binutils-gdb/ld/testsuite/ld-elf/pr20828-b.sd

# Make sure `_edata' is global rather than local in the dynamic symbol table,
# e.g.:
#    Num:    Value  Size Type    Bind   Vis      Ndx Name
#      1: 00000000     0 NOTYPE  GLOBAL DEFAULT    1 _edata
# vs:
#      1: 00000000     0 NOTYPE  LOCAL  DEFAULT    1 _edata
#...
 *[0-9]+: +[0-9a-f]+ +0 +NOTYPE +GLOBAL +DEFAULT +[0-9]+ +_edata
#pass
PR ld/20828: Fix linker script symbols wrongly forced local with section GC Fix a generic ELF linker regression introduced with a chain of changes made to unused input section garbage collection: - commit 1a766c6843ce ("Also hide symbols without PLT nor GOT references."), <https://sourceware.org/ml/binutils/2011-09/msg00076.html>, - commit 1d5316ab67e1 ("PR ld/13177: garbage collector retains zombie references to external libraries"), <https://sourceware.org/ml/binutils/2011-10/msg00161.html>, - commit 6673f753c019 ("Fix PR 12772, garbage collection of dynamic syms"), <https://sourceware.org/ml/binutils/2011-12/msg00077.html>, causing the garbage collection of unused symbols present in a DSO involved in a link to make identically named symbols ordinarily defined (i.e. not hidden or PROVIDEd) by a linker script local, even though the latter symbols are supposed to be global as if no DSO defined them as well. This is because linker script assignments are processed very late as `lang_process' proceeds, down in the call to `ldemul_before_allocation', which is made after the call to `lang_gc_sections' to do input section garbage collecting. Consequently if unused, then any such DSO-defined symbol has already been garbage-collected and internally marked local. It would ordinarily be removed from dynamic symbol table output, however a linker script assignment correctly replaces its original definition with the new one and enters it into the dynamic symbol table produced as it is supposed to be exported. The original local marking is however retained making the symbol local in the dynamic symbol table and therefore not available externally. This also causes a sorting problem with the MIPS target, which does not expect non-section local dynamic symbols to be output and produces an invalid binary. Fix the problem then, by removing the `forced_local' marking for the offending case and add suitable test cases. First to verify that unused symbols ordinarily defined with linker script assignments remain exported in the context of input section garbage collection whether or not a DSO defining identically named symbols is present in the link. Second that a linker version script still correctly retains or removes such symbols as requested. bfd/ PR ld/20828 * elflink.c (bfd_elf_record_link_assignment): Clear any `forced_local' marking for DSO symbols that are not being provided. ld/ PR ld/20828 * testsuite/ld-elf/pr20828-1.sd: New test. * testsuite/ld-elf/pr20828-2a.sd: New test. * testsuite/ld-elf/pr20828-2b.sd: New test. * testsuite/ld-elf/pr20828.ld: New test linker script. * testsuite/ld-elf/pr20828.ver: New test version script. * testsuite/ld-elf/pr20828.s: New test source. * testsuite/ld-elf/shared.exp: Run the new test. 2017-01-17 06:10:57 +08:00			# Make sure `_edata' is global rather than local in the dynamic symbol table,
			`# e.g.:`
			`# Num: Value Size Type Bind Vis Ndx Name`
			`# 1: 00000000 0 NOTYPE GLOBAL DEFAULT 1 _edata`
			`# vs:`
			`# 1: 00000000 0 NOTYPE LOCAL DEFAULT 1 _edata`
			`#...`
			`*[0-9]+: +[0-9a-f]+ +0 +NOTYPE +GLOBAL +DEFAULT +[0-9]+ +_edata`
			`#pass`