve/change/accommodate move semantics, etc.

llvm-svn: 222319
2014-11-19 05:49:42 +00:00
Rafael Espindola 5cb9c82a5d Factor common code it Linker::init.
The TypeFinder was not being used in one of the constructors.

llvm-svn: 222172
2014-11-17 20:51:01 +00:00
Duncan P. N. Exon Smith de36e8040f Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

llvm-svn: 221711
2014-11-11 21:30:22 +00:00
Duncan P. N. Exon Smith c5754a65e6 IR: MDNode => Value: NamedMDNode::getOperator()
Change `NamedMDNode::getOperator()` from returning `MDNode *` to
returning `Value *`.  To reduce boilerplate at some call sites, add a
`getOperatorAsMDNode()` for named metadata that's expected to only
return `MDNode` -- for now, that's everything, but debug node named
metadata (such as llvm.dbg.cu and llvm.dbg.sp) will soon change.  This
is part of PR21433.

Note that there's a follow-up patch to clang for the API change.

llvm-svn: 221375
2014-11-05 18:16:03 +00:00
Rafael Espindola 778fcc770b Revert r221096 bringing back r221014 with a fix.
The issue was that linkAppendingVarProto does the full linking job, including
deleting the old dst variable. The fix is just to call it and return early
if we have a GV with appending linkage.

original message:

    Refactor duplicated code in liking GlobalValues.

    There is quiet a bit of logic that is common to any GlobalValue but was
    duplicated for Functions, GlobalVariables and GlobalAliases.

    While at it, merge visibility even when comdats are used, fixing pr21415.

llvm-svn: 221098
2014-11-02 13:28:57 +00:00
Chandler Carruth fd38af2d13 Revert r221014: "Refactor duplicated code in liking GlobalValues."
This commit introduces heap-use-after-free detected by ASan. Here is the output
for one of several tests that detect it:

******************** TEST 'LLVM :: Linker/AppendingLinkage.ll' FAILED ********************
Command Output (stderr):
--
=================================================================
==2122==ERROR: AddressSanitizer: heap-use-after-free on address 0x60c00000b9c8 at pc 0x0000005d05d1 bp 0x7fff64ed27c0 sp 0x7fff64ed27b8
READ of size 4 at 0x60c00000b9c8 thread T0
    #0 0x5d05d0 in llvm::GlobalValue::setUnnamedAddr(bool) /usr/local/google/home/chandlerc/src/llvm/build/../include/llvm/IR/GlobalValue.h:115:35
    #1 0x69fff1 in (anonymous namespace)::ModuleLinker::linkGlobalValueProto(llvm::GlobalValue*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1041:5
    #2 0x697229 in (anonymous namespace)::ModuleLinker::run() /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1485:9
    #3 0x696542 in llvm::Linker::linkInModule(llvm::Module*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1621:10
    #4 0x4a2db7 in main /usr/local/google/home/chandlerc/src/llvm/build/../tools/llvm-link/llvm-link.cpp:116:9
    #5 0x7f4ae61e5ec4 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287
    #6 0x41eb71 in _start (/usr/local/google/home/chandlerc/src/llvm/build/bin/llvm-link+0x41eb71)

0x60c00000b9c8 is located 72 bytes inside of 128-byte region [0x60c00000b980,0x60c00000ba00)
freed by thread T0 here:
    #0 0x4a1e6b in operator delete(void*) /usr/local/google/home/chandlerc/src/llvm/opt-build/../projects/compiler-rt/lib/asan/asan_new_delete.cc:94:3
    #1 0x5d1a7a in llvm::iplist<llvm::GlobalVariable, llvm::ilist_traits<llvm::GlobalVariable> >::erase(llvm::ilist_iterator<llvm::GlobalVariable>) /usr/local/google/home/chandlerc/src/llvm/build/../inclu
de/llvm/ADT/ilist.h:466:5
    #2 0x5d1980 in llvm::GlobalVariable::eraseFromParent() /usr/local/google/home/chandlerc/src/llvm/build/../lib/IR/Globals.cpp:204:3
    #3 0x6a8a4d in (anonymous namespace)::ModuleLinker::linkAppendingVarProto(llvm::GlobalVariable*, llvm::GlobalVariable const*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.
cpp:980:3
    #4 0x6a7403 in (anonymous namespace)::ModuleLinker::linkGlobalVariableProto(llvm::GlobalVariable const*, llvm::GlobalValue*, bool) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkMod
ules.cpp:1074:11
    #5 0x69ff4e in (anonymous namespace)::ModuleLinker::linkGlobalValueProto(llvm::GlobalValue*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1028:13
    #6 0x697229 in (anonymous namespace)::ModuleLinker::run() /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1485:9
    #7 0x696542 in llvm::Linker::linkInModule(llvm::Module*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1621:10
    #8 0x4a2db7 in main /usr/local/google/home/chandlerc/src/llvm/build/../tools/llvm-link/llvm-link.cpp:116:9
    #9 0x7f4ae61e5ec4 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287

previously allocated by thread T0 here:
    #0 0x4a192b in operator new(unsigned long) /usr/local/google/home/chandlerc/src/llvm/opt-build/../projects/compiler-rt/lib/asan/asan_new_delete.cc:62:35
    #1 0x61d85c in llvm::User::operator new(unsigned long, unsigned int) /usr/local/google/home/chandlerc/src/llvm/build/../lib/IR/User.cpp:57:19
    #2 0x6a7525 in (anonymous namespace)::ModuleLinker::linkGlobalVariableProto(llvm::GlobalVariable const*, llvm::GlobalValue*, bool) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkMod
ules.cpp:1100:3
    #3 0x69ff4e in (anonymous namespace)::ModuleLinker::linkGlobalValueProto(llvm::GlobalValue*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1028:13
    #4 0x697229 in (anonymous namespace)::ModuleLinker::run() /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1485:9
    #5 0x696542 in llvm::Linker::linkInModule(llvm::Module*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1621:10
    #6 0x4a2db7 in main /usr/local/google/home/chandlerc/src/llvm/build/../tools/llvm-link/llvm-link.cpp:116:9
    #7 0x7f4ae61e5ec4 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287

SUMMARY: AddressSanitizer: heap-use-after-free /usr/local/google/home/chandlerc/src/llvm/build/../include/llvm/IR/GlobalValue.h:115 llvm::GlobalValue::setUnnamedAddr(bool)
Shadow bytes around the buggy address:
  0x0c187fff96e0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  0x0c187fff96f0: 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa fa
  0x0c187fff9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fa
  0x0c187fff9710: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  0x0c187fff9720: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa
=>0x0c187fff9730: fd fd fd fd fd fd fd fd fd[fd]fd fd fd fd fd fd
  0x0c187fff9740: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd
  0x0c187fff9750: fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa fa
  0x0c187fff9760: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c187fff9770: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd
  0x0c187fff9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  ASan internal:           fe
==2122==ABORTING

llvm-svn: 221096
2014-11-02 09:10:31 +00:00
Rafael Espindola 246c4fb5d9 Remove redundant calls to isMaterializable.
This removes calls to isMaterializable in the following cases:

* It was redundant with a call to isDeclaration now that isDeclaration returns
  the correct answer for materializable functions.
* It was followed by a call to Materialize. Just call Materialize and check EC.

llvm-svn: 221050
2014-11-01 16:46:18 +00:00
Rafael Espindola 4e27567a12 Refactor duplicated code in liking GlobalValues.
There is quiet a bit of logic that is common to any GlobalValue but was
duplicated for Functions, GlobalVariables and GlobalAliases.

While at it, merge visibility even when comdats are used, fixing pr21415.

llvm-svn: 221014
2014-10-31 23:10:07 +00:00
Rafael Espindola 3e8bc6a8c3 Mark a few variables const. NFC.
llvm-svn: 220964
2014-10-31 16:08:17 +00:00
Rafael Espindola 0ae225b6b5 Move definition closer to use. NFC.
llvm-svn: 220949
2014-10-31 04:46:38 +00:00
Rafael Espindola d1e64b1e93 Fix the merging of the constantness of declarations.
The langref says:

LLVM explicitly allows declarations of global variables to be marked
constant, even if the final definition of the global is not. This
capability can be used to enable slightly better optimization of the
program, but requires the language definition to guarantee that
optimizations based on the ‘constantness’ are valid for the
translation units that do not include the definition.

Given that definition, when merging two declarations, we have to drop
constantness if of of them is not marked contant, since the Module
without the constant marker might not have the necessary guarantees.

llvm-svn: 220927
2014-10-30 20:50:23 +00:00
Rafael Espindola 9f8eff31db Remove the PreserveSource linker mode.
I noticed that it was untested, and forcing it on caused some tests to fail:

    LLVM :: Linker/metadata-a.ll
    LLVM :: Linker/prefixdata.ll
    LLVM :: Linker/type-unique-odr-a.ll
    LLVM :: Linker/type-unique-simple-a.ll
    LLVM :: Linker/type-unique-simple2-a.ll
    LLVM :: Linker/type-unique-simple2.ll
    LLVM :: Linker/type-unique-type-array-a.ll
    LLVM :: Linker/unnamed-addr1-a.ll
    LLVM :: Linker/visibility1.ll

If it is to be resurrected, it has to be fixed and we should probably have a
-preserve-source command line option in llvm-mc and run tests with and without
it.

llvm-svn: 220741
2014-10-28 00:24:16 +00:00
Rafael Espindola 4160f5d3ac Make it easier to pass a custom diagnostic handler to the IR linker.
llvm-svn: 220732
2014-10-27 23:02:10 +00:00
Rafael Espindola 18c89411b8 LinkModules.cpp: don't repeat names in comments.
llvm-svn: 220662
2014-10-27 02:35:46 +00:00
Rafael Espindola 98ab63ce98 Allow the C API users to keep relying on the OutMessages parameter.
Should fix the Ocaml tests.

llvm-svn: 220611
2014-10-25 04:31:08 +00:00
Rafael Espindola d12b4a334b Update the error handling of lib/Linker.
Instead of passing a std::string&, use the new diagnostic infrastructure.

llvm-svn: 220608
2014-10-25 04:06:10 +00:00
Rafael Espindola 5a52e6dc9e Modernize the error handling of the Materialize function.
llvm-svn: 220600
2014-10-24 22:50:48 +00:00
Rafael Espindola d4bcefc7d9 Don't ever call materializeAllPermanently during LTO.
To do this, change the representation of lazy loaded functions.

The previous representation cannot differentiate between a function whose body
has been removed and one whose body hasn't been read from the .bc file. That
means that in order to drop a function, the entire body had to be read.

llvm-svn: 220580
2014-10-24 18:13:04 +00:00
Rafael Espindola fe3842cda7 Merge alignment of common GlobalValue.
Fixes pr20882.

llvm-svn: 217455
2014-09-09 17:48:18 +00:00
Rafael Espindola 0910605af6 When merging two common GlobalValues, keep the largest.
llvm-svn: 217451
2014-09-09 15:59:12 +00:00
Rafael Espindola dbb0bd1a42 Move some logic to ModuleLinker::shouldLinkFromSource. NFC.
llvm-svn: 217449
2014-09-09 15:21:00 +00:00
Rafael Espindola c83c8d4e74 Fix a use of an undefined value (the linkage).
llvm-svn: 217445
2014-09-09 14:52:27 +00:00
Rafael Espindola 7fc29546f9 Prefer common over weak linkage when linking.
This matches the behavior of ELF linkers.

llvm-svn: 217443
2014-09-09 14:27:09 +00:00
Rafael Espindola 83a7ddbc9a Simplify ModuleLinker::getLinkageResult. NFC.
llvm-svn: 217441
2014-09-09 14:07:40 +00:00
Rafael Espindola d31dc048ca Fix pr20078.
When linking llvm.global_ctors with the optional third element we have to handle
it specially and only copy the elements whose keys were also copied.

llvm-svn: 217281
2014-09-05 21:27:52 +00:00
Rafael Espindola 3931c28b03 Set comdats when lazily linking functions.
We were setting the comdat when functions were copied in the initial pass, but
not when they were linked only when we found out that they are needed.

llvm-svn: 215765
2014-08-15 20:17:08 +00:00
Duncan P. N. Exon Smith 09d84addb7 Don't upgrade global constructors when reading bitcode
An optional third field was added to `llvm.global_ctors` (and
`llvm.global_dtors`) in r209015.  Most of the code has been changed to
deal with both versions of the variables.  Users of the C API might
create either version, the helper functions in LLVM create the two-field
version, and clang now creates the three-field version.

However, the BitcodeReader was changed to always upgrade to the
three-field version.  This created an unnecessary inconsistency in the
IR before/after serializing to bitcode.

This commit resolves the inconsistency by making the third field truly
optional (and not upgrading in the bitcode reader).  Since `llvm-link`
was relying on this upgrade code, rather than deleting it I've moved it
into `ModuleLinker`, where it upgrades these arrays as necessary to
resolve inconsistencies between modules.

The ideal resolution would be to remove the 2-field version and make the
third field required.  I filed PR20506 to track that.

I changed `test/Bitcode/upgrade-global-ctors.ll` to a negative test and
duplicated the `llvm-link` check in `test/Linker/global_ctors.ll` to
check both upgrade directions.

Since I came across this as part of PR5680 (serializing use-list order),
I've also added the missing `verify-uselistorder` RUN line to
`test/Bitcode/metadata-2.ll`.

llvm-svn: 215457
2014-08-12 16:46:37 +00:00
Justin Bogner c0087f3611 IR: Print a newline when dumping Types
Type::dump() doesn't print a newline, which makes for a poor
experience in a debugger. This looks like it was an ommission
considering Value::dump() two lines above, so I've changed Type to add
a newline as well.

Of the two in-tree callers, one added a newline anyway, and I've
updated the other one to use Type::print instead.

llvm-svn: 215421
2014-08-12 03:24:59 +00:00
Rafael Espindola b16196a3e0 Fix use of uninitialized variable.
Fixes linking bitcode files that use the new style comdats for constructors
with ones that don't.

llvm-svn: 215364
2014-08-11 17:07:34 +00:00
Rafael Espindola 2ef3f299d5 Use an early return. NFC.
llvm-svn: 215363
2014-08-11 16:55:42 +00:00
David Majnemer 82d6ff6b5b Include <tuple> to make buildbots happy
llvm-svn: 211949
2014-06-27 18:38:12 +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
Craig Topper 2a30d7889f Replace some assert(0)'s with llvm_unreachable.
llvm-svn: 211141
2014-06-18 05:05:13 +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
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 f1bedd3747 Use create methods since msvc doesn't handle delegating constructors.
llvm-svn: 209076
2014-05-17 21:29:57 +00:00
Rafael Espindola 8370565820 Reduce abuse of default values in the GlobalAlias constructor.
This is in preparation for adding an optional offset.

llvm-svn: 209073
2014-05-17 19:57:46 +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
Rafael Espindola 4fe0094fd1 Change the GlobalAlias constructor to look a bit more like GlobalVariable.
This is part of the fix for pr10367. A GlobalAlias always has a pointer type,
so just have the constructor build the type.

llvm-svn: 208983
2014-05-16 13:34:04 +00:00
Rafael Espindola 99e05cf163 Split GlobalValue into GlobalValue and GlobalObject.
This allows code to statically accept a Function or a GlobalVariable, but
not an alias. This is already a cleanup by itself IMHO, but the main
reason for it is that it gives a lot more confidence that the refactoring to fix
the design of GlobalAlias is correct. That will be a followup patch.

llvm-svn: 208716
2014-05-13 18:45:48 +00:00
Rafael Espindola ed6dc3730a Delete trailing whitespace.
llvm-svn: 208416
2014-05-09 14:39:25 +00:00
Duncan P. N. Exon Smith b2becfdbae LTO: Assert visibility of local linkage when merging symbols
`ModuleLinker::getLinkageResult()` shouldn't create symbols with local
linkage and non-default visibility -- in fact, symbols with local
linkage shouldn't be merged at all.  Assert to that effect.

llvm-svn: 208262
2014-05-07 22:55:46 +00:00
Rafael Espindola a7d9c69cc8 Be more strict about not calling setAlignment on global aliases.
The fact that GlobalAlias::setAlignment exists at all is a side effect of
how the classes are organized, it should never be used.

llvm-svn: 208094
2014-05-06 14:51:36 +00:00
Craig Topper 2617dccea2 [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 206252
2014-04-15 06:32:26 +00:00
Chandler Carruth 6cc07df4ec [Layering] Sink Linker.h into a Linker subdirectory to make it
consistent with every other sub-library header in LLVM.

llvm-svn: 203065
2014-03-06 03:42:23 +00:00
JF Bastien 026fc5f6ab Improve LinkModules warnings
Provide triple and data layout as well as module names (or empty string) when there's a mismatch.

Differential Revision: http://llvm-reviews.chandlerc.com/D2971

llvm-svn: 203009
2014-03-05 21:26:42 +00:00
Craig Topper 8548299aa8 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 202946
2014-03-05 07:52:44 +00:00
Rafael Espindola ae593f1563 Compare DataLayout by Value, not by pointer.
This fixes spurious warnings in llvm-link about the datalayout not matching.

Thanks to Zalman Stern for reporting the bug!

llvm-svn: 202276
2014-02-26 17:02:08 +00:00
Rafael Espindola f863ee2949 Store a DataLayout in Module.
Now that DataLayout is not a pass, store one in Module.

Since the C API expects to be able to get a char* to the datalayout description,
we have to keep a std::string somewhere. This patch keeps it in Module and also
uses it to represent modules without a DataLayout.

Once DataLayout is mandatory, we should probably move the string to DataLayout
itself since it won't be necessary anymore to represent the special case of a
module without a DataLayout.

llvm-svn: 202190
2014-02-25 20:01:08 +00:00
Eli Bendersky 7da92ed879 Set the SuppressWarnings option on tool level and propagate to the library.
The SuppressWarnings flag, unfortunately, isn't very useful for custom tools
that want to use the LLVM module linker. So I'm changing it to a parameter of
the Linker, and the flag itself moves to the llvm-link tool.

For the time being as SuppressWarnings is pretty much the only "option" it
seems reasonable to propagate it to Linker objects. If we end up with more
options in the future, some sort of "struct collecting options" may be a
better idea.

llvm-svn: 201819
2014-02-20 22:19:24 +00:00
Eli Bendersky e17f37082b Add a -suppress-warnings option to bitcode linking.
llvm-svn: 200927
2014-02-06 18:01:56 +00:00
Bill Wendling 91686d6dee Reapply r194218 with fix:
Move copying of global initializers below the cloning of functions.

The BlockAddress doesn't have access to the correct basic blocks until the
functions have been cloned. This causes the BlockAddress to point to the old
values. Just wait until the functions have been cloned before copying the
initializers.
PR13163

llvm-svn: 199354
2014-01-16 06:29:36 +00:00
Nico Rieck 7157bb765e Decouple dllexport/dllimport from linkage
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

llvm-svn: 199218
2014-01-14 15:22:47 +00:00
Nico Rieck 9d2e0df049 Revert "Decouple dllexport/dllimport from linkage"
Revert this for now until I fix an issue in Clang with it.

This reverts commit r199204.

llvm-svn: 199207
2014-01-14 12:38:32 +00:00
Nico Rieck e43aaf7967 Decouple dllexport/dllimport from linkage
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

llvm-svn: 199204
2014-01-14 11:55:03 +00:00
Adrian Prantl a473a2ba19 Revert "Move copying of global initializers below the cloning of functions."
This would cause internal symbols that are only referenced by global initializers to be removed.

This reverts commit 194219.

llvm-svn: 194304
2013-11-09 00:43:18 +00:00
Bill Wendling 8890460431 Move copying of global initializers below the cloning of functions.
The BlockAddress doesn't have access to the correct basic blocks until the
functions have been cloned. This causes the BlockAddress to point to the old
values. Just wait until the functions have been cloned before copying the
initializers.
PR13163

llvm-svn: 194218
2013-11-07 20:14:51 +00:00
Bill Wendling 91e6f6e198 Add a 'deleteModule' method to the Linker class.
This deletes the Module ivar instead of having the LTO code generater do it. It
also sets the pointer to 'NULL', so that if it's used again it will abort
quickly.

llvm-svn: 192778
2013-10-16 08:59:57 +00:00
Will Dietz 981af0021b Add missing #include's to cctype when using isdigit/alpha/etc.
llvm-svn: 192519
2013-10-12 00:55:57 +00:00
Peter Collingbourne 3fa50f9b05 Implement function prefix data as an IR feature.
Previous discussion:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-July/063909.html

Differential Revision: http://llvm-reviews.chandlerc.com/D1191

llvm-svn: 190773
2013-09-16 01:08:15 +00:00
Rafael Espindola fac3a018d1 Error on linking appending globals with different unnamed_addr.
llvm-svn: 189950
2013-09-04 15:33:34 +00:00
Rafael Espindola fd9a9415f5 Fix linking of unnamed_addr in functions.
llvm-svn: 189945
2013-09-04 14:59:03 +00:00
Rafael Espindola d4885daefa Fix linking of unnamed_addr.
This was regression from r134829. When linking we have to be conservative. If
one of the symbols has a significant address, then the result should have it
too.

llvm-svn: 189935
2013-09-04 14:05:09 +00:00
James Molloy f6f121e277 Extend RemapInstruction and friends to take an optional new parameter, a ValueMaterializer.
Extend LinkModules to pass a ValueMaterializer to RemapInstruction and friends to lazily create Functions for lazily linked globals. This is a big win when linking small modules with large (mostly unused) library modules.

llvm-svn: 182776
2013-05-28 15:17:05 +00:00
Rafael Espindola aa9918aac7 Fix a performance bug in the Linker.
Now that we hava a convinient place to keep it, remeber the set of
identified structs as we merge modules.

This speeds up the linking of all the bitcode files in clang with the
gold plugin and -plugin-opt=emit-llvm (i.e., link only, no codegen) from
5:25 minutes to 13.6 seconds!

Patch by Xiaofei Wan!

llvm-svn: 181104
2013-05-04 05:05:18 +00:00
Rafael Espindola 287f18b4b8 Implement Linker::LinkModules with Linker::linkInModule.
Flipping which one is the implementation will let us optimize linkInModule.

llvm-svn: 181102
2013-05-04 04:08:02 +00:00
Rafael Espindola 3df61b7bef Now that Linker.cpp is almost empty, merge it into LinkModules.cpp.
Also remove unused includes.

llvm-svn: 181100
2013-05-04 03:48:37 +00:00
Rafael Espindola a8023c1c9f Last batch of cleanups to Linker.h.
Update comments, fix * placement, fix method names that are not
used in clang, add a linkInModule that takes a Mode and put it
in Linker.cpp.

llvm-svn: 181099
2013-05-04 03:06:50 +00:00
Rafael Espindola 0229acaa0f Don't construct or delete a module on the Linker.
The linker is now responsible only for actually linking the modules, it
is up to the clients to create and destroy them.

llvm-svn: 181098
2013-05-04 02:43:00 +00:00