Stream: git-wasmtime

Topic: wasmtime / Issue #1164 C api

Wasmtime GitHub notifications bot (Jun 06 2020 at 14:13):

carlokok commented on Issue #1164:

If it's of any interest to anyone, I wrote a C api that allows this.

api: https://gist.github.com/carlokok/d0d079dba76ee253a1571d58f2e791fb

#include <cranelift.h>
#include <stdio.h>

void cb1(uintptr_t userdata, const char* err, const char* fn) {
  printf("Error %s: %s\n", fn, err);
}

void cb2(uintptr_t userdata, const char* err, const char* fn) {
  printf("Message %s: %s\n", fn, err);
}

void cb(uintptr_t userdata, FunctionData* fd)
{
  BlockCode entry = cranelift_create_block(fd);
  BlockCode larger = cranelift_create_block(fd);
  BlockCode exit = cranelift_create_block(fd);

  cranelift_append_block_params_for_function_params(fd, entry);

  cranelift_switch_to_block(fd, entry);

  ValueCode res[2];
  cranelift_block_params(fd, entry, res);

  VariableCode a = cranelift_declare_var(fd, TypeI32);
  cranelift_def_var(fd, a, res[0]);

  VariableCode b = cranelift_declare_var(fd, TypeI32);
  cranelift_def_var(fd, b, res[1]);

  VariableCode retvar = cranelift_declare_var(fd, TypeI32);
  cranelift_def_var(fd, retvar, cranelift_iconst(fd, TypeI32, 0));

  cranelift_ins_br_icmp(fd, CraneliftIntCCSignedLessThan, a, b, larger, 0, NULL);

  cranelift_def_var(fd, retvar, cranelift_use_var(fd, a));

  cranelift_ins_jump(fd, exit, 0, NULL);

  cranelift_switch_to_block(fd, larger);

  cranelift_def_var(fd, retvar, cranelift_use_var(fd, b));

  cranelift_ins_jump(fd, exit, 0, NULL);

  cranelift_switch_to_block(fd, exit);

  ValueCode retval = cranelift_use_var(fd, retvar);
  cranelift_return(fd, 1, &retval);

  cranelift_seal_all_blocks(fd);


}

void cbp(uintptr_t ud, char* data)
{
  printf("\n%s\n", data);
}

int main()
{
  ModuleData* mod = cranelift_module_new("x86_64-pc-windows", "is_pic,enable_simd,enable_atomics,enable_verifier", "mymodule", 0, cb1, cb2);

  cranelift_signature_builder_add_param(mod, TypeI32);
  cranelift_signature_builder_add_param(mod, TypeI32);
  cranelift_signature_builder_add_result(mod, TypeI32);
  cranelift_build_function(mod, 0, cb);
  cranelift_function_to_string(mod, 0, cbp);
  uint32_t id;
  cranelift_declare_function(mod, "max", Export, &id);
  cranelift_define_function(mod, id);

  uint32_t id2;
  uint8_t c[4] = { 1,2,3,4 };
  cranelift_set_data_value(mod, c, 4);
  cranelift_define_data(mod, "testdata_w", Export, Writable, 0, &id2);
  cranelift_assign_data_to_global(mod, id2);
  cranelift_clear_data(mod);

  cranelift_set_data_value(mod, c, 4);
  cranelift_define_data(mod, "testdata_r", Export, None, 0, &id2);
  cranelift_assign_data_to_global(mod, id2);
  cranelift_clear_data(mod);

  cranelift_set_data_value(mod, c, 4);
  cranelift_define_data(mod, "testdata_w2", Export, Writable, 0, &id2);
  cranelift_set_data_section(mod, "SEG", "SEC");
  cranelift_assign_data_to_global(mod, id2);
  //  cranelift_clear_data(mod);

  cranelift_module_emit_object(mod, "c:\\projects\\test.o");
  cranelift_module_delete(mod);
}

Wasmtime GitHub notifications bot (Jun 06 2020 at 14:43):

bjorn3 commented on Issue #1164:

I think cranelift_block_params should take the expected param count as argument to prevent accidental out-of-bounds memory accesses.

Wasmtime GitHub notifications bot (Jun 06 2020 at 14:44):

bjorn3 commented on Issue #1164:

It would also be nice if cranelift-codegen-meta automatically generated all cranelift_ins_* functions.

Wasmtime GitHub notifications bot (Jun 06 2020 at 14:47):

carlokok commented on Issue #1164:

agreed :) but if there's no interest or if the interfaces don't want to be tied down then I won't bother. Also this was my very first foray into Rust.

Last updated: Dec 23 2024 at 12:05 UTC