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which elf symbol?
- From: Andrew Cagney <cagney at redhat dot com>
- To: frysk at sourceware dot org, Roland McGrath <roland at redhat dot com>
- Date: Mon, 23 Jul 2007 12:58:01 -0400
- Subject: which elf symbol?
Hi,
I've replaced the frysk-stackframe program with an expanded
frysk-symbols program that has more elf symbol lookup edge cases; for
instance nested symbols. I've also expanded frysk.rt.TestSymbol to
exercise them. For some of the cases though, the results are not what I
expected. I've noted the failures below and provided a simplified
assembler.
1)
testGlobalAfterNested(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol global_outer expected:<global_outer> but was:<local_st_size_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testGlobalAfterNested(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
2)
testLocalAfterNested(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol local_outer expected:<...outer> but was:<...st_size_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testLocalAfterNested(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
These two are effectively the same. The layout is:
local_st_size_0: // this symbol has no size
global_outer:
nop
local_in_global:
nop
.size local_in_global, .-local_in_global
nop
<<you-are-here>>
.size global_outer, .-global_outer
that is global_outer contains a nested symbol but the "pc" is beyond
that back in the outer/global symbol.
I'm guessing that "global_outer" should be returned. Currently
local_st_size_0 is returned :-(
3)
testNoSymbolAfterGlobal(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol [unknown] expected:<[unknown]> but was:<local_st_size_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testNoSymbolAfterGlobal(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
4)
testNoSymbolAfterLocal(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol [unknown] expected:<[unknown]> but was:<local_st_size_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testNoSymbolAfterLocal(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
This is the no-symbol case, there is a hole in the memory where there is
no valid symbol vis:
local_st_size_0: // this symbol has no size
global_symbol:
nop
nop
.size global_symbol, .-global_symbol
<< you are here >>
I'm guessing it should not get a symbol at all (the [unknown]). It
currently gets the nearest unsized symbol.
5)
testGlobalSize0InGlobal(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol global_0_in_global expected:<...0_in_global> but was:<...after_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testGlobalSize0InGlobal(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
6)
testLocalSize0InGlobal(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol local_0_in_global expected:<local_0_in_global> but
was:<global_after_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testLocalSize0InGlobal(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
7)
testGlobalSize0InLocal(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol global_0_in_local expected:<global_0_in_local> but
was:<local_after_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testGlobalSize0InLocal(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
8)
testLocalSize0InLocal(frysk.rt.TestSymbol)junit.framework.ComparisonFailure:
symbol local_0_in_local expected:<...0_in_local> but was:<...after_0>
at frysk.rt.TestSymbol.symbolTest(TestRunner)
at frysk.rt.TestSymbol.testLocalSize0InLocal(TestRunner)
at frysk.junit.Runner.runCases(TestRunner)
at frysk.junit.Runner.runArchCases(TestRunner)
at frysk.junit.Runner.runTestCases(TestRunner)
at TestRunner.main(TestRunner)
These are cases where there is a nested symbol within a sized symbol vis:
global_after_0:
nop
local_0_in_global:
<< you are here >>
nop
.size global_after_0, .-global_after_0
here, since the PC is exactly at the unsized local symbol I'm guessing
that it should return that. It currently gets the containing sized symbol.