Initializers of global data that can appear multiple TUs (static data
members of class templates or __declspec(selectany) data) are now in a
comdat group keyed on the global variable being initialized. On
non-Windows platforms, this is a code size and startup time
optimization. On Windows, this is necessary for ABI compatibility with
MSVC.
Fixes PR16959.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D3811
llvm-svn: 209555
This makes it easier to see where a global ctor comes from, and it also makes
ASan's init order analyzer output easier to understand. gcc does this too,
but only in -fPIC mode for some reason. Don't do this for constructors with
explicit init priority.
Also prepend "sub_" before the 'I', that way regular constructors stay
lexicographically after symbols with init priority (because
ord('s') > ord('I')). gold seems to ignore the name of constructor symbols,
and ld only looks at the symbol if it includes an init priority, which this
patch doesn't change.
Before: __GLOBAL_I_a
Now: __GLOBAL_sub_I_myfile.cc
llvm-svn: 208128
Reid Kleckner