Fix "catch exception" with dynamic linking

When an Ada program is dynamically linked against libgnat, and when
one of the standard exceptions is used, the exception object may be
referenced by the main executable using a copy relocation.

In this situation, a "catch exception" for those exceptions will not
manage to stop.  This happens because, under the hood, "catch
exception" creates an expression object that examines the object
addresses -- but in this case, the address will be incorrect.

This patch fixes the problem by arranging for these filter expressions
to examine all the relevant minimal symbols.  This way, the object
from libgnat will be found as well.

Tested on x86-64 Fedora 29.

gdb/ChangeLog
2019-04-30  Tom Tromey  <tromey@adacore.com>

	* ada-lang.c (ada_lookup_simple_minsyms): New function.
	(create_excep_cond_exprs): Iterate over program spaces.
	(ada_exception_catchpoint_cond_string): Examine all minimal
	symbols for exception types.

gdb/testsuite/ChangeLog
2019-04-30  Tom Tromey  <tromey@adacore.com>

	* lib/ada.exp (find_ada_tool): New proc.
	* lib/gdb.exp (gdb_compile_shlib): Allow .o files as inputs.
	* gdb.ada/catch_ex_std.exp: New file.
	* gdb.ada/catch_ex_std/foo.adb: New file.
	* gdb.ada/catch_ex_std/some_package.adb: New file.
	* gdb.ada/catch_ex_std/some_package.ads: New file.

2 files changed, 37 insertions, 5 deletions

diff --git a/gdb/testsuite/lib/ada.exp b/gdb/testsuite/lib/ada.exp
index ee9ade1..1345c74 100644
--- a/gdb/testsuite/lib/ada.exp
+++ b/gdb/testsuite/lib/ada.exp
@@ -78,3 +78,30 @@ proc standard_ada_testfile {base_file {dir ""}} {
     set srcfile $srcdir/$subdir/$testdir/$testfile.adb
     set binfile [standard_output_file $testfile]
 }
+
+# A helper function to find the appropriate version of a tool.
+# TOOL is the tool's name, e.g., "gnatbind" or "gnatlink".
+
+proc find_ada_tool {tool} {
+    set upper [string toupper $tool]
+
+    set targname ${upper}_FOR_TARGET
+    global $targname
+    if {[info exists $targname]} {
+	return $targname
+    }
+
+    global tool_root_dir
+    set root "$tool_root_dir/gcc"
+    set result ""
+
+    if {![is_remote host]} {
+        set result [lookfor_file $root $tool]
+    }
+
+    if {$result == ""} {
+        set result [transform $tool]
+    }
+
+    return $result
+}
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 25d370e..57866da 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3832,11 +3832,16 @@ proc gdb_compile_shlib {sources dest options} {
     set outdir [file dirname $dest]
     set objects ""
     foreach source $sources {
-       set sourcebase [file tail $source]
-       if {[gdb_compile $source "${outdir}/${sourcebase}.o" object $obj_options] != ""} {
-           return -1
-       }
-       lappend objects ${outdir}/${sourcebase}.o
+	set sourcebase [file tail $source]
+	if {[file extension $source] == ".o"} {
+	    # Already a .o file.
+	    lappend objects $source
+	} elseif {[gdb_compile $source "${outdir}/${sourcebase}.o" object \
+		       $obj_options] != ""} {
+	    return -1
+	} else {
+	    lappend objects ${outdir}/${sourcebase}.o
+	}
     }
 
     set link_options $options