[llvm] r199681 - Debug info: On ARM ensure that all __TEXT sections come before the

[Adrian Prantl]

Author: adrian
Date: Mon Jan 20 13:15:59 2014
New Revision: 199681

URL: http://llvm.org/viewvc/llvm-project?rev=199681&view=rev
Log:
Debug info: On ARM ensure that all __TEXT sections come before the
optional DWARF sections, so compiling with -g does not result in
different code being generated for PC-relative loads.

This is reapplying a diet r197922 (__TEXT-only).

Added:
    llvm/trunk/test/DebugInfo/ARM/sectionorder.ll
Modified:
    llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp?rev=199681&r1=199680&r2=199681&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp Mon Jan 20 13:15:59 2014
@@ -489,6 +489,13 @@ void ARMAsmPrinter::EmitStartOfAsmFile(M
                                    SectionKind::getText());
       OutStreamer.SwitchSection(StaticInitSect);
     }
+
+    // Compiling with debug info should not affect the code
+    // generation.  Ensure the cstring section comes before the
+    // optional __DWARF secion. Otherwise, PC-relative loads would
+    // have to use different instruction sequences at "-g" in order to
+    // reach global data in the same object file.
+    OutStreamer.SwitchSection(getObjFileLowering().getCStringSection());
   }
 
   // Use unified assembler syntax.

Added: llvm/trunk/test/DebugInfo/ARM/sectionorder.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/ARM/sectionorder.ll?rev=199681&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/ARM/sectionorder.ll (added)
+++ llvm/trunk/test/DebugInfo/ARM/sectionorder.ll Mon Jan 20 13:15:59 2014
@@ -0,0 +1,18 @@
+; RUN: llc  -filetype=asm %s -o - | FileCheck %s
+
+; Verifies that the DWARF* sections come _after_ the __TEXT sections.
+; rdar://problem/15623193
+
+; CHECK: .section	__TEXT,__text,
+; CHECK-NOT: __DWARF,__debug
+; CHECK: .section	__TEXT,__cstring,cstring_literals
+target triple = "thumbv7-apple-ios"
+
+!llvm.module.flags = !{!3, !4}
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 786449, i32 0, i32 12, metadata !"test.c", metadata !"/Volumes/Data/radar/15623193", metadata !"LLVM", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !1, metadata !1} ; [ DW_TAG_compile_unit ] [/Volumes/Data/radar/15623193/test.c] [DW_LANG_C99]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}
+!4 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}