Darwin: Make sanitizer local vars linker-visible.

Another case where we need a linker-visible symbols in order to
preserve the ld64 atom model.  If these symbols are emitted as
'local' the linker cannot see that they are separate from any
global weak entry that precedes them.  This will cause the linker
to complain that there is (apparently) direct access to such a
weak global, preventing it from being replaced.

This is a short-term fix for the problem - we need generic
handling for relevant cases (that also does not pessimise objects
by emitting unnecessary symbols and relocations).

gcc/ChangeLog:

2020-05-23  Iain Sandoe  <iain@sandoe.co.uk>

	* config/darwin.h (ASM_GENERATE_INTERNAL_LABEL):
	Make ubsan_{data,type},ASAN symbols linker-visible.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7a7b599..ede1f15 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2020-05-23 Iain Sandoe <iain@sandoe.co.uk>
+
+       * config/darwin.h (ASM_GENERATE_INTERNAL_LABEL): Make
+       ubsan_{data,type},ASAN symbols linker-visible.
+
 2020-05-22  Jan Hubicka  <hubicka@ucw.cz>
 
        * lto-streamer-out.c (DFS::DFS): Silence warning.

diff --git a/gcc/config/darwin.h b/gcc/config/darwin.h
index 27665b3..f528b17 100644 (file)
--- a/gcc/config/darwin.h
+++ b/gcc/config/darwin.h
@@ -808,6 +808,12 @@ extern GTY(()) section * darwin_sections[NUM_DARWIN_SECTIONS];
   do {                                                 \
     if (strcmp ("LC", PREFIX) == 0)                    \
       sprintf (LABEL, "*%s%ld", "lC", (long)(NUM));    \
+    else if (strcmp ("Lubsan_data", PREFIX) == 0)      \
+      sprintf (LABEL, "*%s%ld", "lubsan_data", (long)(NUM));\
+    else if (strcmp ("Lubsan_type", PREFIX) == 0)      \
+      sprintf (LABEL, "*%s%ld", "lubsan_type", (long)(NUM));\
+    else if (strcmp ("LASAN", PREFIX) == 0)    \
+      sprintf (LABEL, "*%s%ld", "lASAN", (long)(NUM));\
     else                                               \
       sprintf (LABEL, "*%s%ld", PREFIX, (long)(NUM));  \
   } while (0)