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 #include "llvm-c/TargetMachine.h"
16
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
createDemoModule(LLVMContextRef Ctx)26 LLVMModuleRef createDemoModule(LLVMContextRef Ctx) {
27 // Create a new LLVM module.
28 LLVMModuleRef M = LLVMModuleCreateWithNameInContext("demo", Ctx);
29
30 // Add a "sum" function":
31 // - Create the function type and function instance.
32 LLVMTypeRef ParamTypes[] = {LLVMInt32Type(), LLVMInt32Type()};
33 LLVMTypeRef SumFunctionType =
34 LLVMFunctionType(LLVMInt32Type(), ParamTypes, 2, 0);
35 LLVMValueRef SumFunction = LLVMAddFunction(M, "sum", SumFunctionType);
36
37 // - Add a basic block to the function.
38 LLVMBasicBlockRef EntryBB = LLVMAppendBasicBlock(SumFunction, "entry");
39
40 // - Add an IR builder and point it at the end of the basic block.
41 LLVMBuilderRef Builder = LLVMCreateBuilder();
42 LLVMPositionBuilderAtEnd(Builder, EntryBB);
43
44 // - Get the two function arguments and use them co construct an "add"
45 // instruction.
46 LLVMValueRef SumArg0 = LLVMGetParam(SumFunction, 0);
47 LLVMValueRef SumArg1 = LLVMGetParam(SumFunction, 1);
48 LLVMValueRef Result = LLVMBuildAdd(Builder, SumArg0, SumArg1, "result");
49
50 // - Build the return instruction.
51 LLVMBuildRet(Builder, Result);
52
53 // - Free the builder.
54 LLVMDisposeBuilder(Builder);
55
56 return M;
57 }
58
main(int argc,char * argv[])59 int main(int argc, char *argv[]) {
60
61 int MainResult = 0;
62
63 // Parse command line arguments and initialize LLVM Core.
64 LLVMParseCommandLineOptions(argc, (const char **)argv, "");
65 LLVMInitializeCore(LLVMGetGlobalPassRegistry());
66
67 // Initialize native target codegen and asm printer.
68 LLVMInitializeNativeTarget();
69 LLVMInitializeNativeAsmPrinter();
70
71 // Create the JIT instance.
72 LLVMOrcLLJITRef J;
73 {
74 LLVMErrorRef Err;
75 if ((Err = LLVMOrcCreateLLJIT(&J, 0))) {
76 MainResult = handleError(Err);
77 goto llvm_shutdown;
78 }
79 }
80
81 // Create our demo object file.
82 LLVMMemoryBufferRef ObjectFileBuffer;
83 {
84 // Create a module.
85 LLVMContextRef Ctx = LLVMContextCreate();
86 LLVMModuleRef M = createDemoModule(Ctx);
87
88 // Get the Target.
89 const char *Triple = LLVMOrcLLJITGetTripleString(J);
90 LLVMTargetRef Target = 0;
91 char *ErrorMsg = 0;
92 if (LLVMGetTargetFromTriple(Triple, &Target, &ErrorMsg)) {
93 fprintf(stderr, "Error getting target for %s: %s\n", Triple, ErrorMsg);
94 LLVMDisposeModule(M);
95 LLVMContextDispose(Ctx);
96 goto jit_cleanup;
97 }
98
99 // Construct a TargetMachine.
100 LLVMTargetMachineRef TM =
101 LLVMCreateTargetMachine(Target, Triple, "", "", LLVMCodeGenLevelNone,
102 LLVMRelocDefault, LLVMCodeModelDefault);
103
104 // Run CodeGen to produce the buffer.
105 if (LLVMTargetMachineEmitToMemoryBuffer(TM, M, LLVMObjectFile, &ErrorMsg,
106 &ObjectFileBuffer)) {
107 fprintf(stderr, "Error emitting object: %s\n", ErrorMsg);
108 LLVMDisposeTargetMachine(TM);
109 LLVMDisposeModule(M);
110 LLVMContextDispose(Ctx);
111 goto jit_cleanup;
112 }
113
114 // CodeGen succeeded -- We have our module, so free the Module, LLVMContext,
115 // and TargetMachine.
116 LLVMDisposeModule(M);
117 LLVMContextDispose(Ctx);
118 LLVMDisposeTargetMachine(TM);
119 }
120
121 // Add our object file buffer to the JIT.
122 {
123 LLVMOrcJITDylibRef MainJD = LLVMOrcLLJITGetMainJITDylib(J);
124 LLVMErrorRef Err;
125 if ((Err = LLVMOrcLLJITAddObjectFile(J, MainJD, ObjectFileBuffer))) {
126 MainResult = handleError(Err);
127 goto jit_cleanup;
128 }
129 }
130
131 // Look up the address of our demo entry point.
132 LLVMOrcJITTargetAddress SumAddr;
133 {
134 LLVMErrorRef Err;
135 if ((Err = LLVMOrcLLJITLookup(J, &SumAddr, "sum"))) {
136 MainResult = handleError(Err);
137 goto jit_cleanup;
138 }
139 }
140
141 // If we made it here then everything succeeded. Execute our JIT'd code.
142 int32_t (*Sum)(int32_t, int32_t) = (int32_t(*)(int32_t, int32_t))SumAddr;
143 int32_t Result = Sum(1, 2);
144
145 // Print the result.
146 printf("1 + 2 = %i\n", Result);
147
148 jit_cleanup:
149 // Destroy our JIT instance. This will clean up any memory that the JIT has
150 // taken ownership of. This operation is non-trivial (e.g. it may need to
151 // JIT static destructors) and may also fail. In that case we want to render
152 // the error to stderr, but not overwrite any existing return value.
153 {
154 LLVMErrorRef Err;
155 if ((Err = LLVMOrcDisposeLLJIT(J))) {
156 int NewFailureResult = handleError(Err);
157 if (MainResult == 0)
158 MainResult = NewFailureResult;
159 }
160 }
161
162 llvm_shutdown:
163 // Shut down LLVM.
164 LLVMShutdown();
165
166 return MainResult;
167 }
168