xref: /llvm-project/llvm/include/llvm/PassSupport.h (revision 293df8afae3ec1f99e44d6bc015e4edf2c165c8d)
1 //===- llvm/PassSupport.h - Pass Support code -------------------*- 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 stuff that is used to define and "use" Passes.  This file
10 // is automatically #included by Pass.h, so:
11 //
12 //           NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY
13 //
14 // Instead, #include Pass.h.
15 //
16 // This file defines Pass registration code and classes used for it.
17 //
18 //===----------------------------------------------------------------------===//
19 
20 #if !defined(LLVM_PASS_H) || defined(LLVM_PASSSUPPORT_H)
21 #error "Do not include <PassSupport.h>; include <Pass.h> instead"
22 #endif
23 
24 #ifndef LLVM_PASSSUPPORT_H
25 #define LLVM_PASSSUPPORT_H
26 
27 #include "llvm/ADT/StringRef.h"
28 #include "llvm/PassInfo.h"
29 #include "llvm/PassRegistry.h"
30 #include "llvm/Support/Error.h"
31 #include "llvm/Support/Threading.h"
32 #include <functional>
33 
34 namespace llvm {
35 
36 class Pass;
37 
38 #define INITIALIZE_PASS(passName, arg, name, cfg, analysis)                    \
39   static void *initialize##passName##PassOnce(PassRegistry &Registry) {        \
40     PassInfo *PI = new PassInfo(                                               \
41         name, arg, &passName::ID,                                              \
42         PassInfo::NormalCtor_t(callDefaultCtor<passName>), cfg, analysis);     \
43     Registry.registerPass(*PI, true);                                          \
44     return PI;                                                                 \
45   }                                                                            \
46   static llvm::once_flag Initialize##passName##PassFlag;                       \
47   void llvm::initialize##passName##Pass(PassRegistry &Registry) {              \
48     llvm::call_once(Initialize##passName##PassFlag,                            \
49                     initialize##passName##PassOnce, std::ref(Registry));       \
50   }
51 
52 #define INITIALIZE_PASS_BEGIN(passName, arg, name, cfg, analysis)              \
53   static void *initialize##passName##PassOnce(PassRegistry &Registry) {
54 
55 #define INITIALIZE_PASS_DEPENDENCY(depName) initialize##depName##Pass(Registry);
56 
57 #define INITIALIZE_PASS_END(passName, arg, name, cfg, analysis)                \
58   PassInfo *PI = new PassInfo(                                                 \
59       name, arg, &passName::ID,                                                \
60       PassInfo::NormalCtor_t(callDefaultCtor<passName>), cfg, analysis);       \
61   Registry.registerPass(*PI, true);                                            \
62   return PI;                                                                   \
63   }                                                                            \
64   static llvm::once_flag Initialize##passName##PassFlag;                       \
65   void llvm::initialize##passName##Pass(PassRegistry &Registry) {              \
66     llvm::call_once(Initialize##passName##PassFlag,                            \
67                     initialize##passName##PassOnce, std::ref(Registry));       \
68   }
69 
70 #define INITIALIZE_PASS_WITH_OPTIONS(PassName, Arg, Name, Cfg, Analysis)       \
71   INITIALIZE_PASS_BEGIN(PassName, Arg, Name, Cfg, Analysis)                    \
72   PassName::registerOptions();                                                 \
73   INITIALIZE_PASS_END(PassName, Arg, Name, Cfg, Analysis)
74 
75 #define INITIALIZE_PASS_WITH_OPTIONS_BEGIN(PassName, Arg, Name, Cfg, Analysis) \
76   INITIALIZE_PASS_BEGIN(PassName, Arg, Name, Cfg, Analysis)                    \
77   PassName::registerOptions();
78 
79 template <
80     class PassName,
81     std::enable_if_t<std::is_default_constructible<PassName>{}, bool> = true>
82 Pass *callDefaultCtor() {
83   return new PassName();
84 }
85 
86 template <
87     class PassName,
88     std::enable_if_t<!std::is_default_constructible<PassName>{}, bool> = true>
89 Pass *callDefaultCtor() {
90   // Some codegen passes should only be testable via
91   // `llc -{start|stop}-{before|after}=<passname>`, not via `opt -<passname>`.
92   report_fatal_error("target-specific codegen-only pass");
93 }
94 
95 //===---------------------------------------------------------------------------
96 /// RegisterPass<t> template - This template class is used to notify the system
97 /// that a Pass is available for use, and registers it into the internal
98 /// database maintained by the PassManager.  Unless this template is used, opt,
99 /// for example will not be able to see the pass and attempts to create the pass
100 /// will fail. This template is used in the follow manner (at global scope, in
101 /// your .cpp file):
102 ///
103 /// static RegisterPass<YourPassClassName> tmp("passopt", "My Pass Name");
104 ///
105 /// This statement will cause your pass to be created by calling the default
106 /// constructor exposed by the pass.
107 template <typename passName> struct RegisterPass : public PassInfo {
108   // Register Pass using default constructor...
109   RegisterPass(StringRef PassArg, StringRef Name, bool CFGOnly = false,
110                bool is_analysis = false)
111       : PassInfo(Name, PassArg, &passName::ID,
112                  PassInfo::NormalCtor_t(callDefaultCtor<passName>), CFGOnly,
113                  is_analysis) {
114     PassRegistry::getPassRegistry()->registerPass(*this);
115   }
116 };
117 
118 //===---------------------------------------------------------------------------
119 /// PassRegistrationListener class - This class is meant to be derived from by
120 /// clients that are interested in which passes get registered and unregistered
121 /// at runtime (which can be because of the RegisterPass constructors being run
122 /// as the program starts up, or may be because a shared object just got
123 /// loaded).
124 struct PassRegistrationListener {
125   PassRegistrationListener() = default;
126   virtual ~PassRegistrationListener() = default;
127 
128   /// Callback functions - These functions are invoked whenever a pass is loaded
129   /// or removed from the current executable.
130   virtual void passRegistered(const PassInfo *) {}
131 
132   /// enumeratePasses - Iterate over the registered passes, calling the
133   /// passEnumerate callback on each PassInfo object.
134   void enumeratePasses();
135 
136   /// passEnumerate - Callback function invoked when someone calls
137   /// enumeratePasses on this PassRegistrationListener object.
138   virtual void passEnumerate(const PassInfo *) {}
139 };
140 
141 } // end namespace llvm
142 
143 #endif // LLVM_PASSSUPPORT_H
144