PE/COFF: auto-promote oversized objects to bigobj

PE/COFF object files use 16-bit section numbers in normal symbols.
When an object grows past that limit, current BFD already rejects it with
a "too many sections" / "file too big" error.

BFD already has PE bigobj targets for the backends that support them, but
oversized PE/COFF output still requires selecting bigobj explicitly.

Teach coff_compute_section_file_positions to switch PE/COFF output to the
corresponding bigobj target when the normal section-number limit is
exceeded. This preserves the existing hard error for targets without
bigobj support, but lets supported PE targets transparently emit a valid
bigobj object instead of requiring manual selection.

bfd/
	* coffcode.h (coff_compute_section_file_positions): Auto-promote
	oversized PE/COFF objects to the bigobj target.

gas/
	* testsuite/gas/pe/big-obj-auto.d: New test.
	* testsuite/gas/pe/big-obj-auto.s: New test.
	* testsuite/gas/pe/pe.exp: Run big-obj-auto.

Signed-off-by: Oleg Tolmatcev <oleg.tolmatcev@gmail.com>

diff --git a/bfd/coffcode.h b/bfd/coffcode.h
index 7439fca676369791c34150a6d053cd8079aa5795..12cc7c3ca791134655ccdccc4c0934034e96fe1a 100644 (file)
--- a/bfd/coffcode.h
+++ b/bfd/coffcode.h
@@ -360,6 +360,10 @@ CODE_FRAGMENT
 #include "coffswap.h"
 #endif
 
+#ifdef COFF_WITH_PE_BIGOBJ
+extern const bfd_target TARGET_SYM_BIG;
+#endif
+
 #define STRING_SIZE_SIZE 4
 
 #define DOT_DEBUG      ".debug"
@@ -3154,6 +3158,16 @@ coff_compute_section_file_positions (bfd * abfd)
 
   if (target_index >= bfd_coff_max_nscns (abfd))
     {
+#if defined(COFF_WITH_PE_BIGOBJ) && !defined(COFF_IMAGE_WITH_PE)
+      if (abfd->xvec != &TARGET_SYM_BIG)
+       {
+         /* Regular PE/COFF uses 16-bit section numbers in symbols.
+            Promote oversized objects to the matching bigobj target
+            before any headers or symbols are finalized.  */
+         abfd->xvec = &TARGET_SYM_BIG;
+         return coff_compute_section_file_positions (abfd);
+       }
+#endif
       bfd_set_error (bfd_error_file_too_big);
       _bfd_error_handler
        /* xgettext:c-format */

diff --git a/gas/testsuite/gas/pe/big-obj-auto.d b/gas/testsuite/gas/pe/big-obj-auto.d
new file mode 100644 (file)
index 0000000..7b4d0ef
--- /dev/null
+++ b/gas/testsuite/gas/pe/big-obj-auto.d
@@ -0,0 +1,9 @@
+#objdump: -h
+#name: PE big obj auto-promotion
+
+.*: *file format pe-bigobj-.*
+
+Sections:
+#...
+80002 +\.data\$a79999  .*
+                  CONTENTS, ALLOC, LOAD, DATA

diff --git a/gas/testsuite/gas/pe/big-obj-auto.s b/gas/testsuite/gas/pe/big-obj-auto.s
new file mode 100644 (file)
index 0000000..f09ccd0
--- /dev/null
+++ b/gas/testsuite/gas/pe/big-obj-auto.s
@@ -0,0 +1,16 @@
+       .file "big-obj-auto.s"
+
+       .irp n,0,1,2,3,4,5,6,7
+       .irp m,0,1,2,3,4,5,6,7,8,9
+       .irp c,0,1,2,3,4,5,6,7,8,9
+       .irp d,0,1,2,3,4,5,6,7,8,9
+       .irp u,0,1,2,3,4,5,6,7,8,9
+       .globl a\n\m\c\d\u
+       .section .data$a\n\m\c\d\u,"w"
+a\n\m\c\d\u :
+       .byte 1
+       .endr
+       .endr
+       .endr
+       .endr
+       .endr

diff --git a/gas/testsuite/gas/pe/pe.exp b/gas/testsuite/gas/pe/pe.exp
index e25de3cfa9d9fa74c5ef1e8f7696ec3fe6cf3918..82f217cf9485e157f689ff517542565f738ab289 100644 (file)
--- a/gas/testsuite/gas/pe/pe.exp
+++ b/gas/testsuite/gas/pe/pe.exp
@@ -68,6 +68,9 @@ if {[istarget "aarch64-*-pe*"] || [istarget "aarch64-*-mingw*"]} {
 # Big obj
 
 
-if ([istarget "*-*-mingw*"]) then {
+if { [istarget "aarch64-*-*"]
+     || ([istarget "i*86-*-*"] && ![istarget "*-*-interix*"])
+     || [istarget "x86_64-*-*"] } then {
        run_dump_test "big-obj"
+       run_dump_test "big-obj-auto"
 }