[clang] [Darwin][Driver][clang] apple-none-macho orders the resource directory after internal-externc-isystem when nostdlibinc is used (PR #120507)

[Ian Anderson via cfe-commits]

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+// UNSUPPORTED: system-windows
+//   Windows is unsupported because we use the Unix path separator `/` in the test.
+
+// Unlike the Darwin driver, the MachO driver doesn't add any framework search paths,
+// only the normal header ones.
+// RUN: %clang -x c -target arm64-apple-none-macho -isysroot %S/Inputs/MacOSX15.1.sdk -### -c %s 2>&1 \
+// RUN: | FileCheck --check-prefixes=CC1,NO-CXX,ULI,CI,UI,NO-FW -DSDKROOT=%S/Inputs/MacOSX15.1.sdk %s
+
+// Unlike the Darwin driver, the MachO driver doesn't default to libc++
+// RUN: %clang -x c++ -target arm64-apple-none-macho -isysroot %S/Inputs/MacOSX15.1.sdk -### -c %s 2>&1 \
+// RUN: | FileCheck --check-prefixes=CC1,NO-CXX,ULI,CI,UI,NO-FW -DSDKROOT=%S/Inputs/MacOSX15.1.sdk %s
+
+// However, if the user requests libc++, the MachO driver should find the search path.
+// RUN: %clang -x c++ -stdlib=libc++ -target arm64-apple-none-macho -isysroot %S/Inputs/MacOSX15.1.sdk -### -c %s 2>&1 \
+// RUN: | FileCheck --check-prefixes=CC1,CXX,ULI,CI,UI,NO-FW -DSDKROOT=%S/Inputs/MacOSX15.1.sdk %s
+
+// Verify that embedded uses can swap in alternate usr/include and usr/local/include directories.
+// usr/local/include is specified in the driver as -internal-isystem, however, the driver generated
+// paths come before the paths in the driver arguments. In order to keep usr/local/include in the
+// same position, -isystem has to be used instead of -Xclang -internal-isystem. There isn't an
+// -externc-isystem, but it's ok to use -Xclang -internal-externc-isystem since the driver doesn't
+// use that if -nostdlibinc or -nostdinc is passed.
+// RUN: %clang -x c++ -stdlib=libc++ -target arm64-apple-none-macho -isysroot %S/Inputs/MacOSX15.1.sdk \
+// RUN:        -nostdlibinc -isystem %S/Inputs/MacOSX15.1.sdk/embedded/usr/local/include \
+// RUN:        -Xclang -internal-externc-isystem -Xclang %S/Inputs/MacOSX15.1.sdk/embedded/usr/include \
+// RUN:        -### -c %s 2>&1 | FileCheck --check-prefixes=CC1,NO-CXX,EULI,CI,EUI,NO-FW -DSDKROOT=%S/Inputs/MacOSX15.1.sdk %s
+
+
+// The ordering of these flags doesn't matter, and so this test is a little
+// fragile. i.e. all of the -internal-isystem paths will be searched before the
+// -internal-externc-isystem ones, and their order on the command line doesn't
+// matter. The line order here is just the current order that the driver writes
+// the cc1 arguments.
+
+// CC1: "-cc1"
+// NO-CXX-NOT: "-internal-isystem" "[[SDKROOT]]/usr/include/c++/v1"
+// CXX-SAME: "-internal-isystem" "[[SDKROOT]]/usr/include/c++/v1"
+// ULI-SAME: "-internal-isystem" "[[SDKROOT]]/usr/local/include"
+// EULI-SAME: "-isystem" "[[SDKROOT]]/embedded/usr/local/include"
+// CI-SAME: "-internal-isystem" "{{.*}}/clang/{{[[:digit:].]*}}/include"
+// UI-SAME: "-internal-externc-isystem" "[[SDKROOT]]/usr/include"
+// EUI-SAME: "-internal-externc-isystem" "[[SDKROOT]]/embedded/usr/include"
+// NO-FW-NOT: "-internal-iframework"
----------------
ian-twilightcoder wrote:

If you put the `NOT` first then it will only check for matches before the next match, in other words it will fail for `usr/include/c++/v1 -cc1` but it will pass for `-cc1 usr/include/c++/v1 -cc1`. So the `NOT`s need to be where they are. It's kind of annoying because we can't easily check that the `NOT` isn't present anywhere in the cc1 command, but we already have to hard code the order of the flags that we are checking for, so it's probably ok? I don't think there's an easy way to be more sophisticated about it. Like ideally we would filter the arguments we care about in buckets since we don't care how the different arguments order. But then within each bucket we care about the order of each path. And then there are the paths that we don't want in any bucket. I dunno, what we have is probably good enough?

https://github.com/llvm/llvm-project/pull/120507