testsuite: add coverage for diagnostics relating to inlining (PR tree-optimization/83336)

In theory, the diagnostics subsystem can print context information on
code inlining when diagnostics are emitted by the middle-end, describing
the chain of inlined callsites that led to a particular warning,
but PR tree-optimization/83336 describes various issues with this.

An underlying issue is that we have very little automated testing for
this code: gcc.dg/tm/pr52141.c has a test, but in general, prune.exp
filters out the various "inlined from" lines.

The following patch adds test coverage for it for C and C++ via a new
testsuite plugin, which emits a warning from the middle-end; the test
cases use dg-regexp to verify that the "inlined from" lines are
emitted correctly, with the correct function names and source locations.

Doing so requires a change to prune.exp: the dg-regexp lines have to
be handled *before* the "inlined from" lines are stripped.

gcc/testsuite/ChangeLog:
	PR tree-optimization/83336
	* g++.dg/cpp0x/missing-initializer_list-include.C: Update for
	changes to prune.exp's handling of dg-regexp.
	* g++.dg/plugin/diagnostic-test-inlining-1.C: New test case.
	* g++.dg/plugin/plugin.exp (plugin_test_list): Add it, via
	gcc.dg's plugin/diagnostic_plugin_test_inlining.c.
	* gcc.dg/plugin/diagnostic-test-inlining-1.c: New test case.
	* gcc.dg/plugin/diagnostic-test-inlining-2.c: Likewise.
	* gcc.dg/plugin/diagnostic-test-inlining-3.c: Likewise.
	* gcc.dg/plugin/diagnostic-test-inlining-4.c: Likewise.
	* gcc.dg/plugin/diagnostic_plugin_test_inlining.c: New test
	plugin.
	* gcc.dg/plugin/plugin.exp (plugin_test_list): Add them.
	* lib/prune.exp (prune_gcc_output): Move call to handle-dg-regexps
	to before the various text stripping regsup invocations,
	in particular, to before the stripping of "inlined from".

From-SVN: r255786

gcc/testsuite/ChangeLog

+2017-12-18  David Malcolm  <dmalcolm@redhat.com>
+
+	PR tree-optimization/83336
+	* g++.dg/cpp0x/missing-initializer_list-include.C: Update for
+	changes to prune.exp's handling of dg-regexp.
+	* g++.dg/plugin/diagnostic-test-inlining-1.C: New test case.
+	* g++.dg/plugin/plugin.exp (plugin_test_list): Add it, via
+	gcc.dg's plugin/diagnostic_plugin_test_inlining.c.
+	* gcc.dg/plugin/diagnostic-test-inlining-1.c: New test case.
+	* gcc.dg/plugin/diagnostic-test-inlining-2.c: Likewise.
+	* gcc.dg/plugin/diagnostic-test-inlining-3.c: Likewise.
+	* gcc.dg/plugin/diagnostic-test-inlining-4.c: Likewise.
+	* gcc.dg/plugin/diagnostic_plugin_test_inlining.c: New test
+	plugin.
+	* gcc.dg/plugin/plugin.exp (plugin_test_list): Add them.
+	* lib/prune.exp (prune_gcc_output): Move call to handle-dg-regexps
+	to before the various text stripping regsup invocations,
+	in particular, to before the stripping of "inlined from".
+
 2017-12-18  Jeff Law  <law@redhat.com>
 
 	PR middle-end/83460

gcc/testsuite/g++.dg/cpp0x/missing-initializer_list-include.C

@@ -24,5 +24,6 @@ void test (int i)
 +#include <initializer_list>
  /* This is padding (to avoid the generated patch containing DejaGnu
     directives).  */
+ 
 { dg-end-multiline-output "" }
 #endif

gcc/testsuite/g++.dg/plugin/diagnostic-test-inlining-1.C

+/* { dg-do compile } */
+/* { dg-options "-Wno-attributes -fdiagnostics-show-caret" } */
+
+extern void __emit_warning (const char *message);
+
+/* Verify that the diagnostic subsytem describes the chain of inlining
+   when reporting the warning.  */
+
+__attribute__((always_inline))
+static void foo (void)
+{
+  __emit_warning ("message");
+}
+
+__attribute__((always_inline))
+static void bar (void)
+{
+  foo ();
+}
+
+int main()
+{
+  bar ();
+  return 0;
+}
+
+/* { dg-regexp "In function 'void foo\\(\\)'," "" } */
+/* { dg-regexp "    inlined from 'void bar\\(\\)' at .+/diagnostic-test-inlining-1.C:18:7," "" } */
+/* { dg-regexp "    inlined from 'int main\\(\\)' at .+/diagnostic-test-inlining-1.C:23:7:" "" } */
+/* { dg-warning "18: message" "" { target *-*-* } 12 } */
+/* { dg-begin-multiline-output "" }
+   __emit_warning ("message");
+   ~~~~~~~~~~~~~~~^~~~~~~~~~~
+   { dg-end-multiline-output "" } */

gcc/testsuite/g++.dg/plugin/plugin.exp

@@ -65,6 +65,8 @@ set plugin_test_list [list \
     { def_plugin.c def-plugin-test.C } \
     { ../../gcc.dg/plugin/diagnostic_plugin_test_tree_expression_range.c \
 	  diagnostic-test-expressions-1.C } \
+    { ../../gcc.dg/plugin/diagnostic_plugin_test_inlining.c \
+	  diagnostic-test-inlining-1.C } \
     { show_template_tree_color_plugin.c \
     	  show-template-tree-color.C \
     	  show-template-tree-color-no-elide-type.C } \

gcc/testsuite/gcc.dg/plugin/diagnostic-test-inlining-1.c

+/* { dg-do compile } */
+/* { dg-options "-Wno-attributes -fdiagnostics-show-caret" } */
+
+extern void __emit_warning (const char *message);
+
+__attribute__((always_inline))
+static void foo (void)
+{
+  __emit_warning ("message");
+}
+
+__attribute__((always_inline))
+static void bar (void)
+{
+  foo ();
+}
+
+int main()
+{
+  bar ();
+  return 0;
+}
+
+/* Verify that the diagnostic subsytem describes the chain of inlining
+   when reporting the warning.  */
+
+/* { dg-regexp "In function 'foo'," "" } */
+/* { dg-regexp "    inlined from 'bar' at .+/diagnostic-test-inlining-1.c:15:3," "" } */
+/* { dg-regexp "    inlined from 'main' at .+/diagnostic-test-inlining-1.c:20:3:" "" } */
+/* { dg-warning "3: message" "" { target *-*-* } 9 } */
+/* { dg-begin-multiline-output "" }
+   __emit_warning ("message");
+   ^~~~~~~~~~~~~~~~~~~~~~~~~~
+   { dg-end-multiline-output "" } */

gcc/testsuite/gcc.dg/plugin/diagnostic-test-inlining-2.c

+/* { dg-do compile } */
+/* { dg-options "-Wno-attributes -fdiagnostics-show-caret" } */
+
+extern void __emit_warning (const char *message);
+
+#define INNER_WARNING(MSG) __emit_warning (MSG)
+
+#define OUTER_WARNING(MSG) INNER_WARNING (MSG)
+
+__attribute__((always_inline))
+static void foo (void)
+{
+  OUTER_WARNING ("message");
+}
+
+__attribute__((always_inline))
+static void bar (void)
+{
+  foo ();
+}
+
+int main()
+{
+  bar ();
+  return 0;
+}
+
+/* Verify that the diagnostic subsytem describes both the chains of
+   inlining and of macro expansion when reporting the warning.  */
+
+/* { dg-regexp "In function 'foo'," "" } */
+/* { dg-regexp "    inlined from 'bar' at .+/diagnostic-test-inlining-2.c:19:3," "" } */
+/* { dg-regexp "    inlined from 'main' at .+/diagnostic-test-inlining-2.c:24:3:" "" } */
+/* { dg-warning "28: message" "" { target c } 6 } */
+/* { dg-begin-multiline-output "" }
+ #define INNER_WARNING(MSG) __emit_warning (MSG)
+                            ^~~~~~~~~~~~~~~~~~~~
+   { dg-end-multiline-output "" } */
+/* { dg-message "28: in expansion of macro 'INNER_WARNING'" "" { target c } 8 } */
+/* { dg-begin-multiline-output "" }
+ #define OUTER_WARNING(MSG) INNER_WARNING (MSG)
+                            ^~~~~~~~~~~~~
+   { dg-end-multiline-output "" } */
+/* { dg-message "3: in expansion of macro 'OUTER_WARNING'" "" { target c } 13 } */
+/* { dg-begin-multiline-output "" }
+   OUTER_WARNING ("message");
+   ^~~~~~~~~~~~~
+   { dg-end-multiline-output "" } */

gcc/testsuite/gcc.dg/plugin/diagnostic-test-inlining-3.c

+/* { dg-do compile } */
+/* { dg-options "-Wno-attributes -fdiagnostics-show-caret -O1" } */
+
+extern void __emit_warning (const char *message);
+
+__attribute__((always_inline))
+static void foo (void)
+{
+  __emit_warning ("message");
+}
+
+__attribute__((always_inline))
+static void bar (void)
+{
+  foo ();
+}
+
+int main()
+{
+  bar ();
+  return 0;
+}
+
+/* Reproducer for PR tree-optimization/83336: when optimization is
+   enabled, but debuginfo isn't, the diagnostics subsystem doesn't
+   report the full inlining chain at a middle-end warning.
+
+   This is a copy of diagnostic-test-inlining-1.c, but with -O1.
+
+   Ideally the diagnostics subsystem would report:
+     In function 'foo', inlined from 'bar' at LOC A, inlined from 'main' at LOC B:
+   but with -O1 it only reports:
+     In function 'foo', inlined from 'main' at LOC A:
+
+   This test case captures this behavior.  */
+
+/* { dg-regexp "In function 'foo'," "" } */
+/* { dg-regexp "    inlined from 'main' at .+/diagnostic-test-inlining-3.c:15:3:" "" } */
+/* { dg-warning "3: message" "" { target *-*-* } 9 } */
+/* { dg-begin-multiline-output "" }
+   __emit_warning ("message");
+   ^~~~~~~~~~~~~~~~~~~~~~~~~~
+   { dg-end-multiline-output "" } */

gcc/testsuite/gcc.dg/plugin/diagnostic-test-inlining-4.c

+/* { dg-do compile } */
+/* { dg-options "-Wno-attributes -fdiagnostics-show-caret" } */
+
+extern void __emit_warning (const char *message);
+
+__attribute__((always_inline))
+static void depth_0 (void)
+{
+  __emit_warning ("message");
+}
+
+__attribute__((always_inline))
+static void depth_1 (void)
+{
+  depth_0 ();
+}
+
+__attribute__((always_inline))
+static void depth_2 (void)
+{
+  depth_1 ();
+}
+
+__attribute__((always_inline))
+static void depth_3 (void)
+{
+  depth_2 ();
+}
+
+__attribute__((always_inline))
+static void depth_4 (void)
+{
+  depth_3 ();
+}
+
+int main()
+{
+  depth_4 ();
+  return 0;
+}
+
+/* Verify that the diagnostic subsytem describes the chain of inlining
+   when reporting the warning, for an example showing many levels of
+   inlining.  */
+
+/* { dg-regexp "In function 'depth_0'," "" } */
+/* { dg-regexp "    inlined from 'depth_1' at .+/diagnostic-test-inlining-4.c:15:3," "" } */
+/* { dg-regexp "    inlined from 'depth_2' at .+/diagnostic-test-inlining-4.c:21:3," "" } */
+/* { dg-regexp "    inlined from 'depth_3' at .+/diagnostic-test-inlining-4.c:27:3," "" } */
+/* { dg-regexp "    inlined from 'depth_4' at .+/diagnostic-test-inlining-4.c:33:3," "" } */
+/* { dg-regexp "    inlined from 'main' at .+/diagnostic-test-inlining-4.c:38:3:" "" } */
+/* { dg-warning "3: message" "" { target *-*-* } 9 } */
+/* { dg-begin-multiline-output "" }
+   __emit_warning ("message");
+   ^~~~~~~~~~~~~~~~~~~~~~~~~~
+   { dg-end-multiline-output "" } */

gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_inlining.c

+/* { dg-options "-O" } */
+
+#include "gcc-plugin.h"
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "stringpool.h"
+#include "toplev.h"
+#include "basic-block.h"
+#include "hash-table.h"
+#include "vec.h"
+#include "ggc.h"
+#include "basic-block.h"
+#include "tree-ssa-alias.h"
+#include "internal-fn.h"
+#include "gimple-fold.h"
+#include "tree-eh.h"
+#include "gimple-expr.h"
+#include "is-a.h"
+#include "gimple.h"
+#include "gimple-iterator.h"
+#include "tree.h"
+#include "tree-pass.h"
+#include "intl.h"
+#include "plugin-version.h"
+#include "c-family/c-common.h"
+#include "diagnostic.h"
+#include "context.h"
+#include "print-tree.h"
+#include "cpplib.h"
+#include "c-family/c-pragma.h"
+#include "substring-locations.h"
+
+int plugin_is_GPL_compatible;
+
+/* A custom pass for emitting dummy warnings from the middle-end.  */
+
+const pass_data pass_data_test_inlining =
+{
+  GIMPLE_PASS, /* type */
+  "test_inlining", /* name */
+  OPTGROUP_NONE, /* optinfo_flags */
+  TV_NONE, /* tv_id */
+  PROP_ssa, /* properties_required */
+  0, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  0, /* todo_flags_finish */
+};
+
+class pass_test_inlining : public gimple_opt_pass
+{
+public:
+  pass_test_inlining(gcc::context *ctxt)
+    : gimple_opt_pass(pass_data_test_inlining, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  bool gate (function *) { return true; }
+  virtual unsigned int execute (function *);
+
+}; // class pass_test_inlining
+
+/* Determine if STMT is a call with NUM_ARGS arguments to a function
+   named FUNCNAME.
+   If so, return STMT as a gcall *.  Otherwise return NULL.  */
+
+static gcall *
+check_for_named_call (gimple *stmt,
+		      const char *funcname, unsigned int num_args)
+{
+  gcc_assert (funcname);
+
+  gcall *call = dyn_cast <gcall *> (stmt);
+  if (!call)
+    return NULL;
+
+  tree fndecl = gimple_call_fndecl (call);
+  if (!fndecl)
+    return NULL;
+
+  if (strcmp (IDENTIFIER_POINTER (DECL_NAME (fndecl)), funcname))
+    return NULL;
+
+  if (gimple_call_num_args (call) != num_args)
+    {
+      error_at (stmt->location, "expected number of args: %i (got %i)",
+		num_args, gimple_call_num_args (call));
+      return NULL;
+    }
+
+  return call;
+}
+
+/* Emit a warning at LOC.  */
+
+static void
+emit_warning (location_t loc)
+{
+  source_range src_range = get_range_from_loc (line_table, loc);
+  warning_at (loc, 0, "range %i:%i-%i:%i",
+	      LOCATION_LINE (src_range.m_start),
+	      LOCATION_COLUMN (src_range.m_start),
+	      LOCATION_LINE (src_range.m_finish),
+	      LOCATION_COLUMN (src_range.m_finish));
+}
+
+/* Code for simulating the emission of a warning from the middle-end.
+   Emit a warning for each call to a function named "__emit_warning".  */
+
+static void
+test_inlining (gimple *stmt)
+{
+  gcall *call = check_for_named_call (stmt, "__emit_warning", 1);
+  if (!call)
+    return;
+
+  /* We expect an ADDR_EXPR with a STRING_CST inside it for the
+     initial arg.  */
+  tree t_addr_string = gimple_call_arg (call, 0);
+  if (TREE_CODE (t_addr_string) != ADDR_EXPR)
+    {
+      error_at (call->location, "string literal required for arg 1");
+      return;
+    }
+
+  tree t_string = TREE_OPERAND (t_addr_string, 0);
+  if (TREE_CODE (t_string) != STRING_CST)
+    {
+      error_at (call->location, "string literal required for arg 1");
+      return;
+    }
+
+  warning_at (call->location, 0, "%G%s", call,
+	      TREE_STRING_POINTER (t_string));
+}
+
+/* Call test_inlining on every statement within FUN.  */
+
+unsigned int
+pass_test_inlining::execute (function *fun)
+{
+  gimple_stmt_iterator gsi;
+  basic_block bb;
+
+  FOR_EACH_BB_FN (bb, fun)
+    for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+      {
+	gimple *stmt = gsi_stmt (gsi);
+	test_inlining (stmt);
+      }
+
+  return 0;
+}
+
+/* Entrypoint for the plugin.  Create and register the custom pass.  */
+
+int
+plugin_init (struct plugin_name_args *plugin_info,
+	     struct plugin_gcc_version *version)
+{
+  struct register_pass_info pass_info;
+  const char *plugin_name = plugin_info->base_name;
+  int argc = plugin_info->argc;
+  struct plugin_argument *argv = plugin_info->argv;
+
+  if (!plugin_default_version_check (version, &gcc_version))
+    return 1;
+
+  pass_info.pass = new pass_test_inlining (g);
+  pass_info.reference_pass_name = "*warn_function_noreturn";
+  pass_info.ref_pass_instance_number = 1;
+  pass_info.pos_op = PASS_POS_INSERT_AFTER;
+  register_callback (plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL,
+		     &pass_info);
+
+  return 0;
+}

gcc/testsuite/gcc.dg/plugin/plugin.exp

@@ -83,6 +83,11 @@ set plugin_test_list [list \
 	  diagnostic-test-string-literals-2.c \
 	  diagnostic-test-string-literals-3.c \
 	  diagnostic-test-string-literals-4.c } \
+    { diagnostic_plugin_test_inlining.c \
+	  diagnostic-test-inlining-1.c \
+	  diagnostic-test-inlining-2.c \
+	  diagnostic-test-inlining-3.c \
+	  diagnostic-test-inlining-4.c } \
     { location_overflow_plugin.c \
 	  location-overflow-test-1.c \
 	  location-overflow-test-2.c } \

gcc/testsuite/lib/prune.exp

@@ -28,6 +28,9 @@ proc prune_gcc_output { text } {
 
     #send_user "Before:$text\n"
 
+    # Handle any freeform regexps.
+    set text [handle-dg-regexps $text]
+
     regsub -all "(^|\n)(\[^\n\]*: )?In ((static member |lambda )?function|member|method|(copy )?constructor|destructor|instantiation|substitution|program|subroutine|block-data)\[^\n\]*" $text "" text
     regsub -all "(^|\n)\[^\n\]*(: )?At (top level|global scope):\[^\n\]*" $text "" text
     regsub -all "(^|\n)\[^\n\]*:   (recursively )?required \[^\n\]*" $text "" text
@@ -73,9 +76,6 @@ proc prune_gcc_output { text } {
     # Call into multiline.exp to handle any multiline output directives.
     set text [handle-multiline-outputs $text]
 
-    # Handle any freeform regexps.
-    set text [handle-dg-regexps $text]
-
     #send_user "After:$text\n"
 
     return $text