PR28149 part 2, purge generated line info

Mixing compiler generated line info with gas generated line info is
generally just confusing.  Also .loc directives with non-zero view
fields might reference a previous .loc.  It becomes a little more
tricky to locate that previous .loc if there might be gas generated
line info present too.  Mind you, we turn off gas generation of line
info on seeing compiler generated line info, so any reference back
won't hit gas generated line info.  At least, if the view info is
sane.  Unfortunately, gas needs to handle mangled source.

	PR 28149
	* dwarf2dbg.c (purge_generated_debug): New function.
	(dwarf2_directive_filename): Call the above.
	(out_debug_line): Don't segfault after purging.
	* testsuite/gas/i386/dwarf2-line-4.d: Update expected output.
	* testsuite/gas/i386/dwarf4-line-1.d: Likewise.
	* testsuite/gas/i386/dwarf5-line-1.d: Likewise.
	* testsuite/gas/i386/dwarf5-line-2.d: Likewise.

5 files changed, 40 insertions, 48 deletions

diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index c6303ba..1250fce 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -782,6 +782,32 @@ do_allocate_filenum (struct line_entry *e)
   while (e);
 }
 
+/* Remove any generated line entries.  These don't live comfortably
+   with compiler generated line info.  */
+
+static void
+purge_generated_debug (void)
+{
+  struct line_seg *s;
+
+  for (s = all_segs; s; s = s->next)
+    {
+      struct line_subseg *lss = s->head;
+      struct line_entry *e, *next;
+
+      for (e = lss->head; e; e = next)
+	{
+	  know (e->loc.filenum == -1u);
+	  next = e->next;
+	  free (e);
+	}
+
+      lss->head = NULL;
+      lss->ptail = &lss->head;
+      lss->pmove_tail = &lss->head;
+    }
+}
+
 /* Allocate slot NUM in the .debug_line file table to FILENAME.
    If DIRNAME is not NULL or there is a directory component to FILENAME
    then this will be stored in the directory table, if not already present.
@@ -1146,6 +1172,8 @@ dwarf2_directive_filename (void)
 
   /* A .file directive implies compiler generated debug information is
      being supplied.  Turn off gas generated debug info.  */
+  if (debug_type == DEBUG_DWARF2)
+    purge_generated_debug ();
   debug_type = DEBUG_NONE;
 
   if (num != (unsigned int) num
@@ -2414,7 +2442,7 @@ out_debug_line (segT line_seg)
   for (s = all_segs; s; s = s->next)
     /* Paranoia - this check should have already have
        been handled in dwarf2_gen_line_info_1().  */
-    if (SEG_NORMAL (s->seg))
+    if (s->head->head && SEG_NORMAL (s->seg))
       process_entries (s->seg, s->head->head);
 
   if (flag_dwarf_sections)
diff --git a/gas/testsuite/gas/i386/dwarf2-line-4.d b/gas/testsuite/gas/i386/dwarf2-line-4.d
index a01fd05..0403c3e 100644
--- a/gas/testsuite/gas/i386/dwarf2-line-4.d
+++ b/gas/testsuite/gas/i386/dwarf2-line-4.d
@@ -28,21 +28,15 @@ Raw dump of debug contents of section \.z?debug_line:
   Opcode 11 has 0 args
   Opcode 12 has 1 arg
 
- The Directory Table \(offset 0x.*\):
-  .*
+ The Directory Table is empty\.
 
  The File Name Table \(offset 0x.*\):
   Entry	Dir	Time	Size	Name
   1	0	0	0	dwarf2-test.c
-  2	1	0	0	dwarf2-line-4.s
 
  Line Number Statements:
-  \[0x.*\]  Set File Name to entry 2 in the File Name Table
-  \[0x.*\]  Extended opcode 2: set Address to 0x0
-  \[0x.*\]  Special opcode 13: advance Address by 0 to 0x0 and Line by 8 to 9
-  \[0x.*\]  Set File Name to entry 1 in the File Name Table
-  \[0x.*\]  Advance Line by -8 to 1
-  \[0x.*\]  Special opcode 19: advance Address by 1 to 0x1 and Line by 0 to 1
+  \[0x.*\]  Extended opcode 2: set Address to 0x1
+  \[0x.*\]  Copy
   \[0x.*\]  Advance PC by 1 to 0x2
   \[0x.*\]  Extended opcode 1: End of Sequence
 
diff --git a/gas/testsuite/gas/i386/dwarf4-line-1.d b/gas/testsuite/gas/i386/dwarf4-line-1.d
index 8199efb..762bdce 100644
--- a/gas/testsuite/gas/i386/dwarf4-line-1.d
+++ b/gas/testsuite/gas/i386/dwarf4-line-1.d
@@ -29,24 +29,11 @@ Raw dump of debug contents of section \.z?debug_line:
   Opcode 11 has 0 args
   Opcode 12 has 1 arg
 
- The Directory Table \(offset 0x.*\):
-  1	.*/gas/testsuite/gas/i386
+ The Directory Table is empty\.
 
  The File Name Table \(offset 0x.*\):
   Entry	Dir	Time	Size	Name
   1	0	0	0	foo.c
   2	0	0	0	foo.h
-  3	1	0	0	dwarf4-line-1.s
-
- Line Number Statements:
-  \[0x.*\]  Set File Name to entry 2 in the File Name Table
-  \[0x.*\]  Extended opcode 2: set Address to 0x0
-  \[0x.*\]  Advance Line by 81 to 82
-  \[0x.*\]  Copy
-  \[0x.*\]  Set File Name to entry 3 in the File Name Table
-  \[0x.*\]  Advance Line by -73 to 9
-  \[0x.*\]  Special opcode 19: advance Address by 1 to 0x1 and Line by 0 to 9
-  \[0x.*\]  Advance PC by 3 to 0x4
-  \[0x.*\]  Extended opcode 1: End of Sequence
-
 
+ No Line Number Statements\.
diff --git a/gas/testsuite/gas/i386/dwarf5-line-1.d b/gas/testsuite/gas/i386/dwarf5-line-1.d
index 2c2cf56..6ec5191 100644
--- a/gas/testsuite/gas/i386/dwarf5-line-1.d
+++ b/gas/testsuite/gas/i386/dwarf5-line-1.d
@@ -31,22 +31,13 @@ Raw dump of debug contents of section \.z?debug_line:
   Opcode 11 has 0 args
   Opcode 12 has 1 arg
 
- The Directory Table \(offset 0x.*, lines 2, columns 1\):
+ The Directory Table \(offset 0x.*, lines 1, columns 1\):
   Entry	Name
   0	\(indirect line string, offset: 0x.*\): .*/gas/testsuite
-  1	\(indirect line string, offset: 0x.*\): .*/gas/testsuite/gas/i386
 
- The File Name Table \(offset 0x.*, lines 3, columns 3\):
+ 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 0x0	\(indirect line string, offset: 0x.*\): types.h
-  2	1 0x0	\(indirect line string, offset: 0x.*\): dwarf5-line-1.s
-
- Line Number Statements:
-  \[0x.*\]  Set File Name to entry 2 in the File Name Table
-  \[0x.*\]  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
-
 
+ No Line Number Statements\.
diff --git a/gas/testsuite/gas/i386/dwarf5-line-2.d b/gas/testsuite/gas/i386/dwarf5-line-2.d
index 85f98c8..4bb849b 100644
--- a/gas/testsuite/gas/i386/dwarf5-line-2.d
+++ b/gas/testsuite/gas/i386/dwarf5-line-2.d
@@ -31,20 +31,12 @@ Raw dump of debug contents of section \.z?debug_line:
   Opcode 11 has 0 args
   Opcode 12 has 1 arg
 
- The Directory Table \(offset 0x.*, lines 2, columns 1\):
+ The Directory Table \(offset 0x.*, lines 1, columns 1\):
   Entry	Name
   0	\(indirect line string, offset: 0x.*\): .*/gas/testsuite
-  1	\(indirect line string, offset: 0x.*\): .*/gas/testsuite/gas/i386
 
- The File Name Table \(offset 0x.*, lines 2, columns 3\):
+ The File Name Table \(offset 0x.*, lines 1, columns 3\):
   Entry	Dir	MD5				Name
   0	0 0xbbd69fc03ce253b2dbaab2522dd519ae	\(indirect line string, offset: 0x.*\): core.c
-  1	1 0x0	\(indirect line string, offset: .*\): dwarf5-line-2.s
-
- 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
-
 
+ No Line Number Statements\.