Compile this code, reduced from gdb.cp/templates.cc:
===
char name[3];
template<char *V> struct Qux
{
int foo();
};
template<char *V> int Qux<V>::foo()
{
return V[0];
}
Qux<name> qux;
===
Look at the resulting debug information, by building with -c -g and using
readelf -wi, or by compiling with -S -dA. Take a look at the type of the
instantiated foo. G++ calls it Qux<(char*)(& name)>::foo(). But that's not
right.
For the first thing, I believe it's not valid C++. G++ certainly rejects the
obvious ways of writing this. But worse is that it is representable in the
mangling. The actual method:
_ZN3QuxIXadL_Z4nameEEE3fooEv -> Qux<&(name)>::foo()
But this is validly mangled:
_ZN3QuxIXcvPcadL_Z4nameEEE3fooEv -> Qux<(char*)(&(name))>::foo()
There are tons of other places where GCC emits debug info different from the
demangler, usually in spacing or in the spelling of basic types (long unsigned
int vs unsigned long); I have code in GDB to correct for all such cosmetic
differences but I am reluctant to make it remove casts that could be important.
--
Summary: Debugging info for C++ template parameters is incorrect
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: drow at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33861
