Rewrite of build system.

Notable changes:
- We now only build things by default that require
  no dependencies.  So you can build upb even if you
  don't have Lua or Google protobuf installed.
- Checked in a pre-built version of the JIT, so you
  don't need Lua installed at build time to run DynASM.
  It will still notice if you change the .dasc file and
  attempt to re-run DynASM in that case.
- The build system now builds all modules of upb into
  separate libraries, reflecting the modularity that
  is already inherent in upb's design.  This should
  make it easier to trim the fat.
- removed the GDB JIT interface.  I wasn't using it
  much; using a .so is easier and more robust.

4 files changed, 4 insertions, 90 deletions

diff --git a/upb/bindings/lua/upb.c b/upb/bindings/lua/upb.c
index dbeb937..f938b26 100644
--- a/upb/bindings/lua/upb.c
+++ b/upb/bindings/lua/upb.c
@@ -1622,6 +1622,7 @@ static void lupb_sethasbit(lupb_msg *msg, uint32_t hasbit) {
 
 static size_t strhandler(void *closure, const void *hd, const char *str,
                          size_t len, const upb_bufhandle *handle) {
+  UPB_UNUSED(handle);
   lupb_msg *msg = closure;
   const lupb_handlerdata *data = hd;
   lua_State *L = msg->lmd->L;
diff --git a/upb/bindings/ruby/extconf.rb b/upb/bindings/ruby/extconf.rb
index 67fddba..3637511 100644
--- a/upb/bindings/ruby/extconf.rb
+++ b/upb/bindings/ruby/extconf.rb
@@ -2,6 +2,8 @@
 
 require 'mkmf'
 find_header("upb/upb.h", "../../..") or raise "Can't find upb headers"
-find_library("upb_pic", "upb_msgdef_new", "../..") or raise "Can't find upb lib"
+find_library("upb_pic", "upb_msgdef_new", "../../../lib") or raise "Can't find upb lib"
+find_library("upb.pb_pic", "upb_decoder_init", "../../../lib") or raise "Can't find upb.pb lib"
+find_library("upb.descriptor_pic", "upb_descreader_init", "../../../lib") or raise "Can't find upb.descriptor lib"
 $CFLAGS += " -Wall"
 create_makefile("upb")
diff --git a/upb/pb/compile_decoder_x64.c b/upb/pb/compile_decoder_x64.c
index 1d8b861..d8af013 100644
--- a/upb/pb/compile_decoder_x64.c
+++ b/upb/pb/compile_decoder_x64.c
@@ -259,8 +259,6 @@ static int pcofs(jitcompiler *jc) {
   return jc->pc - jc->group->bytecode;
 }
 
-static void upb_reg_jit_gdb(jitcompiler *jc);
-
 // Returns a machine code offset corresponding to the given key.
 // Requires that this key was defined with define_jmptarget.
 static int machine_code_ofs(jitcompiler *jc, const void *key) {
@@ -470,7 +468,6 @@ void upb_pbdecoder_jit(mgroup *group) {
                         MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
   dasm_encode(jc, jit_code);
   mprotect(jit_code, jc->group->jit_size, PROT_EXEC | PROT_READ);
-  upb_reg_jit_gdb(jc);
   jc->group->jit_code = (upb_string_handlerfunc *)jit_code;
 
 #ifdef UPB_JIT_LOAD_SO
@@ -496,84 +493,4 @@ void upb_pbdecoder_freejit(mgroup *group) {
     munmap(group->jit_code, group->jit_size);
   }
   free(group->debug_info);
-  // TODO: unregister GDB JIT interface.
-}
-
-// To debug JIT-ted code with GDB we need to tell GDB about the JIT-ted code
-// at runtime.  GDB 7.x+ has defined an interface for doing this, and these
-// structure/function defintions are copied out of gdb/jit.h
-//
-// We need to give GDB an ELF file at runtime describing the symbols we have
-// generated.  To avoid implementing the ELF format, we generate an ELF file
-// at compile-time and compile it in as a character string.  We can replace
-// a few key constants (address of JIT-ted function and its size) by looking
-// for a few magic numbers and doing a dumb string replacement.
-//
-// Unfortunately this approach is showing its limits; we can only define one
-// symbol, and this approach only works with GDB.  The .so approach above is
-// more reliable.
-
-#ifndef __APPLE__
-const unsigned char upb_jit_debug_elf_file[] = {
-#include "upb/pb/jit_debug_elf_file.h"
-};
-
-typedef enum {
-  GDB_JIT_NOACTION = 0,
-  GDB_JIT_REGISTER,
-  GDB_JIT_UNREGISTER
-} jit_actions_t;
-
-typedef struct gdb_jit_entry {
-  struct gdb_jit_entry *next_entry;
-  struct gdb_jit_entry *prev_entry;
-  const char *symfile_addr;
-  uint64_t symfile_size;
-} gdb_jit_entry;
-
-typedef struct {
-  uint32_t version;
-  uint32_t action_flag;
-  gdb_jit_entry *relevant_entry;
-  gdb_jit_entry *first_entry;
-} gdb_jit_descriptor;
-
-gdb_jit_descriptor __jit_debug_descriptor = {1, GDB_JIT_NOACTION, NULL, NULL};
-
-void __attribute__((noinline)) __jit_debug_register_code() {
-  __asm__ __volatile__("");
 }
-
-static void upb_reg_jit_gdb(jitcompiler *jc) {
-  // Create debug info.
-  size_t elf_len = sizeof(upb_jit_debug_elf_file);
-  jc->group->debug_info = malloc(elf_len);
-  memcpy(jc->group->debug_info, upb_jit_debug_elf_file, elf_len);
-  uint64_t *p = (void *)jc->group->debug_info;
-  for (; (void *)(p + 1) <= (void *)jc->group->debug_info + elf_len; ++p) {
-    if (*p == 0x12345678) {
-      *p = (uintptr_t)jc->group->jit_code;
-    }
-    if (*p == 0x321) {
-      *p = jc->group->jit_size;
-    }
-  }
-
-  // Register the JIT-ted code with GDB.
-  gdb_jit_entry *e = malloc(sizeof(gdb_jit_entry));
-  e->next_entry = __jit_debug_descriptor.first_entry;
-  e->prev_entry = NULL;
-  if (e->next_entry) e->next_entry->prev_entry = e;
-  e->symfile_addr = jc->group->debug_info;
-  e->symfile_size = elf_len;
-  __jit_debug_descriptor.first_entry = e;
-  __jit_debug_descriptor.relevant_entry = e;
-  __jit_debug_descriptor.action_flag = GDB_JIT_REGISTER;
-  __jit_debug_register_code();
-}
-
-#else
-
-static void upb_reg_jit_gdb(jitcompiler *jc) { (void)jc; }
-
-#endif
diff --git a/upb/pb/jit_debug_elf_file.s b/upb/pb/jit_debug_elf_file.s
deleted file mode 100644
index 2c3d6fb..0000000
--- a/upb/pb/jit_debug_elf_file.s
+++ /dev/null
@@ -1,6 +0,0 @@
-   .file "JIT mcode"
-   .text
-upb_jit_compiled_decoder:
-   .globl upb_jit_compiled_decoder
-   .size upb_jit_compiled_decoder, 0x321
-   .space 0x321