1 //===-------- BasicOrcV2CBindings.c - Basic OrcV2 C Bindings Demo ---------===//
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 "llvm-c/Core.h"
10 #include "llvm-c/Error.h"
11 #include "llvm-c/Initialization.h"
12 #include "llvm-c/LLJIT.h"
13 #include "llvm-c/Support.h"
14 #include "llvm-c/Target.h"
15
16 #include <assert.h>
17 #include <stdio.h>
18
handleError(LLVMErrorRef Err)19 int handleError(LLVMErrorRef Err) {
20 char *ErrMsg = LLVMGetErrorMessage(Err);
21 fprintf(stderr, "Error: %s\n", ErrMsg);
22 LLVMDisposeErrorMessage(ErrMsg);
23 return 1;
24 }
25
add(int32_t X,int32_t Y)26 int32_t add(int32_t X, int32_t Y) { return X + Y; }
27
mul(int32_t X,int32_t Y)28 int32_t mul(int32_t X, int32_t Y) { return X * Y; }
29
allowedSymbols(void * Ctx,LLVMOrcSymbolStringPoolEntryRef Sym)30 int allowedSymbols(void *Ctx, LLVMOrcSymbolStringPoolEntryRef Sym) {
31 assert(Ctx && "Cannot call allowedSymbols with a null context");
32
33 LLVMOrcSymbolStringPoolEntryRef *AllowList =
34 (LLVMOrcSymbolStringPoolEntryRef *)Ctx;
35
36 // If Sym appears in the allowed list then return true.
37 LLVMOrcSymbolStringPoolEntryRef *P = AllowList;
38 while (*P) {
39 if (Sym == *P)
40 return 1;
41 ++P;
42 }
43
44 // otherwise return false.
45 return 0;
46 }
47
createDemoModule(void)48 LLVMOrcThreadSafeModuleRef createDemoModule(void) {
49 // Create a new ThreadSafeContext and underlying LLVMContext.
50 LLVMOrcThreadSafeContextRef TSCtx = LLVMOrcCreateNewThreadSafeContext();
51
52 // Get a reference to the underlying LLVMContext.
53 LLVMContextRef Ctx = LLVMOrcThreadSafeContextGetContext(TSCtx);
54
55 // Create a new LLVM module.
56 LLVMModuleRef M = LLVMModuleCreateWithNameInContext("demo", Ctx);
57
58 // Add a "sum" function":
59 // - Create the function type and function instance.
60 LLVMTypeRef I32BinOpParamTypes[] = {LLVMInt32Type(), LLVMInt32Type()};
61 LLVMTypeRef I32BinOpFunctionType =
62 LLVMFunctionType(LLVMInt32Type(), I32BinOpParamTypes, 2, 0);
63 LLVMValueRef AddI32Function = LLVMAddFunction(M, "add", I32BinOpFunctionType);
64 LLVMValueRef MulI32Function = LLVMAddFunction(M, "mul", I32BinOpFunctionType);
65
66 LLVMTypeRef MulAddParamTypes[] = {LLVMInt32Type(), LLVMInt32Type(),
67 LLVMInt32Type()};
68 LLVMTypeRef MulAddFunctionType =
69 LLVMFunctionType(LLVMInt32Type(), MulAddParamTypes, 3, 0);
70 LLVMValueRef MulAddFunction =
71 LLVMAddFunction(M, "mul_add", MulAddFunctionType);
72
73 // - Add a basic block to the function.
74 LLVMBasicBlockRef EntryBB = LLVMAppendBasicBlock(MulAddFunction, "entry");
75
76 // - Add an IR builder and point it at the end of the basic block.
77 LLVMBuilderRef Builder = LLVMCreateBuilder();
78 LLVMPositionBuilderAtEnd(Builder, EntryBB);
79
80 // - Get the three function arguments and use them co construct calls to
81 // 'mul' and 'add':
82 //
83 // i32 mul_add(i32 %0, i32 %1, i32 %2) {
84 // %t = call i32 @mul(i32 %0, i32 %1)
85 // %r = call i32 @add(i32 %t, i32 %2)
86 // ret i32 %r
87 // }
88 LLVMValueRef SumArg0 = LLVMGetParam(MulAddFunction, 0);
89 LLVMValueRef SumArg1 = LLVMGetParam(MulAddFunction, 1);
90 LLVMValueRef SumArg2 = LLVMGetParam(MulAddFunction, 2);
91
92 LLVMValueRef MulArgs[] = {SumArg0, SumArg1};
93 LLVMValueRef MulResult = LLVMBuildCall2(Builder, I32BinOpFunctionType,
94 MulI32Function, MulArgs, 2, "t");
95
96 LLVMValueRef AddArgs[] = {MulResult, SumArg2};
97 LLVMValueRef AddResult = LLVMBuildCall2(Builder, I32BinOpFunctionType,
98 AddI32Function, AddArgs, 2, "r");
99
100 // - Build the return instruction.
101 LLVMBuildRet(Builder, AddResult);
102
103 // - Free the builder.
104 LLVMDisposeBuilder(Builder);
105
106 // Our demo module is now complete. Wrap it and our ThreadSafeContext in a
107 // ThreadSafeModule.
108 LLVMOrcThreadSafeModuleRef TSM = LLVMOrcCreateNewThreadSafeModule(M, TSCtx);
109
110 // Dispose of our local ThreadSafeContext value. The underlying LLVMContext
111 // will be kept alive by our ThreadSafeModule, TSM.
112 LLVMOrcDisposeThreadSafeContext(TSCtx);
113
114 // Return the result.
115 return TSM;
116 }
117
main(int argc,char * argv[])118 int main(int argc, char *argv[]) {
119
120 int MainResult = 0;
121
122 // Parse command line arguments and initialize LLVM Core.
123 LLVMParseCommandLineOptions(argc, (const char **)argv, "");
124 LLVMInitializeCore(LLVMGetGlobalPassRegistry());
125
126 // Initialize native target codegen and asm printer.
127 LLVMInitializeNativeTarget();
128 LLVMInitializeNativeAsmPrinter();
129
130 // Create the JIT instance.
131 LLVMOrcLLJITRef J;
132 {
133 LLVMErrorRef Err;
134 if ((Err = LLVMOrcCreateLLJIT(&J, 0))) {
135 MainResult = handleError(Err);
136 goto llvm_shutdown;
137 }
138 }
139
140 // Build a filter to allow JIT'd code to only access allowed symbols.
141 // This filter is optional: If a null value is suppled for the Filter
142 // argument to LLVMOrcCreateDynamicLibrarySearchGeneratorForProcess then
143 // all process symbols will be reflected.
144 LLVMOrcSymbolStringPoolEntryRef AllowList[] = {
145 LLVMOrcLLJITMangleAndIntern(J, "mul"),
146 LLVMOrcLLJITMangleAndIntern(J, "add"), 0};
147
148 {
149 LLVMOrcDefinitionGeneratorRef ProcessSymbolsGenerator = 0;
150 LLVMErrorRef Err;
151 if ((Err = LLVMOrcCreateDynamicLibrarySearchGeneratorForProcess(
152 &ProcessSymbolsGenerator, LLVMOrcLLJITGetGlobalPrefix(J),
153 allowedSymbols, AllowList))) {
154 MainResult = handleError(Err);
155 goto jit_cleanup;
156 }
157
158 LLVMOrcJITDylibAddGenerator(LLVMOrcLLJITGetMainJITDylib(J),
159 ProcessSymbolsGenerator);
160 }
161
162 // Create our demo module.
163 LLVMOrcThreadSafeModuleRef TSM = createDemoModule();
164
165 // Add our demo module to the JIT.
166 {
167 LLVMOrcJITDylibRef MainJD = LLVMOrcLLJITGetMainJITDylib(J);
168 LLVMErrorRef Err;
169 if ((Err = LLVMOrcLLJITAddLLVMIRModule(J, MainJD, TSM))) {
170 // If adding the ThreadSafeModule fails then we need to clean it up
171 // ourselves. If adding it succeeds the JIT will manage the memory.
172 LLVMOrcDisposeThreadSafeModule(TSM);
173 MainResult = handleError(Err);
174 goto jit_cleanup;
175 }
176 }
177
178 // Look up the address of our demo entry point.
179 LLVMOrcJITTargetAddress MulAddAddr;
180 {
181 LLVMErrorRef Err;
182 if ((Err = LLVMOrcLLJITLookup(J, &MulAddAddr, "mul_add"))) {
183 MainResult = handleError(Err);
184 goto jit_cleanup;
185 }
186 }
187
188 // If we made it here then everything succeeded. Execute our JIT'd code.
189 int32_t (*MulAdd)(int32_t, int32_t, int32_t) =
190 (int32_t(*)(int32_t, int32_t, int32_t))MulAddAddr;
191 int32_t Result = MulAdd(3, 4, 5);
192
193 // Print the result.
194 printf("3 * 4 + 5 = %i\n", Result);
195
196 jit_cleanup:
197 // Release all symbol string pool entries that we have allocated. In this
198 // example that's just our allowed entries.
199 {
200 LLVMOrcSymbolStringPoolEntryRef *P = AllowList;
201 while (*P)
202 LLVMOrcReleaseSymbolStringPoolEntry(*P++);
203 }
204
205 // Destroy our JIT instance. This will clean up any memory that the JIT has
206 // taken ownership of. This operation is non-trivial (e.g. it may need to
207 // JIT static destructors) and may also fail. In that case we want to render
208 // the error to stderr, but not overwrite any existing return value.
209 {
210 LLVMErrorRef Err;
211 if ((Err = LLVMOrcDisposeLLJIT(J))) {
212 int NewFailureResult = handleError(Err);
213 if (MainResult == 0)
214 MainResult = NewFailureResult;
215 }
216 }
217
218 llvm_shutdown:
219 // Shut down LLVM.
220 LLVMShutdown();
221
222 return MainResult;
223 }
224