Support setting default value for -rtlib at build time
This patch introduces a new cmake variable: CLANG_DEFAULT_RTLIB, thru
which we can specify a default value for -rtlib (libgcc or
compiler-rt) at build time, just like how we set the default C++
stdlib thru CLANG_DEFAULT_CXX_STDLIB.
With these two options, we can configure clang to build binaries on
Linux that have no runtime dependence on any gcc libs (libstdc++ or
libgcc_s).
Patch by Lei Zhang!
Differential Revision: https://reviews.llvm.org/D22663
llvm-svn: 276848
diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 66b76cd..91b3641 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -534,15 +534,19 @@
ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
const ArgList &Args) const {
- if (Arg *A = Args.getLastArg(options::OPT_rtlib_EQ)) {
- StringRef Value = A->getValue();
- if (Value == "compiler-rt")
- return ToolChain::RLT_CompilerRT;
- if (Value == "libgcc")
- return ToolChain::RLT_Libgcc;
- getDriver().Diag(diag::err_drv_invalid_rtlib_name)
- << A->getAsString(Args);
- }
+ const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
+ StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
+
+ // "platform" is only used in tests to override CLANG_DEFAULT_RTLIB
+ if (LibName == "compiler-rt")
+ return ToolChain::RLT_CompilerRT;
+ else if (LibName == "libgcc")
+ return ToolChain::RLT_Libgcc;
+ else if (LibName == "platform")
+ return GetDefaultRuntimeLibType();
+
+ if (A)
+ getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
return GetDefaultRuntimeLibType();
}
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index f05261a..610285e1 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -403,18 +403,23 @@
/*AddRPath*/ true);
}
+ToolChain::RuntimeLibType DarwinClang::GetRuntimeLibType(
+ const ArgList &Args) const {
+ if (Arg* A = Args.getLastArg(options::OPT_rtlib_EQ)) {
+ StringRef Value = A->getValue();
+ if (Value != "compiler-rt")
+ getDriver().Diag(diag::err_drv_unsupported_rtlib_for_platform)
+ << Value << "darwin";
+ }
+
+ return ToolChain::RLT_CompilerRT;
+}
+
void DarwinClang::AddLinkRuntimeLibArgs(const llvm::Triple &EffectiveTriple,
const ArgList &Args,
ArgStringList &CmdArgs) const {
- // Darwin only supports the compiler-rt based runtime libraries.
- switch (GetRuntimeLibType(Args)) {
- case ToolChain::RLT_CompilerRT:
- break;
- default:
- getDriver().Diag(diag::err_drv_unsupported_rtlib_for_platform)
- << Args.getLastArg(options::OPT_rtlib_EQ)->getValue() << "darwin";
- return;
- }
+ // Call once to ensure diagnostic is printed if wrong value was specified
+ GetRuntimeLibType(Args);
// Darwin doesn't support real static executables, don't link any runtime
// libraries with -static.
diff --git a/clang/lib/Driver/ToolChains.h b/clang/lib/Driver/ToolChains.h
index 25dae72..d36a799 100644
--- a/clang/lib/Driver/ToolChains.h
+++ b/clang/lib/Driver/ToolChains.h
@@ -575,6 +575,8 @@
/// @name Apple ToolChain Implementation
/// {
+ RuntimeLibType GetRuntimeLibType(const llvm::opt::ArgList &Args) const override;
+
void AddLinkRuntimeLibArgs(const llvm::Triple &EffectiveTriple,
const llvm::opt::ArgList &Args,
llvm::opt::ArgStringList &CmdArgs) const override;