| Summary: | Pointer arithmetic in libgccjit seems to require an extra cast | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Roger Ferrer Ibanez <rofirrim> |
| Component: | jit | Assignee: | David Malcolm <dmalcolm> |
| Status: | UNCONFIRMED --- | ||
| Severity: | normal | ||
| Priority: | P3 | ||
| Version: | 5.2.0 | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Known to work: | ||
| Known to fail: | Last reconfirmed: | ||
| Attachments: | Small reproducer | ||
// text++; Can't this be computed as: text = text POINTER_PLUS 1; ? Thanks for reporting this. That error message: libgccjit.so: error: gcc_jit_block_add_assignment: mismatching types: assignment to text (type: const char *) from &text[(int)1] (type: const char *) looks wrong. Please can you attach the full reproducer as a .c file (perhaps using gcc_jit_context_dump_reproducer_to_file; see https://gcc.gnu.org/onlinedocs/jit/topics/contexts.html#gcc_jit_context_dump_reproducer_to_file ). Created attachment 36729 [details]
Small reproducer
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Hi, maybe I'm doing something wrong, but libgccjit rejects an assignment of pointer arithmetic where the types (according to the diagnostic) are OK. This is not a blocker as it can be worked around using an explicit cast. I am using GCC 5.2.0. I have a function "int test(const char* text)" with a single block. gcc_jit_type *int_type = gcc_jit_context_get_type (ctx, GCC_JIT_TYPE_INT); gcc_jit_type *const_char_ptr_type = gcc_jit_context_get_type (ctx, GCC_JIT_TYPE_CONST_CHAR_PTR); // param: const char* text; gcc_jit_param *param_text = gcc_jit_context_new_param (ctx, /* loc */ NULL, const_char_ptr_type, "text"); gcc_jit_rvalue *rval_text = gcc_jit_param_as_rvalue (param_text); // int test(const char* text); gcc_jit_param *params[] = { param_text }; gcc_jit_function *test_fun = gcc_jit_context_new_function (ctx, /* loc */ NULL, GCC_JIT_FUNCTION_EXPORTED, int_type, "test", 1, params, /* is_variadic */ 0); gcc_jit_block *block = gcc_jit_function_new_block (test_fun, "test-block"); and then I want to compute text++; According to the documentation this has to be done like this. text = &text[1]; But if I write // text = &text[1]; // does not work gcc_jit_block_add_assignment (block, /* loc */ NULL, gcc_jit_param_as_lvalue (param_text), gcc_jit_lvalue_get_address( gcc_jit_context_new_array_access(ctx, /* loc */ NULL, rval_text, gcc_jit_context_one (ctx, int_type)), /* loc */ NULL)); libgccjit rejects it with libgccjit.so: error: gcc_jit_block_add_assignment: mismatching types: assignment to text (type: const char *) from &text[(int)1] (type: const char *) This can be worked around using a cast: gcc_jit_block_add_assignment (block, /* loc */ NULL, gcc_jit_param_as_lvalue (param_text), gcc_jit_context_new_cast (ctx, /* loc */ NULL, gcc_jit_lvalue_get_address( gcc_jit_context_new_array_access(ctx, /* loc */ NULL, rval_text, gcc_jit_context_one (ctx, int_type)), /* loc */ NULL), const_char_type)); Kind regards,