LLVM.lua does not get VS version from build.sh ("Error finding an LLVM build")

[cmcneish]

Brief Description

build/llvm/LLVM.lua detects the VS version from either cl.exe or msbuild.exe, but build/build.sh specifies (currently) vs=vs2022.

If build.sh is run from a VS developer command prompt corresponding to a different version then generate() will fail the following way:

[~]\CppSharp\build>sh build.sh generate -configuration Release -platform x64
Downloading and unpacking Premake...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100 4064k  100 4064k    0     0  4064k      0  0:00:01 --:--:--  0:00:01 12.6M
Archive:  premake-5.0.0-beta2-windows.zip
  inflating: [~]/CppSharp/build/premake/premake5.exe
Downloading: https://github.com/mono/CppSharp/releases/download/CppSharp/llvm-6eb36a-windows-vs2019-x64-RelWithDebInfo.7z
"C:\Program Files\7-Zip\7z.exe" x llvm-6eb36a-windows-vs2019-x64-RelWithDebInfo.7z -ollvm-6eb36a-windows-vs2019-x64-RelWithDebInfo -y

7-Zip 23.01 (x64) : Copyright (c) 1999-2023 Igor Pavlov : 2023-06-20

Scanning the drive for archives:
1 file, 173727674 bytes (166 MiB)

Extracting archive: llvm-6eb36a-windows-vs2019-x64-RelWithDebInfo.7z
--
Path = llvm-6eb36a-windows-vs2019-x64-RelWithDebInfo.7z
Type = 7z
Physical Size = 173727674
Headers Size = 50259
Method = LZMA2:26
Solid = +
Blocks = 1

Everything is Ok

Folders: 410
Files: 3815
Size:       2164174658
Compressed: 173727674
Error: [~]/CppSharp/build/LLVM.lua:23: Error finding an LLVM build

[~]\CppSharp\build>

OS: Windows / OS X / Linux (include version and/or distro)

Used headers

N/A

Used settings

Target: MSVC/GCC/Clang

Other settings:

• mingw sh, unzip; activated in "Visual Studio 2019 Developer Command Prompt v16.11.34"

Stack trace or incompilable generated code

N/A

---

Sample fix (I didn't check if other uses of premake.sh need --vs as well):

[~]\CppSharp\build>git diff -w
diff --git a/build/LLVM.lua b/build/LLVM.lua
index 9ac89c54..85e1b12b 100644
--- a/build/LLVM.lua
+++ b/build/LLVM.lua
@@ -20,7 +20,7 @@ function SearchLLVM()
   elseif os.isdir(LLVMRootDir) then
     print("Using LLVM build: " .. LLVMRootDir)
   else
-    error("Error finding an LLVM build")
+    error("Error finding an LLVM build. Tried: " .. LLVMRootDirDebug .. " and " .. LLVMRootDirRelease)
   end
 end

diff --git a/build/build.sh b/build/build.sh
index 5cd81557..b9916bce 100755
--- a/build/build.sh
+++ b/build/build.sh
@@ -129,7 +129,7 @@ download_premake()

 download_llvm()
 {
-  "$builddir/premake.sh" --file="$builddir/llvm/LLVM.lua" download_llvm --os=$os --arch=$platform --configuration=$configuration
+  "$builddir/premake.sh" --file="$builddir/llvm/LLVM.lua" download_llvm --vs=$vs --os=$os --arch=$platform --configuration=$configuration
 }

 clone_llvm()
diff --git a/build/llvm/LLVM.lua b/build/llvm/LLVM.lua
index 0a08c061..61c47de8 100644
--- a/build/llvm/LLVM.lua
+++ b/build/llvm/LLVM.lua
@@ -52,6 +52,10 @@ function clone_llvm()
 end

 function get_vs_version()
+  if _OPTIONS["vs"] then
+    return _OPTIONS["vs"]
+  end
+
   local function map_msvc_to_vs_version(major, minor)
   if major == "19" and minor >= "30" then return "vs2022"
     elseif major == "19" and minor >= "20" then return "vs2019"

[tritao]

Can you send a PR?