[master] 77d5d0f08 Align symbol table columns in the generated C code

[Dridi Boukelmoune]

commit 77d5d0f08af9a53f8171d915115f70dd96ba4543
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Mon Dec 2 11:46:14 2019 +0100

    Align symbol table columns in the generated C code
    
    At the end of the VGC we output the contents of the symbol table inside
    a C comment. It might look like this:
    
        /*
         * Symbol Table
         *
         * reserved  VOID       41 41 acl
         * reserved  VOID       41 41 backend
         * action    VOID       40 41 ban
         * var       HTTP        0 99 bereq
         * var       BACKEND     0 99 bereq.backend
         * [...]
         */
    
    All columns are currently aligned because we know all the native VCL
    types and only the last column with the symbol names has unpredictable
    and arbitrary entries lengths.
    
    However, considering the following snippet:
    
        new fb = directors.fallback();
    
    The involved symbols will look like:
    
        object    VOID      41 41 directors.fallback
        instance  INSTANCE  41 41 fb
        func      VOID      40 41 fb.add_backend
        func      BACKEND   40 41 fb.backend
        func      VOID      40 41 fb.remove_backend
    
    In the future VMOD objects will likely grow their own types and for the
    same snippet we may have this instead:
    
        object    directors.fallback  41 41 directors.fallback
        method    VOID                40 41 directors.fallback.add_backend
        method    BACKEND             40 41 directors.fallback.backend
        method    VOID                40 41 directors.fallback.remove_backend
        instance  directors.fallback  41 41 fb
    
    This change was initially submitted as part of #3147, but was considered
    trivial and fast-track-able by PHK.

diff --git a/lib/libvcc/vcc_xref.c b/lib/libvcc/vcc_xref.c
index fbabf77ce..271f787fd 100644
--- a/lib/libvcc/vcc_xref.c
+++ b/lib/libvcc/vcc_xref.c
@@ -322,6 +322,21 @@ vcc_CheckUses(struct vcc *tl)
 
 /*---------------------------------------------------------------------*/
 
+static int sym_type_len = 0;
+
+static void v_matchproto_(symwalk_f)
+vcc_xreftable_len(struct vcc *tl, const struct symbol *sym)
+{
+	int len;
+
+	(void)tl;
+	CHECK_OBJ_NOTNULL(sym, SYMBOL_MAGIC);
+	CHECK_OBJ_NOTNULL(sym->type, TYPE_MAGIC);
+	len = strlen(sym->type->name);
+	if (sym_type_len < len)
+		sym_type_len = len;
+}
+
 static void v_matchproto_(symwalk_f)
 vcc_xreftable(struct vcc *tl, const struct symbol *sym)
 {
@@ -330,7 +345,7 @@ vcc_xreftable(struct vcc *tl, const struct symbol *sym)
 	CHECK_OBJ_NOTNULL(sym->kind, KIND_MAGIC);
 	CHECK_OBJ_NOTNULL(sym->type, TYPE_MAGIC);
 	Fc(tl, 0, " * %-8s ", sym->kind->name);
-	Fc(tl, 0, " %-9s ", sym->type->name);
+	Fc(tl, 0, " %-*s ", sym_type_len, sym->type->name);
 	Fc(tl, 0, " %2u %2u ", sym->lorev, sym->hirev);
 	VCC_SymName(tl->fc, sym);
 	if (sym->wildcard != NULL)
@@ -343,6 +358,7 @@ VCC_XrefTable(struct vcc *tl)
 {
 
 	Fc(tl, 0, "\n/*\n * Symbol Table\n *\n");
+	VCC_WalkSymbols(tl, vcc_xreftable_len, SYM_NONE);
 	VCC_WalkSymbols(tl, vcc_xreftable, SYM_NONE);
 	Fc(tl, 0, "*/\n\n");
 }