For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.
To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.
To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
This patch enables marshalling of the exception model options while enforcing their mutual exclusivity. The clang driver interface remains the same, this only affects the cc1 command line.
Depends on D93215.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D93216
Previously, it would just always use the ObjC DWARF personality, even with SjLj
or SEH exceptions.
Patch by Jonathan Schleifer, test case by me.
llvm-svn: 299306
Fangrui Song