From 94f597df228750eec6d5c28134edd45022b0394a Mon Sep 17 00:00:00 2001 From: David Malcolm Date: Wed, 30 Nov 2016 01:13:37 +0000 Subject: [PATCH] substring locations and # line directives (PR preprocessor/78569) The ICE in PR preprocessor/78569 appears to be due to an attempt to generate substring locations in a .i file where the underlying .c file has changed since the .i file was generated. This can't work, so it seems safest for the on-demand substring locations to be unavailable for such files, falling back to "whole string" locations for such cases. gcc/ChangeLog: PR preprocessor/78569 * input.c (get_substring_ranges_for_loc): Fail gracefully if line directives were present. gcc/testsuite/ChangeLog: PR preprocessor/78569 * gcc.dg/format/pr78569.c: New test case. From-SVN: r242990 --- gcc/ChangeLog | 6 ++++++ gcc/input.c | 10 ++++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/format/pr78569.c | 24 ++++++++++++++++++++++++ 4 files changed, 45 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/format/pr78569.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6c37db0..2af1d97 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-11-29 David Malcolm + + PR preprocessor/78569 + * input.c (get_substring_ranges_for_loc): Fail gracefully if + line directives were present. + 2016-11-30 Matthias Klose * doc/install.texi: Document configure options --enable-objc-gc diff --git a/gcc/input.c b/gcc/input.c index 611e18b5..1c7228a 100644 --- a/gcc/input.c +++ b/gcc/input.c @@ -1331,6 +1331,16 @@ get_substring_ranges_for_loc (cpp_reader *pfile, if (cpp_get_options (pfile)->track_macro_expansion != 2) return "track_macro_expansion != 2"; + /* If #line or # 44 "file"-style directives are present, then there's + no guarantee that the line numbers we have can be used to locate + the strings. For example, we might have a .i file with # directives + pointing back to lines within a .c file, but the .c file might + have been edited since the .i file was created. + In such a case, the safest course is to disable on-demand substring + locations. */ + if (line_table->seen_line_directive) + return "seen line directive"; + /* If string concatenation has occurred at STRLOC, get the locations of all of the literal tokens making up the compound string. Otherwise, just use STRLOC. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index f548855..aeac71a 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-11-29 David Malcolm + + PR preprocessor/78569 + * gcc.dg/format/pr78569.c: New test case. + 2016-11-29 Martin Sebor avoid false positives on ILP32 targets. diff --git a/gcc/testsuite/gcc.dg/format/pr78569.c b/gcc/testsuite/gcc.dg/format/pr78569.c new file mode 100644 index 0000000..e827087 --- /dev/null +++ b/gcc/testsuite/gcc.dg/format/pr78569.c @@ -0,0 +1,24 @@ +/* { dg-do compile } */ +/* { dg-options "-Wformat-length" } */ + +/* A run of blank lines, so that we would fail the assertion in input.c:1388: + gcc_assert (line_width >= (start.column - 1 + literal_length)); */ + + + + + +void test (void) +{ + char tmp[128]; + /* Point to the run of blank lines, so that the components of the overlong + string appear to be present within the run of blank lines. */ +# 6 "../../../../src/gcc/testsuite/gcc.dg/format/pr78569.c" + __builtin_snprintf (tmp, sizeof(tmp), + "The Base Band sends this value as a response to a " + "request for IMSI detach sent over the control " + "channel uplink (see section 7.6.1)."); + + /* { dg-warning "output truncated" "" { target *-*-* } 7 } */ + /* { dg-message "format output" "" { target *-*-* } 6 } */ +} -- 2.7.4