[PATCH 3/6] DWARF Two Level Line Tables: check_line_address

[Doug Evans <dje at google dot com>]

Hi.

This patch just factors out the checking of a line address
to improve the S/N ratio of the calling function.

2015-03-12  Doug Evans  <dje@google.com>

	* dwarf2read.c (record_line_ftype): New typedef.
	(check_line_address): New function.
	(dwarf_decode_lines_1): Call it.

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index d980b1a..fff5474 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -17429,6 +17429,11 @@ psymtab_include_file_name (const struct line_header *lh, int file_index,
   return include_name;
 }
 
+/* Function to record a line number.  */
+
+typedef void (record_line_ftype) (struct subfile *subfile, int line,
+				  CORE_ADDR pc);
+
 /* Ignore this record_line request.  */
 
 static void
@@ -17528,6 +17533,36 @@ dwarf_finish_line (struct gdbarch *gdbarch, struct subfile *subfile,
   dwarf_record_line (gdbarch, subfile, 0, address, p_record_line);
 }
 
+/* Check address and if invalid nop-out the rest of the lines in this
+   sequence.  */
+
+static void
+check_line_address (struct dwarf2_cu *cu, record_line_ftype **p_record_line,
+		    const gdb_byte *line_ptr,
+		    CORE_ADDR lowpc, CORE_ADDR address)
+{
+  /* If address < lowpc then it's not a usable value, it's outside the
+     pc range of the CU.  However, we restrict the test to only address
+     values of zero to preserve GDB's previous behaviour which is to
+     handle the specific case of a function being GC'd by the linker.  */
+
+  if (address == 0 && address < lowpc)
+    {
+      /* This line table is for a function which has been
+	 GCd by the linker.  Ignore it.  PR gdb/12528 */
+
+      struct objfile *objfile = cu->objfile;
+      long line_offset = line_ptr - get_debug_line_section (cu)->buffer;
+
+      complaint (&symfile_complaints,
+		 _(".debug_line address at offset 0x%lx is 0 [in module %s]"),
+		 line_offset, objfile_name (objfile));
+      *p_record_line = noop_record_line;
+      /* Note: *p_record_line is left as noop_record_line
+	 until we see DW_LNE_end_sequence.  */
+    }
+}
+
 /* Subroutine of dwarf_decode_lines to simplify it.
    Process the line number information in LH.  */
 
@@ -17661,31 +17696,10 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
 		  break;
 		case DW_LNE_set_address:
 		  address = read_address (abfd, line_ptr, cu, &bytes_read);
-
-		  /* If address < lowpc then it's not a usable value, it's
-		     outside the pc range of the CU.  However, we restrict
-		     the test to only address values of zero to preserve
-		     GDB's previous behaviour which is to handle the specific
-		     case of a function being GC'd by the linker.  */
-		  if (address == 0 && address < lowpc)
-		    {
-		      /* This line table is for a function which has been
-			 GCd by the linker.  Ignore it.  PR gdb/12528 */
-
-		      long line_offset
-			= line_ptr - get_debug_line_section (cu)->buffer;
-
-		      complaint (&symfile_complaints,
-				 _(".debug_line address at offset 0x%lx is 0 "
-				   "[in module %s]"),
-				 line_offset, objfile_name (objfile));
-		      p_record_line = noop_record_line;
-		      /* Note: p_record_line is left as noop_record_line
-			 until we see DW_LNE_end_sequence.  */
-		    }
-
-		  op_index = 0;
 		  line_ptr += bytes_read;
+		  check_line_address (cu, &p_record_line, line_ptr,
+				      lowpc, address);
+		  op_index = 0;
 		  address += baseaddr;
 		  address = gdbarch_adjust_dwarf2_line (gdbarch, address, 0);
 		  break;