[PATCH] D158206: [Driver] Add PIE support on Solaris

[Rainer Orth via Phabricator via cfe-commits]

ro marked an inline comment as done.
ro added inline comments.


================
Comment at: clang/lib/Driver/ToolChains/Solaris.cpp:136
+    const char *crtbegin = nullptr;
+    if (Args.hasArg(options::OPT_shared) || IsPIE)
+      crtbegin = "crtbeginS.o";
----------------
MaskRay wrote:
> Q: Interesting. If -shared used crtbegin.o before, how did it work?
> 
> On Linux, using GCC crtbegin.o (compiled with `-fno-PIC` or similar non-PIC option) will cause:
> ```
> ld.lld: error: relocation R_X86_64_32S cannot be used against local symbol; recompile with -fPIC
> >>> defined in /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o
> >>> referenced by crtstuff.c
> >>>               /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o:(.text+0x7)
> 
> ld.lld: error: relocation R_X86_64_32 cannot be used against symbol '_ITM_deregisterTMCloneTable'; recompile with -fPIC
> >>> defined in /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o
> >>> referenced by crtstuff.c
> >>>               /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o:(.text+0xE)
> 
> ld.lld: error: relocation R_X86_64_32 cannot be used against local symbol; recompile with -fPIC
> >>> defined in /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o
> >>> referenced by crtstuff.c
> >>>               /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o:(.text+0x18)
> ```
When the Solaris crts were reworked for Solaris 11.4 back in 2015, the were intentionally built as PIC to avoid issues just like that.


================
Comment at: clang/test/Driver/solaris-ld.c:110
+// Check the right ld flags are present with -pie.
+// RUN: %clang -### %s -pie 2>&1 \
+// RUN:     --target=sparc-sun-solaris2.11 \
----------------
MaskRay wrote:
> ro wrote:
> > MaskRay wrote:
> > > The convention is to put `2>&1` at the end of the command, aka before `|`
> > I've changed just the newly added tests.  There are a few others, but I've left the as is for now to avoid cluttering the patch with unrelated changes.
> Ultra nit: you may pack --target=sparc-sun-solaris2.11 on the first line to make the commands compacter, like `%clang --target=sparc-sun-solaris2.11 -### %s` below.
> 
Good point, done.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D158206/new/

https://reviews.llvm.org/D158206