From ae9c3e354440c4a0f105a9eabfb2f77be085ebc1 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Thu, 18 Aug 2016 17:59:16 +0200 Subject: [PATCH] libgcc/mkmap-symver: support skip_underscore Some platforms, such as Blackfin, have a special prefix for assembly symbols as opposed to C symbols. For this reason, a function named "foo()" in C will in fact be visible as a symbol called "_foo" in the ELF binary. The current linker version script logic in libgcc doesn't take into account this situation properly. The Blackfin specific libgcc/config/bfin/libgcc-glibc.ver has an additional "_" in front of every symbol so that it matches the output of "nm" (which gets parsed to produce the final linker version script). But due to this additional "_", ld no longer matches with the symbols since "ld" does the matching with the original symbol name, not the one prefixed with "_". Due to this, none of the symbols in libgcc/config/bfin/libgcc-glibc.ver are actually matched with symbols in libgcc. This causes all libgcc symbols to be left as "LOCAL", which causes lots of "undefined reference" whenever some C or C++ code that calls a function of libgcc is compiled. To address this, this commit introduces a "skip_underscore" variable to the mkmap-symver script. It tells mkmap-symver to ignore the leading underscore from the "nm" output. Note that this new argument is different from the existing "leading_underscore" argument, which *adds* an additional underscore to the generated linker version script. Having this functionality paves the way to using the generic linker version information for Blackfin, instead of using a custom one. Signed-off-by: Thomas Petazzoni --- libgcc/mkmap-symver.awk | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libgcc/mkmap-symver.awk b/libgcc/mkmap-symver.awk index 266832a..30bb179 100644 --- a/libgcc/mkmap-symver.awk +++ b/libgcc/mkmap-symver.awk @@ -47,7 +47,11 @@ state == "nm" && ($1 == "U" || $2 == "U") { state == "nm" && NF == 3 { split ($3, s, "@") - def[s[1]] = 1; + if (skip_underscore) + symname = substr(s[1], 2); + else + symname = s[1]; + def[symname] = 1; sawsymbol = 1; next; } -- 2.7.4