Revert use of Clang config files

This reverts commit 49db4a3a15,
9f1f0104f1,
4f95c14adf,
c34dc64028,
570fdcd251,
4bff0298c5 and
6939aee0c0.

When relying on Clang config files, two issues appeared:

- Running the compiler-rt tests fails, because the compiler-rt tests
  disable any default config files, breaking the compiler
  in this case:
  https://github.com/llvm/llvm-project/blob/llvmorg-19.1.1/compiler-rt/test/lit.common.cfg.py#L983

- Wine fails to build using llvm-mingw as cross compiler, because
  Wine adds the --no-default-config flag to Clang while compiling,
  if supported:
  https://gitlab.winehq.org/wine/wine/-/blob/wine-9.19/configure.ac?ref_type=tags#L866-868
  This causes llvm-mingw to omit the -rtlib=compiler-rt option
  (specified in a config file), making the compiler look for libgcc
  instead. Doing a check to see that linking succeeds doesn't necessarily
  help here - such a check already exists, but it tests linking with
  -nostdlib -nodefaultlibs:
  https://gitlab.winehq.org/wine/wine/-/blob/wine-9.19/aclocal.m4?ref_type=tags#L193-L206

wrappers/aarch64-w64-windows-gnu.cfg

@@ -1,3 +0,0 @@
--target aarch64-w64-mingw32
-@mingw32-common.cfg
-# SEH is the default for aarch64.

wrappers/armv7-w64-windows-gnu.cfg

@@ -1,3 +0,0 @@
--target armv7-w64-mingw32
-@mingw32-common.cfg
-# SEH is the default for armv7.

wrappers/clang-scan-deps-wrapper.c

@@ -63,7 +63,7 @@ int _tmain(int argc, TCHAR *argv[]) {
         if (sep)
             *sep = '\0';
         TCHAR *dash = _tcsrchr(cmd_exe, '-');
-        int has_target = 0;
+        const TCHAR *target = NULL;
         if (dash) {
             *dash = '\0';
             const TCHAR *cmd_exe_suffix = dash + 1;
@@ -76,15 +76,14 @@ int _tmain(int argc, TCHAR *argv[]) {
                 !_tcscmp(cmd_exe_suffix, _T("cc")) ||
                 !_tcscmp(cmd_exe_suffix, _T("c99")) ||
                 !_tcscmp(cmd_exe_suffix, _T("c11"))) {
-                has_target = 1;
+                target = cmd_exe;
             }
         }
-        const TCHAR *target = NULL;
 #ifdef _WIN32
         // On Windows, we want to set our default target even if no target
         // was found in cmd_exe, as we want to support running with a foreign
         // clang-scan-deps-real.exe binary, that could have any default.
-        if (!has_target)
+        if (!target)
             target = _T(DEFAULT_TARGET);
 #endif
 
@@ -93,6 +92,7 @@ int _tmain(int argc, TCHAR *argv[]) {
             // -target after cmd_exe.
             exec_argv[arg++] = _T("-target");
             exec_argv[arg++] = target;
+            exec_argv[arg++] = _T("-stdlib=libc++");
         }
     }
 

wrappers/clang-scan-deps-wrapper.sh

@@ -0,0 +1,67 @@
+#!/bin/bash
+#
+# Copyright (c) 2024 Martin Storsjo
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+get_dir() {
+    target="$1"
+    while [ -L "$target" ]; do
+        cd "$(dirname "$target")"
+        target="$(readlink "$(basename "$target")")"
+    done
+    cd "$(dirname "$target")"
+    pwd
+}
+
+DIR="$(get_dir "$0")"
+
+# If changing this wrapper, change clang-scan-deps-wrapper.c accordingly.
+EXE="$DIR/clang-scan-deps"
+FLAGS=()
+while [ $# -gt 0 ]; do
+    if [ -n "$got_flags" ]; then
+        CMD_EXE="$1"
+        FLAGS+=("$1")
+        shift
+        break
+    elif [ "$1" = "--" ]; then
+        got_flags=1
+        FLAGS+=("$1")
+    else
+        FLAGS+=("$1")
+    fi
+    shift
+done
+
+if [ -n "$CMD_EXE" ]; then
+    # If CMD_EXE is a <triple>-<exe> style command, pick up the
+    # target triple from there.
+    CMD_BASENAME="$(basename "$CMD_EXE")"
+    CMD_BASENAME="${CMD_BASENAME%.*}"
+    CMD_TARGET="${CMD_BASENAME%-*}"
+    CMD_EXE_SUFFIX="${CMD_BASENAME##*-}"
+    if [ "$CMD_TARGET" != "$CMD_BASENAME" ]; then
+        case $CMD_EXE_SUFFIX in
+        clang|clang++|gcc|g++|c++|as|cc|c99|c11)
+            TARGET="$CMD_TARGET"
+            ;;
+        esac
+    fi
+fi
+
+if [ -n "$TARGET" ]; then
+    "$EXE" "${FLAGS[@]}" -target $TARGET -stdlib=libc++ "$@"
+else
+    "$EXE" "${FLAGS[@]}" "$@"
+fi

wrappers/clang-target-wrapper.c

@@ -50,7 +50,7 @@ int _tmain(int argc, TCHAR* argv[]) {
         }
     }
 
-    int max_arg = argc + 18;
+    int max_arg = argc + 22;
     const TCHAR **exec_argv = malloc((max_arg + 1) * sizeof(*exec_argv));
     int arg = 0;
     if (getenv("CCACHE"))
@@ -66,6 +66,16 @@ int _tmain(int argc, TCHAR* argv[]) {
     else if (!_tcscmp(exe, _T("c11")))
         exec_argv[arg++] = _T("-std=c11");
 
+    if (!_tcscmp(arch, _T("i686"))) {
+        // Dwarf is the default for i686.
+    } else if (!_tcscmp(arch, _T("x86_64"))) {
+        // SEH is the default for x86_64.
+    } else if (!_tcscmp(arch, _T("armv7"))) {
+        // SEH is the default for armv7.
+    } else if (!_tcscmp(arch, _T("aarch64"))) {
+        // SEH is the default for aarch64.
+    }
+
     if (target_os && !_tcscmp(target_os, _T("mingw32uwp"))) {
         // the UWP target is for Windows 10
         exec_argv[arg++] = _T("-D_WIN32_WINNT=0x0A00");
@@ -80,6 +90,10 @@ int _tmain(int argc, TCHAR* argv[]) {
 
     exec_argv[arg++] = _T("-target");
     exec_argv[arg++] = target;
+    exec_argv[arg++] = _T("-rtlib=compiler-rt");
+    exec_argv[arg++] = _T("-unwindlib=libunwind");
+    exec_argv[arg++] = _T("-stdlib=libc++");
+    exec_argv[arg++] = _T("-fuse-ld=lld");
     exec_argv[arg++] = _T("--end-no-unused-arguments");
 
     for (int i = 1; i < argc; i++)

wrappers/clang-target-wrapper.sh

@@ -67,6 +67,20 @@ c11)
     FLAGS="$FLAGS -std=c11"
     ;;
 esac
+case $ARCH in
+i686)
+    # Dwarf is the default for i686.
+    ;;
+x86_64)
+    # SEH is the default for x86_64.
+    ;;
+armv7)
+    # SEH is the default for armv7.
+    ;;
+aarch64)
+    # SEH is the default for aarch64.
+    ;;
+esac
 LINKER_FLAGS=""
 case $TARGET_OS in
 mingw32uwp)
@@ -93,6 +107,10 @@ mingw32uwp)
 esac
 
 FLAGS="$FLAGS -target $TARGET"
+FLAGS="$FLAGS -rtlib=compiler-rt"
+FLAGS="$FLAGS -unwindlib=libunwind"
+FLAGS="$FLAGS -stdlib=libc++"
+FLAGS="$FLAGS -fuse-ld=lld"
 FLAGS="$FLAGS --end-no-unused-arguments"
 
 $CCACHE "$CLANG" $FLAGS "$@" $LINKER_FLAGS

wrappers/i686-w64-windows-gnu.cfg

@@ -1,3 +0,0 @@
--target i686-w64-mingw32
-@mingw32-common.cfg
-# Dwarf is the default for i686.

wrappers/mingw32-common.cfg

@@ -1,4 +0,0 @@
--rtlib=compiler-rt
--unwindlib=libunwind
--stdlib=libc++
--fuse-ld=lld

wrappers/x86_64-w64-windows-gnu.cfg

@@ -1,3 +0,0 @@
--target x86_64-w64-mingw32
-@mingw32-common.cfg
-# SEH is the default for x86_64.