gas: Reuse the input file entry in the file table

Some instructions can be emitted (dwarf2_emit_insn is called) before the
first .file <NUMBER> directive has been seen, which allocates the input
file as the first file entry.  Reuse the input file entry in the file
table.

	PR gas/25878
	PR gas/26740
	* dwarf2dbg.c (file_entry): Remove auto_assigned.
	(assign_file_to_slot): Remove the auto_assign argument.
	(allocate_filenum): Updated.
	(allocate_filename_to_slot): Reuse the input file entry in the
	file table.
	(dwarf2_where): Replace as_where with as_where_physical.
	* testsuite/gas/i386/dwarf5-line-1.d: New file.
	* testsuite/gas/i386/dwarf5-line-1.s: Likewise.
	* testsuite/gas/i386/i386.exp: Run dwarf5-line-1.

5 files changed, 84 insertions, 19 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index c5235ba..a74362b 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,6 +1,22 @@
+2020-10-16  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/25878
+	PR gas/26740
+	* dwarf2dbg.c (file_entry): Remove auto_assigned.
+	(assign_file_to_slot): Remove the auto_assign argument.
+	(allocate_filenum): Updated.
+	(allocate_filename_to_slot): Reuse the input file entry in the
+	file table.
+	(dwarf2_where): Replace as_where with as_where_physical.
+	* testsuite/gas/i386/dwarf5-line-1.d: New file.
+	* testsuite/gas/i386/dwarf5-line-1.s: Likewise.
+	* testsuite/gas/i386/i386.exp: Run dwarf5-line-1.
+
 2020-10-16  Lili Cui  <lili.cui@intel.com>
 
-	* config/tc-i386.c: Move Pseudo Prefix check to match_template.
+	* config/tc-i386.c (cpu_flags_match): Move Pseudo Prefix check
+	to ...
+	(match_template): Here.
 	* testsuite/gas/i386/avx-vnni-inval.l: New file.
 	* testsuite/gas/i386/avx-vnni-inval.s: Likewise.
 	* testsuite/gas/i386/avx-vnni.d: Delete invalid {vex2} test.
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index 1c21d58..6943dbf 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -211,7 +211,6 @@ struct file_entry
 {
   const char *   filename;
   unsigned int   dir;
-  bfd_boolean    auto_assigned;
   unsigned char  md5[NUM_MD5_BYTES];
 };
 
@@ -633,7 +632,7 @@ get_directory_table_entry (const char *  dirname,
 }
 
 static bfd_boolean
-assign_file_to_slot (unsigned long i, const char *file, unsigned int dir, bfd_boolean auto_assign)
+assign_file_to_slot (unsigned long i, const char *file, unsigned int dir)
 {
   if (i >= files_allocated)
     {
@@ -653,7 +652,6 @@ assign_file_to_slot (unsigned long i, const char *file, unsigned int dir, bfd_bo
 
   files[i].filename = file;
   files[i].dir = dir;
-  files[i].auto_assigned = auto_assign;
   memset (files[i].md5, 0, NUM_MD5_BYTES);
 
   if (files_in_use < i + 1)
@@ -717,7 +715,7 @@ allocate_filenum (const char * pathname)
 	return i;
       }
 
-  if (!assign_file_to_slot (i, file, dir, TRUE))
+  if (!assign_file_to_slot (i, file, dir))
     return -1;
 
   last_used = i;
@@ -792,18 +790,12 @@ allocate_filename_to_slot (const char *  dirname,
 	}
 
     fail:
-      /* If NUM was previously allocated automatically then
-	 choose another slot for it, so that we can reuse NUM.  */
-      if (files[num].auto_assigned)
-	{
-	  /* Find an unused slot.  */
-	  for (i = 1; i < files_in_use; ++i)
-	    if (files[i].filename == NULL)
-	      break;
-	  if (! assign_file_to_slot (i, files[num].filename, files[num].dir, TRUE))
-	    return FALSE;
-	  files[num].filename = NULL;
-	}
+      /* Reuse NUM if it is 1 and was assigned to the input file before
+	 the first .file <NUMBER> directive was seen.  */
+      file = as_where_physical (&i);
+      file = get_basename (file);
+      if (num == 1 && filename_cmp (file, files[num].filename) == 0)
+	files[num].filename = NULL;
       else
 	{
 	  as_bad (_("file table slot %u is already occupied by a different file (%s%s%s vs %s%s%s)"),
@@ -833,7 +825,7 @@ allocate_filename_to_slot (const char *  dirname,
   d = get_directory_table_entry (dirname, dirlen, num == 0);
   i = num;
 
-  if (! assign_file_to_slot (i, file, d, FALSE))
+  if (! assign_file_to_slot (i, file, d))
     return FALSE;
 
   if (with_md5)
@@ -902,7 +894,7 @@ dwarf2_where (struct dwarf2_line_info *line)
       const char *filename;
 
       memset (line, 0, sizeof (*line));
-      filename = as_where (&line->line);
+      filename = as_where_physical (&line->line);
       line->filenum = allocate_filenum (filename);
       /* FIXME: We should check the return value from allocate_filenum.  */
       line->column = 0;
diff --git a/gas/testsuite/gas/i386/dwarf5-line-1.d b/gas/testsuite/gas/i386/dwarf5-line-1.d
new file mode 100644
index 0000000..7d602d0
--- /dev/null
+++ b/gas/testsuite/gas/i386/dwarf5-line-1.d
@@ -0,0 +1,50 @@
+#as: -gdwarf-5
+#readelf: -wl
+#name: DWARF5 .debug_line 1
+
+Raw dump of debug contents of section \.z?debug_line:
+
+  Offset:                      0x0
+  Length:                      .*
+  DWARF Version:               5
+  Address size \(bytes\):        .*
+  Segment selector \(bytes\):    0
+  Prologue Length:             .*
+  Minimum Instruction Length:  1
+  Maximum Ops per Instruction: 1
+  Initial value of 'is_stmt':  1
+  Line Base:                   -5
+  Line Range:                  14
+  Opcode Base:                 13
+
+ Opcodes:
+  Opcode 1 has 0 args
+  Opcode 2 has 1 arg
+  Opcode 3 has 1 arg
+  Opcode 4 has 1 arg
+  Opcode 5 has 1 arg
+  Opcode 6 has 0 args
+  Opcode 7 has 0 args
+  Opcode 8 has 0 args
+  Opcode 9 has 1 arg
+  Opcode 10 has 0 args
+  Opcode 11 has 0 args
+  Opcode 12 has 1 arg
+
+ The Directory Table \(offset 0x.*, lines 2, columns 1\):
+  Entry	Name
+  0	\(indirect line string, offset: 0x.*\): .*/gas/testsuite/gas/i386
+  1	\(indirect line string, offset: 0x.*\): .*/gas/testsuite/gas/i386
+
+ The File Name Table \(offset 0x.*, lines 2, columns 3\):
+  Entry	Dir	MD5				Name
+  0	0 0xbbd69fc03ce253b2dbaab2522dd519ae	\(indirect line string, offset: 0x.*\): core.c
+  1	0 0x00000000000000000000000000000000	\(indirect line string, offset: 0x.*\): types.h
+
+ Line Number Statements:
+  \[0x.*\]  Extended opcode 2: set Address to 0x0
+  \[0x.*\]  Special opcode 8: advance Address by 0 to 0x0 and Line by 3 to 4
+  \[0x.*\]  Advance PC by 1 to 0x1
+  \[0x.*\]  Extended opcode 1: End of Sequence
+
+
diff --git a/gas/testsuite/gas/i386/dwarf5-line-1.s b/gas/testsuite/gas/i386/dwarf5-line-1.s
new file mode 100644
index 0000000..6e343ad
--- /dev/null
+++ b/gas/testsuite/gas/i386/dwarf5-line-1.s
@@ -0,0 +1,6 @@
+	.text
+	.global kretprobe_trampoline
+kretprobe_trampoline:
+	ret
+	.file	0 "core.c" md5 0xbbd69fc03ce253b2dbaab2522dd519ae
+	.file	1 "types.h"
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 068813d..6834749 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -614,6 +614,7 @@ if [gas_32_check] then {
 	run_dump_test "dwarf2-line-2"
 	run_dump_test "dwarf2-line-3"
 	run_dump_test "dwarf2-line-4"
+	run_dump_test "dwarf5-line-1"
 
 	run_dump_test "dw2-compress-2"
 	run_dump_test "dw2-compressed-2"