[RISCV] Allow YAML file to control multilib selection

llvm · Jul 15, 2024 · 628d665 · 628d665
1 parent 5c8eb83
commit 628d665
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Showing 2 changed files with 21 additions and 7 deletions.
diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
@@ -9,6 +9,7 @@
 #include "clang/Driver/ToolChain.h"
 #include "ToolChains/Arch/AArch64.h"
 #include "ToolChains/Arch/ARM.h"
+#include "ToolChains/Arch/RISCV.h"
 #include "ToolChains/Clang.h"
 #include "ToolChains/CommonArgs.h"
 #include "ToolChains/Flang.h"
@@ -258,6 +259,13 @@ static void getARMMultilibFlags(const Driver &D,
   }
 }
 
+static void getRISCVMultilibFlags(const Driver &D, const llvm::Triple &Triple,
+                                  const llvm::opt::ArgList &Args,
+                                  Multilib::flags_list &Result) {
+  Result.push_back("-march=" + riscv::getRISCVArch(Args, Triple));
+  Result.push_back(("-mabi=" + riscv::getRISCVABI(Args, Triple)).str());
+}
+
 Multilib::flags_list
 ToolChain::getMultilibFlags(const llvm::opt::ArgList &Args) const {
   using namespace clang::driver::options;
@@ -278,6 +286,10 @@ ToolChain::getMultilibFlags(const llvm::opt::ArgList &Args) const {
   case llvm::Triple::thumbeb:
     getARMMultilibFlags(D, Triple, Args, Result);
     break;
+  case llvm::Triple::riscv32:
+  case llvm::Triple::riscv64:
+    getRISCVMultilibFlags(D, Triple, Args, Result);
+    break;
   default:
     break;
   }

diff --git a/clang/lib/Driver/ToolChains/BareMetal.cpp b/clang/lib/Driver/ToolChains/BareMetal.cpp
@@ -218,17 +218,19 @@ static std::string computeBaseSysRoot(const Driver &D,
 void BareMetal::findMultilibs(const Driver &D, const llvm::Triple &Triple,
                               const ArgList &Args) {
   DetectedMultilibs Result;
-  if (isRISCVBareMetal(Triple)) {
+  // Look for a multilib.yaml before trying target-specific hardwired logic.
+  // If it exists, always do what it specifies.
+  llvm::SmallString<128> MultilibPath(computeBaseSysRoot(D, Triple));
+  llvm::sys::path::append(MultilibPath, MultilibFilename);
+  if (D.getVFS().exists(MultilibPath)) {
+    findMultilibsFromYAML(*this, D, MultilibPath, Args, Result);
+    SelectedMultilibs = Result.SelectedMultilibs;
+    Multilibs = Result.Multilibs;
+  } else if (isRISCVBareMetal(Triple)) {
     if (findRISCVMultilibs(D, Triple, Args, Result)) {
       SelectedMultilibs = Result.SelectedMultilibs;
       Multilibs = Result.Multilibs;
     }
-  } else {
-    llvm::SmallString<128> MultilibPath(computeBaseSysRoot(D, Triple));
-    llvm::sys::path::append(MultilibPath, MultilibFilename);
-    findMultilibsFromYAML(*this, D, MultilibPath, Args, Result);
-    SelectedMultilibs = Result.SelectedMultilibs;
-    Multilibs = Result.Multilibs;
   }
 }