<html>
    <head>
      <base href="http://llvm.org/bugs/" />
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - -fasynchronous-unwind-tables different result .c -> .so versus .c -> .s -> .so"
   href="http://llvm.org/bugs/show_bug.cgi?id=15448">15448</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>-fasynchronous-unwind-tables different result .c -> .so versus .c -> .s -> .so
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>3.2
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>FreeBSD
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>-New Bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>tijl@coosemans.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Starting with the following C code test.c:

----
int func( void ) {
  return( 0 );
}
----

Create libtest-1.so:

clang -o libtest-1.so test.c -shared -fasynchronous-unwind-tables -fPIC

Create libtest-2.so:

clang -S test.c -fasynchronous-unwind-tables -fPIC
clang -o libtest-2.so test.s -shared

These two libraries are different. Moreover libtest-2.so contains text
relocations (DF_TEXTREL).

Running the same commands with gcc 4.7 results in two identical libraries.

When comparing the object files test-1.o and test-2.o there's a difference in
the .rel.eh_frame section:
clang -o test-1.o -c test.c -fasynchronous-unwind-tables -fPIC
clang -o test-2.o -c test.s

readelf -r test-1.o

Relocation section '.rel.eh_frame' at offset 0x2e0 contains 1 entries:
 Offset     Info    Type            Sym.Value  Sym. Name
00000020  00000202 R_386_PC32        00000000   .text

readelf -r test-2.o

Relocation section '.rel.eh_frame' at offset 0x364 contains 1 entries:
 Offset     Info    Type            Sym.Value  Sym. Name
00000020  00000201 R_386_32          00000000   .text

With gcc the type of the relocation is R_386_PC32 in both cases.

OS: FreeBSD 10.0 x86</pre>
        </div>
      </p>
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