[flang-commits] [flang] cb7c223 - [clang][driver] Fix -fveclib=ArmPL issue: with -nostdlib do not link against libm (#133578)

[via flang-commits]

Author: Paul Osmialowski
Date: 2025-03-31T21:55:58+01:00
New Revision: cb7c223625f950c5ad14fed39aad8b358874fcf0

URL: https://github.com/llvm/llvm-project/commit/cb7c223625f950c5ad14fed39aad8b358874fcf0
DIFF: https://github.com/llvm/llvm-project/commit/cb7c223625f950c5ad14fed39aad8b358874fcf0.diff

LOG: [clang][driver] Fix -fveclib=ArmPL issue: with -nostdlib do not link against libm (#133578)

Although combining -fveclib=ArmPL with -nostdlib is a rare situation, it
should still be supported correctly and should effect in avoidance of
linking against libm.

Added: 
    

Modified: 
    clang/lib/Driver/ToolChains/CommonArgs.cpp
    clang/test/Driver/fveclib.c
    flang/test/Driver/fveclib.f90

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 41cfa3d2e4f8c..5aac20e1cdf44 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -515,7 +515,7 @@ void tools::AddLinkerInputs(const ToolChain &TC, const InputInfoList &Inputs,
       //
       // 1. On Linux, link only when actually needed.
       //
-      // 2. Prefer libm functions over libamath.
+      // 2. Prefer libm functions over libamath (when no -nostdlib in use).
       //
       // 3. Link against libm to resolve libamath dependencies.
       //
@@ -523,9 +523,11 @@ void tools::AddLinkerInputs(const ToolChain &TC, const InputInfoList &Inputs,
         CmdArgs.push_back(Args.MakeArgString("--push-state"));
         CmdArgs.push_back(Args.MakeArgString("--as-needed"));
       }
-      CmdArgs.push_back(Args.MakeArgString("-lm"));
+      if (!Args.hasArg(options::OPT_nostdlib))
+        CmdArgs.push_back(Args.MakeArgString("-lm"));
       CmdArgs.push_back(Args.MakeArgString("-lamath"));
-      CmdArgs.push_back(Args.MakeArgString("-lm"));
+      if (!Args.hasArg(options::OPT_nostdlib))
+        CmdArgs.push_back(Args.MakeArgString("-lm"));
       if (Triple.isOSLinux())
         CmdArgs.push_back(Args.MakeArgString("--pop-state"));
       addArchSpecificRPath(TC, Args, CmdArgs);

diff  --git a/clang/test/Driver/fveclib.c b/clang/test/Driver/fveclib.c
index 7d0985c4dd4f4..78b5316b67e47 100644
--- a/clang/test/Driver/fveclib.c
+++ b/clang/test/Driver/fveclib.c
@@ -116,11 +116,17 @@
 /// Verify that vectorized routines library is being linked in.
 // RUN: %clang -### --target=aarch64-pc-windows-msvc -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-MSVC %s
 // RUN: %clang -### --target=aarch64-linux-gnu -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-LINUX %s
+// RUN: %clang -### --target=aarch64-linux-gnu -fveclib=ArmPL %s -nostdlib 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-NOSTDLIB-LINUX %s
 // RUN: %clang -### --target=aarch64-linux-gnu -fveclib=ArmPL %s -lamath 2>&1 | FileCheck --check-prefix=CHECK-LINKING-AMATH-BEFORE-ARMPL-LINUX %s
 // RUN: %clang -### --target=arm64-apple-darwin -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-DARWIN %s
+// RUN: %clang -### --target=arm64-apple-darwin -fveclib=ArmPL -nostdlib %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-NOSTDLIB-DARWIN %s
 // RUN: %clang -### --target=arm64-apple-darwin -fveclib=ArmPL %s -lamath 2>&1 | FileCheck --check-prefix=CHECK-LINKING-AMATH-BEFORE-ARMPL-DARWIN %s
 // CHECK-LINKING-ARMPL-LINUX: "--push-state" "--as-needed" "-lm" "-lamath" "-lm" "--pop-state"
+// CHECK-LINKING-ARMPL-NOSTDLIB-LINUX: "--push-state" "--as-needed" "-lamath" "--pop-state"
+// CHECK-LINKING-ARMPL-NOSTDLIB-LINUX-NOT: "-lm"
 // CHECK-LINKING-ARMPL-DARWIN: "-lm" "-lamath" "-lm"
+// CHECK-LINKING-ARMPL-NOSTDLIB-DARWIN: "-lamath"
+// CHECK-LINKING-ARMPL-NOSTDLIB-DARWIN-NOT: "-lm"
 // CHECK-LINKING-ARMPL-MSVC: "--dependent-lib=amath"
 // CHECK-LINKING-AMATH-BEFORE-ARMPL-LINUX: "-lamath" {{.*}}"--push-state" "--as-needed" "-lm" "-lamath" "-lm" "--pop-state"
 // CHECK-LINKING-AMATH-BEFORE-ARMPL-DARWIN: "-lamath" {{.*}}"-lm" "-lamath" "-lm"

diff  --git a/flang/test/Driver/fveclib.f90 b/flang/test/Driver/fveclib.f90
index 490ce974724a6..7c2540b91ba79 100644
--- a/flang/test/Driver/fveclib.f90
+++ b/flang/test/Driver/fveclib.f90
@@ -33,11 +33,17 @@
 
 ! RUN: %flang -### --target=aarch64-pc-windows-msvc -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-MSVC %s
 ! RUN: %flang -### --target=aarch64-linux-gnu -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-LINUX %s
+! RUN: %flang -### --target=aarch64-linux-gnu -fveclib=ArmPL -nostdlib %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-NOSTDLIB-LINUX %s
 ! RUN: %flang -### --target=aarch64-linux-gnu -fveclib=ArmPL %s -lamath 2>&1 | FileCheck --check-prefix=CHECK-LINKING-AMATH-BEFORE-ARMPL-LINUX %s
 ! RUN: %flang -### --target=arm64-apple-darwin -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-DARWIN %s
+! RUN: %flang -### --target=arm64-apple-darwin -fveclib=ArmPL -nostdlib %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL-NOSTDLIB-DARWIN %s
 ! RUN: %flang -### --target=arm64-apple-darwin -fveclib=ArmPL %s -lamath 2>&1 | FileCheck --check-prefix=CHECK-LINKING-AMATH-BEFORE-ARMPL-DARWIN %s
 ! CHECK-LINKING-ARMPL-LINUX: "--push-state" "--as-needed" "-lm" "-lamath" "-lm" "--pop-state"
+! CHECK-LINKING-ARMPL-NOSTDLIB-LINUX: "--push-state" "--as-needed" "-lamath" "--pop-state"
+! CHECK-LINKING-ARMPL-NOSTDLIB-LINUX-NOT: "-lm"
 ! CHECK-LINKING-ARMPL-DARWIN: "-lm" "-lamath" "-lm"
+! CHECK-LINKING-ARMPL-NOSTDLIB-DARWIN: "-lamath"
+! CHECK-LINKING-ARMPL-NOSTDLIB-DARWIN-NOT: "-lm"
 ! CHECK-LINKING-ARMPL-MSVC: "--dependent-lib=amath"
 ! CHECK-LINKING-AMATH-BEFORE-ARMPL-LINUX: "-lamath" {{.*}}"--push-state" "--as-needed" "-lm" "-lamath" "-lm" "--pop-state"
 ! CHECK-LINKING-AMATH-BEFORE-ARMPL-DARWIN: "-lamath" {{.*}}"-lm" "-lamath" "-lm"