[Darwin] Amend section for constants with relocations.

Darwin's linker doesn't like text section relocations (they require special
enabling).  The Fortran FE, at least, seems to generate cases where the
initialiser for a pointer constant can need a relocation.  We can handle
this by special-casing SECCAT_RODATA when the relocation is present by
placing the constant in the .const_data section.

gcc/

2019-10-18  Iain Sandoe  <iain@sandoe.co.uk>

	Backport from mainline
	2019-10-05  Iain Sandoe  <iain@sandoe.co.uk>

	PR target/59888
	* config/darwin.c (darwin_rodata_section): Add relocation flag,
	choose const_data section for constants with relocations.
	(machopic_select_section): Pass relocation flag to
	darwin_rodata_section ().

From-SVN: r277145

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ae17be5a74c40c4531a7dd76049e5711acb06be9..9179ad4b3b6106ebbc3a9cf1f4c2033e5df7a899 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2019-10-18  Iain Sandoe  <iain@sandoe.co.uk>
+
+       Backport from mainline
+       2019-10-05  Iain Sandoe  <iain@sandoe.co.uk>
+
+       PR target/59888
+       * config/darwin.c (darwin_rodata_section): Add relocation flag,
+       choose const_data section for constants with relocations.
+       (machopic_select_section): Pass relocation flag to
+       darwin_rodata_section ().
+
 2019-10-18  Iain Sandoe  <iain@sandoe.co.uk>
 
        Backport from mainline

diff --git a/gcc/config/darwin.c b/gcc/config/darwin.c
index 5e0110c48d94d3d914f8dfff803e094299ed3619..55759df79c8af37b76d0eae0eddb3e87e72107d0 100644 (file)
--- a/gcc/config/darwin.c
+++ b/gcc/config/darwin.c
@@ -1252,12 +1252,13 @@ darwin_mark_decl_preserved (const char *name)
 }
 
 static section *
-darwin_rodata_section (int use_coal, bool zsize)
+darwin_rodata_section (int use_coal, bool zsize, int reloc)
 {
   return (use_coal
          ? darwin_sections[const_coal_section]
          : (zsize ? darwin_sections[zobj_const_section]
-                  : darwin_sections[const_section]));
+                  : reloc ? darwin_sections[const_data_section]
+                          : darwin_sections[const_section]));
 }
 
 static section *
@@ -1550,7 +1551,7 @@ machopic_select_section (tree decl,
 
     case SECCAT_RODATA:
     case SECCAT_SRODATA:
-      base_section = darwin_rodata_section (use_coal, zsize);
+      base_section = darwin_rodata_section (use_coal, zsize, reloc);
       break;
 
     case SECCAT_RODATA_MERGE_STR: