[clang] d1f0d1b - [clang][AMDGPU] Reject malformed target IDs with empty components (#196140)

[via cfe-commits]

Author: Edward Nathan Varghese
Date: 2026-05-09T07:00:52Z
New Revision: d1f0d1b37eb77c64c9a54479ad339e22f9b80c1e

URL: https://github.com/llvm/llvm-project/commit/d1f0d1b37eb77c64c9a54479ad339e22f9b80c1e
DIFF: https://github.com/llvm/llvm-project/commit/d1f0d1b37eb77c64c9a54479ad339e22f9b80c1e.diff

LOG: [clang][AMDGPU] Reject malformed target IDs with empty components (#196140)

Fixes #196078

An extra colon in `-mcpu` (e.g. `gfx900::xnack+`) produced an empty
feature component and triggered an assertion in `StringRef::back()`.

Return `std::nullopt` for malformed target IDs instead.

Added: 
    

Modified: 
    clang/lib/Basic/TargetID.cpp
    clang/test/Driver/amdgpu-invalid-target-id.s

Removed: 
    


################################################################################
diff  --git a/clang/lib/Basic/TargetID.cpp b/clang/lib/Basic/TargetID.cpp
index 0aca490e17903..446577930b017 100644
--- a/clang/lib/Basic/TargetID.cpp
+++ b/clang/lib/Basic/TargetID.cpp
@@ -89,6 +89,8 @@ parseTargetIDWithFormatCheckingOnly(llvm::StringRef TargetID,
 
   while (!Features.empty()) {
     auto Splits = Features.split(':');
+    if (Splits.first.empty())
+      return std::nullopt;
     auto Sign = Splits.first.back();
     auto Feature = Splits.first.drop_back();
     if (Sign != '+' && Sign != '-')

diff  --git a/clang/test/Driver/amdgpu-invalid-target-id.s b/clang/test/Driver/amdgpu-invalid-target-id.s
index 7d1d8e4772338..4fe5493a3e6bb 100644
--- a/clang/test/Driver/amdgpu-invalid-target-id.s
+++ b/clang/test/Driver/amdgpu-invalid-target-id.s
@@ -39,3 +39,9 @@
 // RUN:   %s 2>&1 | FileCheck -check-prefix=NOCOLON %s
 
 // NOCOLON: error: invalid target ID 'gfx900+xnack'
+
+// RUN: not %clang --target=amdgcn-amd-amdhsa \
+// RUN:   -mcpu=gfx900::xnack+ -nostdlib \
+// RUN:   %s 2>&1 | FileCheck -check-prefix=EXTRACOL %s
+
+// EXTRACOL: error: invalid target ID 'gfx900::xnack+'