Merge pull request #6514 from jamessan/gcc-7-fixes

Fix GCC 7 issues

15 files changed, 70 insertions, 12 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4d1c0e8fd5..eb259bc983 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -221,6 +221,11 @@ else()
   add_definitions(-Wall -Wextra -pedantic -Wno-unused-parameter
     -Wstrict-prototypes -std=gnu99)
 
+  check_c_compiler_flag(-Wimplicit-fallthrough HAS_WIMPLICIT_FALLTHROUGH_FLAG)
+  if(HAS_WIMPLICIT_FALLTHROUGH_FLAG)
+    add_definitions(-Wimplicit-fallthrough)
+  endif()
+
   # On FreeBSD 64 math.h uses unguarded C11 extension, which taints clang
   # 3.4.1 used there.
   if(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index f54979eb1e..e3897e3929 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -3607,6 +3607,7 @@ int build_stl_str_hl(
 
     case STL_OFFSET_X:
       base = kNumBaseHexadecimal;
+      // fallthrough
     case STL_OFFSET:
     {
       long l = ml_find_line_or_offset(wp->w_buffer, wp->w_cursor.lnum, NULL);
@@ -3617,6 +3618,7 @@ int build_stl_str_hl(
     }
     case STL_BYTEVAL_X:
       base = kNumBaseHexadecimal;
+      // fallthrough
     case STL_BYTEVAL:
       num = byteval;
       if (num == NL)
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 678fa851eb..bfdec90a32 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -4916,14 +4916,17 @@ static unsigned quote_meta(char_u *dest, char_u *src, int len)
       if (ctrl_x_mode == CTRL_X_DICTIONARY
           || ctrl_x_mode == CTRL_X_THESAURUS)
         break;
+      // fallthrough
     case '~':
       if (!p_magic)             /* quote these only if magic is set */
         break;
+      // fallthrough
     case '\\':
       if (ctrl_x_mode == CTRL_X_DICTIONARY
           || ctrl_x_mode == CTRL_X_THESAURUS)
         break;
-    case '^':                   /* currently it's not needed. */
+      // fallthrough
+    case '^':                   // currently it's not needed.
     case '$':
       m++;
       if (dest != NULL)
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 56a6632fad..31e5ae8806 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -9596,13 +9596,15 @@ static void f_getcwd(typval_T *argvars, typval_T *rettv, FunPtr fptr)
       if (from) {
         break;
       }
-    case kCdScopeTab:         // FALLTHROUGH
+      // fallthrough
+    case kCdScopeTab:
       assert(tp);
       from = tp->tp_localdir;
       if (from) {
         break;
       }
-    case kCdScopeGlobal:      // FALLTHROUGH
+      // fallthrough
+    case kCdScopeGlobal:
       if (globaldir) {        // `globaldir` is not always set.
         from = globaldir;
       } else if (os_dirname(cwd, MAXPATHL) == FAIL) {  // Get the OS CWD.
diff --git a/src/nvim/eval/typval.c b/src/nvim/eval/typval.c
index 786b766689..19d9d56058 100644
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -1869,7 +1869,7 @@ void tv_free(typval_T *tv)
       }
       case VAR_FUNC: {
         func_unref(tv->vval.v_string);
-        // FALLTHROUGH
+        FALLTHROUGH;
       }
       case VAR_STRING: {
         xfree(tv->vval.v_string);
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 018a228843..a528a65abb 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -4878,8 +4878,9 @@ void fix_help_buffer(void)
                   continue;
                 e1 = vim_strrchr(t1, '.');
                 e2 = vim_strrchr(path_tail(f2), '.');
-                if (e1 == NUL || e2 == NUL)
+                if (e1 == NULL || e2 == NULL) {
                   continue;
+                }
                 if (fnamecmp(e1, ".txt") != 0
                     && fnamecmp(e1, fname + 4) != 0) {
                   /* Not .txt and not .abx, remove it. */
@@ -5949,9 +5950,8 @@ void set_context_in_sign_cmd(expand_T *xp, char_u *arg)
   // :sign define {name} {args}... {last}=
   //                               |     |
   //                            last     p
-  if (p == NUL)
-  {
-    /* Expand last argument name (before equal sign). */
+  if (p == NULL) {
+    // Expand last argument name (before equal sign).
     xp->xp_pattern = last;
     switch (cmd_idx)
     {
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index f74086e45a..0c14bf4255 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -1268,6 +1268,7 @@ static int command_line_handle_key(CommandLineState *s)
       }
       return command_line_changed(s);
     }
+    // fallthrough
 
   case K_UP:
   case K_DOWN:
diff --git a/src/nvim/func_attr.h b/src/nvim/func_attr.h
index 9146a1a8ea..cc94a41f80 100644
--- a/src/nvim/func_attr.h
+++ b/src/nvim/func_attr.h
@@ -89,6 +89,10 @@
 # undef FUNC_ATTR_NONNULL_RET
 #endif
 
+#ifdef FUNC_ATTR_NORETURN
+# undef FUNC_ATTR_NORETURN
+#endif
+
 #ifndef DID_REAL_ATTR
 # define DID_REAL_ATTR
 # ifdef __GNUC__
@@ -107,6 +111,7 @@
 #  define REAL_FATTR_UNUSED __attribute__((unused))
 #  define REAL_FATTR_NONNULL_ALL __attribute__((nonnull))
 #  define REAL_FATTR_NONNULL_ARG(...) __attribute__((nonnull(__VA_ARGS__)))
+#  define REAL_FATTR_NORETURN __attribute__((noreturn))
 
 #  ifdef __clang__
 // clang only
@@ -176,6 +181,10 @@
 # ifndef REAL_FATTR_NONNULL_RET
 #  define REAL_FATTR_NONNULL_RET
 # endif
+
+# ifndef REAL_FATTR_NORETURN
+#  define REAL_FATTR_NORETURN
+# endif
 #endif
 
 #ifdef DEFINE_FUNC_ATTRIBUTES
@@ -196,6 +205,7 @@
 # define FUNC_ATTR_NONNULL_ALL REAL_FATTR_NONNULL_ALL
 # define FUNC_ATTR_NONNULL_ARG(...) REAL_FATTR_NONNULL_ARG(__VA_ARGS__)
 # define FUNC_ATTR_NONNULL_RET REAL_FATTR_NONNULL_RET
+# define FUNC_ATTR_NORETURN REAL_FATTR_NORETURN
 #elif !defined(DO_NOT_DEFINE_EMPTY_ATTRIBUTES)
 # define FUNC_ATTR_MALLOC
 # define FUNC_ATTR_ALLOC_SIZE(x)
@@ -209,4 +219,5 @@
 # define FUNC_ATTR_NONNULL_ALL
 # define FUNC_ATTR_NONNULL_ARG(...)
 # define FUNC_ATTR_NONNULL_RET
+# define FUNC_ATTR_NORETURN
 #endif
diff --git a/src/nvim/macros.h b/src/nvim/macros.h
index 214af82422..9ab6dc5d2b 100644
--- a/src/nvim/macros.h
+++ b/src/nvim/macros.h
@@ -153,4 +153,22 @@
 #define STR_(x) #x
 #define STR(x) STR_(x)
 
+#ifndef __has_attribute
+# define NVIM_HAS_ATTRIBUTE(x) 0
+#elif defined(__clang__) && __clang__ == 1 \
+    && (__clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ <= 5))
+// Starting in Clang 3.6, __has_attribute was fixed to only report true for
+// GNU-style attributes.  Prior to that, it reported true if _any_ backend
+// supported the attribute.
+# define NVIM_HAS_ATTRIBUTE(x) 0
+#else
+# define NVIM_HAS_ATTRIBUTE __has_attribute
+#endif
+
+#if NVIM_HAS_ATTRIBUTE(fallthrough)
+# define FALLTHROUGH __attribute__((fallthrough))
+#else
+# define FALLTHROUGH
+#endif
+
 #endif  // NVIM_MACROS_H
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index f73e3079b9..050020d79d 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -1861,6 +1861,7 @@ void do_pending_operator(cmdarg_T *cap, int old_col, bool gui_yank)
       } else {
         bangredo = true;  // do_bang() will put cmd in redo buffer.
       }
+      // fallthrough
 
     case OP_INDENT:
     case OP_COLON:
diff --git a/src/nvim/os_unix.c b/src/nvim/os_unix.c
index c5a42204be..7cf0d7817c 100644
--- a/src/nvim/os_unix.c
+++ b/src/nvim/os_unix.c
@@ -133,7 +133,7 @@ void mch_free_acl(vim_acl_T aclent)
 }
 #endif
 
-void mch_exit(int r)
+void mch_exit(int r) FUNC_ATTR_NORETURN
 {
   exiting = true;
 
diff --git a/src/nvim/regexp_nfa.c b/src/nvim/regexp_nfa.c
index 85fae9d82e..24c156d2ba 100644
--- a/src/nvim/regexp_nfa.c
+++ b/src/nvim/regexp_nfa.c
@@ -634,6 +634,7 @@ static int nfa_recognize_char_class(char_u *start, char_u *end, int extra_newl)
           config |= CLASS_o7;
           break;
         }
+        return FAIL;
       case 'a':
         if (*(p + 2) == 'z') {
           config |= CLASS_az;
@@ -642,6 +643,7 @@ static int nfa_recognize_char_class(char_u *start, char_u *end, int extra_newl)
           config |= CLASS_af;
           break;
         }
+        return FAIL;
       case 'A':
         if (*(p + 2) == 'Z') {
           config |= CLASS_AZ;
@@ -650,7 +652,7 @@ static int nfa_recognize_char_class(char_u *start, char_u *end, int extra_newl)
           config |= CLASS_AF;
           break;
         }
-      /* FALLTHROUGH */
+        return FAIL;
       default:
         return FAIL;
       }
@@ -4194,6 +4196,7 @@ skip_add:
       subs = addstate(l, state->out, subs, pim, off_arg);
       break;
     }
+    // fallthrough
   case NFA_MCLOSE1:
   case NFA_MCLOSE2:
   case NFA_MCLOSE3:
diff --git a/src/nvim/shada.c b/src/nvim/shada.c
index a6d8cb6563..e1879ca8c0 100644
--- a/src/nvim/shada.c
+++ b/src/nvim/shada.c
@@ -2047,7 +2047,7 @@ static inline ShaDaWriteResult shada_read_when_writing(
       }
       case kSDReadStatusNotShaDa: {
         ret = kSDWriteReadNotShada;
-        // fallthrough
+        FALLTHROUGH;
       }
       case kSDReadStatusReadError: {
         return ret;
diff --git a/src/nvim/testdir/runtest.vim b/src/nvim/testdir/runtest.vim
index 64ad0f0103..6832622cdf 100644
--- a/src/nvim/testdir/runtest.vim
+++ b/src/nvim/testdir/runtest.vim
@@ -134,7 +134,7 @@ else
 endif
 
 " Names of flaky tests.
-let s:flaky = ['Test_with_partial_callback']
+let s:flaky = ['Test_with_partial_callback()']
 
 " Locate Test_ functions and execute them.
 set nomore
diff --git a/test/functional/legacy/036_regexp_character_classes_spec.lua b/test/functional/legacy/036_regexp_character_classes_spec.lua
index 110f7dd852..38e8145d1c 100644
--- a/test/functional/legacy/036_regexp_character_classes_spec.lua
+++ b/test/functional/legacy/036_regexp_character_classes_spec.lua
@@ -275,4 +275,16 @@ describe('character classes in regexp', function()
     diff(sixlines(string.sub(punct1, 1)..digits..punct2..upper..punct3..
       lower..punct4..ctrl2..iso_text))
   end)
+  it('does not convert character class ranges to an incorrect class', function()
+    source([[
+      1 s/\%#=0[0-z]//g
+      2 s/\%#=1[0-z]//g
+      3 s/\%#=2[0-z]//g
+      4 s/\%#=0[^0-z]//g
+      5 s/\%#=1[^0-z]//g
+      6 s/\%#=2[^0-z]//g
+    ]])
+    diff(string.rep(ctrl1..punct1..punct4..ctrl2..iso_text..'\n', 3)
+      ..string.rep(digits..punct2..upper..punct3..lower..'\n', 3))
+  end)
 end)