Fix bpf_pseudo_fd() type conversion error

With llvm15 and llvm16, the following command line
  sudo ./trace.py 'smp_call_function_single "%K", arg1'
will cause error:
  /virtual/main.c:60:36: error: incompatible integer to pointer conversion passing 'u64'
    (aka 'unsigned long long') to parameter of type 'void *' [-Wint-conversion]
        bpf_perf_event_output(ctx, bpf_pseudo_fd(1, -1), CUR_CPU_IDENTIFIER, &__data, sizeof(__data));
                                   ^~~~~~~~~~~~~~~~~~~~
  1 error generated.
  Failed to compile BPF module <text>

In helpers.h, we have
  u64 bpf_pseudo_fd(u64, u64) asm("llvm.bpf.pseudo");
Apparently, <= llvm14 can tolerate u64 -> 'void *' conversion, but
llvm15 by default will cause an error.

Let us explicitly convert bpf_pseudo_fd to 'void *' to avoid
such errors.

Signed-off-by: Yonghong Song <[email protected]>

src/cc/frontends/clang/b_frontend_action.cc

@@ -957,7 +957,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
  string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange()));
  string args_other = rewriter_.getRewrittenText(expansionRange(SourceRange(GET_BEGINLOC(Call->getArg(1)),
  GET_ENDLOC(Call->getArg(2)))));
- txt = "bpf_perf_event_output(" + arg0 + ", bpf_pseudo_fd(1, " + fd + ")";
+ txt = "bpf_perf_event_output(" + arg0 + ", (void *)bpf_pseudo_fd(1, " + fd + ")";
  txt += ", CUR_CPU_IDENTIFIER, " + args_other + ")";
 
  // e.g.
@@ -986,7 +986,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
  string meta_len = rewriter_.getRewrittenText(expansionRange(Call->getArg(3)->getSourceRange()));
  txt = "bpf_perf_event_output(" +
  skb + ", " +
- "bpf_pseudo_fd(1, " + fd + "), " +
+ "(void *)bpf_pseudo_fd(1, " + fd + "), " +
  "((__u64)" + skb_len + " << 32) | BPF_F_CURRENT_CPU, " +
  meta + ", " +
  meta_len + ");";
@@ -1006,12 +1006,12 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
  string keyp = rewriter_.getRewrittenText(expansionRange(Call->getArg(1)->getSourceRange()));
  string flag = rewriter_.getRewrittenText(expansionRange(Call->getArg(2)->getSourceRange()));
  txt = "bpf_" + string(memb_name) + "(" + ctx + ", " +
- "bpf_pseudo_fd(1, " + fd + "), " + keyp + ", " + flag + ");";
+ "(void *)bpf_pseudo_fd(1, " + fd + "), " + keyp + ", " + flag + ");";
  } else if (memb_name == "ringbuf_output") {
  string name = string(Ref->getDecl()->getName());
  string args = rewriter_.getRewrittenText(expansionRange(SourceRange(GET_BEGINLOC(Call->getArg(0)),
  GET_ENDLOC(Call->getArg(2)))));
- txt = "bpf_ringbuf_output(bpf_pseudo_fd(1, " + fd + ")";
+ txt = "bpf_ringbuf_output((void *)bpf_pseudo_fd(1, " + fd + ")";
  txt += ", " + args + ")";
 
  // e.g.
@@ -1033,7 +1033,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
  } else if (memb_name == "ringbuf_reserve") {
  string name = string(Ref->getDecl()->getName());
  string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange()));
- txt = "bpf_ringbuf_reserve(bpf_pseudo_fd(1, " + fd + ")";
+ txt = "bpf_ringbuf_reserve((void *)bpf_pseudo_fd(1, " + fd + ")";
  txt += ", " + arg0 + ", 0)"; // Flags in reserve are meaningless
  } else if (memb_name == "ringbuf_discard") {
  string name = string(Ref->getDecl()->getName());