From e2186926728dbef0c8b3aedbd2bfa51d3ea88c84 Mon Sep 17 00:00:00 2001
From: Rui Ueyama <rui314@gmail.com>
Date: Thu, 14 Oct 2021 20:54:28 +0900
Subject: [PATCH] [Mach-O] wip

---
 macho/main.cc          |  9 ++++-----
 macho/mold.h           |  7 +++----
 macho/output-chunks.cc | 25 +++++++++++++++++++++++++
 3 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/macho/main.cc b/macho/main.cc
index 91d69ed9..c4139665 100644
--- a/macho/main.cc
+++ b/macho/main.cc
@@ -38,11 +38,10 @@ static void create_synthetic_chunks(Context &ctx) {
 
   ctx.padding.hdr.size = 14808;
 
-  OutputSection *text = new OutputSection("__text");
-  text->hdr.attr = S_ATTR_PURE_INSTRUCTIONS | S_ATTR_SOME_INSTRUCTIONS;
-  text->hdr.p2align = 4;
-  add_section(ctx, *text, "__TEXT", "__text");
-  ctx.text_seg.chunks.push_back(text);
+  ctx.text.hdr.attr = S_ATTR_PURE_INSTRUCTIONS | S_ATTR_SOME_INSTRUCTIONS;
+  ctx.text.hdr.p2align = 4;
+  add_section(ctx, ctx.text, "__TEXT", "__text");
+  ctx.text_seg.chunks.push_back(&ctx.text);
 
   ctx.text_seg.chunks.push_back(&ctx.stubs);
   ctx.text_seg.chunks.push_back(&ctx.stub_helper);
diff --git a/macho/mold.h b/macho/mold.h
index e2317f79..d3aa4df2 100644
--- a/macho/mold.h
+++ b/macho/mold.h
@@ -303,14 +303,12 @@ class OutputFunctionStartsSection : public Chunk {
 public:
   OutputFunctionStartsSection() {
     is_hidden = true;
-    hdr.size = contents.size();
   }
 
+  void compute_size(Context &ctx) override;
   void copy_buf(Context &ctx) override;
 
-  std::vector<u8> contents = {
-    0xd0, 0x7e, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00
-  };
+  std::vector<u8> contents;
 };
 
 class OutputSymtabSection : public Chunk {
@@ -519,6 +517,7 @@ struct Context {
   OutputSymtabSection symtab;
   OutputIndirectSymtabSection indir_symtab;
   OutputStrtabSection strtab;
+  OutputSection text{"__text"};
 
   std::vector<OutputSegment *> segments;
 };
diff --git a/macho/output-chunks.cc b/macho/output-chunks.cc
index 3dbeed13..59f3b50d 100644
--- a/macho/output-chunks.cc
+++ b/macho/output-chunks.cc
@@ -544,6 +544,31 @@ void OutputExportSection::copy_buf(Context &ctx) {
   enc.write_trie(ctx.buf + hdr.offset);
 }
 
+void OutputFunctionStartsSection::compute_size(Context &ctx) {
+  std::vector<u64> addrs;
+
+  for (ObjectFile *obj : ctx.objs)
+    for (Symbol *sym : obj->syms)
+      if (sym->file == obj)
+        if (sym->subsec->isec.osec == &ctx.text)
+          addrs.push_back(sym->get_addr(ctx));
+
+  std::sort(addrs.begin(), addrs.end());
+
+  contents.resize(addrs.size() * 5);
+
+  u8 *p = contents.data();
+  u64 last = PAGE_ZERO_SIZE;
+
+  for (u64 val : addrs) {
+    p += write_uleb(p, val - last);
+    last = val;
+  }
+
+  hdr.size = p - contents.data();
+  contents.resize(hdr.size);
+}
+
 void OutputFunctionStartsSection::copy_buf(Context &ctx) {
   write_vector(ctx.buf + hdr.offset, contents);
 }