Fix coverage when /fo is used

[pdagobert]

Fixes #87304

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[llvmbot]

@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-clang

Author: None (pdagobert)

Changes

Fixes #87304

---

Full diff: https://github.com/llvm/llvm-project/pull/88201.diff

1 Files Affected:

• (modified) clang/lib/Driver/ToolChains/Clang.cpp (+4)

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 766a9b91e3c0ad..44d18acd25a589 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -802,6 +802,10 @@ static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C,
     } else if (Arg *FinalOutput =
                    C.getArgs().getLastArg(options::OPT__SLASH_Fo)) {
       CoverageFilename = FinalOutput->getValue();
+      StringRef V = FinalOutput->getValue();
+      if (llvm::sys::path::is_separator(V.back())) {
+        CoverageFilename += llvm::sys::path::filename(Output.getBaseInput());
+      }
     } else if (Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o)) {
       CoverageFilename = FinalOutput->getValue();
     } else {