Tool for checking consistency between lib and ABI

Fixes 
This commit is contained in:
Norman Feske 2018-01-10 12:31:43 +01:00 committed by Christian Helmuth
parent fbd545ae70
commit 95785a9c46
2 changed files with 158 additions and 0 deletions

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@ -66,3 +66,17 @@ of Genode.
Autopilot is a tool for the automatic execution of run scripts among multiple Autopilot is a tool for the automatic execution of run scripts among multiple
base platforms. base platforms.
:'abi_symbols':
The utility assists with the initial creation of a ABI-symbols file, taking
a shared object as a starting point. For more information, refer to the
header of the 'abi_symbols' script.
:'check_abi':
The 'check_abi' helper is used by the build system to detect violations of
an ABI by a shared library. Most importantly, it reports incompatibilities of
symbol sizes, which require an adaptation of the ABI. For more information,
refer to the header of the 'check_abi' script.

144
tool/check_abi Executable file
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@ -0,0 +1,144 @@
#!/usr/bin/tclsh
#
# \brief Detect inconsistencies between a shared library and its ABI
# \author Norman Feske
# \date 2018-01-10
#
# The tool takes a shared library and an ABI-symbols file as arguments.
# It checks for violations of the ABI by the shared library. Additionally,
# it examines the ABI-symbols file for unexpected content such as duplicated
# symbols or trailing whitespace.
#
# normalize sort order across platforms
set env(LC_COLLATE) C
set lib_path [lindex $argv 0]
set abi_path [lindex $argv 1]
# obtain symbol information for the shared library via 'nm'
set lib_content [split [exec nm --format posix --dynamic $lib_path | sort] "\n"]
set abi_content [split [exec cat $abi_path] "\n"]
set abi_name [lindex [file split $abi_path] end]
set num_errors 0
proc report_error { message } {
global num_errors
puts stderr "Error: $message"
incr num_errors
}
#
# Extract symbol list w/o comments and empty lines, check for trailing spaces
#
proc line_contains_symbol { line } {
if {$line == ""} { return 0 }
if {[regexp {^#} $line]} { return 0 }
return 1
}
set abi_symbols ""
set num_lines 0
foreach line $abi_content {
if {[line_contains_symbol $line]} {
lappend abi_symbols $line }
if {[regexp {\s+$} $line]} {
report_error "trailing whitespace at $abi_path line $num_lines" }
incr num_lines
}
#
# Check for absence of Genode-internal linking artifacts from ABI
#
#
# The following symbols may appear in shared objects but should not by part
# of any ABI.
#
set symbol_blacklist {
__bss_start
__eh_frame_start__
__exidx_end
__exidx_start
__l4sys_invoke_indirect
_ctors_end
_ctors_start
_edata
_end
_init
_parent_cap
_parent_cap_local_name
_parent_cap_thread_id
}
foreach line $abi_symbols {
set name [lindex $line 0]
foreach blacklisted_symbol $symbol_blacklist {
if {$name == $blacklisted_symbol} {
report_error "$abi_name ABI contains Genode-internal symbol '$name'"
}
}
}
#
# Check for duplicates in the ABI
#
proc abi_symbol_name { line } { return [lindex $line 0] }
foreach line $abi_symbols { set count([abi_symbol_name $line]) 0 }
foreach line $abi_symbols { incr count([abi_symbol_name $line]) }
set duplicates {}
foreach line $abi_symbols {
if {$count([abi_symbol_name $line]) > 1} {
lappend duplicates [abi_symbol_name $line] } }
# sort the list to report each duplicate only once
foreach name [lsort -unique $duplicates] {
report_error "$abi_name ABI contains duplicate symbol '$name'" }
#
# Validate that library symbol sizes do not exceed their ABI symbol sizes
#
proc abi_symbol_has_size { line } { return [expr [llength $line] == 3] }
# determine decimal symbol size of library symbols
foreach lib_line $lib_content {
if {[regexp {^([\w.]+) (\w) \w+ ?(\w*)$} $lib_line dummy name type size_hex]} {
set lib_symbol_size($name) [expr 0x0$size_hex]
}
}
foreach abi_line $abi_symbols {
if {![abi_symbol_has_size $abi_line]} {
continue }
set name [lindex $abi_line 0]
if {![info exists lib_symbol_size($name)]} {
continue }
set abi_symbol_size [lindex $abi_line end]
if {$lib_symbol_size($name) > $abi_symbol_size} {
set message "size of '$name' symbol violates $abi_name ABI "
append message "($abi_symbol_size bytes in ABI, $lib_symbol_size($name) bytes in library)"
report_error $message
}
}
if {$num_errors > 0} { exit -1 }