Add -W[no-]error=OPTION specific abortions

libtcc.c

@@ -1230,8 +1230,9 @@ LIBTCCAPI void tcc_set_lib_path(TCCState *s, const char *path)
     s->tcc_lib_path = tcc_strdup(path);
 }
 
-#define WD_ALL    0x0001 /* warning is activated when using -Wall */
-#define FD_INVERT 0x0002 /* invert value before storing */
+#define WD_ALL    (1u<<0) /* warning is activated when using -Wall */
+#define WD_ERROR  (1u<<1) /* can be used with -W[no-]error=X */
+#define FD_INVERT (1u<<2) /* invert value before storing */
 
 typedef struct FlagDef {
     uint16_t offset;
@@ -1279,6 +1280,49 @@ ST_FUNC int set_flag(TCCState *s, const FlagDef *flags, const char *name)
     return ret;
 }
 
+ST_FUNC int set_W_flag(TCCState *s, const FlagDef *flags, const char *optarg)
+{
+    int value, ret;
+    const FlagDef *p;
+    const char *r, *sub;
+
+    value = 1;
+    r = optarg;
+    if (no_flag(&r))
+        value = 0;
+
+    if ((sub = strchr(r, '=')) != NULL) {
+        if (strncmp(r, "error", (uintptr_t)(sub - r)))
+           return -1;
+        r = ++sub;
+        if (value)
+           value = 1 | 2;
+    }
+
+    /* .offset for "all" is 0 */
+    for (ret = -1, p = flags; p->name; ++p) {
+        if (ret) {
+            if (strcmp(r, p->name))
+                continue;
+            if (sub != NULL && !(p->flags & WD_ERROR))
+                break;
+        } else {
+            if (0 == (p->flags & WD_ALL))
+                continue;
+        }
+        if (p->offset) {
+            *((unsigned char *)s + p->offset) = value;
+            if (ret) {
+               ret = 0;
+               break;
+            }
+        } else {
+            ret = 0;
+        }
+    }
+    return ret;
+}
+
 static int strstart(const char *val, const char **str)
 {
     const char *p, *q;
@@ -1469,7 +1513,7 @@ static int tcc_set_linker(TCCState *s, const char *option)
             tcc_error("unsupported linker option '%s'", option);
         }
 
-        if (ignoring && s->warn_unsupported)
+        if (ignoring && NEED_WARNING(s, unsupported))
             tcc_warning("unsupported linker option '%s'", option);
 
         option = skip_linker_arg(&p);
@@ -1616,12 +1660,13 @@ static const TCCOption tcc_options[] = {
 
 static const FlagDef options_W[] = {
     { 0, 0, "all" },
-    { offsetof(TCCState, warn_unsupported), 0, "unsupported" },
-    { offsetof(TCCState, warn_write_strings), WD_ALL, "write-strings" },
     { offsetof(TCCState, warn_error), 0, "error" },
-    { offsetof(TCCState, warn_gcc_compat), 0, "gcc-compat" },
-    { offsetof(TCCState, warn_implicit_function_declaration), WD_ALL,
-      "implicit-function-declaration" },
+    { offsetof(TCCState, warn_unsupported), WD_ERROR, "unsupported" },
+    { offsetof(TCCState, warn_gcc_compat), WD_ERROR, "gcc-compat" },
+    { offsetof(TCCState, warn_write_strings), WD_ERROR | WD_ALL,
+      "write-strings" },
+    { offsetof(TCCState, warn_implicit_function_declaration),
+      WD_ERROR | WD_ALL, "implicit-function-declaration" },
     { 0, 0, NULL }
 };
 
@@ -1920,7 +1965,7 @@ reparse:
             break;
         case TCC_OPTION_W:
             s->warn_none = 0;
-            if (optarg[0] && set_flag(s, options_W, optarg) < 0)
+            if (optarg[0] && set_W_flag(s, options_W, optarg) < 0)
                 goto unsupported_option;
             break;
         case TCC_OPTION_w:
@@ -2007,7 +2052,7 @@ reparse:
             break;
         default:
 unsupported_option:
-            if (s->warn_unsupported)
+            if (NEED_WARNING(s, unsupported))
                 tcc_warning("unsupported option '%s'", r);
             break;
         }

tcc-doc.texi

@@ -267,10 +267,13 @@ Make string constants be of type @code{const char *} instead of @code{char
 *}.
 
 @item -Werror
-Abort compilation if warnings are issued.
+Abort compilation if a warning is issued.
+Can be given an option to enable the specified warning
+and turn it into an error, for example @option{-Werror=unsupported}.
+(Enabling general abortion and disabling specifics is not supported.)
 
 @item -Wall 
-Activate all warnings, except @option{-Werror}, @option{-Wunusupported} and
+Activate all warnings, except @option{-Werror}, @option{-Wunsupported} and
 @option{-Wwrite-strings}.
 
 @end table

tcc.h

@@ -767,13 +767,17 @@ struct TCCState {
     unsigned char dollars_in_identifiers;  /* allows '$' char in identifiers */
     unsigned char ms_bitfields; /* if true, emulate MS algorithm for aligning bitfields */
 
-    /* warning switches */
-    unsigned char warn_write_strings;
-    unsigned char warn_unsupported;
-    unsigned char warn_error;
+    /* warning switches; but for first two, W[no-]error=X is supported */
+    /* XXX TCC_IS_WARN_OR_ERR(X,Y) used to drive W[[no-]error]=X */
     unsigned char warn_none;
-    unsigned char warn_implicit_function_declaration;
+    unsigned char warn_error;
+    unsigned char warn_unsupported;
     unsigned char warn_gcc_compat;
+    unsigned char warn_write_strings;
+    unsigned char warn_implicit_function_declaration;
+#define NEED_WARNING(SELF,SWITCH) \
+    ((SELF)->warn_ ## SWITCH \
+     ? (((SELF)->warn_ ## SWITCH & 2) ? (SELF)->warn_error = 1 : 1) : 0)
 
     /* compile with debug symbol (and use them if error during execution) */
     unsigned char do_debug;

tccasm.c

@@ -775,7 +775,7 @@ static void asm_parse_directive(TCCState *s1, int global)
             else
                 pstrcat(filename, sizeof(filename), get_tok_str(tok, NULL));
 
-            if (s1->warn_unsupported)
+            if (NEED_WARNING(s1, unsupported))
                 tcc_warning("ignoring .file %s", filename);
 
             next();
@@ -793,7 +793,7 @@ static void asm_parse_directive(TCCState *s1, int global)
             else
                 pstrcat(ident, sizeof(ident), get_tok_str(tok, NULL));
 
-            if (s1->warn_unsupported)
+            if (NEED_WARNING(s1, unsupported))
                 tcc_warning("ignoring .ident %s", ident);
 
             next();
@@ -810,7 +810,7 @@ static void asm_parse_directive(TCCState *s1, int global)
             }
 
             /* XXX .size name,label2-label1 */
-            if (s1->warn_unsupported)
+            if (NEED_WARNING(s1, unsupported))
                 tcc_warning("ignoring .size %s,*", get_tok_str(tok, NULL));
 
             next();
@@ -840,7 +840,7 @@ static void asm_parse_directive(TCCState *s1, int global)
             if (!strcmp(newtype, "function") || !strcmp(newtype, "STT_FUNC")) {
                 sym->type.t = (sym->type.t & ~VT_BTYPE) | VT_FUNC;
             }
-            else if (s1->warn_unsupported)
+            else if (NEED_WARNING(s1, unsupported))
                 tcc_warning("change type of '%s' from 0x%x to '%s' ignored", 
                     get_tok_str(sym->v, NULL), sym->type.t, newtype);
 

tccgen.c

@@ -4506,7 +4506,7 @@ redo:
             ad->a.dllimport = 1;
             break;
         default:
-            if (tcc_state->warn_unsupported)
+            if (NEED_WARNING(tcc_state, unsupported))
                 tcc_warning("'%s' attribute ignored", get_tok_str(t, NULL));
             /* skip parameters */
             if (tok == '(') {
@@ -5915,7 +5915,7 @@ ST_FUNC void unary(void)
             len = strlen(funcname) + 1;
             /* generate char[len] type */
             type.t = VT_BYTE;
-            if (tcc_state->warn_write_strings)
+            if (NEED_WARNING(tcc_state, write_strings))
                 type.t |= VT_CONSTANT;
             mk_pointer(&type);
             type.t |= VT_ARRAY;
@@ -5942,7 +5942,7 @@ ST_FUNC void unary(void)
         if (tcc_state->char_is_unsigned)
             t = VT_BYTE | VT_UNSIGNED;
     str_init:
-        if (tcc_state->warn_write_strings)
+        if (NEED_WARNING(tcc_state, write_strings))
             t |= VT_CONSTANT;
         type.t = t;
         mk_pointer(&type);
@@ -6378,9 +6378,9 @@ special_math_val:
                 tcc_error("'%s' undeclared", name);
             /* for simple function calls, we tolerate undeclared
                external reference to int() function */
-            if (tcc_state->warn_implicit_function_declaration
+            if (NEED_WARNING(tcc_state, implicit_function_declaration)
 #ifdef TCC_TARGET_PE
-                /* people must be warned about using undeclared WINAPI functions
+                /* must warn about using undeclared WINAPI functions
                    (which usually start with uppercase letter) */
                 || (name[0] >= 'A' && name[0] <= 'Z')
 #endif

tccpp.c

@@ -1770,9 +1770,8 @@ static void pragma_parse(TCCState *s1)
             tcc_free(p);
         }
 
-    } else if (s1->warn_unsupported) {
+    } else if (NEED_WARNING(s1, unsupported))
         tcc_warning("#pragma %s is ignored", get_tok_str(tok, &tokc));
-    }
     return;
 
 pragma_err: