1b57560502
A more automatic approach to code suppression (aka. nocode_wanted) The simple rules are: - Clear 'nocode_wanted' at (im/explicit) label IF it was used - Set 'nocode_wanted' after unconditional jumps Also in order to test this then I did add the "function might return no value" warning, and then to make that work again I did add the __attribute__((noreturn)). Also moved the look ahead label check into the type parser to gain a little speed.
58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
/* This checks if enums needing 8 bit but only having positive
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values are correctly zero extended (instead of sign extended)
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when stored into/loaded from a 8 bit bit-field of enum type (which
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itself is implementation defined, so isn't necessarily supported by all
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other compilers). */
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enum tree_code {
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SOME_CODE = 148, /* has bit 7 set, and hence all further enum values as well */
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LAST_AND_UNUSED_TREE_CODE
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};
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typedef union tree_node *tree;
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struct tree_common
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{
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union tree_node *chain;
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union tree_node *type;
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enum tree_code code : 8;
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unsigned side_effects_flag : 1;
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};
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union tree_node
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{
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struct tree_common common;
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};
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enum c_tree_code {
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C_DUMMY_TREE_CODE = LAST_AND_UNUSED_TREE_CODE,
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STMT_EXPR,
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LAST_C_TREE_CODE
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};
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enum cplus_tree_code {
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CP_DUMMY_TREE_CODE = LAST_C_TREE_CODE,
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AMBIG_CONV,
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LAST_CPLUS_TREE_CODE
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};
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extern int printf(const char *, ...);
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int blah(){return 0;}
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int convert_like_real (tree convs)
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{
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switch (((enum tree_code) (convs)->common.code))
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{
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case AMBIG_CONV: /* This has bit 7 set, which must not be the sign
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bit in tree_common.code, i.e. the bitfield must
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be somehow marked unsigned. */
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return blah();
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default:
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break;
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};
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printf("unsigned enum bit-fields broken\n");
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return 0;
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}
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int main()
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{
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union tree_node convs;
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convs.common.code = AMBIG_CONV;
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convert_like_real (&convs);
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return 0;
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}
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