[Driver][Gnu] Support -shared -static: pass -shared to ld and use crtbeginS.o

This mode never works (mismatching crtbeginT.o and crtendS.o) and probably
unsupported by GCC on glibc based Linux distro (incorrect crtbeginT.o causes
linker error) but makes sense (-shared means building a shared object, -static
means avoid shared object dependencies) and can be used on musl based Linux
distro.

mingw supports this mode as well.

diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index fe5bda5..80e379c 100644 (file)
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -473,17 +473,16 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     return;
   }
 
+  if (Args.hasArg(options::OPT_shared))
+    CmdArgs.push_back("-shared");
+
   if (IsStatic) {
     if (Arch == llvm::Triple::arm || Arch == llvm::Triple::armeb ||
         Arch == llvm::Triple::thumb || Arch == llvm::Triple::thumbeb)
       CmdArgs.push_back("-Bstatic");
     else
       CmdArgs.push_back("-static");
-  } else if (Args.hasArg(options::OPT_shared)) {
-    CmdArgs.push_back("-shared");
-  }
-
-  if (!IsStatic) {
+  } else {
     if (Args.hasArg(options::OPT_rdynamic))
       CmdArgs.push_back("-export-dynamic");
 
@@ -534,10 +533,10 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       }
       if (P.empty()) {
         const char *crtbegin;
-        if (IsStatic)
-          crtbegin = isAndroid ? "crtbegin_static.o" : "crtbeginT.o";
-        else if (Args.hasArg(options::OPT_shared))
+        if (Args.hasArg(options::OPT_shared))
           crtbegin = isAndroid ? "crtbegin_so.o" : "crtbeginS.o";
+        else if (IsStatic)
+          crtbegin = isAndroid ? "crtbegin_static.o" : "crtbeginT.o";
         else if (IsPIE || IsStaticPIE)
           crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbeginS.o";
         else

diff --git a/clang/test/Driver/Inputs/basic_linux_tree/usr/lib/gcc/x86_64-unknown-linux/10.2.0/crtbeginS.o b/clang/test/Driver/Inputs/basic_linux_tree/usr/lib/gcc/x86_64-unknown-linux/10.2.0/crtbeginS.o
new file mode 100644 (file)
index 0000000..e69de29

diff --git a/clang/test/Driver/Inputs/basic_linux_tree/usr/lib/gcc/x86_64-unknown-linux/10.2.0/crtendS.o b/clang/test/Driver/Inputs/basic_linux_tree/usr/lib/gcc/x86_64-unknown-linux/10.2.0/crtendS.o
new file mode 100644 (file)
index 0000000..e69de29

diff --git a/clang/test/Driver/linux-ld.c b/clang/test/Driver/linux-ld.c
index cc50558..102deda 100644 (file)
--- a/clang/test/Driver/linux-ld.c
+++ b/clang/test/Driver/linux-ld.c
@@ -319,7 +319,13 @@
 // CHECK-LD-64-STATIC: "-L[[SYSROOT]]/lib"
 // CHECK-LD-64-STATIC: "-L[[SYSROOT]]/usr/lib"
 // CHECK-LD-64-STATIC: "--start-group" "-lgcc" "-lgcc_eh" "-lc" "--end-group"
-//
+
+// RUN: %clang -### %s --target=x86_64-unknown-linux -rtlib=platform --unwindlib=platform -shared -static \
+// RUN:   --gcc-toolchain= --sysroot=%S/Inputs/basic_linux_tree 2>&1 | FileCheck --check-prefix=CHECK-LD-SHARED-STATIC %s
+// CHECK-LD-SHARED-STATIC: "-shared" "-static"
+// CHECK-LD-SHARED-STATIC: "{{.*}}/usr/lib/gcc/x86_64-unknown-linux/10.2.0{{/|\\\\}}crtbeginS.o"
+// CHECK-LD-SHARED-STATIC: "{{.*}}/usr/lib/gcc/x86_64-unknown-linux/10.2.0{{/|\\\\}}crtendS.o"
+
 // Check that flags can be combined. The -static dominates.
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
 // RUN:     --target=x86_64-unknown-linux -rtlib=platform --unwindlib=platform \