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111
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1 /* The goal here is to ensure that we never consider a call to a noreturn
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2 function as a potential tail call.
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3
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4 Right now GCC discovers potential tail calls by looking at the
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5 predecessors of the exit block. A call to a non-return function
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6 has no successors and thus can never match that first filter.
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7
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8 But that could change one day and we want to catch it. The problem
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9 is the compiler could potentially optimize a tail call to a nonreturn
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10 function, even if the caller has a frame. That breaks the assumption
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11 that calls probe *sp when saving the return address that some targets
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12 depend on to elide stack probes. */
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13
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14 /* { dg-do compile } */
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15 /* { dg-options "-O2 -fstack-clash-protection -fdump-tree-tailc -fdump-tree-optimized" } */
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16 /* { dg-require-effective-target supports_stack_clash_protection } */
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17
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18 extern void foo (void) __attribute__ ((__noreturn__));
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19
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20
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21 void
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22 test_direct_1 (void)
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23 {
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24 foo ();
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25 }
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26
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27 void
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28 test_direct_2 (void)
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29 {
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30 return foo ();
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31 }
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32
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33 void (*indirect)(void)__attribute__ ((noreturn));
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34
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35
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36 void
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37 test_indirect_1 ()
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38 {
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39 (*indirect)();
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40 }
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41
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42 void
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43 test_indirect_2 (void)
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44 {
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45 return (*indirect)();;
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46 }
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47
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48
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49 typedef void (*pvfn)() __attribute__ ((noreturn));
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50
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51 void (*indirect_casted)(void);
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52
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53 void
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54 test_indirect_casted_1 ()
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55 {
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56 (*(pvfn)indirect_casted)();
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57 }
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58
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59 void
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60 test_indirect_casted_2 (void)
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61 {
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62 return (*(pvfn)indirect_casted)();
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63 }
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64 /* { dg-final { scan-tree-dump-not "tail call" "tailc" } } */
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65 /* { dg-final { scan-tree-dump-not "tail call" "optimized" } } */
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66
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