From 296ae418583b7fd04d5847319e1a905763e6d3e5 Mon Sep 17 00:00:00 2001
From: "MATSUMOTO, Katsuyoshi" <github@katsyoshi.org>
Date: Sat, 18 Apr 2026 20:10:23 +0900
Subject: [PATCH 1/2] add start-based tests for glibc linking

---
 test/caotral/linker/needed_test.rb | 40 ++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/test/caotral/linker/needed_test.rb b/test/caotral/linker/needed_test.rb
index fe0ac94..b45345b 100644
--- a/test/caotral/linker/needed_test.rb
+++ b/test/caotral/linker/needed_test.rb
@@ -38,4 +38,44 @@ def test_needed_in_executable
     pid, exit_code = check_process($?.to_i)
     assert_equal(0, exit_code)
   end
+
+  def test_start_in_dynamic_section
+    @input = "start.o"
+    @output = "start"
+    compile_path = Pathname.new("sample/C/start.c").to_s
+    IO.popen(["gcc", "-fPIC", "-c", "-o", @input, "%s" % compile_path]).close
+
+    Caotral::Linker.link!(inputs: [@input], output: @output, linker: "self", pie: true, needed: ["libc.so.6"], executable: false)
+
+    elf = Caotral::Binary::ELF::Reader.read!(input: @output, debug: false)
+    dynstr = elf.find_by_name(".dynstr")
+    dynsym = elf.find_by_name(".dynsym")
+    needed = elf.find_by_name(".dynamic").body.select(&:needed?)
+    got_plt = elf.find_by_name(".dynamic").body.select(&:plt_got?)
+    jmp_rel = elf.find_by_name(".dynamic").body.select(&:jmp_rel?)
+    dynsym_names = dynsym.body.map(&:name_string)
+    assert_equal(1, needed.size)
+    assert_equal(dynstr.body.lookup(needed.first.un), "libc.so.6")
+    assert_include(dynsym_names, "_exit")
+    assert_include(dynsym_names, "_start")
+    assert_equal(1, got_plt.size)
+    assert_equal(1, jmp_rel.size)
+  end
+
+  def test_start_in_executable
+    @input = "start.o"
+    @output = "start"
+
+    compile_path = Pathname.new("sample/C/start.c").to_s
+    IO.popen(["gcc", "-fPIC", "-c", "-o", @input, "%s" % compile_path]).close
+
+    Caotral::Linker.link!(inputs: [@input], output: @output, linker: "self", pie: true, needed: ["libc.so.6"], executable: true)
+
+    io = IO.popen(["./#{@output}"])
+    stdout = io.read
+    io.close
+    pid, exit_code = check_process($?.to_i)
+    assert_equal("hello, world!!!\n", stdout)
+    assert_equal(0, exit_code)
+  end
 end

From 0b9f417628f6594970a7bc8b0bb313a6d481ff58 Mon Sep 17 00:00:00 2001
From: "MATSUMOTO, Katsuyoshi" <github@katsyoshi.org>
Date: Sat, 18 Apr 2026 21:28:38 +0900
Subject: [PATCH 2/2] add glibc linker test for start and shared objects

---
 test/caotral/linker/needed_test.rb | 41 ++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/test/caotral/linker/needed_test.rb b/test/caotral/linker/needed_test.rb
index b45345b..2facfa3 100644
--- a/test/caotral/linker/needed_test.rb
+++ b/test/caotral/linker/needed_test.rb
@@ -39,6 +39,23 @@ def test_needed_in_executable
     assert_equal(0, exit_code)
   end
 
+  def test_needed_in_shared_object
+    @output = "libneeded.so"
+    compile_path = Pathname.new("sample/C/needed.c").to_s
+    IO.popen(["gcc", "-fPIC", "-c", "-o", @input, "%s" % compile_path]).close
+
+    Caotral::Linker.link!(inputs: [@input], output: @output, linker: "self", needed: ["libc.so.6"], executable: false, shared: true)
+
+    elf = Caotral::Binary::ELF::Reader.read!(input: @output, debug: false)
+    dynstr = elf.find_by_name(".dynstr")
+    dynsym = elf.find_by_name(".dynsym")
+    needed = elf.find_by_name(".dynamic").body.select(&:needed?)
+
+    assert_equal(1, needed.size)
+    assert_equal(dynstr.body.lookup(needed.first.un), "libc.so.6")
+    assert_include(dynsym.body.map(&:name_string), "puts")
+  end
+
   def test_start_in_dynamic_section
     @input = "start.o"
     @output = "start"
@@ -78,4 +95,28 @@ def test_start_in_executable
     assert_equal("hello, world!!!\n", stdout)
     assert_equal(0, exit_code)
   end
+
+  def test_start_in_shared_object
+    @input = "start.o"
+    @output = "libstart.so"
+
+    compile_path = Pathname.new("sample/C/start.c").to_s
+    IO.popen(["gcc", "-fPIC", "-c", "-o", @input, "%s" % compile_path]).close
+
+    Caotral::Linker.link!(inputs: [@input], output: @output, linker: "self", needed: ["libc.so.6"], executable: false, shared: true)
+
+    elf = Caotral::Binary::ELF::Reader.read!(input: @output, debug: false)
+    dynstr = elf.find_by_name(".dynstr")
+    dynsym = elf.find_by_name(".dynsym")
+    needed = elf.find_by_name(".dynamic").body.select(&:needed?)
+    got_plt = elf.find_by_name(".dynamic").body.select(&:plt_got?)
+    jmp_rel = elf.find_by_name(".dynamic").body.select(&:jmp_rel?)
+    dynsym_names = dynsym.body.map(&:name_string)
+    assert_equal(1, needed.size)
+    assert_equal(dynstr.body.lookup(needed.first.un), "libc.so.6")
+    assert_include(dynsym_names, "_exit")
+    assert_include(dynsym_names, "_start")
+    assert_equal(1, got_plt.size)
+    assert_equal(1, jmp_rel.size)
+  end
 end