[hackers] [scc] [cc1] Add support for -U in cc1 || Roberto E. Vargas Caballero

[git]

commit 23e5d28bcfafb191be14957906a01453dd911353
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Tue Jun 14 12:31:06 2016 +0200
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Tue Jun 14 12:31:06 2016 +0200

    [cc1] Add support for -U in cc1
    
    POSIX indicates that -U remove any definition of a macro,
    and it means that we have to parse -U options after having
    initialized the preprocessor and having parsed -D options.

diff --git a/cc1/cc1.h b/cc1/cc1.h
index 0dda636..bdf1f6d 100644
--- a/cc1/cc1.h
+++ b/cc1/cc1.h
@@ -4,6 +4,8 @@
 
 #define GLOBALCTX 0
 
+#define NR_USWITCHES 20
+
 /*
  * Definition of enumerations
  */
@@ -417,6 +419,7 @@ extern int expand(char *begin, Symbol *sym);
 extern void incdir(char *dir);
 extern void outcpp(void);
 extern Symbol *defmacro(char *s);
+extern void undefmacro(char *s);
 
 /*
  * Definition of global variables
diff --git a/cc1/cpp.c b/cc1/cpp.c
index f06fe95..81caa5a 100644
--- a/cc1/cpp.c
+++ b/cc1/cpp.c
@@ -39,6 +39,12 @@ defmacro(char *s)
 }
 
 void
+undefmacro(char *s)
+{
+       killsym(lookup(NS_CPP, s));
+}
+
+void
 icpp(void)
 {
        static char sdate[17], stime[14];
diff --git a/cc1/main.c b/cc1/main.c
index 9e542c7..19bcb39 100644
--- a/cc1/main.c
+++ b/cc1/main.c
@@ -38,8 +38,10 @@ int
 main(int argc, char *argv[])
 {
        char *base;
+       static char *uvec[NR_USWITCHES], **umacro = uvec;
 
        atexit(clean);
+       icpp();
 
        ARGBEGIN {
        case 'w':
@@ -51,6 +53,11 @@ main(int argc, char *argv[])
        case 'D':
                defmacro(EARGF(usage()));
                break;
+       case 'U':
+               if (umacro == &uvec[NR_USWITCHES])
+                       die("too many -U switches");
+               *umacro++ = EARGF(usage());
+               break;
        case 'd':
                DBGON();
                break;
@@ -64,6 +71,9 @@ main(int argc, char *argv[])
                usage();
        } ARGEND
 
+       for (umacro = uvec; *umacro; umacro++)
+               undefmacro(*umacro);
+
        if (argc > 1)
                usage();
 
@@ -78,9 +88,7 @@ main(int argc, char *argv[])
        if (output && !freopen(output, "w", stdout))
                die("error opening output: %s", strerror(errno));
 
-       icpp();
        ilex(*argv);
-
        if (onlycpp) {
                outcpp();
        } else {