PR driver/69265: add hint for options with misspelled arguments

opts-common.c's cmdline_handle_error handles invalid arguments
for options with CL_ERR_ENUM_ARG by building a string listing the
valid arguments.  By also building a vec of valid arguments, we
can use find_closest_string and provide a hint if we see a close
misspelling.

gcc/ChangeLog:
	PR driver/69265
	* Makefile.in (GCC_OBJS): Move spellcheck.o to...
	(OBJS-libcommon-target): ...here.
	* opts-common.c: Include spellcheck.h.
	(cmdline_handle_error): Build a vec of valid options and use it
	to suggest provide hints for misspelled arguments.

gcc/testsuite/ChangeLog:
	PR driver/69265
	* gcc.dg/spellcheck-options-11.c: New test case.

From-SVN: r236439

5 files changed, 33 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3b94d64..cde433e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2016-05-18  David Malcolm  <dmalcolm@redhat.com>
+
+	PR driver/69265
+	* Makefile.in (GCC_OBJS): Move spellcheck.o to...
+	(OBJS-libcommon-target): ...here.
+	* opts-common.c: Include spellcheck.h.
+	(cmdline_handle_error): Build a vec of valid options and use it
+	to suggest provide hints for misspelled arguments.
+
 2016-05-18  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/71100
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 673f87d..587417b 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1160,7 +1160,7 @@ CXX_TARGET_OBJS=@cxx_target_objs@
 FORTRAN_TARGET_OBJS=@fortran_target_objs@
 
 # Object files for gcc many-languages driver.
-GCC_OBJS = gcc.o gcc-main.o ggc-none.o spellcheck.o
+GCC_OBJS = gcc.o gcc-main.o ggc-none.o
 
 c-family-warn = $(STRICT_WARN)
 
@@ -1549,7 +1549,7 @@ OBJS-libcommon = diagnostic.o diagnostic-color.o diagnostic-show-locus.o \
 # compiler and containing target-dependent code.
 OBJS-libcommon-target = $(common_out_object_file) prefix.o params.o \
 	opts.o opts-common.o options.o vec.o hooks.o common/common-targhooks.o \
-	hash-table.o file-find.o
+	hash-table.o file-find.o spellcheck.o
 
 # This lists all host objects for the front ends.
 ALL_HOST_FRONTEND_OBJS = $(foreach v,$(CONFIG_LANGUAGES),$($(v)_OBJS))
diff --git a/gcc/opts-common.c b/gcc/opts-common.c
index bb68982..4e1ef49 100644
--- a/gcc/opts-common.c
+++ b/gcc/opts-common.c
@@ -24,6 +24,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "opts.h"
 #include "options.h"
 #include "diagnostic.h"
+#include "spellcheck.h"
 
 static void prune_options (struct cl_decoded_option **, unsigned int *);
 
@@ -1113,6 +1114,7 @@ cmdline_handle_error (location_t loc, const struct cl_option *option,
       for (i = 0; e->values[i].arg != NULL; i++)
 	len += strlen (e->values[i].arg) + 1;
 
+      auto_vec <const char *> candidates;
       s = XALLOCAVEC (char, len);
       p = s;
       for (i = 0; e->values[i].arg != NULL; i++)
@@ -1123,9 +1125,16 @@ cmdline_handle_error (location_t loc, const struct cl_option *option,
 	  memcpy (p, e->values[i].arg, arglen);
 	  p[arglen] = ' ';
 	  p += arglen + 1;
+	  candidates.safe_push (e->values[i].arg);
 	}
       p[-1] = 0;
-      inform (loc, "valid arguments to %qs are: %s", option->opt_text, s);
+      const char *hint = find_closest_string (arg, &candidates);
+      if (hint)
+	inform (loc, "valid arguments to %qs are: %s; did you mean %qs?",
+		option->opt_text, s, hint);
+      else
+	inform (loc, "valid arguments to %qs are: %s", option->opt_text, s);
+
       return true;
     }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6a684fc..642fee3 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-05-18  David Malcolm  <dmalcolm@redhat.com>
+
+	PR driver/69265
+	* gcc.dg/spellcheck-options-11.c: New test case.
+
 2016-05-18  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/71100
diff --git a/gcc/testsuite/gcc.dg/spellcheck-options-11.c b/gcc/testsuite/gcc.dg/spellcheck-options-11.c
new file mode 100644
index 0000000..8e27141
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/spellcheck-options-11.c
@@ -0,0 +1,7 @@
+/* Verify that we provide a hint if the user misspells an option argument
+   (PR driver/69265).  */
+
+/* { dg-do compile } */
+/* { dg-options "-ftls-model=global-dinamic" } */
+/* { dg-error "unknown TLS model 'global-dinamic'"  "" { target *-*-* } 0 } */
+/* { dg-message "valid arguments to '-ftls-model=' are: global-dynamic initial-exec local-dynamic local-exec; did you mean 'global-dynamic'?"  "" { target *-*-* } 0 } */