microsoft/compiler: fix returning _Bool instead of pointer

When building for C23 the compiler warns about returning a boolean when
a different type is expected instead.

Change the code to return NULL instead of false, fixing the following
errors:

-----------------------------------------------------------------------
../src/microsoft/compiler/dxil_module.c: In function ‘create_call_instr’:
../src/microsoft/compiler/dxil_module.c:3311:17: error: incompatible types when returning type ‘_Bool’ but ‘struct dxil_instr *’ was expected
 3311 |          return false;
      |                 ^~~~~
../src/microsoft/compiler/dxil_module.c: In function ‘dxil_emit_load’:
../src/microsoft/compiler/dxil_module.c:3469:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 3469 |       return false;
      |              ^~~~~
../src/microsoft/compiler/dxil_module.c: In function ‘dxil_emit_cmpxchg’:
../src/microsoft/compiler/dxil_module.c:3511:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 3511 |       return false;
      |              ^~~~~
../src/microsoft/compiler/dxil_module.c: In function ‘dxil_emit_atomicrmw’:
../src/microsoft/compiler/dxil_module.c:3535:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 3535 |       return false;
      |              ^~~~~
../src/microsoft/compiler/dxil_function.c: In function ‘dxil_alloc_func_with_rettype’:
../src/microsoft/compiler/dxil_function.c:251:17: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_func *’ was expected
  251 |          return false;
      |                 ^~~~~
../src/microsoft/compiler/dxil_function.c:261:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_func *’ was expected
  261 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_atomic_binop’:
../src/microsoft/compiler/nir_to_dxil.c:959:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
  959 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_atomic_cmpxchg’:
../src/microsoft/compiler/nir_to_dxil.c:984:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
  984 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_threads’:
../src/microsoft/compiler/nir_to_dxil.c:1793:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_mdnode *’ was expected
 1793 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘call_unary_external_function’:
../src/microsoft/compiler/nir_to_dxil.c:3223:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 3223 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c:3228:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 3228 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_texture_size’:
../src/microsoft/compiler/nir_to_dxil.c:4305:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 4305 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_sample_grad’:
../src/microsoft/compiler/nir_to_dxil.c:5350:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 5350 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_sample_cmp_grad’:
../src/microsoft/compiler/nir_to_dxil.c:5370:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 5370 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_texel_fetch’:
../src/microsoft/compiler/nir_to_dxil.c:5393:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 5393 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_texture_lod’:
../src/microsoft/compiler/nir_to_dxil.c:5413:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 5413 |       return false;
      |              ^~~~~
../src/microsoft/compiler/nir_to_dxil.c: In function ‘emit_texture_gather’:
../src/microsoft/compiler/nir_to_dxil.c:5434:14: error: incompatible types when returning type ‘_Bool’ but ‘const struct dxil_value *’ was expected
 5434 |       return false;
      |              ^~~~~
-----------------------------------------------------------------------

Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36323>

src/microsoft/compiler/dxil_function.c

@@ -248,7 +248,7 @@ dxil_alloc_func_with_rettype(struct dxil_module *mod, const char *name,
    while (param_descr[num_params]) {
       const struct dxil_type *t = get_type_from_string(mod, param_descr, overload, &index);
       if (!t)
-         return false;
+         return NULL;
       assert(num_params < MAX_FUNC_PARAMS);
       arg_types[num_params++] = t;
    }
@@ -258,7 +258,7 @@ dxil_alloc_func_with_rettype(struct dxil_module *mod, const char *name,
                                     arg_types, num_params);
    if (!func_type) {
       fprintf(stderr, "%s: Func type allocation failed\n", __func__);
-      return false;
+      return NULL;
    }
 
    char full_name[100];

src/microsoft/compiler/dxil_module.c

@@ -3308,7 +3308,7 @@ create_call_instr(struct dxil_module *m,
       instr->call.func = func;
       instr->call.args = ralloc_array(instr, struct dxil_value *, num_args);
       if (!args)
-         return false;
+         return NULL;
       memcpy(instr->call.args, args, sizeof(struct dxil_value *) * num_args);
       instr->call.num_args = num_args;
    }
@@ -3466,7 +3466,7 @@ dxil_emit_load(struct dxil_module *m, const struct dxil_value *ptr,
 
    struct dxil_instr *instr = create_instr(m, INSTR_LOAD, type);
    if (!instr)
-      return false;
+      return NULL;
 
    instr->load.ptr = ptr;
    instr->load.type = type;
@@ -3508,7 +3508,7 @@ dxil_emit_cmpxchg(struct dxil_module *m, const struct dxil_value *cmpval,
    struct dxil_instr *instr = create_instr(m, INSTR_CMPXCHG,
                                            ptr->type->ptr_target_type);
    if (!instr)
-      return false;
+      return NULL;
 
    instr->cmpxchg.cmpval = cmpval;
    instr->cmpxchg.newval = newval;
@@ -3532,7 +3532,7 @@ dxil_emit_atomicrmw(struct dxil_module *m, const struct dxil_value *value,
    struct dxil_instr *instr = create_instr(m, INSTR_ATOMICRMW,
                                            ptr->type->ptr_target_type);
    if (!instr)
-      return false;
+      return NULL;
 
    instr->atomicrmw.value = value;
    instr->atomicrmw.ptr = ptr;

src/microsoft/compiler/nir_to_dxil.c

@@ -956,7 +956,7 @@ emit_atomic_binop(struct ntd_context *ctx,
    const struct dxil_func *func = dxil_get_function(&ctx->mod, "dx.op.atomicBinOp", DXIL_I32);
 
    if (!func)
-      return false;
+      return NULL;
 
    const struct dxil_value *opcode =
       dxil_module_get_int32_const(&ctx->mod, DXIL_INTR_ATOMIC_BINOP);
@@ -981,7 +981,7 @@ emit_atomic_cmpxchg(struct ntd_context *ctx,
       dxil_get_function(&ctx->mod, "dx.op.atomicCompareExchange", DXIL_I32);
 
    if (!func)
-      return false;
+      return NULL;
 
    const struct dxil_value *opcode =
       dxil_module_get_int32_const(&ctx->mod, DXIL_INTR_ATOMIC_CMPXCHG);
@@ -1790,7 +1790,7 @@ emit_threads(struct ntd_context *ctx)
    const struct dxil_mdnode *threads_y = dxil_get_metadata_int32(&ctx->mod, MAX2(s->info.workgroup_size[1], 1));
    const struct dxil_mdnode *threads_z = dxil_get_metadata_int32(&ctx->mod, MAX2(s->info.workgroup_size[2], 1));
    if (!threads_x || !threads_y || !threads_z)
-      return false;
+      return NULL;
 
    const struct dxil_mdnode *threads_nodes[] = { threads_x, threads_y, threads_z };
    return dxil_get_metadata_node(&ctx->mod, threads_nodes, ARRAY_SIZE(threads_nodes));
@@ -3220,12 +3220,12 @@ call_unary_external_function(struct ntd_context *ctx,
    const struct dxil_func *func =
       dxil_get_function(&ctx->mod, name, overload);
    if (!func)
-      return false;
+      return NULL;
 
    const struct dxil_value *opcode =
       dxil_module_get_int32_const(&ctx->mod, dxil_intr);
    if (!opcode)
-      return false;
+      return NULL;
 
    const struct dxil_value *args[] = {opcode};
 
@@ -4302,7 +4302,7 @@ emit_texture_size(struct ntd_context *ctx, struct texop_parameters *params)
 {
    const struct dxil_func *func = dxil_get_function(&ctx->mod, "dx.op.getDimensions", DXIL_NONE);
    if (!func)
-      return false;
+      return NULL;
 
    const struct dxil_value *args[] = {
       dxil_module_get_int32_const(&ctx->mod, DXIL_INTR_TEXTURE_SIZE),
@@ -5347,7 +5347,7 @@ emit_sample_grad(struct ntd_context *ctx, struct texop_parameters *params)
 {
    const struct dxil_func *func = dxil_get_function(&ctx->mod, "dx.op.sampleGrad", params->overload);
    if (!func)
-      return false;
+      return NULL;
 
    const struct dxil_value *args[17] = {
       dxil_module_get_int32_const(&ctx->mod, DXIL_INTR_SAMPLE_GRAD),
@@ -5367,7 +5367,7 @@ emit_sample_cmp_grad(struct ntd_context *ctx, struct texop_parameters *params)
 {
    const struct dxil_func *func = dxil_get_function(&ctx->mod, "dx.op.sampleCmpGrad", params->overload);
    if (!func)
-      return false;
+      return NULL;
    
    ctx->mod.feats.sample_cmp_bias_gradient = 1;
 
@@ -5390,7 +5390,7 @@ emit_texel_fetch(struct ntd_context *ctx, struct texop_parameters *params)
 {
    const struct dxil_func *func = dxil_get_function(&ctx->mod, "dx.op.textureLoad", params->overload);
    if (!func)
-      return false;
+      return NULL;
 
    if (!params->lod_or_sample)
       params->lod_or_sample = dxil_module_get_undef(&ctx->mod, dxil_module_get_int_type(&ctx->mod, 32));
@@ -5410,7 +5410,7 @@ emit_texture_lod(struct ntd_context *ctx, struct texop_parameters *params, bool
 {
    const struct dxil_func *func = dxil_get_function(&ctx->mod, "dx.op.calculateLOD", DXIL_F32);
    if (!func)
-      return false;
+      return NULL;
 
    const struct dxil_value *args[] = {
       dxil_module_get_int32_const(&ctx->mod, DXIL_INTR_TEXTURE_LOD),
@@ -5431,7 +5431,7 @@ emit_texture_gather(struct ntd_context *ctx, struct texop_parameters *params, un
    const struct dxil_func *func = dxil_get_function(&ctx->mod,
       params->cmp ? "dx.op.textureGatherCmp" : "dx.op.textureGather", params->overload);
    if (!func)
-      return false;
+      return NULL;
 
    const struct dxil_value *args[] = {
       dxil_module_get_int32_const(&ctx->mod, params->cmp ?