From a00804a22da906034f7ab9e44af9b750c41db7e8 Mon Sep 17 00:00:00 2001
From: James Benton <james.benton2@gmail.com>
Date: Mon, 11 Jun 2018 15:36:21 +0100
Subject: [PATCH] readrpl: Add --exports-def to generate exports.def file for
 an rpl.

---
 tools/readrpl/CMakeLists.txt           |  12 ++-
 tools/readrpl/generate_exports_def.cpp | 106 +++++++++++++++++++++++++
 tools/readrpl/generate_exports_def.h   |   8 ++
 tools/readrpl/main.cpp                 |  29 ++++++-
 4 files changed, 150 insertions(+), 5 deletions(-)
 create mode 100644 tools/readrpl/generate_exports_def.cpp
 create mode 100644 tools/readrpl/generate_exports_def.h

diff --git a/tools/readrpl/CMakeLists.txt b/tools/readrpl/CMakeLists.txt
index b2e55992..c4d0b0ca 100644
--- a/tools/readrpl/CMakeLists.txt
+++ b/tools/readrpl/CMakeLists.txt
@@ -1,10 +1,14 @@
 project(readrpl)
 
-file(GLOB_RECURSE SOURCE_FILES *.cpp)
-file(GLOB_RECURSE HEADER_FILES *.h)
-
 add_executable(readrpl
-   ${SOURCE_FILES} ${HEADER_FILES})
+   generate_exports_def.cpp
+   generate_exports_def.h
+   main.cpp
+   print.cpp
+   print.h
+   readrpl.h
+   verify.cpp
+   verify.h)
 
 target_link_libraries(readrpl
    excmd
diff --git a/tools/readrpl/generate_exports_def.cpp b/tools/readrpl/generate_exports_def.cpp
new file mode 100644
index 00000000..b9099b3a
--- /dev/null
+++ b/tools/readrpl/generate_exports_def.cpp
@@ -0,0 +1,106 @@
+#include "generate_exports_def.h"
+
+#include <cstdio>
+#include <cstring>
+#include <fmt/format.h>
+
+static const char *
+sExportBlacklist[] = {
+   "__get_eh_globals",
+   "__get_eh_init_block",
+   "__get_eh_mem_manage",
+   "__get_eh_store_globals",
+   "__get_eh_store_globals_tdeh",
+   "__gh_errno_ptr",
+   "__gh_get_errno",
+   "__gh_iob_init",
+   "__gh_lock_init",
+   "__gh_set_errno",
+   "__ghsLock",
+   "__ghsUnlock",
+   "__ghs_at_exit",
+   "__ghs_at_exit_cleanup",
+   "__ghs_flock_create",
+   "__ghs_flock_destroy",
+   "__ghs_flock_file",
+   "__ghs_flock_ptr",
+   "__ghs_ftrylock_file",
+   "__ghs_funlock_file",
+   "__ghs_mtx_dst",
+   "__ghs_mtx_init",
+   "__ghs_mtx_lock",
+   "__ghs_mtx_unlock",
+   "__tls_get_addr",
+   "memclr",
+   "memcpy",
+   "memmove",
+   "memset",
+   "__atexit_cleanup",
+   "__cpp_exception_cleanup_ptr",
+   "__cpp_exception_init_ptr",
+   "__gh_FOPEN_MAX",
+   "__ghs_cpp_locks",
+   "__stdio_cleanup",
+   "_iob",
+   "_iob_lock",
+   "environ",
+   "errno",
+};
+
+static bool
+inBlacklist(const char *name)
+{
+   for (auto i = 0u; i < sizeof(sExportBlacklist) / sizeof(sExportBlacklist[0]); ++i) {
+      if (strcmp(name, sExportBlacklist[i]) == 0) {
+         return true;
+      }
+   }
+
+   return false;
+}
+
+bool
+generateExportsDef(const Rpl &rpl,
+                   const std::string &rplName,
+                   const std::string &outFileName)
+{
+   FILE *fh = fopen(outFileName.c_str(), "w");
+   if (!fh) {
+      fmt::print("Failed to open {} for writing!", outFileName);
+      return false;
+   }
+
+   fmt::print(fh, ":NAME {}\n", rplName);
+
+   for (auto &section : rpl.sections) {
+      if (section.header.type == elf::SHT_RPL_EXPORTS) {
+         auto exports = reinterpret_cast<const elf::RplExport *>(section.data.data());
+         auto strTab = section.data.data();
+
+         if (section.header.flags & elf::SHF_EXECINSTR) {
+            fmt::print(fh, "\n:TEXT\n");
+         } else {
+            fmt::print(fh, "\n:DATA\n");
+         }
+
+         for (auto i = 0u; i < exports->count; ++i) {
+            if (exports->exports[i].name & 0x80000000) {
+               // Skip TLS exports for now.
+               continue;
+            }
+
+            auto name = strTab + (exports->exports[i].name & 0x7FFFFFFF);
+
+            if (inBlacklist(name)) {
+               fmt::print(fh, "//");
+            }
+
+            fmt::print(fh, "{}\n", name);
+         }
+
+      }
+   }
+
+   fclose(fh);
+   return true;
+}
diff --git a/tools/readrpl/generate_exports_def.h b/tools/readrpl/generate_exports_def.h
new file mode 100644
index 00000000..581fa0fd
--- /dev/null
+++ b/tools/readrpl/generate_exports_def.h
@@ -0,0 +1,8 @@
+#pragma once
+#include "readrpl.h"
+#include <string>
+
+bool
+generateExportsDef(const Rpl &rpl,
+                   const std::string &rplName,
+                   const std::string &outFileName);
diff --git a/tools/readrpl/main.cpp b/tools/readrpl/main.cpp
index 3b678714..35b501a5 100644
--- a/tools/readrpl/main.cpp
+++ b/tools/readrpl/main.cpp
@@ -1,4 +1,5 @@
 #include "elf.h"
+#include "generate_exports_def.h"
 #include "print.h"
 #include "verify.h"
 
@@ -9,6 +10,22 @@
 #include <vector>
 #include <zlib.h>
 
+static std::string
+getFileBasename(std::string path)
+{
+   auto pos = path.find_last_of("\\/");
+   if (pos != std::string::npos) {
+      path.erase(0, pos + 1);
+   }
+
+   pos = path.rfind('.');
+   if (pos != std::string::npos) {
+      path.erase(pos);
+   }
+
+   return path;
+}
+
 uint32_t
 getSectionIndex(const Rpl &rpl,
                 const Section &section)
@@ -109,7 +126,10 @@ int main(int argc, char **argv)
          .add_option("c,crc",
                      description { "Display the RPL crc" })
          .add_option("f,file-info",
-                     description { "Display the RPL file info" });
+                     description { "Display the RPL file info" })
+         .add_option("exports-def",
+                     description { "Generate exports.def for wut library linking" },
+                     value<std::string> {});
 
       parser.default_command()
          .add_argument("path",
@@ -267,5 +287,12 @@ int main(int argc, char **argv)
       }
    }
 
+   if (options.has("exports-def")) {
+      auto output = options.get<std::string>("exports-def");
+      if (!generateExportsDef(rpl, getFileBasename(path), output)) {
+         return -1;
+      }
+   }
+
    return 0;
 }