[clang] a6439b5 - [clang][driver] Only warn once about invalid library values

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2021-02-10T06:19:52+01:00
New Revision: a6439b52088b1d58d8e7aa9891c9011648710593

URL: https://github.com/llvm/llvm-project/commit/a6439b52088b1d58d8e7aa9891c9011648710593
DIFF: https://github.com/llvm/llvm-project/commit/a6439b52088b1d58d8e7aa9891c9011648710593.diff

LOG: [clang][driver] Only warn once about invalid library values

Since ToolChain::GetCXXStdlibType() is a simple getter that might emit
the "invalid library name in argument" warning, it can conceivably be
called several times while initializing the build pipeline.

Before this patch, a simple 'clang++ -stdlib=foo ./test.cpp' would print
the warning twice, -rt=lib=foo would print 6 times.

Change this and always only print the warning once. Keep the rest of the
semantics of the functions.

Differential Revision: https://reviews.llvm.org/D95915

Added: 
    clang/test/Driver/undefined-libs.cpp

Modified: 
    clang/include/clang/Driver/ToolChain.h
    clang/lib/Driver/ToolChain.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Driver/ToolChain.h b/clang/include/clang/Driver/ToolChain.h
index 59fdd2997fec..fed688c0f1ce 100644
--- a/clang/include/clang/Driver/ToolChain.h
+++ b/clang/include/clang/Driver/ToolChain.h
@@ -166,6 +166,10 @@ class ToolChain {
     EffectiveTriple = std::move(ET);
   }
 
+  mutable llvm::Optional<CXXStdlibType> cxxStdlibType;
+  mutable llvm::Optional<RuntimeLibType> runtimeLibType;
+  mutable llvm::Optional<UnwindLibType> unwindLibType;
+
 protected:
   MultilibSet Multilibs;
   Multilib SelectedMultilib;

diff  --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index c83638086048..d0f404d8cbaa 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -884,66 +884,86 @@ void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
 
 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
     const ArgList &Args) const {
+  if (runtimeLibType)
+    return *runtimeLibType;
+
   const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
 
   // Only use "platform" in tests to override CLANG_DEFAULT_RTLIB!
   if (LibName == "compiler-rt")
-    return ToolChain::RLT_CompilerRT;
+    runtimeLibType = ToolChain::RLT_CompilerRT;
   else if (LibName == "libgcc")
-    return ToolChain::RLT_Libgcc;
+    runtimeLibType = ToolChain::RLT_Libgcc;
   else if (LibName == "platform")
-    return GetDefaultRuntimeLibType();
+    runtimeLibType = GetDefaultRuntimeLibType();
+  else {
+    if (A)
+      getDriver().Diag(diag::err_drv_invalid_rtlib_name)
+          << A->getAsString(Args);
 
-  if (A)
-    getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
+    runtimeLibType = GetDefaultRuntimeLibType();
+  }
 
-  return GetDefaultRuntimeLibType();
+  return *runtimeLibType;
 }
 
 ToolChain::UnwindLibType ToolChain::GetUnwindLibType(
     const ArgList &Args) const {
+  if (unwindLibType)
+    return *unwindLibType;
+
   const Arg *A = Args.getLastArg(options::OPT_unwindlib_EQ);
   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_UNWINDLIB;
 
   if (LibName == "none")
-    return ToolChain::UNW_None;
+    unwindLibType = ToolChain::UNW_None;
   else if (LibName == "platform" || LibName == "") {
     ToolChain::RuntimeLibType RtLibType = GetRuntimeLibType(Args);
     if (RtLibType == ToolChain::RLT_CompilerRT)
-      return ToolChain::UNW_None;
+      unwindLibType = ToolChain::UNW_None;
     else if (RtLibType == ToolChain::RLT_Libgcc)
-      return ToolChain::UNW_Libgcc;
+      unwindLibType = ToolChain::UNW_Libgcc;
   } else if (LibName == "libunwind") {
     if (GetRuntimeLibType(Args) == RLT_Libgcc)
       getDriver().Diag(diag::err_drv_incompatible_unwindlib);
-    return ToolChain::UNW_CompilerRT;
+    unwindLibType = ToolChain::UNW_CompilerRT;
   } else if (LibName == "libgcc")
-    return ToolChain::UNW_Libgcc;
+    unwindLibType = ToolChain::UNW_Libgcc;
+  else {
+    if (A)
+      getDriver().Diag(diag::err_drv_invalid_unwindlib_name)
+          << A->getAsString(Args);
 
-  if (A)
-    getDriver().Diag(diag::err_drv_invalid_unwindlib_name)
-        << A->getAsString(Args);
+    unwindLibType = GetDefaultUnwindLibType();
+  }
 
-  return GetDefaultUnwindLibType();
+  return *unwindLibType;
 }
 
 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
+  if (cxxStdlibType)
+    return *cxxStdlibType;
+
   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;
 
   // Only use "platform" in tests to override CLANG_DEFAULT_CXX_STDLIB!
   if (LibName == "libc++")
-    return ToolChain::CST_Libcxx;
+    cxxStdlibType = ToolChain::CST_Libcxx;
   else if (LibName == "libstdc++")
-    return ToolChain::CST_Libstdcxx;
+    cxxStdlibType = ToolChain::CST_Libstdcxx;
   else if (LibName == "platform")
-    return GetDefaultCXXStdlibType();
+    cxxStdlibType = GetDefaultCXXStdlibType();
+  else {
+    if (A)
+      getDriver().Diag(diag::err_drv_invalid_stdlib_name)
+          << A->getAsString(Args);
 
-  if (A)
-    getDriver().Diag(diag::err_drv_invalid_stdlib_name) << A->getAsString(Args);
+    cxxStdlibType = GetDefaultCXXStdlibType();
+  }
 
-  return GetDefaultCXXStdlibType();
+  return *cxxStdlibType;
 }
 
 /// Utility function to add a system include directory to CC1 arguments.

diff  --git a/clang/test/Driver/undefined-libs.cpp b/clang/test/Driver/undefined-libs.cpp
new file mode 100644
index 000000000000..25a15328cbdd
--- /dev/null
+++ b/clang/test/Driver/undefined-libs.cpp
@@ -0,0 +1,15 @@
+
+// Check that all the following options print a warning when given a non-existent
+// value. But only one warning.
+
+// RUN: not %clangxx -stdlib=nostdlib %s 2>&1 | FileCheck --check-prefix=STDLIB %s
+// STDLIB: error: invalid library name in argument '-stdlib=nostdlib'
+// STDLIB-EMPTY:
+//
+// RUN: not %clangxx -rtlib=nortlib %s 2>&1 | FileCheck --check-prefix=RTLIB %s
+// RTLIB: error: invalid runtime library name in argument '-rtlib=nortlib'
+// RTLIB-EMPTY:
+//
+// RUN: not %clangxx -unwindlib=nounwindlib %s 2>&1 | FileCheck --check-prefix=UNWINDLIB %s
+// UNWINDLIB: error: invalid unwind library name in argument '-unwindlib=nounwindlib'
+// UNWINDLIB-EMPTY: