LLVM  17.0.0git
GCStrategy.cpp
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1 //===- GCStrategy.cpp - Garbage Collector Description ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the policy object GCStrategy which describes the
10 // behavior of a given garbage collector.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/IR/GCStrategy.h"
15 #include "llvm/ADT/Twine.h"
16 #include "llvm/IR/BuiltinGCs.h"
17 
18 using namespace llvm;
19 
21 
22 GCStrategy::GCStrategy() = default;
23 
24 std::unique_ptr<GCStrategy> llvm::getGCStrategy(const StringRef Name) {
25  for (auto &S : GCRegistry::entries())
26  if (S.getName() == Name)
27  return S.instantiate();
28 
29  // We need to link all the builtin GCs when LLVM is used as a static library.
30  // The linker will quite happily remove the static constructors that register
31  // the builtin GCs if we don't use a function from that object. This function
32  // does nothing but we need to make sure it is (or at least could be, even
33  // with all optimisations enabled) called *somewhere*, and this is a good
34  // place to do that: if the GC strategies are being used then this function
35  // obviously can't be removed by the linker, and here it won't affect
36  // performance, since there's about to be a fatal error anyway.
38 
40  // In normal operation, the registry should not be empty. There should
41  // be the builtin GCs if nothing else. The most likely scenario here is
42  // that we got here without running the initializers used by the Registry
43  // itself and it's registration mechanism.
44  const std::string error =
45  std::string("unsupported GC: ") + Name.str() +
46  " (did you remember to link and initialize the library?)";
48  } else
49  report_fatal_error(Twine(std::string("unsupported GC: ") + Name.str()));
50 }
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::Registry::end
static iterator end()
Definition: Registry.h:99
error
#define error(X)
Definition: SymbolRecordMapping.cpp:14
llvm::GCStrategy::GCStrategy
GCStrategy()
llvm::Registry::entries
static iterator_range< iterator > entries()
Definition: Registry.h:101
Twine.h
llvm::report_fatal_error
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:145
BuiltinGCs.h
llvm::StringRef
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
S
add sub stmia L5 ldr r0 bl L_printf $stub Instead of a and a wouldn t it be better to do three moves *Return an aggregate type is even return S
Definition: README.txt:210
llvm::Twine
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
LLVM_INSTANTIATE_REGISTRY
#define LLVM_INSTANTIATE_REGISTRY(REGISTRY_CLASS)
Instantiate a registry class.
Definition: Registry.h:137
llvm::Registry
A global registry used in conjunction with static constructors to make pluggable components (like tar...
Definition: Registry.h:44
llvm::getGCStrategy
std::unique_ptr< GCStrategy > getGCStrategy(const StringRef Name)
Lookup the GCStrategy object associated with the given gc name.
Definition: GCStrategy.cpp:24
llvm::linkAllBuiltinGCs
void linkAllBuiltinGCs()
FIXME: Collector instances are not useful on their own.
Definition: BuiltinGCs.cpp:132
llvm::Registry::begin
static iterator begin()
GCStrategy.h