Control color output with C2_COLORS environment variable

* use style names instead of hard-coded color names
* customize color output via environment variable `C2_COLORS`:
  eg: `C2_COLORS=none`, `C2_COLORS="blue:bright-blue"`,
      `C2_COLORS="error:bright-blue"`, `C2_COLORS="error:#d0d0d0"`
* use `console` to output error messages in `source_mgr` and `c2recipe_parser`.
* use cache to avoid multiple calls to `unix.isatty()` and `stdlib.getenv()`
* share global colors with plugins
* simplify error formating in **source_mgr.c2**
* add c2cat color customisation

Author: chqrlie

ast/utils.c2

@@ -120,6 +120,7 @@ public type Globals struct @(opaque) {
 #if AstStatistics
     Stats stats;
 #endif
+    Color[15] colors;
 }
 
 // The only globals for AST are here, since they must be set explicitly for plugins!!
@@ -129,7 +130,24 @@ Globals* globals;
 public fn Globals* getGlobals() { return globals; }
 
 // only used by plugins
-public fn void setGlobals(Globals* g) @(unused) { globals = g; }
+public fn void setGlobals(Globals* g) @(unused) {
+    globals = g;
+    col_Normal     = g.colors[0];
+    col_Error      = g.colors[1];
+    col_Warning    = g.colors[2];
+    col_Keyword    = g.colors[3];
+    col_Identifier = g.colors[4];
+    col_Literal    = g.colors[5];
+    col_Comment    = g.colors[6];
+    col_Stmt       = g.colors[7];
+    col_Decl       = g.colors[8];
+    col_Expr       = g.colors[9];
+    col_Attr       = g.colors[10];
+    col_Template   = g.colors[11];
+    col_Type       = g.colors[12];
+    col_Value      = g.colors[13];
+    col_Calc       = g.colors[14];
+}
 
 // wordsize in bytes, must NOT be called from Plugin!
 public fn void initialize(Context* c, string_pool.Pool* astPool, u32 wordsize, bool use_color) {
@@ -176,22 +194,43 @@ public fn void initialize(Context* c, string_pool.Pool* astPool, u32 wordsize, b
         globals.builtinType_baseTypes[ISize] = Int64;
         globals.builtinType_baseTypes[USize] = UInt64;
     }
+
+    globals.colors[0]  = color.getConfigColor("normal",       color.Normal);
+    globals.colors[1]  = color.getConfigColor("error",        color.Red);
+    globals.colors[2]  = color.getConfigColor("warning",      color.Yellow);
+    globals.colors[3]  = color.getConfigColor("keyword",      color.Green);
+    globals.colors[4]  = color.getConfigColor("identifier",   color.Cyan);
+    globals.colors[5]  = color.getConfigColor("literal",      color.Cyan);
+    globals.colors[6]  = color.getConfigColor("comment",      color.Cyan);
+    globals.colors[7]  = color.getConfigColor("ast.stmt",     color.Bmagenta);
+    globals.colors[8]  = color.getConfigColor("ast.decl",     color.Bgreen);
+    globals.colors[9]  = color.getConfigColor("ast.expr",     color.Bmagenta);
+    globals.colors[10] = color.getConfigColor("ast.attr",     color.Blue);
+    globals.colors[11] = color.getConfigColor("ast.template", color.Green);
+    globals.colors[12] = color.getConfigColor("ast.type",     color.Green);
+    globals.colors[13] = color.getConfigColor("ast.value",    color.Bcyan);
+    globals.colors[14] = color.getConfigColor("ast.calc",     color.Yellow);    // all calculated values
+
+    setGlobals(globals);
 }
 
 public fn void deinit(bool print_stats) {
+    Globals* g = globals;
+    if (!g) return;
 #if AstStatistics
-    if (print_stats) globals.stats.dump();
+    if (print_stats) g.stats.dump();
 #endif
-    globals.names_pool = nil;
-    globals.ast_count = 0;
-    globals.ast_capacity = 0;
-    stdlib.free(globals.ast_list);
-    globals.ast_list = nil;
-    globals.pointers.clear();
-    globals.string_types.clear();
-    globals.dump_buf.free();
-    stdlib.free(globals);
+    g.names_pool = nil;
+    g.ast_count = 0;
+    g.ast_capacity = 0;
+    stdlib.free(g.ast_list);
+    g.ast_list = nil;
+    g.pointers.clear();
+    g.string_types.clear();
+    g.dump_buf.free();
+    stdlib.free(g);
     globals = nil;
+    color.freeConfigColors();
 }
 
 public fn u32 getWordSize() {
@@ -319,9 +358,14 @@ Color col_Template = Color.Green;
 //Color col_Cast = Color.Red;
 Color col_Type = Color.Green;
 Color col_Value = Color.Bcyan;
-Color col_Error = Color.Red;
+public Color col_Error = Color.Red;
 Color col_Calc = Color.Yellow;    // all calculated value
-Color col_Normal = Color.Normal;
+public Color col_Normal = Color.Normal;
+public Color col_Warning = color.Yellow;
+public Color col_Keyword = color.Green;
+public Color col_Identifier = color.Cyan;
+public Color col_Literal = color.Cyan;
+public Color col_Comment = color.Cyan;
 
 public type AttrHandlerFn fn bool (void* arg, Decl* d, const Attr* a);
 

ast_utils/color.c2

@@ -14,7 +14,10 @@
  */
 
 module color;
-import unistd;
+
+import stdlib local;
+import string local;
+import unistd local;
 
 public type Color enum u8 {
     None,
@@ -35,6 +38,9 @@ public type Color enum u8 {
     Bcyan,
     White,
     Normal,
+
+    CustomStart,
+    CustomEnd = Color.CustomStart + 15,
 }
 
 public const Color Black    = Black;
@@ -55,7 +61,7 @@ public const Color Bcyan    = Bcyan;
 public const Color White    = White;
 public const Color Normal   = Normal;
 
-const char*[elemsof(Color)] defaultColors = {
+const char*[] standardColors = {
     [Color.None]     = "",
     [Color.Black]    = "\033[0;30m",
     [Color.Red]      = "\033[0;31m",
@@ -76,8 +82,27 @@ const char*[elemsof(Color)] defaultColors = {
     [Color.Normal]   = "\033[0m",
 }
 
+i8 use_color = -1;
+const char* c2_colors;
+char[elemsof(Color)][32] defaultColors;
+
 public fn bool useColor() {
-    return unistd.isatty(1);
+    if (use_color < 0) {
+        use_color = isatty(1) != 0;
+        if (use_color) {
+            c2_colors = getenv("C2_COLORS");
+            if (c2_colors && !strcmp(c2_colors, "none")) {
+                use_color = 0;
+                c2_colors = nil;
+            } else {
+                for (u32 i = 0; i < elemsof(standardColors); i++) {
+                    strcpy(defaultColors[i], standardColors[i]);
+                }
+                if (c2_colors) customizeStandardColors(c2_colors);
+            }
+        }
+    }
+    return use_color;
 }
 
 public fn const char* Color.str(Color col) {

ast_utils/color_config.c2

@@ -0,0 +1,212 @@
+/* Copyright 2022-2025 Bas van den Berg, Charlie Gordon
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+module color;
+
+import ctype local;
+import stdio local;
+import stdlib local;
+import string local;
+
+const char*[] standardColorNames = {
+    [Color.Black]    = "black",
+    [Color.Red]      = "red",
+    [Color.Green]    = "green",
+    [Color.Yellow]   = "yellow",
+    [Color.Blue]     = "blue",
+    [Color.Magenta]  = "magenta",
+    [Color.Cyan]     = "cyan",
+    [Color.Grey]     = "grey",
+    [Color.Darkgrey] = "darkgrey",
+    [Color.Bred]     = "bred",
+    [Color.Bgreen]   = "bgreen",
+    [Color.Byellow]  = "byellow",
+    [Color.Bblue]    = "bblue",
+    [Color.Bmagenta] = "bmagenta",
+    [Color.Bcyan]    = "bcyan",
+    [Color.White]    = "white",
+    [Color.Normal]   = "normal",
+}
+
+fn Color findStandardColor(const char* name, bool use_custom = false) {
+    if (!name) return Color.None;
+    for (u32 i = 0; i < elemsof(standardColorNames); i++) {
+        if (!strcmp(name, standardColorNames[i]))
+            return (Color)i;
+    }
+    if (use_custom && !strncmp(name, "custom", 6)) {
+        i32 n = atoi(name + 6);
+        if (n > 0 && n <= Color.CustomEnd - Color.CustomStart + 1)
+            return (Color)(Color.CustomStart + n - 1);
+    }
+    return Color.None;
+}
+
+fn bool setPaletteColor(Color col, const char *val) {
+    u32 pal;
+    if (sscanf(val, "%*1[pP]%u", &pal) == 1) {
+        snprintf(defaultColors[col], elemsof(defaultColors[col]), "\033[38;5;%dm", pal);
+        return true;
+    }
+    u32 r, g, b;
+    if (sscanf(val, "#%2x%2x%2x", &r, &g, &b) == 3
+    ||  sscanf(val, "rgb(%u,%u,%u)", &r, &g, &b) == 3) {
+        snprintf(defaultColors[col], elemsof(defaultColors[col]), "\033[38;2;%d;%d;%dm", r, g, b);
+        return true;
+    }
+    return false;
+}
+
+fn bool setColorString(Color col, const char *val) {
+    if (!val || *val == '\0') {
+        *defaultColors[col] = '\0';
+        return true;
+    }
+    if (!strcmp(val, "default")) {
+        *defaultColors[col] = '\0';
+        if (col < elemsof(standardColors) && standardColors[col])
+            strcpy(defaultColors[col], standardColors[col]);
+        return true;
+    }
+    if (Color col1 = findStandardColor(val)) {
+        strcpy(defaultColors[col], standardColors[col1]);
+        return true;
+    }
+    return setPaletteColor(col, val);
+}
+
+// Normalize a color name into array dest.
+// s and dest can point to the same array
+fn char* normalizeColor(char *dest, u32 size, const char* s) {
+    if (!size) return nil;
+    u32 len = size - 1;
+    u32 i = 0;
+    if (s) {
+        for (const char* p = s; *p && i < len; p++) {
+            char c = (char)tolower(*p);
+            if (c != '-' && c != '_') {
+                if (i < len) dest[i++] = c;
+            }
+        }
+    }
+    dest[i] = '\0';
+    if (*dest == 'b' && !strncmp(dest + 1, "right", 5)) {
+        memmove(dest + 1, dest + 6, i + 1 - 6);
+    }
+    return dest;
+}
+
+fn void customizeStandardColors(const char *p) {
+    if (!p) return;
+
+    char[16] name;
+    char[16] val;
+    while (getConfigEntry(name, elemsof(name), val, elemsof(val), &p)) {
+        // check for standard color customisation
+        if (Color col = findStandardColor(normalizeColor(name, elemsof(name), name), true)) {
+            setColorString(col, normalizeColor(val, elemsof(val), val));
+        }
+    }
+}
+
+fn bool getConfigEntry(char* buf1, u32 size1, char* buf2, u32 size2, const char** pp) {
+    const char *p = *pp;
+    for (;;) {
+        while (isspace(*p))
+            p++;
+        if (*p == '\0' || *p == '[')
+            return false;
+        if (*p != '#')
+            break;
+        while (*p && *p++ != '\n')
+            continue;
+    }
+    u32 i = 0;
+    u32 j = 0;
+    while (*p && *p != '=' && *p != ':' && *p != ';' && !isspace(*p)) {
+        char c = *p++;
+        if (i + 1 < size1)
+            buf1[i++] = c;
+        if (j + 1 < size2)
+            buf2[j++] = c;
+    }
+    if (size1) buf1[i] = '\0';
+    if (size2) buf2[j] = '\0';
+    while (*p == ' ') p++;
+    if (*p == '=' || *p == ':') {
+        p++;
+        while (*p == ' ') p++;
+        j = 0;
+        while (*p && *p != ';' && *p != '\n') {
+            char c = *p++;
+            if (j + 1 < size2) buf2[j++] = c;
+        }
+        if (size2) buf2[j] = '\0';
+    }
+    while (*p) {
+        char c = *p++;
+        if (c == '\n' || c == ';')
+            break;
+    }
+    *pp = p;
+    return true;
+}
+
+fn Color convertColor(const char *val, Color def) {
+    if (!val || *val == '\0')
+        return None;
+
+    if (Color col = findStandardColor(val))
+        return col;
+
+    //if (!strcmp(val, "default"))
+    //    return def;
+
+    for (u32 i = Color.CustomStart; i <= Color.CustomEnd; i++) {
+        if (!defaultColors[i]) {
+            Color col = (Color)i;
+            if (setPaletteColor(col, val)) return col;
+            // TODO: complain about unknown color
+            return def;
+        }
+    }
+    // TODO: complain about out of custom colors
+    return def;
+}
+
+public fn Color getConfigColor(const char* cat, Color def) {
+    if (!use_color)
+        return None;
+    if (c2_colors) {
+        const char *p = c2_colors;
+        char[16] cat1;
+        char[16] style;
+        char[16] val;
+        if (!strcmp(p, "none"))
+            return None;
+        normalizeColor(cat1, elemsof(cat1), cat);
+        while (getConfigEntry(style, elemsof(style), val, elemsof(val), &p)) {
+            if (!strcmp(normalizeColor(style, elemsof(style), style), cat1))
+                return convertColor(normalizeColor(val, elemsof(val), val), def);
+        }
+    }
+    return def;
+}
+
+public fn void freeConfigColors() {
+    for (u32 i = Color.CustomStart; i <= Color.CustomEnd; i++) {
+        *defaultColors[i] = '\0';
+    }
+}