From d4ba945c48a3af674bdd95157d18d6236f7c2472 Mon Sep 17 00:00:00 2001
From: Raphael Gozzo <raphael.rg91@gmail.com>
Date: Mon, 6 Dec 2021 15:03:10 -0300
Subject: CMakeParseLibraryArchitecture: Fix parsing /lib/<arch> implicit
 object path

The current regular expression is able to match `/usr/lib/<arch>`,
`/usr/usr/lib/<arch>`, `/usr/usr/usr/lib/<arch>`, ... but not
`/lib/<arch>`.

This behavior ends up causing the detected architecture to
be x86_64-pc-linux-gnu when the Clang compiler is installed on
a "non-system" location (like /opt/llvm-13) which, in turn, makes
almost every 'find_library()' fail because the correct
architecture is x86_64-linux-gnu.

This is due to a typo in commit 764606e256 (CMakeDetermineCompilerABI:
Extract lib arch from implicit object file paths, 2021-04-05,
v3.20.1~10^2), which used `+` instead of `?`.
---
 Modules/CMakeParseLibraryArchitecture.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'Modules/CMakeParseLibraryArchitecture.cmake')

diff --git a/Modules/CMakeParseLibraryArchitecture.cmake b/Modules/CMakeParseLibraryArchitecture.cmake
index 6fb9c6bfce..f7a4b29c34 100644
--- a/Modules/CMakeParseLibraryArchitecture.cmake
+++ b/Modules/CMakeParseLibraryArchitecture.cmake
@@ -23,7 +23,7 @@ function(cmake_parse_library_architecture lang implicit_dirs implicit_objs outpu
 
     foreach(obj IN LISTS implicit_objs)
       get_filename_component(dir "${obj}" DIRECTORY)
-      if("${dir}" MATCHES "(/usr)+/lib/${CMAKE_LIBRARY_ARCHITECTURE_REGEX}$")
+      if("${dir}" MATCHES "(/usr)?/lib/${CMAKE_LIBRARY_ARCHITECTURE_REGEX}$")
         get_filename_component(arch "${dir}" NAME)
         set(library_arch "${arch}")
         break()
-- 
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