Handle Ada Pragma Import and Pragma Export

Ada can import C APIs and also export Ada constructs to C via Pragma
Import and Pragma Export.  This patch adds support for these to gdb,
by arranging to either defer some aspects of a symbol to the
underlying C symbol (for Import) or by introducing a second symbol
(for Export).  A somewhat tricky approach is needed, both because gdb
doesn't generally handle symbol aliasing, and because Ada treats
symbol names in an unusual way (as compared to the rest of gdb).

8 files changed, 189 insertions, 4 deletions

diff --git a/gdb/testsuite/gdb.ada/complete.exp b/gdb/testsuite/gdb.ada/complete.exp
index 57b6546..9e92505 100644
--- a/gdb/testsuite/gdb.ada/complete.exp
+++ b/gdb/testsuite/gdb.ada/complete.exp
@@ -160,6 +160,7 @@ test_gdb_complete "pck" \
                               "p pck.ambiguous_func" \
                               "p pck.external_identical_one" \
                               "p pck.inner.inside_variable" \
+			      "p pck.internal_capitalized" \
                               "p pck.local_identical_one" \
                               "p pck.local_identical_two" \
                               "p pck.my_global_variable" \
@@ -172,6 +173,7 @@ test_gdb_complete "pck." \
                               "p pck.ambiguous_func" \
                               "p pck.external_identical_one" \
                               "p pck.inner.inside_variable" \
+			      "p pck.internal_capitalized" \
                               "p pck.local_identical_one" \
                               "p pck.local_identical_two" \
                               "p pck.my_global_variable" \
diff --git a/gdb/testsuite/gdb.ada/complete/pck.ads b/gdb/testsuite/gdb.ada/complete/pck.ads
index 77f8967..034c142 100644
--- a/gdb/testsuite/gdb.ada/complete/pck.ads
+++ b/gdb/testsuite/gdb.ada/complete/pck.ads
@@ -17,8 +17,8 @@ package Pck is
 
    My_Global_Variable : Integer := 1;
 
-   Exported_Capitalized : Integer := 2;
-   pragma Export (C, Exported_Capitalized, "Exported_Capitalized");
+   Internal_Capitalized : Integer := 2;
+   pragma Export (C, Internal_Capitalized, "Exported_Capitalized");
 
    Local_Identical_One : Integer := 4;
    Local_Identical_Two : Integer := 8;
diff --git a/gdb/testsuite/gdb.ada/import.exp b/gdb/testsuite/gdb.ada/import.exp
new file mode 100644
index 0000000..866b431
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/import.exp
@@ -0,0 +1,58 @@
+# Copyright 2023 Free Software Foundation, Inc.
+#
+# This program 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.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+load_lib "ada.exp"
+
+require allow_ada_tests
+
+standard_ada_testfile prog
+
+set cfile "inc"
+set csrcfile ${srcdir}/${subdir}/${testdir}/${cfile}.c
+set cobject [standard_output_file ${cfile}.o]
+
+if {[gdb_compile "${csrcfile}" "${cobject}" object debug] != ""} {
+    untested "could not compile C file"
+    return
+}
+if {[gdb_compile_ada "${srcfile}" "${binfile}" executable \
+	 [list debug additional_flags=-largs \
+	      additional_flags=${cobject} additional_flags=-margs]] != ""} {
+    return -1
+}
+
+clean_restart ${testfile}
+
+set bp_location [gdb_get_line_number "BREAK" ${testdir}/prog.adb]
+runto "prog.adb:$bp_location"
+
+gdb_test "print ordinary_var" " = 78"
+
+gdb_test "print imported_var" " = 42"
+gdb_test "print imported_var_ada" " = 42"
+gdb_test "print local_imported_var" " = 42"
+gdb_test "print pkg.imported_var_ada" " = 42"
+
+gdb_test "print pkg.exported_var_ada" " = 99"
+gdb_test "print exported_var_ada" " = 99"
+
+gdb_breakpoint "pkg.imported_func_ada" message
+gdb_breakpoint "imported_func" message
+gdb_breakpoint "imported_func_ada" message
+
+gdb_breakpoint "local_imported_func" message
+gdb_breakpoint "pkg.exported_func_ada" message
+gdb_breakpoint "exported_func_ada" message
+gdb_breakpoint "exported_func" message
diff --git a/gdb/testsuite/gdb.ada/import/inc.c b/gdb/testsuite/gdb.ada/import/inc.c
new file mode 100644
index 0000000..c3a1ea1
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/import/inc.c
@@ -0,0 +1,27 @@
+/* Copyright 2023 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program 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.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+extern int exported_var;
+extern int exported_func (void);
+
+int imported_var = 42;
+
+int
+imported_func (void)
+{
+  return exported_var + exported_func ();
+}
diff --git a/gdb/testsuite/gdb.ada/import/pkg.adb b/gdb/testsuite/gdb.ada/import/pkg.adb
new file mode 100644
index 0000000..e4f1c1a
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/import/pkg.adb
@@ -0,0 +1,28 @@
+--  Copyright 2023 Free Software Foundation, Inc.
+--
+--  This program 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.
+--
+--  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package body Pkg is
+
+   function Exported_Func_Ada return Integer is
+   begin
+      return Imported_Var_Ada;
+   end Exported_Func_Ada;
+
+   procedure Do_Nothing (A : System.Address) is
+   begin
+      null;
+   end Do_Nothing;
+
+end Pkg;
diff --git a/gdb/testsuite/gdb.ada/import/pkg.ads b/gdb/testsuite/gdb.ada/import/pkg.ads
new file mode 100644
index 0000000..5576d1b
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/import/pkg.ads
@@ -0,0 +1,33 @@
+--  Copyright 2023 Free Software Foundation, Inc.
+--
+--  This program 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.
+--
+--  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+with System;
+package Pkg is
+
+   Imported_Var_Ada : Integer;
+   pragma Import (C, Imported_Var_Ada, "imported_var");
+
+   function Imported_Func_Ada return Integer;
+   pragma Import (C, Imported_Func_Ada, "imported_func");
+
+   Exported_Var_Ada : Integer := 99;
+   pragma Export (C, Exported_Var_Ada, "exported_var");
+
+   function Exported_Func_Ada return Integer;
+   pragma Export (C, Exported_Func_Ada, "exported_func");
+
+   procedure Do_Nothing (A : System.Address);
+
+end Pkg;
diff --git a/gdb/testsuite/gdb.ada/import/prog.adb b/gdb/testsuite/gdb.ada/import/prog.adb
new file mode 100644
index 0000000..77f2073
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/import/prog.adb
@@ -0,0 +1,31 @@
+--  Copyright 2023 Free Software Foundation, Inc.
+--
+--  This program 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.
+--
+--  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+with Pkg;
+
+procedure Prog is
+   Ordinary_Var : Integer := 78;
+
+   Local_Imported_Var : Integer;
+   pragma Import (C, Local_Imported_Var, "imported_var");
+
+   function Local_Imported_Func return Integer;
+   pragma Import (C, Local_Imported_Func, "imported_func");
+begin
+   Local_Imported_Var := Local_Imported_Func;  --  BREAK
+   Pkg.Imported_Var_Ada := Pkg.Imported_Func_Ada;
+   Pkg.Do_Nothing (Pkg.Imported_Func_Ada'Address);
+   Pkg.Do_Nothing (Pkg.Exported_Func_Ada'Address);
+end Prog;
diff --git a/gdb/testsuite/gdb.ada/info_auto_lang.exp b/gdb/testsuite/gdb.ada/info_auto_lang.exp
index 5202605..5134643 100644
--- a/gdb/testsuite/gdb.ada/info_auto_lang.exp
+++ b/gdb/testsuite/gdb.ada/info_auto_lang.exp
@@ -51,8 +51,14 @@ if {![runto "some_c.c:$bp_location"]} {
 
 set func_in_c(c_syntax)      "${decimal}:	void proc_in_c\\\(void\\\);"
 set func_in_c(ada_syntax)    "${decimal}:	procedure proc_in_c;"
-set func_in_ada(c_syntax)    "${decimal}:	void proc_in_ada\\\(void\\\);"
-set func_in_ada(ada_syntax)  "${decimal}:	procedure proc_in_ada;"
+set func_in_ada(c_syntax) \
+    [string cat \
+	 "${decimal}:	void proc_in_ada\\\(void\\\);\r\n" \
+	 "${decimal}:	void proc_in_ada.something_in_c\\\(void\\\);"]
+set func_in_ada(ada_syntax) \
+    [string cat \
+	 "${decimal}:	procedure proc_in_ada;\r\n" \
+	 "${decimal}:	procedure proc_in_ada.something_in_c;"]
 
 set type_in_c(c_syntax) "${decimal}:	typedef struct {\\.\\.\\.} some_type_in_c;"
 set type_in_c(ada_syntax) [multi_line \