[pushed] dwarf2read: Silence -Wenum-compare-switch warning

[Simon Marchi <simon.marchi@ericsson.com>]

Compiling with Clang 6 gives:

/home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:24385:14: error: comparison of two values with different enumeration types in switch statement ('enum dwarf_macro_record_type' and 'dwarf_macinfo_record_type') [-Werror,-Wenum-compare-switch]
        case DW_MACINFO_vendor_ext:
             ^~~~~~~~~~~~~~~~~~~~~
/home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:24561:7: error: comparison of two values with different enumeration types in switch statement ('enum dwarf_macro_record_type' and 'dwarf_macinfo_record_type') [-Werror,-Wenum-compare-switch]
        case DW_MACINFO_vendor_ext:
             ^~~~~~~~~~~~~~~~~~~~~

This code uses the two enum types on purpose, because it handles both
.debug_macro and .debug_macinfo sections.  Add some pragmas to disable
the warning in these specific cases.

gdb/ChangeLog:

	* dwarf2read.c (dwarf_decode_macro_bytes): Ignore
	-Wenum-compare-switch warning.
	(dwarf_decode_macros): Likewise.
---
 gdb/ChangeLog    | 6 ++++++
 gdb/dwarf2read.c | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 54b7041..7689e0e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-12-30  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* dwarf2read.c (dwarf_decode_macro_bytes): Ignore
+	-Wenum-compare-switch warning.
+	(dwarf_decode_macros): Likewise.
+
 2017-12-30  Tom Tromey  <tom@tromey.com>
 	    Simon Marchi  <simon.marchi@ericsson.com>
 
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 85e33f0..fcd5e99 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -24179,6 +24179,8 @@ dwarf_decode_macro_bytes (bfd *abfd,
 
       /* Note that we rely on the fact that the corresponding GNU and
 	 DWARF constants are the same.  */
+      DIAGNOSTIC_PUSH
+      DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES
       switch (macinfo_type)
 	{
 	  /* A zero macinfo type indicates the end of the macro
@@ -24403,6 +24405,7 @@ dwarf_decode_macro_bytes (bfd *abfd,
 	    return;
 	  break;
         }
+      DIAGNOSTIC_POP
     } while (macinfo_type != 0);
 }
 
@@ -24495,6 +24498,8 @@ dwarf_decode_macros (struct dwarf2_cu *cu, unsigned int offset,
 
       /* Note that we rely on the fact that the corresponding GNU and
 	 DWARF constants are the same.  */
+      DIAGNOSTIC_PUSH
+      DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES
       switch (macinfo_type)
         {
           /* A zero macinfo type indicates the end of the macro
@@ -24575,6 +24580,7 @@ dwarf_decode_macros (struct dwarf2_cu *cu, unsigned int offset,
 	    return;
 	  break;
 	}
+      DIAGNOSTIC_POP
     } while (macinfo_type != 0 && current_file == NULL);
 
   /* Second pass: Process all entries.
-- 
2.7.4