tools/llvm-c-test/calc.c

   1 /*===-- calc.c - tool for testing libLLVM and llvm-c API ------------------===*\
   2 |*                                                                            *|
   3 |* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
   4 |* Exceptions.                                                                *|
   5 |* See https://llvm.org/LICENSE.txt for license information.                  *|
   6 |* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
   7 |*                                                                            *|
   8 |*===----------------------------------------------------------------------===*|
   9 |*                                                                            *|
  10 |* This file implements the --calc command in llvm-c-test. --calc reads lines *|
  11 |* from stdin, parses them as a name and an expression in reverse polish      *|
  12 |* notation and prints a module with a function with the expression.          *|
  13 |*                                                                            *|
  14 \*===----------------------------------------------------------------------===*/
  15
  16 #include "llvm-c-test.h"
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <assert.h>
  21
  22 typedef LLVMValueRef (*binop_func_t)(LLVMBuilderRef, LLVMValueRef LHS,
  23                                      LLVMValueRef RHS, const char *Name);
  24
  25 static LLVMOpcode op_to_opcode(char op) {
  26   switch (op) {
  27   case '+': return LLVMAdd;
  28   case '-': return LLVMSub;
  29   case '*': return LLVMMul;
  30   case '/': return LLVMSDiv;
  31   case '&': return LLVMAnd;
  32   case '|': return LLVMOr;
  33   case '^': return LLVMXor;
  34   }
  35   assert(0 && "unknown operation");
  36   return 0;
  37 }
  38
  39 #define MAX_DEPTH 32
  40
  41 static LLVMValueRef build_from_tokens(char **tokens, int ntokens,
  42                                       LLVMBuilderRef builder,
  43                                       LLVMValueRef param) {
  44   LLVMValueRef stack[MAX_DEPTH];
  45   int depth = 0;
  46   int i;
  47
  48   for (i = 0; i < ntokens; i++) {
  49     char tok = tokens[i][0];
  50     switch (tok) {
  51     case '+':
  52     case '-':
  53     case '*':
  54     case '/':
  55     case '&':
  56     case '|':
  57     case '^':
  58       if (depth < 2) {
  59         printf("stack underflow\n");
  60         return NULL;
  61       }
  62
  63       stack[depth - 2] = LLVMBuildBinOp(builder, op_to_opcode(tok),
  64                                         stack[depth - 1], stack[depth - 2], "");
  65       depth--;
  66
  67       break;
  68
  69     case '@': {
  70       LLVMValueRef off;
  71
  72       if (depth < 1) {
  73         printf("stack underflow\n");
  74         return NULL;
  75       }
  76
  77       off = LLVMBuildGEP(builder, param, &stack[depth - 1], 1, "");
  78       stack[depth - 1] = LLVMBuildLoad(builder, off, "");
  79
  80       break;
  81     }
  82
  83     default: {
  84       char *end;
  85       long val = strtol(tokens[i], &end, 0);
  86       if (end[0] != '\0') {
  87         printf("error parsing number\n");
  88         return NULL;
  89       }
  90
  91       if (depth >= MAX_DEPTH) {
  92         printf("stack overflow\n");
  93         return NULL;
  94       }
  95
  96       stack[depth++] = LLVMConstInt(LLVMInt64Type(), val, 1);
  97       break;
  98     }
  99     }
 100   }
 101
 102   if (depth < 1) {
 103     printf("stack underflow at return\n");
 104     return NULL;
 105   }
 106
 107   LLVMBuildRet(builder, stack[depth - 1]);
 108
 109   return stack[depth - 1];
 110 }
 111
 112 static void handle_line(char **tokens, int ntokens) {
 113   char *name = tokens[0];
 114   LLVMValueRef param;
 115   LLVMValueRef res;
 116
 117   LLVMModuleRef M = LLVMModuleCreateWithName(name);
 118
 119   LLVMTypeRef I64ty = LLVMInt64Type();
 120   LLVMTypeRef I64Ptrty = LLVMPointerType(I64ty, 0);
 121   LLVMTypeRef Fty = LLVMFunctionType(I64ty, &I64Ptrty, 1, 0);
 122
 123   LLVMValueRef F = LLVMAddFunction(M, name, Fty);
 124   LLVMBuilderRef builder = LLVMCreateBuilder();
 125   LLVMPositionBuilderAtEnd(builder, LLVMAppendBasicBlock(F, "entry"));
 126
 127   LLVMGetParams(F, &param);
 128   LLVMSetValueName(param, "in");
 129
 130   res = build_from_tokens(tokens + 1, ntokens - 1, builder, param);
 131   if (res) {
 132     char *irstr = LLVMPrintModuleToString(M);
 133     puts(irstr);
 134     LLVMDisposeMessage(irstr);
 135   }
 136
 137   LLVMDisposeBuilder(builder);
 138
 139   LLVMDisposeModule(M);
 140 }
 141
 142 int llvm_calc(void) {
 143
 144   llvm_tokenize_stdin(handle_line);
 145
 146   return 0;
 147 }