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From: Mark Wielaard <mark@klomp.org>
Date: Thu, 26 Jan 2023 17:19:15 +0000 (+0100)
Subject: backends: Handle DW_TAG_unspecified_type in dwarf_peeled_die_type
X-Git-Url: https://sourceware.org/git/?p=elfutils.git;a=commitdiff_plain;h=f2c522567ad63ac293535fba9704895e685ab5bc;hp=3fa98a6f29b0f370e32549ead7eb897c839af980
backends: Handle DW_TAG_unspecified_type in dwarf_peeled_die_type
binutils 2.40 introduces DW_TAG_unspecified_type for assembly
functions with an unknown return type. This breaks the
run-funcretval.sh testcase because dwfl_module_return_value_location
returns an error for such functions because it cannot determine the
return value location. Fix that by treating DW_TAG_unspecified_type
as if the DIE doesn't have a DW_AT_type.
Also update the testcase to explicitly checking for
DW_TAG_unspecified_type and printing "returns unspecified type".
https://sourceware.org/bugzilla/show_bug.cgi?id=30047
Upstream-Status: Backport [https://sourceware.org/git/?p=elfutils.git;a=commitdiff;h=f2c522567ad63ac293535fba9704895e685ab5bc;hp=3fa98a6f29b0f370e32549ead7eb897c839af980]
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
--- a/backends/libebl_CPU.h
+++ b/backends/libebl_CPU.h
@@ -1,5 +1,6 @@
/* Common interface for libebl modules.
Copyright (C) 2000, 2001, 2002, 2003, 2005, 2013, 2014 Red Hat, Inc.
+ Copyright (C) 2023 Mark J. Wielaard <mark@klomp.org>
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
@@ -53,7 +54,9 @@ extern bool (*generic_debugscn_p) (const
dwarf_tag (_die); })
/* Get a type die corresponding to DIE. Peel CV qualifiers off
- it. */
+ it. Returns zero if the DIE doesn't have a type, or the type
+ is DW_TAG_unspecified_type. Returns -1 on error. Otherwise
+ returns the result tag DW_AT value. */
static inline int
dwarf_peeled_die_type (Dwarf_Die *die, Dwarf_Die *result)
{
@@ -69,7 +72,14 @@ dwarf_peeled_die_type (Dwarf_Die *die, D
if (dwarf_peel_type (result, result) != 0)
return -1;
- return DWARF_TAG_OR_RETURN (result);
+ if (result == NULL)
+ return -1;
+
+ int tag = dwarf_tag (result);
+ if (tag == DW_TAG_unspecified_type)
+ return 0; /* Treat an unspecified type as if there was no type. */
+
+ return tag;
}
#endif /* libebl_CPU.h */
--- a/tests/funcretval.c
+++ b/tests/funcretval.c
@@ -1,5 +1,6 @@
/* Test program for dwfl_module_return_value_location.
Copyright (C) 2005 Red Hat, Inc.
+ Copyright (C) 2023 Mark J. Wielaard <mark@klomp.org>
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
@@ -67,7 +68,18 @@ handle_function (Dwarf_Die *funcdie, voi
error (EXIT_FAILURE, 0, "dwfl_module_return_value_location: %s",
dwfl_errmsg (-1));
else if (nlocops == 0)
- puts ("returns no value");
+ {
+ // Check if this is the special unspecified type
+ // https://sourceware.org/bugzilla/show_bug.cgi?id=30047
+ Dwarf_Die die_mem, *typedie = &die_mem;
+ Dwarf_Attribute attr_mem, *attr;
+ attr = dwarf_attr_integrate (funcdie, DW_AT_type, &attr_mem);
+ if (dwarf_formref_die (attr, typedie) != NULL
+ && dwarf_tag (typedie) == DW_TAG_unspecified_type)
+ puts ("returns unspecified type");
+ else
+ puts ("returns no value");
+ }
else
{
printf ("return value location:");
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