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
op_to_opcode(char op)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
build_from_tokens(char ** tokens,int ntokens,LLVMBuilderRef builder,LLVMValueRef param)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 LLVMTypeRef ty = LLVMInt64Type();
78 off = LLVMBuildGEP2(builder, ty, param, &stack[depth - 1], 1, "");
79 stack[depth - 1] = LLVMBuildLoad2(builder, ty, off, "");
80
81 break;
82 }
83
84 default: {
85 char *end;
86 long val = strtol(tokens[i], &end, 0);
87 if (end[0] != '\0') {
88 printf("error parsing number\n");
89 return NULL;
90 }
91
92 if (depth >= MAX_DEPTH) {
93 printf("stack overflow\n");
94 return NULL;
95 }
96
97 stack[depth++] = LLVMConstInt(LLVMInt64Type(), val, 1);
98 break;
99 }
100 }
101 }
102
103 if (depth < 1) {
104 printf("stack underflow at return\n");
105 return NULL;
106 }
107
108 LLVMBuildRet(builder, stack[depth - 1]);
109
110 return stack[depth - 1];
111 }
112
handle_line(char ** tokens,int ntokens)113 static void handle_line(char **tokens, int ntokens) {
114 char *name = tokens[0];
115 LLVMValueRef param;
116 LLVMValueRef res;
117
118 LLVMModuleRef M = LLVMModuleCreateWithName(name);
119
120 LLVMTypeRef I64ty = LLVMInt64Type();
121 LLVMTypeRef I64Ptrty = LLVMPointerType(I64ty, 0);
122 LLVMTypeRef Fty = LLVMFunctionType(I64ty, &I64Ptrty, 1, 0);
123
124 LLVMValueRef F = LLVMAddFunction(M, name, Fty);
125 LLVMBuilderRef builder = LLVMCreateBuilder();
126 LLVMPositionBuilderAtEnd(builder, LLVMAppendBasicBlock(F, "entry"));
127
128 LLVMGetParams(F, ¶m);
129 LLVMSetValueName(param, "in");
130
131 res = build_from_tokens(tokens + 1, ntokens - 1, builder, param);
132 if (res) {
133 char *irstr = LLVMPrintModuleToString(M);
134 puts(irstr);
135 LLVMDisposeMessage(irstr);
136 }
137
138 LLVMDisposeBuilder(builder);
139
140 LLVMDisposeModule(M);
141 }
142
llvm_calc(void)143 int llvm_calc(void) {
144
145 llvm_tokenize_stdin(handle_line);
146
147 return 0;
148 }
149