Allow modulus in constant expressions

Not sure if this was intentional, but I noticed `eval2(...)` will compile-time evaluate a modulus but `is_const_expr(...)` won't. This causes chibicc to try and compile some arrays as VLAs, which was causing problems for me. This change adds `ND_MOD` to the list of allowed constant expressions.

It's possible I'm missing something, but https://en.cppreference.com/w/c/language/constant_expression seems to imply that all numeric operators (including modulus) should be OK in constant expressions. And `ND_DIV` is already allowed in the function so it seems `ND_MOD` should be as well.

This commit is contained in:

Matthew Sotoudeh

2023-07-20 15:00:48 -07:00

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GitHub

parent 90d1f7f199

commit afd9b066b7

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1 changed files with 1 additions and 0 deletions

									
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parse.c

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				@ -1954,6 +1954,7 @@ static bool is_const_expr(Node *node) {

				  case ND_SUB:

				  case ND_MUL:

				  case ND_DIV:

				  case ND_MOD:

				  case ND_BITAND:

				  case ND_BITOR:

				  case ND_BITXOR:

Allow modulus in constant expressions

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