Stop dropping errors from clang

* Refactor the error-writing code to be more compact and flexible

1 files changed, 40 insertions, 36 deletions

diff --git a/src/errmsg.cpp b/src/errmsg.cpp
index edbfd858a8..16d1dcd52f 100644
--- a/src/errmsg.cpp
+++ b/src/errmsg.cpp
@@ -16,51 +16,49 @@ enum ErrType {
 };
 
 static void print_err_msg_type(ErrorMsg *err, ErrColor color, ErrType err_type) {
-    const char *path = buf_ptr(err->path);
-    size_t line = err->line_start + 1;
-    size_t col = err->column_start + 1;
-    const char *text = buf_ptr(err->msg);
-
     bool is_tty = os_stderr_tty();
-    if (color == ErrColorOn || (color == ErrColorAuto && is_tty)) {
-        if (err_type == ErrTypeError) {
-            os_stderr_set_color(TermColorBold);
-            fprintf(stderr, "%s:%" ZIG_PRI_usize ":%" ZIG_PRI_usize ": ", path, line, col);
-            os_stderr_set_color(TermColorRed);
-            fprintf(stderr, "error:");
-            os_stderr_set_color(TermColorBold);
-            fprintf(stderr, " %s", text);
-            os_stderr_set_color(TermColorReset);
-            fprintf(stderr, "\n");
-        } else if (err_type == ErrTypeNote) {
-            os_stderr_set_color(TermColorBold);
-            fprintf(stderr, "%s:%" ZIG_PRI_usize ":%" ZIG_PRI_usize ": ", path, line, col);
-            os_stderr_set_color(TermColorCyan);
-            fprintf(stderr, "note:");
-            os_stderr_set_color(TermColorBold);
-            fprintf(stderr, " %s", text);
-            os_stderr_set_color(TermColorReset);
-            fprintf(stderr, "\n");
-        } else {
+    bool use_colors = color == ErrColorOn || (color == ErrColorAuto && is_tty);
+
+    // Show the error location, if available
+    if (err->path != nullptr) {
+        const size_t line = err->line_start + 1;
+        const size_t col = err->column_start + 1;
+
+        if (use_colors) os_stderr_set_color(TermColorBold);
+        fprintf(stderr, "%s:%" ZIG_PRI_usize ":%" ZIG_PRI_usize ": ", buf_ptr(err->path), line, col);
+    }
+
+    // Write out the error type
+    switch (err_type) {
+        case ErrTypeError:
+            if (use_colors) os_stderr_set_color(TermColorRed);
+            fprintf(stderr, "error: ");
+            break;
+        case ErrTypeNote:
+            if (use_colors) os_stderr_set_color(TermColorCyan);
+            fprintf(stderr, "note: ");
+            break;
+        default:
             zig_unreachable();
-        }
+    }
 
+    // Write out the error message
+    if (use_colors) os_stderr_set_color(TermColorBold);
+    fputs(buf_ptr(err->msg), stderr);
+    if (use_colors) os_stderr_set_color(TermColorReset);
+    fputc('\n', stderr);
+
+    if (buf_len(&err->line_buf) != 0){
+        // Show the referenced line
         fprintf(stderr, "%s\n", buf_ptr(&err->line_buf));
         for (size_t i = 0; i < err->column_start; i += 1) {
             fprintf(stderr, " ");
         }
-        os_stderr_set_color(TermColorGreen);
+        // Draw the caret
+        if (use_colors) os_stderr_set_color(TermColorGreen);
         fprintf(stderr, "^");
-        os_stderr_set_color(TermColorReset);
+        if (use_colors) os_stderr_set_color(TermColorReset);
         fprintf(stderr, "\n");
-    } else {
-        if (err_type == ErrTypeError) {
-            fprintf(stderr, "%s:%" ZIG_PRI_usize ":%" ZIG_PRI_usize ": error: %s\n", path, line, col, text);
-        } else if (err_type == ErrTypeNote) {
-            fprintf(stderr, " %s:%" ZIG_PRI_usize ":%" ZIG_PRI_usize ": note: %s\n", path, line, col, text);
-        } else {
-            zig_unreachable();
-        }
     }
 
     for (size_t i = 0; i < err->notes.length; i += 1) {
@@ -86,6 +84,12 @@ ErrorMsg *err_msg_create_with_offset(Buf *path, size_t line, size_t column, size
     err_msg->column_start = column;
     err_msg->msg = msg;
 
+    if (source == nullptr) {
+        // Must initialize the buffer anyway
+        buf_init_from_str(&err_msg->line_buf, "");
+        return err_msg;
+    }
+
     size_t line_start_offset = offset;
     for (;;) {
         if (line_start_offset == 0) {