Remove B language support

Remove support for compiling B programs (see iovisor#3682 for explanation).

There may be some vestigial logic in other files that needs to be
cleanded up for simplicity - bpf_module.cc most likely - but that can be
addressed in followup commits.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>

src/cc/CMakeLists.txt

@@ -123,15 +123,15 @@ set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${llvm_lib_exclude_f
 
 # bcc_common_libs_for_a for archive libraries
 # bcc_common_libs_for_s for shared libraries
-set(bcc_common_libs b_frontend clang_frontend
+set(bcc_common_libs clang_frontend
   -Wl,--whole-archive ${clang_libs} ${llvm_libs} -Wl,--no-whole-archive
   ${LIBELF_LIBRARIES})
 if (LIBDEBUGINFOD_FOUND)
   list(APPEND bcc_common_libs ${LIBDEBUGINFOD_LIBRARIES})
 endif (LIBDEBUGINFOD_FOUND)
 set(bcc_common_libs_for_a ${bcc_common_libs})
 set(bcc_common_libs_for_s ${bcc_common_libs})
-set(bcc_common_libs_for_lua b_frontend clang_frontend
+set(bcc_common_libs_for_lua clang_frontend
   ${clang_libs} ${llvm_libs} ${LIBELF_LIBRARIES})
 if(LIBBPF_FOUND)
   list(APPEND bcc_common_libs_for_a ${LIBBPF_LIBRARIES})

src/cc/bcc_common.cc

@@ -17,16 +17,6 @@
 #include "bpf_module.h"
 
 extern "C" {
-void * bpf_module_create_b(const char *filename, const char *proto_filename, unsigned flags,
-                           const char *dev_name) {
-  auto mod = new ebpf::BPFModule(flags, nullptr, true, "", true, dev_name);
-  if (mod->load_b(filename, proto_filename) != 0) {
-    delete mod;
-    return nullptr;
-  }
-  return mod;
-}
-
 void * bpf_module_create_c(const char *filename, unsigned flags, const char *cflags[],
                            int ncflags, bool allow_rlimit, const char *dev_name) {
   auto mod = new ebpf::BPFModule(flags, nullptr, true, "", allow_rlimit, dev_name);

src/cc/bcc_common.h

@@ -25,8 +25,6 @@
 extern "C" {
 #endif
 
-void * bpf_module_create_b(const char *filename, const char *proto_filename, unsigned flags,
-                           const char *dev_name);
 void * bpf_module_create_c(const char *filename, unsigned flags, const char *cflags[], int ncflags,
                            bool allow_rlimit, const char *dev_name);
 void * bpf_module_create_c_from_string(const char *text, unsigned flags, const char *cflags[],

src/cc/bpf_module.cc

@@ -38,7 +38,6 @@
 #include "common.h"
 #include "bcc_debug.h"
 #include "bcc_elf.h"
-#include "frontends/b/loader.h"
 #include "frontends/clang/loader.h"
 #include "frontends/clang/b_frontend_action.h"
 #include "bpf_module.h"
@@ -834,43 +833,6 @@ int BPFModule::table_leaf_scanf(size_t id, const char *leaf_str, void *leaf) {
   return 0;
 }
 
-// load a B file, which comes in two parts
-int BPFModule::load_b(const string &filename, const string &proto_filename) {
-  if (!sections_.empty()) {
-    fprintf(stderr, "Program already initialized\n");
-    return -1;
-  }
-  if (filename.empty() || proto_filename.empty()) {
-    fprintf(stderr, "Invalid filenames\n");
-    return -1;
-  }
-
-  // Helpers are inlined in the following file (C). Load the definitions and
-  // pass the partially compiled module to the B frontend to continue with.
-  auto helpers_h = ExportedFiles::headers().find("/virtual/include/bcc/helpers.h");
-  if (helpers_h == ExportedFiles::headers().end()) {
-    fprintf(stderr, "Internal error: missing bcc/helpers.h");
-    return -1;
-  }
-  if (int rc = load_includes(helpers_h->second))
-    return rc;
-
-  BLoader b_loader(flags_);
-  used_b_loader_ = true;
-  if (int rc = b_loader.parse(&*mod_, filename, proto_filename, *ts_, id_,
-                              maps_ns_))
-    return rc;
-  if (rw_engine_enabled_) {
-    if (int rc = annotate())
-      return rc;
-  } else {
-    annotate_light();
-  }
-  if (int rc = finalize())
-    return rc;
-  return 0;
-}
-
 // load a C file
 int BPFModule::load_c(const string &filename, const char *cflags[], int ncflags) {
   if (!sections_.empty()) {

src/cc/bpf_module.h

@@ -99,7 +99,6 @@ class BPFModule {
             const char *dev_name = nullptr);
   ~BPFModule();
   int free_bcc_memory();
-  int load_b(const std::string &filename, const std::string &proto_filename);
   int load_c(const std::string &filename, const char *cflags[], int ncflags);
   int load_string(const std::string &text, const char *cflags[], int ncflags);
   std::string id() const { return id_; }

src/cc/frontends/CMakeLists.txt

@@ -1,5 +1,4 @@
 # Copyright (c) PLUMgrid, Inc.
 # Licensed under the Apache License, Version 2.0 (the "License")
 
-add_subdirectory(b)
 add_subdirectory(clang)