This patch is a second attempt at fixing a link error for MSVC
entry points when calling conventions are specified using a flag.
Calling conventions specified using flags should not be applied to MSVC
entry points. The default calling convention is set in this case. The
default calling convention for MSVC entry points main and wmain is cdecl.
For WinMain, wWinMain and DllMain, the default calling convention is
stdcall on 32 bit Windows.
Explicitly specified calling conventions are applied to MSVC entry points.
For MinGW, the default calling convention for all MSVC entry points is
cdecl.
First attempt: 4cff1b40da
Revert of first attempt: bebfc3b92d
Differential Revision: https://reviews.llvm.org/D97941
ELF -cc1 -mrelocation-model pic will default to no semantic interposition plus
setting dso_local on default visibility external linkage definitions, so that
COFF, Mach-O and ELF output will be similar.
This patch makes tests immune to the differences.
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 `{{.*}} `.
Fix link error for MSVC entry points when calling conventions
are specified. MSVC entry points should have default calling
convention.
Differential Revision: https://reviews.llvm.org/D87701
Summary:
Clang -fpic defaults to -fno-semantic-interposition (GCC -fpic defaults
to -fsemantic-interposition).
Users need to specify -fsemantic-interposition to get semantic
interposition behavior.
Semantic interposition is currently a best-effort feature. There may
still be some cases where it is not handled well.
Reviewers: peter.smith, rnk, serge-sans-paille, sfertile, jfb, jdoerfert
Subscribers: dschuff, jyknight, dylanmckay, nemanjai, jvesely, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, arphaman, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73865
Added support for regcall as default calling convention. Also added code to
exclude main when applying default calling conventions.
Patch-By: eandrews
Differential Revision: https://reviews.llvm.org/D39210
llvm-svn: 317268
Fastcall doesn't support variadic function calls, so
setting the default calling convention to Fastcall would
result in incorrect code being emitted for these conditions.
This patch adds a 'variadic' test to the default calling conv
test, as well as fixes the behavior of fastcall.
llvm-svn: 316528
Elizabeth Andrews