gas: don't ignore .linefile inside false conditionals

When assembling code previously pre-processed by a C compiler, long
enough comments may have been collapsed into "# <line> <file>"
constructs. If we skip these, line numbers (and possibly even file
names) will be off / wrong in both diagnostics and debug info.

4 files changed, 26 insertions, 0 deletions

diff --git a/gas/cond.c b/gas/cond.c
index ee441e1..27977db 100644
--- a/gas/cond.c
+++ b/gas/cond.c
@@ -525,6 +525,10 @@ ignore_input (void)
 	  || !strncasecmp (s, "endc", 4))
 	return 0;
       break;
+    case 'l': case 'L':
+      if (!strncasecmp (s, "linefile", 8))
+	return 0;
+      break;
     }
 
   return (current_cframe != NULL) && (current_cframe->ignoring);
diff --git a/gas/testsuite/gas/all/cond-2.l b/gas/testsuite/gas/all/cond-2.l
new file mode 100644
index 0000000..189c0de
--- /dev/null
+++ b/gas/testsuite/gas/all/cond-2.l
@@ -0,0 +1,12 @@
+# This should match the output of gas -al cond-2.s.
+.*: Assembler messages:
+.*:1005: Warning: line 5
+.*cond-2.s.*
+
+
+[ 	]*[1-9][0-9]*[ 	]+\.if[ 	]+0[ 	]*
+[ 	]*[1-9][0-9]*[ 	]+# 1003 "cond-2\.s"
+[ 	]*[1-9][0-9]*[ 	]+\.endif[ 	]*
+[ 	]*[1-9][0-9]*[ 	]*
+[ 	]*[1-9][0-9]*[ 	]+\.warning[ 	].*
+#pass
diff --git a/gas/testsuite/gas/all/cond-2.s b/gas/testsuite/gas/all/cond-2.s
new file mode 100644
index 0000000..5b8166c
--- /dev/null
+++ b/gas/testsuite/gas/all/cond-2.s
@@ -0,0 +1,5 @@
+	.if 0
+# 1003 "cond-2.s"
+	.endif
+
+	.warning "line 5"
diff --git a/gas/testsuite/gas/all/gas.exp b/gas/testsuite/gas/all/gas.exp
index ae7957b..1b87cf2 100644
--- a/gas/testsuite/gas/all/gas.exp
+++ b/gas/testsuite/gas/all/gas.exp
@@ -461,6 +461,11 @@ if [is_elf_format] {
 
 run_dump_test quoted-sym-names
 
+# Targets where # is not a line comment character don't transform
+# "# <line> <file>" into .linefile (PR gas/29120).
+setup_xfail "tic30-*-*"
+run_list_test cond-2 "-al"
+
 run_list_test macro "-alm"
 
 run_list_test pr20312