[src/trunk]: src/usr.bin/indent indent: don't error out on unrecognized prepr...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/56b72f7ef868
branches:  trunk
changeset: 375911:56b72f7ef868
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun May 21 09:48:22 2023 +0000

description:
indent: don't error out on unrecognized preprocessor directives

This allows indent to be used on the GCC preprocessor output.

diffstat:

 tests/usr.bin/indent/t_errors.sh |   4 +--
 usr.bin/indent/indent.c          |  57 ++++++++-------------------------------
 2 files changed, 13 insertions(+), 48 deletions(-)

diffs (121 lines):

diff -r 0bfcecc4a955 -r 56b72f7ef868 tests/usr.bin/indent/t_errors.sh
--- a/tests/usr.bin/indent/t_errors.sh  Sun May 21 00:35:38 2023 +0000
+++ b/tests/usr.bin/indent/t_errors.sh  Sun May 21 09:48:22 2023 +0000
@@ -1,5 +1,5 @@
 #! /bin/sh
-# $NetBSD: t_errors.sh,v 1.28 2023/05/14 11:29:23 rillig Exp $
+# $NetBSD: t_errors.sh,v 1.29 2023/05/21 09:48:22 rillig Exp $
 #
 # Copyright (c) 2021 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -366,8 +366,6 @@ preprocessing_unrecognized_body()
                #else
        EOF
        cat <<-\EOF > stderr.exp
-               error: code.c:1: Unrecognized cpp directive "unknown"
-               error: code.c:2: Unrecognized cpp directive ""
                error: code.c:3: Unmatched #elif
                error: code.c:4: Unmatched #else
        EOF
diff -r 0bfcecc4a955 -r 56b72f7ef868 usr.bin/indent/indent.c
--- a/usr.bin/indent/indent.c   Sun May 21 00:35:38 2023 +0000
+++ b/usr.bin/indent/indent.c   Sun May 21 09:48:22 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: indent.c,v 1.300 2023/05/20 16:31:31 rillig Exp $      */
+/*     $NetBSD: indent.c,v 1.301 2023/05/21 09:48:22 rillig Exp $      */
 
 /*-
  * SPDX-License-Identifier: BSD-4-Clause
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: indent.c,v 1.300 2023/05/20 16:31:31 rillig Exp $");
+__RCSID("$NetBSD: indent.c,v 1.301 2023/05/21 09:48:22 rillig Exp $");
 
 #include <sys/param.h>
 #include <err.h>
@@ -934,26 +934,6 @@ read_preprocessing_line(void)
                lab.len--;
 }
 
-typedef struct {
-       const char *s;
-       const char *e;
-} substring;
-
-static bool
-substring_equals(substring ss, const char *str)
-{
-       size_t len = (size_t)(ss.e - ss.s);
-       return len == strlen(str) && memcmp(ss.s, str, len) == 0;
-}
-
-static bool
-substring_starts_with(substring ss, const char *prefix)
-{
-       while (ss.s < ss.e && *prefix != '\0' && *ss.s == *prefix)
-               ss.s++, prefix++;
-       return *prefix == '\0';
-}
-
 static void
 process_preprocessing(void)
 {
@@ -965,46 +945,33 @@ process_preprocessing(void)
        ps.is_case_label = false;
 
        const char *end = lab.mem + lab.len;
-       substring dir;
-       dir.s = lab.st + 1;
-       while (dir.s < end && ch_isblank(*dir.s))
-               dir.s++;
-       dir.e = dir.s;
-       while (dir.e < end && ch_isalpha(*dir.e))
-               dir.e++;
+       const char *dir = lab.st + 1;
+       while (dir < end && ch_isblank(*dir))
+               dir++;
+       const char *dir_end = dir;
+       while (dir_end < end && ch_isalpha(*dir_end))
+               dir_end++;
 
-       if (substring_starts_with(dir, "if")) { /* also ifdef, ifndef */
+       if (strncmp(dir, "if", 2) == 0) {       /* also ifdef, ifndef */
                if ((size_t)ifdef_level < array_length(state_stack))
                        state_stack[ifdef_level++] = ps;
                else
                        diag(1, "#if stack overflow");
                out.line_kind = lk_if;
 
-       } else if (substring_starts_with(dir, "el")) {  /* else, elif */
+       } else if (strncmp(dir, "el", 2) == 0) {        /* else, elif */
                if (ifdef_level <= 0)
-                       diag(1, dir.s[2] == 'i'
+                       diag(1, dir[2] == 'i'
                            ? "Unmatched #elif" : "Unmatched #else");
                else
                        ps = state_stack[ifdef_level - 1];
 
-       } else if (substring_equals(dir, "endif")) {
+       } else if (dir_end - dir == 5 && memcmp(dir, "endif", 5) == 0) {
                if (ifdef_level <= 0)
                        diag(1, "Unmatched #endif");
                else
                        ifdef_level--;
                out.line_kind = lk_endif;
-
-       } else {
-               if (!substring_equals(dir, "pragma") &&
-                   !substring_equals(dir, "error") &&
-                   !substring_equals(dir, "line") &&
-                   !substring_equals(dir, "undef") &&
-                   !substring_equals(dir, "define") &&
-                   !substring_equals(dir, "include")) {
-                       diag(1, "Unrecognized cpp directive \"%.*s\"",
-                           (int)(dir.e - dir.s), dir.s);
-                       return;
-               }
        }
 
        /* subsequent processing of the newline character will cause the line