From 799bf33c5afcb0adc9d22331645b4112c7e03f62 Mon Sep 17 00:00:00 2001
From: Ben Boeckel <ben.boeckel@kitware.com>
Date: Wed, 22 Oct 2025 13:52:42 -0400
Subject: [PATCH] VS: do not create `ProgramDataBaseFileName` entries without a
 filepath

The logic in commit f78f592b78 (pchreuse: defer target existence
enforcement to generation time, 2025-06-16, v4.2.0-rc1~481^2~4) caused
generator targets to always respond with something for compilation PDB
files. This may be a directory as the flag supports it (the then
compiler chooses the filename). However, one caller was expecting it to
always be a path to a file in order to specify the
`ProgramDataBaseFileName` element. However, this usage cannot be a
directory.

In addition to not having a PDB path at all, also verify that it is not
a path to a directory before creating the `ProgramDataBaseFileName`
element.

This was observed in builds using `import std` in Debug mode.

Fixes: #27320
---
 Source/cmVisualStudio10TargetGenerator.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/cmVisualStudio10TargetGenerator.cxx b/Source/cmVisualStudio10TargetGenerator.cxx
index 23a726a1a2..3cd9c62d1f 100644
--- a/Source/cmVisualStudio10TargetGenerator.cxx
+++ b/Source/cmVisualStudio10TargetGenerator.cxx
@@ -3765,7 +3765,7 @@ void cmVisualStudio10TargetGenerator::WriteClOptions(
 
     // Specify the compiler program database file if configured.
     std::string pdb = this->GeneratorTarget->GetCompilePDBPath(configName);
-    if (!pdb.empty()) {
+    if (!pdb.empty() && !cmHasSuffix(pdb, '/') && !cmHasSuffix(pdb, '\\')) {
       if (this->GlobalGenerator->IsCudaEnabled()) {
         // CUDA does not quote paths with spaces correctly when forwarding
         // this to the host compiler.  Use a relative path to avoid spaces.