From b57ff6da9c8b281ae9312e245fd3372e7ffaff28 Mon Sep 17 00:00:00 2001
From: Mike Hommey <mh@glandium.org>
Date: Thu, 23 Mar 2023 06:52:28 +0900
Subject: [PATCH] Apply the same fallbacks as runtimes search for stdlib search

When building clang with e.g. LLVM_ENABLE_RUNTIMES=libcxx;libunwind,
those runtimes end up in the stdlib search directory, and when
LLVM_ENABLE_PER_TARGET_RUNTIME_DIR is set, that ends up in a
target-specific subdirectory. The stdlib search does handle the
situation, but when the target in question is Android, the same issues
as those that required fallbacks for runtimes search apply.

Traditionally, those libraries are shipped as part of the Android NDK,
but when one builds their own clang for Android, they may want to use
the runtimes from the same version rather than the ones from the NDK.

Differential Revision: https://reviews.llvm.org/D146664
---
 clang/lib/Driver/ToolChain.cpp | 42 +++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 18 deletions(-)

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 2dba975a5a8f..9052099cad5e 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -569,15 +569,9 @@ const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
   return Args.MakeArgString(getCompilerRT(Args, Component, Type));
 }
 
-ToolChain::path_list ToolChain::getRuntimePaths() const {
-  path_list Paths;
-  auto addPathForTriple = [this, &Paths](const llvm::Triple &Triple) {
-    SmallString<128> P(D.ResourceDir);
-    llvm::sys::path::append(P, "lib", Triple.str());
-    Paths.push_back(std::string(P.str()));
-  };
-
-  addPathForTriple(getTriple());
+template <typename F>
+static void fillPaths(const ToolChain &TC, F addPathForTriple) {
+  addPathForTriple(TC.getTriple());
 
   // When building with per target runtime directories, various ways of naming
   // the Arm architecture may have been normalised to simply "arm".
@@ -594,30 +588,42 @@ ToolChain::path_list ToolChain::getRuntimePaths() const {
   //
   // M profile Arm is bare metal and we know they will not be using the per
   // target runtime directory layout.
-  if (getTriple().getArch() == Triple::arm && !getTriple().isArmMClass()) {
-    llvm::Triple ArmTriple = getTriple();
+  if (TC.getTriple().getArch() == Triple::arm &&
+      !TC.getTriple().isArmMClass()) {
+    llvm::Triple ArmTriple = TC.getTriple();
     ArmTriple.setArch(Triple::arm);
     addPathForTriple(ArmTriple);
   }
 
   // Android targets may include an API level at the end. We still want to fall
   // back on a path without the API level.
-  if (getTriple().isAndroid() &&
-      getTriple().getEnvironmentName() != "android") {
-    llvm::Triple TripleWithoutLevel = getTriple();
+  if (TC.getTriple().isAndroid() &&
+      TC.getTriple().getEnvironmentName() != "android") {
+    llvm::Triple TripleWithoutLevel = TC.getTriple();
     TripleWithoutLevel.setEnvironmentName("android");
     addPathForTriple(TripleWithoutLevel);
   }
+}
 
+ToolChain::path_list ToolChain::getRuntimePaths() const {
+  path_list Paths;
+  auto addPathForTriple = [this, &Paths](const llvm::Triple &Triple) {
+    SmallString<128> P(D.ResourceDir);
+    llvm::sys::path::append(P, "lib", Triple.str());
+    Paths.push_back(std::string(P.str()));
+  };
+  fillPaths(*this, addPathForTriple);
   return Paths;
 }
 
 ToolChain::path_list ToolChain::getStdlibPaths() const {
   path_list Paths;
-  SmallString<128> P(D.Dir);
-  llvm::sys::path::append(P, "..", "lib", getTripleString());
-  Paths.push_back(std::string(P.str()));
-
+  auto addPathForTriple = [this, &Paths](const llvm::Triple &Triple) {
+    SmallString<128> P(D.Dir);
+    llvm::sys::path::append(P, "..", "lib", Triple.str());
+    Paths.push_back(std::string(P.str()));
+  };
+  fillPaths(*this, addPathForTriple);
   return Paths;
 }
 
-- 
2.39.0.1.g6739ec1790