llvm/examples/OrcV2Examples/OrcV2CBindingsReflectProcessSymbols/OrcV2CBindingsReflectProcessSymbols.c

   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
  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
  26 int32_t add(int32_t X, int32_t Y) { return X + Y; }
  27
  28 int32_t mul(int32_t X, int32_t Y) { return X * Y; }
  29
  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
  48 LLVMOrcThreadSafeModuleRef createDemoModule() {
  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   // Our demo module is now complete. Wrap it and our ThreadSafeContext in a
 104   // ThreadSafeModule.
 105   LLVMOrcThreadSafeModuleRef TSM = LLVMOrcCreateNewThreadSafeModule(M, TSCtx);
 106
 107   // Dispose of our local ThreadSafeContext value. The underlying LLVMContext
 108   // will be kept alive by our ThreadSafeModule, TSM.
 109   LLVMOrcDisposeThreadSafeContext(TSCtx);
 110
 111   // Return the result.
 112   return TSM;
 113 }
 114
 115 int main(int argc, char *argv[]) {
 116
 117   int MainResult = 0;
 118
 119   // Parse command line arguments and initialize LLVM Core.
 120   LLVMParseCommandLineOptions(argc, (const char **)argv, "");
 121   LLVMInitializeCore(LLVMGetGlobalPassRegistry());
 122
 123   // Initialize native target codegen and asm printer.
 124   LLVMInitializeNativeTarget();
 125   LLVMInitializeNativeAsmPrinter();
 126
 127   // Create the JIT instance.
 128   LLVMOrcLLJITRef J;
 129   {
 130     LLVMErrorRef Err;
 131     if ((Err = LLVMOrcCreateLLJIT(&J, 0))) {
 132       MainResult = handleError(Err);
 133       goto llvm_shutdown;
 134     }
 135   }
 136
 137   // Build a filter to allow JIT'd code to only access allowed symbols.
 138   // This filter is optional: If a null value is suppled for the Filter
 139   // argument to LLVMOrcCreateDynamicLibrarySearchGeneratorForProcess then
 140   // all process symbols will be reflected.
 141   LLVMOrcSymbolStringPoolEntryRef AllowList[] = {
 142       LLVMOrcLLJITMangleAndIntern(J, "mul"),
 143       LLVMOrcLLJITMangleAndIntern(J, "add"), 0};
 144
 145   {
 146     LLVMOrcDefinitionGeneratorRef ProcessSymbolsGenerator = 0;
 147     LLVMErrorRef Err;
 148     if ((Err = LLVMOrcCreateDynamicLibrarySearchGeneratorForProcess(
 149              &ProcessSymbolsGenerator, LLVMOrcLLJITGetGlobalPrefix(J),
 150              allowedSymbols, AllowList))) {
 151       MainResult = handleError(Err);
 152       goto jit_cleanup;
 153     }
 154
 155     LLVMOrcJITDylibAddGenerator(LLVMOrcLLJITGetMainJITDylib(J),
 156                                 ProcessSymbolsGenerator);
 157   }
 158
 159   // Create our demo module.
 160   LLVMOrcThreadSafeModuleRef TSM = createDemoModule();
 161
 162   // Add our demo module to the JIT.
 163   {
 164     LLVMOrcJITDylibRef MainJD = LLVMOrcLLJITGetMainJITDylib(J);
 165     LLVMErrorRef Err;
 166     if ((Err = LLVMOrcLLJITAddLLVMIRModule(J, MainJD, TSM))) {
 167       // If adding the ThreadSafeModule fails then we need to clean it up
 168       // ourselves. If adding it succeeds the JIT will manage the memory.
 169       LLVMOrcDisposeThreadSafeModule(TSM);
 170       MainResult = handleError(Err);
 171       goto jit_cleanup;
 172     }
 173   }
 174
 175   // Look up the address of our demo entry point.
 176   LLVMOrcJITTargetAddress MulAddAddr;
 177   {
 178     LLVMErrorRef Err;
 179     if ((Err = LLVMOrcLLJITLookup(J, &MulAddAddr, "mul_add"))) {
 180       MainResult = handleError(Err);
 181       goto jit_cleanup;
 182     }
 183   }
 184
 185   // If we made it here then everything succeeded. Execute our JIT'd code.
 186   int32_t (*MulAdd)(int32_t, int32_t, int32_t) =
 187       (int32_t(*)(int32_t, int32_t, int32_t))MulAddAddr;
 188   int32_t Result = MulAdd(3, 4, 5);
 189
 190   // Print the result.
 191   printf("3 * 4 + 5 = %i\n", Result);
 192
 193 jit_cleanup:
 194   // Release all symbol string pool entries that we have allocated. In this
 195   // example that's just our allowed entries.
 196   {
 197     LLVMOrcSymbolStringPoolEntryRef *P = AllowList;
 198     while (*P)
 199       LLVMOrcReleaseSymbolStringPoolEntry(*P++);
 200   }
 201
 202   // Destroy our JIT instance. This will clean up any memory that the JIT has
 203   // taken ownership of. This operation is non-trivial (e.g. it may need to
 204   // JIT static destructors) and may also fail. In that case we want to render
 205   // the error to stderr, but not overwrite any existing return value.
 206   {
 207     LLVMErrorRef Err;
 208     if ((Err = LLVMOrcDisposeLLJIT(J))) {
 209       int NewFailureResult = handleError(Err);
 210       if (MainResult == 0)
 211         MainResult = NewFailureResult;
 212     }
 213   }
 214
 215 llvm_shutdown:
 216   // Shut down LLVM.
 217   LLVMShutdown();
 218
 219   return MainResult;
 220 }