xref: /llvm-project/mlir/lib/Bindings/Python/IRModule.cpp (revision e823abab489390a62ae845e9855ebb36e9c447c6)
1 //===- IRModule.cpp - IR pybind module ------------------------------------===//
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 #include "IRModule.h"
10 #include "Globals.h"
11 #include "PybindUtils.h"
12 
13 #include <vector>
14 
15 #include "mlir-c/Bindings/Python/Interop.h"
16 
17 namespace py = pybind11;
18 using namespace mlir;
19 using namespace mlir::python;
20 
21 // -----------------------------------------------------------------------------
22 // PyGlobals
23 // -----------------------------------------------------------------------------
24 
25 PyGlobals *PyGlobals::instance = nullptr;
26 
27 PyGlobals::PyGlobals() {
28   assert(!instance && "PyGlobals already constructed");
29   instance = this;
30   // The default search path include {mlir.}dialects, where {mlir.} is the
31   // package prefix configured at compile time.
32   dialectSearchPrefixes.emplace_back(MAKE_MLIR_PYTHON_QUALNAME("dialects"));
33 }
34 
35 PyGlobals::~PyGlobals() { instance = nullptr; }
36 
37 void PyGlobals::loadDialectModule(llvm::StringRef dialectNamespace) {
38   if (loadedDialectModulesCache.contains(dialectNamespace))
39     return;
40   // Since re-entrancy is possible, make a copy of the search prefixes.
41   std::vector<std::string> localSearchPrefixes = dialectSearchPrefixes;
42   py::object loaded;
43   for (std::string moduleName : localSearchPrefixes) {
44     moduleName.push_back('.');
45     moduleName.append(dialectNamespace.data(), dialectNamespace.size());
46 
47     try {
48       loaded = py::module::import(moduleName.c_str());
49     } catch (py::error_already_set &e) {
50       if (e.matches(PyExc_ModuleNotFoundError)) {
51         continue;
52       }
53       throw;
54     }
55     break;
56   }
57 
58   // Note: Iterator cannot be shared from prior to loading, since re-entrancy
59   // may have occurred, which may do anything.
60   loadedDialectModulesCache.insert(dialectNamespace);
61 }
62 
63 void PyGlobals::registerDialectImpl(const std::string &dialectNamespace,
64                                     py::object pyClass) {
65   py::object &found = dialectClassMap[dialectNamespace];
66   if (found) {
67     throw SetPyError(PyExc_RuntimeError, llvm::Twine("Dialect namespace '") +
68                                              dialectNamespace +
69                                              "' is already registered.");
70   }
71   found = std::move(pyClass);
72 }
73 
74 void PyGlobals::registerOperationImpl(const std::string &operationName,
75                                       py::object pyClass,
76                                       py::object rawOpViewClass) {
77   py::object &found = operationClassMap[operationName];
78   if (found) {
79     throw SetPyError(PyExc_RuntimeError, llvm::Twine("Operation '") +
80                                              operationName +
81                                              "' is already registered.");
82   }
83   found = std::move(pyClass);
84   rawOpViewClassMap[operationName] = std::move(rawOpViewClass);
85 }
86 
87 llvm::Optional<py::object>
88 PyGlobals::lookupDialectClass(const std::string &dialectNamespace) {
89   loadDialectModule(dialectNamespace);
90   // Fast match against the class map first (common case).
91   const auto foundIt = dialectClassMap.find(dialectNamespace);
92   if (foundIt != dialectClassMap.end()) {
93     if (foundIt->second.is_none())
94       return std::nullopt;
95     assert(foundIt->second && "py::object is defined");
96     return foundIt->second;
97   }
98 
99   // Not found and loading did not yield a registration. Negative cache.
100   dialectClassMap[dialectNamespace] = py::none();
101   return std::nullopt;
102 }
103 
104 llvm::Optional<pybind11::object>
105 PyGlobals::lookupRawOpViewClass(llvm::StringRef operationName) {
106   {
107     auto foundIt = rawOpViewClassMapCache.find(operationName);
108     if (foundIt != rawOpViewClassMapCache.end()) {
109       if (foundIt->second.is_none())
110         return std::nullopt;
111       assert(foundIt->second && "py::object is defined");
112       return foundIt->second;
113     }
114   }
115 
116   // Not found. Load the dialect namespace.
117   auto split = operationName.split('.');
118   llvm::StringRef dialectNamespace = split.first;
119   loadDialectModule(dialectNamespace);
120 
121   // Attempt to find from the canonical map and cache.
122   {
123     auto foundIt = rawOpViewClassMap.find(operationName);
124     if (foundIt != rawOpViewClassMap.end()) {
125       if (foundIt->second.is_none())
126         return std::nullopt;
127       assert(foundIt->second && "py::object is defined");
128       // Positive cache.
129       rawOpViewClassMapCache[operationName] = foundIt->second;
130       return foundIt->second;
131     }
132     // Negative cache.
133     rawOpViewClassMap[operationName] = py::none();
134     return std::nullopt;
135   }
136 }
137 
138 void PyGlobals::clearImportCache() {
139   loadedDialectModulesCache.clear();
140   rawOpViewClassMapCache.clear();
141 }
142