Hello,
within a compile cluster, only the preprocessed output of GCC is transferred to
remote nodes for compilation.
When GCC produces advanced diagnostics (with -fdiagnostics-show-caret), e.g.
prints out the affected source
line and fixit hints, it attempts to read the source file again, even when
compiling a preprocessed file (-fpreprocessed).
This leads to wrong diagnostics when building with a compile cluster, or, more
generally, when changing or deleting the original source file.
This patch attempts to alter the behavior by implementing a
location_get_source_line_preprocessed
function that can be used in diagnostic-show-locus.c in case a preprocessed
file is compiled.
There was some previous discussion on this behavior on PR preprocessor/79106.
This is my first patch to GCC, so in case something is wrong with the format,
please let me know.
Best regards
Lucas
2019-12-16 Lucas Bader <lucas.ba...@sap.com>
PR preprocessor/79106
* c-opts.c (c_common_handle_option): pass -fpreprocessed
option value to global diagnostic configuration
* diagnostic-show-locus.c (layout::layout): read line from source or
preprocessed
file based on -fpreprocessed value
(source_line::source_line): read line from source or preprocessed
file based on -fpreprocessed value
(layout::print_line): read line from source or preprocessed
file based on -fpreprocessed value
* diagnostic.h (diagnostic_context): new members for reading
source lines from preprocessed files
* diagnostic.c (diagnostic_initialize): initialize new members
* input.c (location_get_source_line_preprocessed): new function
to read source lines from preprocessed files
(test_reading_source_line_preprocessed): new test case
(input_c_tests): execute new test case
* opts-global.c (read_cmdline_options): pass input filename to global
diagnostic context
---
diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
index c913291c07c..8634de6eb3f 100644
--- a/gcc/c-family/c-opts.c
+++ b/gcc/c-family/c-opts.c
@@ -485,6 +485,7 @@ c_common_handle_option (size_t scode, const char *arg,
HOST_WIDE_INT value,
case OPT_fpreprocessed:
cpp_opts->preprocessed = value;
+ global_dc->is_preprocessed = value;
break;
case OPT_fdebug_cpp:
diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show-locus.c
index cb920f6b9d0..3a4838605de 100644
--- a/gcc/diagnostic-show-locus.c
+++ b/gcc/diagnostic-show-locus.c
@@ -896,7 +896,12 @@ layout::layout (diagnostic_context * context,
Center the primary caret to fit in max_width; all columns
will be adjusted accordingly. */
size_t max_width = m_context->caret_max_width;
- char_span line = location_get_source_line (m_exploc.file, m_exploc.line);
+ char_span line (NULL, 0);
+ if (global_dc->main_input_file_path != NULL && global_dc->is_preprocessed)
+ line = location_get_source_line_preprocessed (
+ m_exploc.file, global_dc->main_input_file_path, m_exploc.line);
+ else
+ line = location_get_source_line (m_exploc.file, m_exploc.line);
if (line && (size_t)m_exploc.column <= line.length ())
{
size_t right_margin = CARET_LINE_MARGIN;
@@ -1913,7 +1918,12 @@ public:
source_line::source_line (const char *filename, int line)
{
- char_span span = location_get_source_line (filename, line);
+ char_span span (NULL, 0);
+ if (global_dc->main_input_file_path != NULL && global_dc->is_preprocessed)
+ span = location_get_source_line_preprocessed (
+ filename, global_dc->main_input_file_path, line);
+ else
+ span = location_get_source_line (filename, line);
chars = span.get_buffer ();
width = span.length ();
}
@@ -2237,7 +2247,13 @@ layout::show_ruler (int max_column) const
void
layout::print_line (linenum_type row)
{
- char_span line = location_get_source_line (m_exploc.file, row);
+ char_span line (NULL, 0);
+ if (global_dc->main_input_file_path != NULL && global_dc->is_preprocessed)
+ line = location_get_source_line_preprocessed (
+ m_exploc.file, global_dc->main_input_file_path, row);
+ else
+ line = location_get_source_line (m_exploc.file, row);
+
if (!line)
return;
diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c
index a29bcf155e2..6ef99d0e8f1 100644
--- a/gcc/diagnostic.c
+++ b/gcc/diagnostic.c
@@ -218,6 +218,8 @@ diagnostic_initialize (diagnostic_context *context, int
n_opts)
context->begin_group_cb = NULL;
context->end_group_cb = NULL;
context->final_cb = default_diagnostic_final_cb;
+ context->main_input_file_path = NULL;
+ context->is_preprocessed = false;
}
/* Maybe initialize the color support. We require clients to do this
diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h
index 91e4c509605..f233057fbbe 100644
--- a/gcc/diagnostic.h
+++ b/gcc/diagnostic.h
@@ -158,6 +158,12 @@ struct diagnostic_context
/* Maximum number of errors to report. */
int max_errors;
+ /* Original input file. */
+ const char* main_input_file_path;
+
+ /* True if the input file is treated as preprocessed. */
+ bool is_preprocessed;
+
/* This function is called before any message is printed out. It is
responsible for preparing message prefix and such. For example, it
might say:
diff --git a/gcc/input.c b/gcc/input.c
index 00301ef68dd..6fe0dbfbf34 100644
--- a/gcc/input.c
+++ b/gcc/input.c
@@ -767,6 +767,109 @@ location_get_source_line (const char *file_path, int line)
return char_span (buffer, len);
}
+/* Return the physical source line that corresponds to SOURCE_NAME/LINE.
+ Read the line from the preprocessed file at FILE_PATH.
+ The line is not nul-terminated. The returned pointer is only
+ valid until the next call of location_get_source_line.
+ Note that the line can contain several null characters,
+ so the returned value's length has the actual length of the line.
+ If the function fails, a NULL char_span is returned. */
+
+char_span
+location_get_source_line_preprocessed (const char *source_name,
+ const char *file_path, int line)
+{
+ char *buffer = NULL;
+ ssize_t len;
+
+ if (line == 0)
+ return char_span (NULL, 0);
+
+ fcache *c = lookup_or_add_file_to_cache_tab (file_path);
+ if (c == NULL)
+ return char_span (NULL, 0);
+
+ // find linemarker closest to actual line number
+ int linemarker_line = 0; // line no of linemarker in pp file
+ int linemarker_loc = 0; // source line no indicated in linemarker
+ int current_line = 1;
+ size_t source_name_len = strlen (source_name);
+ while (read_line_num (c, current_line, &buffer, &len))
+ {
+ if (len > 2 && buffer[0] == '#' && ISDIGIT (buffer[2]))
+ {
+ // is a linemarker
+ bool is_match = false;
+ for (ssize_t i = 3; i < len && source_name_len < len - i - 1; ++i)
+ {
+ if (buffer[i] == '"')
+ {
+ is_match
+ = memcmp (buffer + i + 1, source_name, source_name_len)
+ == 0;
+ break;
+ }
+ }
+ bool match_past_line = false;
+ if (is_match)
+ {
+ // we found a linemarker that matches the source file
+ // e.g.
+ // # 14 "../../file.h"
+ // we use the last suitable marker we find
+ int loc = atoi (buffer + 2);
+ if (loc <= line && line - loc <= line - linemarker_loc)
+ {
+ // new best candidate
+ linemarker_loc = loc;
+ linemarker_line = current_line;
+ current_line++;
+ continue;
+ }
+ else if (loc > line)
+ {
+ // don't break directly due to validity check
+ match_past_line = true;
+ }
+ }
+ if (linemarker_line != 0
+ && linemarker_line + (line - linemarker_loc) + 1 >= current_line)
+ {
+ // if we find any other linemarker, we have to check if our
+ // potential source line is outside the current candidate if
+ // that's the case, we invalidate the candidate
+ linemarker_line = 0;
+ linemarker_loc = 0;
+ }
+ if (match_past_line)
+ break;
+ }
+ current_line++;
+ }
+ if (linemarker_line != 0)
+ {
+ // line of linemarker in the preprocessed file is the base at which we
+ // start counting the line indicated by the linemarker, e.g. the 5 in # 5
+ // "file.cpp", is the original source line number which starts right
+ // below the linemarker So to read line 7 of the original source file
+ // "file.cpp" we treat line 2055 as line 5 of the original line 7 = 2054
+ // + (7 - 5) + 1 = 2057
+ // ...
+ // 2054: # 5 "file.cpp"
+ // 2055: int func() {
+ // 2056: int a = 4;
+ // 2057: int b = 5;
+ // ...
+ bool read = read_line_num (
+ c, linemarker_line + (line - linemarker_loc) + 1, &buffer, &len);
+ if (!read)
+ return char_span (NULL, 0);
+
+ return char_span (buffer, len);
+ }
+ return char_span (NULL, 0);
+}
+
/* Determine if FILE_PATH missing a trailing newline on its final line.
Only valid to call once all of the file has been loaded, by
requesting a line number beyond the end of the file. */
@@ -1951,6 +2054,70 @@ test_reading_source_line ()
ASSERT_TRUE (source_line.get_buffer () == NULL);
}
+/* Verify reading of preprocessed input files
+ (e.g. for caret-based diagnostics). */
+
+static void
+test_reading_source_line_preprocessed ()
+{
+ /* Create a tempfile and write some valid preprocessor output. */
+ temp_source_file tmp (SELFTEST_LOCATION, ".cpp.ii",
+ "# 1 \"test.cpp\"\n"
+ "# 1 \"test.cpp\"\n"
+ "# 1 \"test.h\" 1\n"
+ "void test_func() {\n"
+ "# 35 \"test.h\"\n"
+ " do_something_else ();\n"
+ "}\n"
+ "# 2 \"test.cpp\" 2\n"
+ "\n"
+ "int main() {\n"
+ " do_something ();\n"
+ "\n"
+ " int i = 5;\n"
+ " unsigned j = 3;\n"
+ " if (i > j)\n"
+ " return 0;\n"
+ "\n"
+ " test_func ();\n"
+ "}");
+
+ /* Read back a specific line from the tempfile. */
+ char_span source_line = location_get_source_line_preprocessed (
+ "test.cpp", tmp.get_filename (), 4);
+ ASSERT_TRUE (source_line);
+ ASSERT_TRUE (source_line.get_buffer () != NULL);
+ ASSERT_EQ (20, source_line.length ());
+ ASSERT_TRUE (!strncmp (" do_something ();", source_line.get_buffer (),
+ source_line.length ()));
+
+ source_line = location_get_source_line_preprocessed (
+ "test.h", tmp.get_filename (), 35);
+ ASSERT_TRUE (source_line);
+ ASSERT_TRUE (source_line.get_buffer () != NULL);
+ ASSERT_EQ (25, source_line.length ());
+ ASSERT_TRUE (!strncmp (" do_something_else ();",
+ source_line.get_buffer (), source_line.length ()));
+
+ // file not present in preprocessor output
+ source_line = location_get_source_line_preprocessed ("other.h",
+ tmp.get_filename (), 4);
+ ASSERT_FALSE (source_line);
+ ASSERT_TRUE (source_line.get_buffer () == NULL);
+
+ // off by one
+ source_line = location_get_source_line_preprocessed (
+ "test.cpp", tmp.get_filename (), 13);
+ ASSERT_FALSE (source_line);
+ ASSERT_TRUE (source_line.get_buffer () == NULL);
+
+ // empty lines omitted by preprocessor
+ source_line = location_get_source_line_preprocessed ("test.h",
+ tmp.get_filename (), 2);
+ ASSERT_FALSE (source_line);
+ ASSERT_TRUE (source_line.get_buffer () == NULL);
+}
+
/* Tests of lexing. */
/* Verify that token TOK from PARSER has cpp_token_as_text
@@ -3629,6 +3796,7 @@ input_c_tests ()
for_each_line_table_case (test_lexer_char_constants);
test_reading_source_line ();
+ test_reading_source_line_preprocessed ();
test_line_offset_overflow ();
}
diff --git a/gcc/input.h b/gcc/input.h
index c459bf28553..99ab002f941 100644
--- a/gcc/input.h
+++ b/gcc/input.h
@@ -83,6 +83,9 @@ class char_span
};
extern char_span location_get_source_line (const char *file_path, int line);
+extern char_span
+location_get_source_line_preprocessed (const char *source_name,
+ const char *file_path, int line);
extern bool location_missing_trailing_newline (const char *file_path);
extern expanded_location
diff --git a/gcc/opts-global.c b/gcc/opts-global.c
index b51c2fbc21c..b48fe527370 100644
--- a/gcc/opts-global.c
+++ b/gcc/opts-global.c
@@ -224,6 +224,10 @@ read_cmdline_options (struct gcc_options *opts, struct
gcc_options *opts_set,
if (opts->x_main_input_filename == NULL)
{
opts->x_main_input_filename = decoded_options[i].arg;
+ // reserve original input filename in diagnostic context
+ // because if a preprocessed file is compiled, this is
+ // changed to the original source file name later
+ dc->main_input_file_path = opts->x_main_input_filename;
opts->x_main_input_baselength
= base_of_path (opts->x_main_input_filename,
&opts->x_main_input_basename);
--
2.12.3
