This makes -g work again in LTO mode for Windows targets by kludging around
the missing support for copying PE-COFF debug sections in the simple object
module of libiberty, thus effectively disabling early debug in LTO mode.
The patch also contains a fixlet for a related oversight in the LTO wrapper.
Bootstrapped and tested on x86-64/Windows, approved by Richard B. in the audit
trail and applied on the mainline.
2018-04-12 Eric Botcazou <ebotca...@adacore.com>
PR target/85238
* lto-wrapper.c (debug_objcopy): Open the files in binary mode.
* dwarf2out.c (dwarf2out_early_finish): Do not generate assembly in LTO
mode for PE-COFF targets.
* config/i386/i386-protos.h (i386_pe_asm_lto_start): Declare.
(i386_pe_asm_lto_end): Likewise.
* config/i386/cygming.h (TARGET_ASM_LTO_START): Define.
(TARGET_ASM_LTO_END): Likewise.
* config/i386/winnt.c (saved_debug_info_level): New static variable.
(i386_pe_asm_lto_start): New function.
(i386_pe_asm_lto_end): Likewise.
--
Eric BotcazouIndex: config/i386/cygming.h
===================================================================
--- config/i386/cygming.h (revision 259205)
+++ config/i386/cygming.h (working copy)
@@ -356,6 +356,12 @@ do { \
#undef TARGET_ASM_FILE_END
#define TARGET_ASM_FILE_END i386_pe_file_end
+/* Kludge because of missing PE-COFF support for early LTO debug. */
+#undef TARGET_ASM_LTO_START
+#define TARGET_ASM_LTO_START i386_pe_asm_lto_start
+#undef TARGET_ASM_LTO_END
+#define TARGET_ASM_LTO_END i386_pe_asm_lto_end
+
#undef ASM_COMMENT_START
#define ASM_COMMENT_START " #"
Index: config/i386/i386-protos.h
===================================================================
--- config/i386/i386-protos.h (revision 259205)
+++ config/i386/i386-protos.h (working copy)
@@ -254,6 +254,8 @@ extern void i386_pe_asm_output_aligned_d
HOST_WIDE_INT,
HOST_WIDE_INT);
extern void i386_pe_file_end (void);
+extern void i386_pe_asm_lto_start (void);
+extern void i386_pe_asm_lto_end (void);
extern void i386_pe_start_function (FILE *, const char *, tree);
extern void i386_pe_end_function (FILE *, const char *, tree);
extern void i386_pe_end_cold_function (FILE *, const char *, tree);
Index: config/i386/winnt.c
===================================================================
--- config/i386/winnt.c (revision 259205)
+++ config/i386/winnt.c (working copy)
@@ -808,6 +808,23 @@ i386_pe_file_end (void)
}
}
+/* Kludge because of missing PE-COFF support for early LTO debug. */
+
+static enum debug_info_levels saved_debug_info_level;
+
+void
+i386_pe_asm_lto_start (void)
+{
+ saved_debug_info_level = debug_info_level;
+ debug_info_level = DINFO_LEVEL_NONE;
+}
+
+void
+i386_pe_asm_lto_end (void)
+{
+ debug_info_level = saved_debug_info_level;
+}
+
/* x64 Structured Exception Handling unwind info. */
Index: dwarf2out.c
===================================================================
--- dwarf2out.c (revision 259205)
+++ dwarf2out.c (working copy)
@@ -31807,7 +31807,11 @@ dwarf2out_early_finish (const char *file
early_dwarf_finished = true;
/* Do not generate DWARF assembler now when not producing LTO bytecode. */
- if (!flag_generate_lto && !flag_generate_offload)
+ if ((!flag_generate_lto && !flag_generate_offload)
+ /* FIXME: Disable debug info generation for PE-COFF targets since the
+ copy_lto_debug_sections operation of the simple object support in
+ libiberty is not implemented for them yet. */
+ || TARGET_PECOFF)
return;
/* Now as we are going to output for LTO initialize sections and labels
Index: lto-wrapper.c
===================================================================
--- lto-wrapper.c (revision 259205)
+++ lto-wrapper.c (working copy)
@@ -983,7 +983,7 @@ debug_objcopy (const char *infile)
infile = fname;
inoff = (off_t) loffset;
}
- int infd = open (infile, O_RDONLY);
+ int infd = open (infile, O_RDONLY | O_BINARY);
if (infd == -1)
return NULL;
simple_object_read *inobj = simple_object_start_read (infd, inoff,
