wrappers: Add a wrapper for clang-scan-deps

This picks the architecture by looking for a triple prefix in the
nested command, and passes it as an explicit flag, to let
clang-scan-deps find it.

We also pass -stdlib=libc++, to let it find the libc++ headers
as expected.

wrappers/clang-scan-deps-wrapper.c

@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2024 Martin Storsjo
+ *
+ * This file is part of llvm-mingw.
+ *
+ * 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.
+ */
+
+#include "native-wrapper.h"
+
+#ifndef DEFAULT_TARGET
+#define DEFAULT_TARGET "x86_64-w64-mingw32"
+#endif
+
+int _tmain(int argc, TCHAR *argv[]) {
+    const TCHAR *dir;
+    split_argv(argv[0], &dir, NULL, NULL, NULL);
+
+    int max_arg = argc + 3;
+    const TCHAR **exec_argv = malloc((max_arg + 1) * sizeof(*exec_argv));
+    int arg = 0;
+    exec_argv[arg++] = concat(dir, _T("clang-scan-deps"));
+
+    // If changing this wrapper, change clang-scan-deps-wrapper.sh accordingly.
+    int i = 1;
+    int got_flags = 0;
+    TCHAR *cmd_exe = NULL;
+    for (; i < argc; i++) {
+        if (got_flags) {
+            cmd_exe = _tcsdup(argv[i]);
+            exec_argv[arg++] = argv[i];
+            i++;
+            break;
+        } else if (!_tcscmp(argv[i], _T("--"))) {
+            got_flags = 1;
+            exec_argv[arg++] = argv[i];
+        } else {
+            exec_argv[arg++] = argv[i];
+        }
+    }
+
+    if (cmd_exe) {
+        // If cmd_exe is a <triple>-<exe> style command, prefer the
+        // target triple from there, rather than from what we might have
+        // had in our name.
+        TCHAR *sep = _tcsrchrs(cmd_exe, '/', '\\');
+        if (sep)
+            cmd_exe = sep + 1;
+        sep = _tcsrchr(cmd_exe, '.');
+        if (sep)
+            *sep = '\0';
+        TCHAR *dash = _tcsrchr(cmd_exe, '-');
+        const TCHAR *target = NULL;
+        if (dash) {
+            *dash = '\0';
+            const TCHAR *cmd_exe_suffix = dash + 1;
+            if (!_tcscmp(cmd_exe_suffix, _T("clang")) ||
+                !_tcscmp(cmd_exe_suffix, _T("clang++")) ||
+                !_tcscmp(cmd_exe_suffix, _T("gcc")) ||
+                !_tcscmp(cmd_exe_suffix, _T("g++")) ||
+                !_tcscmp(cmd_exe_suffix, _T("c++")) ||
+                !_tcscmp(cmd_exe_suffix, _T("as")) ||
+                !_tcscmp(cmd_exe_suffix, _T("cc")) ||
+                !_tcscmp(cmd_exe_suffix, _T("c99")) ||
+                !_tcscmp(cmd_exe_suffix, _T("c11"))) {
+                target = cmd_exe;
+            }
+        }
+#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 (!target)
+            target = _T(DEFAULT_TARGET);
+#endif
+
+        if (target) {
+            // If we did find a cmd_exe and have figured out a target, add
+            // -target after cmd_exe.
+            exec_argv[arg++] = _T("-target");
+            exec_argv[arg++] = target;
+            exec_argv[arg++] = _T("-stdlib=libc++");
+        }
+    }
+
+    for (; i < argc; i++)
+        exec_argv[arg++] = argv[i];
+
+    exec_argv[arg] = NULL;
+    if (arg > max_arg) {
+        fprintf(stderr, "Too many options added\n");
+        abort();
+    }
+
+    return run_final(exec_argv[0], exec_argv);
+}

wrappers/clang-scan-deps-wrapper.sh

@@ -0,0 +1,66 @@
+#!/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"
+        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" "${FLAGS[@]}" "$CMD_EXE" -target $TARGET -stdlib=libc++ "$@"
+else
+    "$EXE" "${FLAGS[@]}" "$@"
+fi