From 35cc4595bf88a4dfb53efc850eeaa32cebd21809 Mon Sep 17 00:00:00 2001
From: Nirbheek Chauhan <nirbheek@centricular.com>
Date: Wed, 12 Aug 2020 15:39:18 +0530
Subject: [PATCH] cmake: Use a mapping when writing compiler ID

Meson and CMake compiler ids are different. This commit adds a mapping
from the meson list:

https://mesonbuild.com/Reference-tables.html#compiler-ids

to the CMake list:

https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_COMPILER_ID.html

The mapping is not 1-1, and not all entries are mapped, so this is
a best-effort attempt. Fallback to GNU as before to try to limp along
and hope that the build files don't rely on an accurate compiler ID.
---
 mesonbuild/cmake/executor.py | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/mesonbuild/cmake/executor.py b/mesonbuild/cmake/executor.py
index 793862f1b..e29e67a04 100644
--- a/mesonbuild/cmake/executor.py
+++ b/mesonbuild/cmake/executor.py
@@ -35,6 +35,31 @@ if T.TYPE_CHECKING:
 
 TYPE_result = T.Tuple[int, T.Optional[str], T.Optional[str]]
 
+MESON_TO_CMAKE_MAPPING = {
+    'arm':          'ARMCC',
+    'armclang':     'ARMClang',
+    'clang':        'Clang',
+    'clang-cl':     'MSVC',
+    'flang':        'Flang',
+    'g95':          'G95',
+    'gcc':          'GNU',
+    'intel':        'Intel',
+    'intel-cl':     'MSVC',
+    'msvc':         'MSVC',
+    'pathscale':    'PathScale',
+    'pgi':          'PGI',
+    'sun':          'SunPro',
+}
+
+def meson_compiler_to_cmake_id(cobj):
+    # cland and apple clang both map to 'clang' in meson, so we need to look at
+    # the linker that's being used
+    if cobj.linker.get_id() == 'ld64':
+        return 'AppleClang'
+    # If no mapping, try GNU and hope that the build files don't care
+    return MESON_TO_CMAKE_MAPPING.get(cobj.get_id(), 'GNU')
+
+
 class CMakeExecutor:
     # The class's copy of the CMake path. Avoids having to search for it
     # multiple times in the same Meson invocation.
@@ -280,7 +305,7 @@ class CMakeExecutor:
 
             if comp_obj is not None:
                 exe_list = comp_obj.get_exelist()
-                comp_id = comp_obj.get_id().upper()
+                comp_id = meson_compiler_to_cmake_id(comp_obj)
                 comp_version = comp_obj.version.upper()
 
             if len(exe_list) == 1: