as: handle the .rodata section

erlang/apps/as/priv/test7.s

@@ -0,0 +1,29 @@
+/*
+ * test7.s
+ * Copyright (C) 2020  Mikael Pettersson
+ *
+ * This file is part of pdp10-tools.
+ *
+ * pdp10-tools is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * pdp10-tools is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with pdp10-tools.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+	.section .text,"ax",@progbits
+	.globl	foo
+	.type	foo,@function
+foo:
+	popj	017,
+	.size	foo,.-foo
+
+	.section .rodata,"a",@progbits
+bar:	.long 42

erlang/apps/as/src/assemble.erl

@@ -1,7 +1,7 @@
 %%% -*- erlang-indent-level: 2 -*-
 %%%
 %%% sections assembler for pdp10-elf as
-%%% Copyright (C) 2013-2019  Mikael Pettersson
+%%% Copyright (C) 2013-2020  Mikael Pettersson
 %%%
 %%% This file is part of pdp10-tools.
 %%%
@@ -44,6 +44,10 @@ section(Section, Tunit) ->
             , sh_type = ?SHT_PROGBITS
             , sh_flags = ?SHF_ALLOC bor ?SHF_WRITE
             } -> stmts(Section, Tunit);
+    #section{ name = ".rodata" ++ _
+            , sh_type = ?SHT_PROGBITS
+            , sh_flags = ?SHF_ALLOC
+            } -> stmts(Section, Tunit);
     #section{ name = ".text" ++ _
             , sh_type = ?SHT_PROGBITS
             , sh_flags = ?SHF_ALLOC bor ?SHF_EXECINSTR

erlang/apps/as/src/input.erl

@@ -404,6 +404,7 @@ pass2_sections([{SectionName, {Section, SubsectionsMap}} | Sections], Tunit0) ->
 pass2_subsections(SectionName, SubsectionsMap, Tunit) ->
   case SectionName of
     ".data" ++ _ -> ok;
+    ".rodata" ++ _ -> ok;
     ".text" ++ _ -> ok
   end,
   pass2_subsections(lists:sort(maps:to_list(SubsectionsMap)), Tunit).
@@ -648,6 +649,7 @@ tunit_init() ->
 section_from_name(SectionName) ->
   case SectionName of
     ".data" -> section_dot_data();
+    ".rodata" -> section_dot_rodata();
     ".text" -> section_dot_text();
     _ -> false
   end.
@@ -680,6 +682,20 @@ section_dot_data() -> % ".data"
           , sh_entsize = 0
           }.
 
+section_dot_rodata() -> % ".rodata"
+  #section{ name = ".rodata"
+          , data = {stmts, []}
+          , dot = 0
+          , shndx = 0
+          , sh_name = 0
+          , sh_type = ?SHT_PROGBITS
+          , sh_offset = 0
+          , sh_flags = ?SHF_ALLOC
+          , sh_link = ?SHN_UNDEF
+          , sh_addralign = 4 % FIXME: target-specific
+          , sh_entsize = 0
+          }.
+
 section_dot_text() -> % ".text"
   #section{ name = ".text"
           , data = {stmts, []}