1 | /* Example on weak aliasing as found in some GCC manual:
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2 | * http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
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3 | */
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4 | #include <stdio.h>
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5 |
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6 | /* GCC Style */
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7 | int __f ()
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8 | {
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9 | return 1;
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10 | }
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11 | int f () __attribute__ ((weak, alias ("__f")));
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12 |
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13 |
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14 | /* SUN style */
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15 | extern int WeakExternalWithLocalDefault_ResolveDefault(void);
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16 | int LocalDefault(void)
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17 | {
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18 | return 2;
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19 | }
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20 | #pragma weak WeakExternalWithLocalDefault_ResolveDefault = LocalDefault
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21 |
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22 | extern int ExternalDefault(void);
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23 | extern int WeakExternalWithExternalDefault_ResolveDefault(void);
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24 | #pragma weak WeakExternalWithExternalDefault_ResolveDefault = ExternalDefault
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25 |
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26 | /* resolve weak external (still SUN style) */
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27 | extern int WeakExternalWithLocalDefault_ResolveWKEXT(void);
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28 | #pragma weak WeakExternalWithLocalDefault_ResolveWKEXT = LocalDefault
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29 |
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30 | #if 0 /* BROKEN_GAS */
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31 | extern int WeakExternalWithExternalDefault_ResolveWKEXT(void);
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32 | #pragma weak WeakExternalWithExternalDefault_ResolveWKEXT = ExternalDefault
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33 | #endif
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34 |
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35 |
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36 | int main()
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37 | {
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38 | int rc = 0;
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39 | int i;
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40 |
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41 | i = f();
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42 | if (i != 1)
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43 | {
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44 | printf("weak3: f() returned %d expected %d\n", i, 1);
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45 | rc++;
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46 | }
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47 |
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48 | i = WeakExternalWithLocalDefault_ResolveDefault();
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49 | if (i != 2)
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50 | {
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51 | printf("weak3: WeakExternalWithLocalDefault_ResolveDefault() returned %d expected %d\n", i, 2);
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52 | rc++;
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53 | }
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54 |
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55 | i = WeakExternalWithExternalDefault_ResolveDefault();
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56 | if (i != -1)
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57 | {
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58 | printf("weak3: WeakExternalWithExternalDefault_ResolveDefault() returned %d expected %d\n", i, -1);
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59 | rc++;
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60 | }
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61 |
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62 | i = WeakExternalWithLocalDefault_ResolveWKEXT();
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63 | if (i != -2)
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64 | {
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65 | printf("weak3: WeakExternalWithLocalDefault_ResolveWKEXT() returned %d expected %d\n", i, -2);
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66 | rc++;
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67 | }
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68 |
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69 | #if 0 /* BROKEN_GAS */
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70 | i = WeakExternalWithExternalDefault_ResolveWKEXT();
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71 | if (i != -3)
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72 | {
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73 | printf("weak3: WeakExternalWithExternalDefault_ResolveWKEXT() returned %d expected %d\n", i, -3);
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74 | rc++;
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75 | }
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76 | #endif
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77 |
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78 | return rc;
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79 | }
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