PR other/69554: avoid excessive source printing for widely-separated locations

gcc/ChangeLog:
	PR other/69554
	* diagnostic-show-locus.c (struct line_span): New struct.
	(layout::get_first_line): Delete.
	(layout::get_last_line): Delete.
	(layout::get_num_line_spans): New member function.
	(layout::get_line_span): Likewise.
	(layout::print_heading_for_line_span_index_p): Likewise.
	(layout::get_expanded_location): Likewise.
	(layout::calculate_line_spans): Likewise.
	(layout::m_first_line): Delete.
	(layout::m_last_line): Delete.
	(layout::m_line_spans): New field.
	(layout::layout): Update comment.  Replace m_first_line and
	m_last_line with m_line_spans, replacing their initialization
	with a call to calculate_line_spans.
	(diagnostic_show_locus): When printing source lines and
	annotations, rather than looping over a single span
	of lines, instead loop over each line_span within
	the layout, with an inner loop over the lines within them.
	Call the context's start_span callback when changing line spans.
	* diagnostic.c (diagnostic_initialize): Initialize start_span.
	(diagnostic_build_prefix): Break out the building of the location
	part of the string into...
	(diagnostic_get_location_text): ...this new function, rewriting
	it from nested ternary expressions to a sequence of "if"
	statements.
	(default_diagnostic_start_span_fn): New function.
	* diagnostic.h (diagnostic_start_span_fn): New typedef.
	(diagnostic_context::start_span): New field.
	(default_diagnostic_start_span_fn): New prototype.

gcc/fortran/ChangeLog:
	PR other/69554
	* error.c (gfc_diagnostic_start_span): New function.
	(gfc_diagnostics_init): Initialize global_dc's start_span.

gcc/testsuite/ChangeLog:
	PR other/69554
	* gcc.dg/pr69554-1.c: New test.
	* gfortran.dg/pr69554-1.F90: New test.
	* gfortran.dg/pr69554-2.F90: New test.
	* lib/gcc-dg.exp (proc dg-locus): New function.
	* lib/gfortran-dg.exp (proc gfortran-dg-test): Update comment to
	distinguish between the caret-printing and non-caret-printing
	cases.  If caret-printing has been explicitly enabled, bail out
	without attempting to fix up the output.

From-SVN: r233386

2 files changed, 44 insertions, 2 deletions

diff --git a/gcc/testsuite/lib/gcc-dg.exp b/gcc/testsuite/lib/gcc-dg.exp
index 3dd8564..b732b54 100644
--- a/gcc/testsuite/lib/gcc-dg.exp
+++ b/gcc/testsuite/lib/gcc-dg.exp
@@ -988,6 +988,33 @@ proc dg-message { args } {
     process-message saved-dg-warning "" $args
 }
 
+# Look for a location marker of the form
+#   file:line:column:
+# with no extra text (e.g. a line-span separator).
+
+proc dg-locus { args } {
+    upvar dg-messages dg-messages
+
+    # Process the dg- directive, including adding the regular expression
+    # to the new message entry in dg-messages.
+    set msgcnt [llength ${dg-messages}]
+    eval saved-dg-warning $args
+
+    # If the target expression wasn't satisfied there is no new message.
+    if { [llength ${dg-messages}] == $msgcnt } {
+	return;
+    }
+
+    # Get the entry for the new message.  Prepend the message prefix to
+    # the regular expression and make it match a single line.
+    set newentry [lindex ${dg-messages} end]
+    set expmsg [lindex $newentry 2]
+
+    set newentry [lreplace $newentry 2 2 $expmsg]
+    set dg-messages [lreplace ${dg-messages} end end $newentry]
+    verbose "process-message:\n${dg-messages}" 2
+}
+
 # Check the existence of a gdb in the path, and return true if there
 # is one.
 #
diff --git a/gcc/testsuite/lib/gfortran-dg.exp b/gcc/testsuite/lib/gfortran-dg.exp
index 52bb341..6b7f98b 100644
--- a/gcc/testsuite/lib/gfortran-dg.exp
+++ b/gcc/testsuite/lib/gfortran-dg.exp
@@ -26,7 +26,15 @@ proc gfortran-dg-test { prog do_what extra_tool_flags } {
     set comp_output [lindex $result 0]
     set output_file [lindex $result 1]
 
-    # gfortran error messages look like this:
+    # gcc's default is to print the caret and source code, but
+    # most test cases implicitly use the flag -fno-diagnostics-show-caret
+    # to disable caret (and source code) printing.
+    #
+    # However, a few test cases override this back to the default by
+    # explicily supplying "-fdiagnostics-show-caret", so that we can have
+    # test coverage for caret/source code printing.
+    #
+    # gfortran error messages with caret-printing look like this:
     #     [name]:[locus]:
     #
     #        some code
@@ -49,7 +57,14 @@ proc gfortran-dg-test { prog do_what extra_tool_flags } {
     #              1       2
     #     Error: Some error at (1) and (2)
     #
-    # or
+    # If this is such a test case, skip the rest of this function, so
+    # that the test case can explicitly verify the output that it expects.
+    if {[string first "-fdiagnostics-show-caret" $extra_tool_flags] >= 0} {
+	return [list $comp_output $output_file]
+    }
+
+    # Otherwise, caret-printing is disabled.
+    # gfortran errors with caret-printing disabled look like this:
     #     [name]:[locus]: Error: Some error
     # or
     #     [name]:[locus]: Error: (1)