From 540506d33cc2c44d135dd35794dbdd29266b3a3f Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@cs.stanford.edu>
Date: Sun, 10 Jan 2021 14:53:29 +0900
Subject: [PATCH] temporary

---
 input_sections.cc | 49 +++++++++++++++++++++++------------------------
 1 file changed, 24 insertions(+), 25 deletions(-)

diff --git a/input_sections.cc b/input_sections.cc
index aaf3c6cf..e13fc862 100644
--- a/input_sections.cc
+++ b/input_sections.cc
@@ -34,31 +34,31 @@ static std::string rel_to_string(u32 r_type) {
   unreachable();
 }
 
-static void overflow_check(std::ostringstream &out, u32 r_type, u64 val) {
+static void overflow_check(std::ostringstream &out, u32 r_type, u8 *loc, u64 val) {
   switch (r_type) {
   case R_X86_64_8:
     if (val != (u8)val)
       out << "relocation R_X86_64_8 out of range: " << val << " is not in [0, 255]";
-    return;
+    break;
   case R_X86_64_PC8:
     if (val != (i8)val)
       out << "relocation R_X86_64_PC8 out of range: " << (i64)val
           << " is not in [-128, 127]";
-    return;
+    break;
   case R_X86_64_16:
     if (val != (u16)val)
       out << "relocation R_X86_64_16 out of range: " << val << " is not in [0, 65535]";
-    return;
+    break;
   case R_X86_64_PC16:
     if (val != (i16)val)
       out << "relocation R_X86_64_PC16 out of range: " << (i64)val
           << " is not in [-32768, 32767]";
-    return;
+    break;
   case R_X86_64_32:
     if (val != (u32)val)
       out << "relocation R_X86_64_32 out of range: " << val
           << " is not in [0, 4294967296]";
-    return;
+    break;
   case R_X86_64_32S:
   case R_X86_64_PC32:
   case R_X86_64_GOT32:
@@ -75,27 +75,30 @@ static void overflow_check(std::ostringstream &out, u32 r_type, u64 val) {
     if (val != (i32)val)
       out << "relocation " << rel_to_string(r_type) << " out of range: "
               << (i64)val << " is not in [-2147483648, 2147483647]";
-    return;
+    break;
   case R_X86_64_NONE:
   case R_X86_64_64:
   case R_X86_64_PC64:
   case R_X86_64_TPOFF64:
   case R_X86_64_DTPOFF64:
-    return;
+    break;
+  default:
+    unreachable();
   }
-  unreachable();
 }
 
-static int get_rel_size(u32 r_type) {
+static void write_val(u32 r_type, u8 *loc, u64 val) {
   switch (r_type) {
   case R_X86_64_NONE:
-    return 0;
+    break;
   case R_X86_64_8:
   case R_X86_64_PC8:
-    return 1;
+    *loc = val;
+    break;
   case R_X86_64_16:
   case R_X86_64_PC16:
-    return 2;
+    *(u16 *)loc = val;
+    break;
   case R_X86_64_32:
   case R_X86_64_32S:
   case R_X86_64_PC32:
@@ -110,14 +113,17 @@ static int get_rel_size(u32 r_type) {
   case R_X86_64_TPOFF32:
   case R_X86_64_DTPOFF32:
   case R_X86_64_GOTTPOFF:
-    return 4;
+    *(u32 *)loc = val;
+    break;
   case R_X86_64_64:
   case R_X86_64_PC64:
   case R_X86_64_TPOFF64:
   case R_X86_64_DTPOFF64:
-    return 8;
+    *(u64 *)loc = val;
+    break;
+  default:
+    unreachable();
   }
-  unreachable();
 }
 
 void InputSection::copy_buf() {
@@ -148,14 +154,8 @@ void InputSection::copy_buf() {
       ref = &rel_pieces[ref_idx++];
 
     auto write = [&](u64 val) {
-      overflow_check(file->err_out, rel.r_type, val);
-      switch (get_rel_size(rel.r_type)) {
-      case 1: *loc = val; return;
-      case 2: *(u16 *)loc = val; return;
-      case 4: *(u32 *)loc = val; return;
-      case 8: *(u64 *)loc = val; return;
-      }
-      unreachable();
+      overflow_check(file->err_out, rel.r_type, loc, val);
+      write_val(rel.r_type, loc, val);
     };
 
 #define S   (ref ? ref->piece->get_addr() : sym.get_addr())
@@ -172,7 +172,6 @@ void InputSection::copy_buf() {
       write(S + A);
 
       if (sym.needs_relative_rel()) {
-        assert(get_rel_size(rel.r_type) == 8);
         memset(dynrel, 0, sizeof(*dynrel));
         dynrel->r_offset = P;
         dynrel->r_type = R_X86_64_RELATIVE;