Drop MapManager and all related classes

Now that map management has been completely moved to BpfBytecode, using
BpfMap objects, we can remove the legacy MapManager and all of the
related classes: IMap, Map, FakeMap.

One problem that popped up is that after the cleanup, RequiredResources
has only 3 methods which are all used by AOT only. This caused linker
error b/c we expect required_resources.cpp to be linked in libruntime.a,
however, since no method was called from the runtime library, the linker
skipped it. This is fixed by adding an explicit definition of a
constructor in required_resources.cpp.

src/CMakeLists.txt

@@ -25,11 +25,8 @@ add_library(runtime
   config.cpp
   disasm.cpp
   dwarf_parser.cpp
-  fake_map.cpp
   format_string.cpp
-  imap.cpp
   log.cpp
-  map.cpp
   mapkey.cpp
   output.cpp
   probe_matcher.cpp

src/ast/passes/codegen_llvm.h

@@ -17,7 +17,6 @@
 #include "bpftrace.h"
 #include "format_string.h"
 #include "location.hh"
-#include "map.h"
 #include "required_resources.h"
 
 namespace bpftrace {

src/ast/passes/config_analyser.h

@@ -9,7 +9,6 @@
 #include "bpffeature.h"
 #include "bpftrace.h"
 #include "config.h"
-#include "map.h"
 #include "types.h"
 
 namespace bpftrace {

src/ast/passes/resource_analyser.cpp

@@ -227,11 +227,6 @@ Pass CreateResourcePass()
       return PassResult::Error("Resource", 1);
     ctx.b.resources = pass_result.value();
 
-    // Create fake maps so that codegen has access to map IDs
-    //
-    // At runtime we will replace the fake maps with real maps
-    ctx.b.resources.create_maps(ctx.b, true);
-
     return PassResult::Success();
   };
 

src/ast/passes/semantic_analyser.cpp

@@ -11,7 +11,6 @@
 #include "ast/ast.h"
 #include "ast/signal_bt.h"
 #include "config.h"
-#include "fake_map.h"
 #include "log.h"
 #include "printf.h"
 #include "probe_matcher.h"

src/ast/passes/semantic_analyser.h

@@ -9,7 +9,6 @@
 #include "bpffeature.h"
 #include "bpftrace.h"
 #include "config.h"
-#include "map.h"
 #include "types.h"
 
 namespace bpftrace {

src/bpfbytecode.h

@@ -2,7 +2,7 @@
 
 #include "bpffeature.h"
 #include "bpfmap.h"
-#include "mapmanager.h"
+#include "types.h"
 
 #include <bpf/libbpf.h>
 #include <cereal/access.hpp>

src/bpfprogram.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "bpfbytecode.h"
-#include "mapmanager.h"
 
 #include <cstdint>
 #include <optional>

src/bpftrace.cpp

@@ -1128,17 +1128,6 @@ int BPFtrace::run(BpfBytecode bytecode)
   if (bytecode.create_maps())
     return 1;
 
-  // Clear fake maps and replace with real maps
-  maps = {};
-  if (resources.create_maps(*this, false))
-    return 1;
-  // BPF maps are now created by BpfBytecode::create_maps and therefore
-  // we copy FDs to MapManager for compatibility. This code will go away once
-  // we get rid of MapManager.
-  for (auto &map : maps) {
-    map->mapfd_ = bytecode.getMap(map->name_).fd;
-  }
-
   if (bytecode.hasMap(MapType::MappedPrintfData)) {
     auto map = bytecode.getMap(MapType::MappedPrintfData);
     uint32_t idx = 0;

src/bpftrace.h

@@ -19,8 +19,6 @@
 #include "child.h"
 #include "config.h"
 #include "dwarf_parser.h"
-#include "map.h"
-#include "mapmanager.h"
 #include "output.h"
 #include "pcap_writer.h"
 #include "printf.h"
@@ -174,7 +172,6 @@ class BPFtrace {
   static volatile sig_atomic_t sigusr1_recv;
 
   RequiredResources resources;
-  MapManager maps;
   BpfBytecode bytecode_;
   StructManager structs;
   std::map<std::string, std::string> macros_;