LLVM 19.0.0git
Config.h
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1//===-Config.h - LLVM Link Time Optimizer Configuration ---------*- C++ -*-===//
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 defines the lto::Config data structure, which allows clients to
10// configure LTO.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_LTO_CONFIG_H
15#define LLVM_LTO_CONFIG_H
16
17#include "llvm/ADT/DenseSet.h"
18#include "llvm/Config/llvm-config.h"
20#include "llvm/IR/GlobalValue.h"
21#include "llvm/IR/LLVMContext.h"
26
27#include <functional>
28#include <optional>
29
30namespace llvm {
31
32class Error;
33class Module;
34class ModuleSummaryIndex;
35class raw_pwrite_stream;
36
37namespace lto {
38
39/// LTO configuration. A linker can configure LTO by setting fields in this data
40/// structure and passing it to the lto::LTO constructor.
41struct Config {
42 enum VisScheme {
45 };
46 // Note: when adding fields here, consider whether they need to be added to
47 // computeLTOCacheKey in LTO.cpp.
48 std::string CPU;
50 std::vector<std::string> MAttrs;
51 std::vector<std::string> MllvmArgs;
52 std::vector<std::string> PassPlugins;
53 /// For adding passes that run right before codegen.
55 std::optional<Reloc::Model> RelocModel = Reloc::PIC_;
56 std::optional<CodeModel::Model> CodeModel;
59 unsigned OptLevel = 2;
60 bool VerifyEach = false;
61 bool DisableVerify = false;
62
63 /// Flag to indicate that the optimizer should not assume builtins are present
64 /// on the target.
65 bool Freestanding = false;
66
67 /// Disable entirely the optimizer, including importing for ThinLTO
68 bool CodeGenOnly = false;
69
70 /// Run PGO context sensitive IR instrumentation.
71 bool RunCSIRInstr = false;
72
73 /// Turn on/off the warning about a hash mismatch in the PGO profile data.
74 bool PGOWarnMismatch = true;
75
76 /// Asserts whether we can assume whole program visibility during the LTO
77 /// link.
79
80 /// We're validating that all native vtables have corresponding type infos.
82 /// If all native vtables have corresponding type infos, allow
83 /// usage of RTTI to block devirtualization on types used in native files.
85
86 /// Always emit a Regular LTO object even when it is empty because no Regular
87 /// LTO modules were linked. This option is useful for some build system which
88 /// want to know a priori all possible output files.
90
91 /// Allows non-imported definitions to get the potentially more constraining
92 /// visibility from the prevailing definition. FromPrevailing is the default
93 /// because it works for many binary formats. ELF can use the more optimized
94 /// 'ELF' scheme.
96
97 /// If this field is set, the set of passes run in the middle-end optimizer
98 /// will be the one specified by the string. Only works with the new pass
99 /// manager as the old one doesn't have this ability.
100 std::string OptPipeline;
101
102 // If this field is set, it has the same effect of specifying an AA pipeline
103 // identified by the string. Only works with the new pass manager, in
104 // conjunction OptPipeline.
105 std::string AAPipeline;
106
107 /// Setting this field will replace target triples in input files with this
108 /// triple.
109 std::string OverrideTriple;
110
111 /// Setting this field will replace unspecified target triples in input files
112 /// with this triple.
113 std::string DefaultTriple;
114
115 /// Context Sensitive PGO profile path.
116 std::string CSIRProfile;
117
118 /// Sample PGO profile path.
119 std::string SampleProfile;
120
121 /// Name remapping file for profile data.
122 std::string ProfileRemapping;
123
124 /// The directory to store .dwo files.
125 std::string DwoDir;
126
127 /// The name for the split debug info file used for the DW_AT_[GNU_]dwo_name
128 /// attribute in the skeleton CU. This should generally only be used when
129 /// running an individual backend directly via thinBackend(), as otherwise
130 /// all objects would use the same .dwo file. Not used as output path.
131 std::string SplitDwarfFile;
132
133 /// The path to write a .dwo file to. This should generally only be used when
134 /// running an individual backend directly via thinBackend(), as otherwise
135 /// all .dwo files will be written to the same path. Not used in skeleton CU.
136 std::string SplitDwarfOutput;
137
138 /// Optimization remarks file path.
139 std::string RemarksFilename;
140
141 /// Optimization remarks pass filter.
142 std::string RemarksPasses;
143
144 /// Whether to emit optimization remarks with hotness informations.
145 bool RemarksWithHotness = false;
146
147 /// The minimum hotness value a diagnostic needs in order to be included in
148 /// optimization diagnostics.
149 ///
150 /// The threshold is an Optional value, which maps to one of the 3 states:
151 /// 1. 0 => threshold disabled. All emarks will be printed.
152 /// 2. positive int => manual threshold by user. Remarks with hotness exceed
153 /// threshold will be printed.
154 /// 3. None => 'auto' threshold by user. The actual value is not
155 /// available at command line, but will be synced with
156 /// hotness threhold from profile summary during
157 /// compilation.
158 ///
159 /// If threshold option is not specified, it is disabled by default.
160 std::optional<uint64_t> RemarksHotnessThreshold = 0;
161
162 /// The format used for serializing remarks (default: YAML).
163 std::string RemarksFormat;
164
165 /// Whether to emit the pass manager debuggging informations.
166 bool DebugPassManager = false;
167
168 /// Statistics output file path.
169 std::string StatsFile;
170
171 /// Specific thinLTO modules to compile.
172 std::vector<std::string> ThinLTOModulesToCompile;
173
174 /// Time trace enabled.
175 bool TimeTraceEnabled = false;
176
177 /// Time trace granularity.
178 unsigned TimeTraceGranularity = 500;
179
182
183 /// Add FSAFDO discriminators.
184 bool AddFSDiscriminator = false;
185
186 /// If this field is set, LTO will write input file paths and symbol
187 /// resolutions here in llvm-lto2 command line flag format. This can be
188 /// used for testing and for running the LTO pipeline outside of the linker
189 /// with llvm-lto2.
190 std::unique_ptr<raw_ostream> ResolutionFile;
191
192 /// Tunable parameters for passes in the default pipelines.
194
195 /// The following callbacks deal with tasks, which normally represent the
196 /// entire optimization and code generation pipeline for what will become a
197 /// single native object file. Each task has a unique identifier between 0 and
198 /// getMaxTasks()-1, which is supplied to the callback via the Task parameter.
199 /// A task represents the entire pipeline for ThinLTO and regular
200 /// (non-parallel) LTO, but a parallel code generation task will be split into
201 /// N tasks before code generation, where N is the parallelism level.
202 ///
203 /// LTO may decide to stop processing a task at any time, for example if the
204 /// module is empty or if a module hook (see below) returns false. For this
205 /// reason, the client should not expect to receive exactly getMaxTasks()
206 /// native object files.
207
208 /// A module hook may be used by a linker to perform actions during the LTO
209 /// pipeline. For example, a linker may use this function to implement
210 /// -save-temps. If this function returns false, any further processing for
211 /// that task is aborted.
212 ///
213 /// Module hooks must be thread safe with respect to the linker's internal
214 /// data structures. A module hook will never be called concurrently from
215 /// multiple threads with the same task ID, or the same module.
216 ///
217 /// Note that in out-of-process backend scenarios, none of the hooks will be
218 /// called for ThinLTO tasks.
219 using ModuleHookFn = std::function<bool(unsigned Task, const Module &)>;
220
221 /// This module hook is called after linking (regular LTO) or loading
222 /// (ThinLTO) the module, before modifying it.
224
225 /// This hook is called after promoting any internal functions
226 /// (ThinLTO-specific).
228
229 /// This hook is called after internalizing the module.
231
232 /// This hook is called after importing from other modules (ThinLTO-specific).
234
235 /// This module hook is called after optimization is complete.
237
238 /// This module hook is called before code generation. It is similar to the
239 /// PostOptModuleHook, but for parallel code generation it is called after
240 /// splitting the module.
242
243 /// A combined index hook is called after all per-module indexes have been
244 /// combined (ThinLTO-specific). It can be used to implement -save-temps for
245 /// the combined index.
246 ///
247 /// If this function returns false, any further processing for ThinLTO tasks
248 /// is aborted.
249 ///
250 /// It is called regardless of whether the backend is in-process, although it
251 /// is not called from individual backend processes.
252 using CombinedIndexHookFn = std::function<bool(
254 const DenseSet<GlobalValue::GUID> &GUIDPreservedSymbols)>;
256
257 /// This is a convenience function that configures this Config object to write
258 /// temporary files named after the given OutputFileName for each of the LTO
259 /// phases to disk. A client can use this function to implement -save-temps.
260 ///
261 /// FIXME: Temporary files derived from ThinLTO backends are currently named
262 /// after the input file name, rather than the output file name, when
263 /// UseInputModulePath is set to true.
264 ///
265 /// Specifically, it (1) sets each of the above module hooks and the combined
266 /// index hook to a function that calls the hook function (if any) that was
267 /// present in the appropriate field when the addSaveTemps function was
268 /// called, and writes the module to a bitcode file with a name prefixed by
269 /// the given output file name, and (2) creates a resolution file whose name
270 /// is prefixed by the given output file name and sets ResolutionFile to its
271 /// file handle.
272 ///
273 /// SaveTempsArgs can be specified to select which temps to save.
274 /// If SaveTempsArgs is not provided, all temps are saved.
275 Error addSaveTemps(std::string OutputFileName,
276 bool UseInputModulePath = false,
277 const DenseSet<StringRef> &SaveTempsArgs = {});
278};
279
283 : Fn(DiagHandlerFn) {}
284 bool handleDiagnostics(const DiagnosticInfo &DI) override {
285 (*Fn)(DI);
286 return true;
287 }
288};
289/// A derived class of LLVMContext that initializes itself according to a given
290/// Config object. The purpose of this class is to tie ownership of the
291/// diagnostic handler to the context, as opposed to the Config object (which
292/// may be ephemeral).
293// FIXME: This should not be required as diagnostic handler is not callback.
295
297 setDiscardValueNames(C.ShouldDiscardValueNames);
300 std::make_unique<LTOLLVMDiagnosticHandler>(&DiagHandler), true);
301 }
303};
304
305}
306}
307
308#endif
This file defines the DenseSet and SmallDenseSet classes.
Machine Check Debug Module
Implements a dense probed hash-table based set.
Definition: DenseSet.h:271
This is the base abstract class for diagnostic reporting in the backend.
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:67
void enableDebugTypeODRUniquing()
void setDiscardValueNames(bool Discard)
Set the Context runtime configuration to discard all value name (but GlobalValue).
void setDiagnosticHandler(std::unique_ptr< DiagnosticHandler > &&DH, bool RespectFilters=false)
setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler to provide custom d...
Class to hold module path string table and global value map, and encapsulate methods for operating on...
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:65
Tunable parameters for passes in the default pipelines.
Definition: PassBuilder.h:43
PassManager manages ModulePassManagers.
Interfaces for registering analysis passes, producing common pass manager configurations,...
@ C
The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
CodeGenFileType
These enums are meant to be passed into addPassesToEmitFile to indicate what type of file to emit,...
Definition: CodeGen.h:83
CodeGenOptLevel
Code generation optimization level.
Definition: CodeGen.h:54
std::function< void(const DiagnosticInfo &)> DiagnosticHandlerFunction
This is the base class for diagnostic handling in LLVM.
LTO configuration.
Definition: Config.h:41
DiagnosticHandlerFunction DiagHandler
Definition: Config.h:181
bool HasWholeProgramVisibility
Asserts whether we can assume whole program visibility during the LTO link.
Definition: Config.h:78
bool ValidateAllVtablesHaveTypeInfos
We're validating that all native vtables have corresponding type infos.
Definition: Config.h:81
std::function< bool(unsigned Task, const Module &)> ModuleHookFn
The following callbacks deal with tasks, which normally represent the entire optimization and code ge...
Definition: Config.h:219
bool DebugPassManager
Whether to emit the pass manager debuggging informations.
Definition: Config.h:166
bool AddFSDiscriminator
Add FSAFDO discriminators.
Definition: Config.h:184
std::optional< uint64_t > RemarksHotnessThreshold
The minimum hotness value a diagnostic needs in order to be included in optimization diagnostics.
Definition: Config.h:160
Error addSaveTemps(std::string OutputFileName, bool UseInputModulePath=false, const DenseSet< StringRef > &SaveTempsArgs={})
This is a convenience function that configures this Config object to write temporary files named afte...
Definition: LTOBackend.cpp:87
std::string StatsFile
Statistics output file path.
Definition: Config.h:169
ModuleHookFn PreOptModuleHook
This module hook is called after linking (regular LTO) or loading (ThinLTO) the module,...
Definition: Config.h:223
CombinedIndexHookFn CombinedIndexHook
Definition: Config.h:255
std::optional< CodeModel::Model > CodeModel
Definition: Config.h:56
std::string AAPipeline
Definition: Config.h:105
std::function< void(legacy::PassManager &)> PreCodeGenPassesHook
For adding passes that run right before codegen.
Definition: Config.h:54
bool CodeGenOnly
Disable entirely the optimizer, including importing for ThinLTO.
Definition: Config.h:68
bool DisableVerify
Definition: Config.h:61
std::function< bool(const ModuleSummaryIndex &Index, const DenseSet< GlobalValue::GUID > &GUIDPreservedSymbols)> CombinedIndexHookFn
A combined index hook is called after all per-module indexes have been combined (ThinLTO-specific).
Definition: Config.h:254
std::vector< std::string > MAttrs
Definition: Config.h:50
std::vector< std::string > MllvmArgs
Definition: Config.h:51
std::vector< std::string > ThinLTOModulesToCompile
Specific thinLTO modules to compile.
Definition: Config.h:172
bool VerifyEach
Definition: Config.h:60
CodeGenOptLevel CGOptLevel
Definition: Config.h:57
PipelineTuningOptions PTO
Tunable parameters for passes in the default pipelines.
Definition: Config.h:193
std::unique_ptr< raw_ostream > ResolutionFile
If this field is set, LTO will write input file paths and symbol resolutions here in llvm-lto2 comman...
Definition: Config.h:190
std::string DefaultTriple
Setting this field will replace unspecified target triples in input files with this triple.
Definition: Config.h:113
bool AlwaysEmitRegularLTOObj
Always emit a Regular LTO object even when it is empty because no Regular LTO modules were linked.
Definition: Config.h:89
std::string CPU
Definition: Config.h:48
std::string DwoDir
The directory to store .dwo files.
Definition: Config.h:125
std::string RemarksFilename
Optimization remarks file path.
Definition: Config.h:139
VisScheme VisibilityScheme
Allows non-imported definitions to get the potentially more constraining visibility from the prevaili...
Definition: Config.h:95
ModuleHookFn PostPromoteModuleHook
This hook is called after promoting any internal functions (ThinLTO-specific).
Definition: Config.h:227
std::string OverrideTriple
Setting this field will replace target triples in input files with this triple.
Definition: Config.h:109
std::string ProfileRemapping
Name remapping file for profile data.
Definition: Config.h:122
bool AllVtablesHaveTypeInfos
If all native vtables have corresponding type infos, allow usage of RTTI to block devirtualization on...
Definition: Config.h:84
TargetOptions Options
Definition: Config.h:49
std::string SplitDwarfFile
The name for the split debug info file used for the DW_AT_[GNU_]dwo_name attribute in the skeleton CU...
Definition: Config.h:131
std::string SplitDwarfOutput
The path to write a .dwo file to.
Definition: Config.h:136
bool TimeTraceEnabled
Time trace enabled.
Definition: Config.h:175
ModuleHookFn PostOptModuleHook
This module hook is called after optimization is complete.
Definition: Config.h:236
std::string RemarksPasses
Optimization remarks pass filter.
Definition: Config.h:142
std::string OptPipeline
If this field is set, the set of passes run in the middle-end optimizer will be the one specified by ...
Definition: Config.h:100
bool RunCSIRInstr
Run PGO context sensitive IR instrumentation.
Definition: Config.h:71
ModuleHookFn PostInternalizeModuleHook
This hook is called after internalizing the module.
Definition: Config.h:230
unsigned TimeTraceGranularity
Time trace granularity.
Definition: Config.h:178
unsigned OptLevel
Definition: Config.h:59
ModuleHookFn PostImportModuleHook
This hook is called after importing from other modules (ThinLTO-specific).
Definition: Config.h:233
bool RemarksWithHotness
Whether to emit optimization remarks with hotness informations.
Definition: Config.h:145
std::vector< std::string > PassPlugins
Definition: Config.h:52
std::string CSIRProfile
Context Sensitive PGO profile path.
Definition: Config.h:116
ModuleHookFn PreCodeGenModuleHook
This module hook is called before code generation.
Definition: Config.h:241
std::optional< Reloc::Model > RelocModel
Definition: Config.h:55
bool ShouldDiscardValueNames
Definition: Config.h:180
bool PGOWarnMismatch
Turn on/off the warning about a hash mismatch in the PGO profile data.
Definition: Config.h:74
CodeGenFileType CGFileType
Definition: Config.h:58
bool Freestanding
Flag to indicate that the optimizer should not assume builtins are present on the target.
Definition: Config.h:65
std::string SampleProfile
Sample PGO profile path.
Definition: Config.h:119
std::string RemarksFormat
The format used for serializing remarks (default: YAML).
Definition: Config.h:163
A derived class of LLVMContext that initializes itself according to a given Config object.
Definition: Config.h:294
DiagnosticHandlerFunction DiagHandler
Definition: Config.h:302
LTOLLVMContext(const Config &C)
Definition: Config.h:296
LTOLLVMDiagnosticHandler(DiagnosticHandlerFunction *DiagHandlerFn)
Definition: Config.h:282
DiagnosticHandlerFunction * Fn
Definition: Config.h:281
bool handleDiagnostics(const DiagnosticInfo &DI) override
Override handleDiagnostics to provide custom implementation.
Definition: Config.h:284