From d82f3052c813f671561362126d0fbe08568542d3 Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Sat, 6 Dec 2025 11:41:44 +0100
Subject: add command-line predefined macros (-D, -U)

---
 amd64/sysv.c |  1 -
 c/lex.c      | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
 common.h     |  3 +++
 io.c         | 39 +++++++++++++++++++++++++++++++++++----
 ir/ir.h      |  2 --
 main.c       |  7 +++++--
 obj/elf.c    |  6 +++---
 targ.c       |  4 +++-
 test/07-pp.c |  6 ++++--
 test/run.sh  |  3 ++-
 10 files changed, 107 insertions(+), 20 deletions(-)

diff --git a/amd64/sysv.c b/amd64/sysv.c
index 712652a..299d35c 100644
--- a/amd64/sysv.c
+++ b/amd64/sysv.c
@@ -298,7 +298,6 @@ const struct mctarg t_amd64_sysv = {
    .rglob = 1<<RSP | 1<<RBP,
    .rnames = amd64_rnames,
    .objkind = OBJELF,
-   .isa = ISamd64,
    .abiret = abiret,
    .abiarg = abiarg,
    .vastart = vastart,
diff --git a/c/lex.c b/c/lex.c
index ca10233..971b81f 100644
--- a/c/lex.c
+++ b/c/lex.c
@@ -1836,6 +1836,23 @@ lexpeek(struct lexer *lx, struct token *tk_)
    return t;
 }
 
+/* Predefined/builtin macros */
+
+static vec_of(uchar) ppcmdline;
+
+void
+cpppredef(bool undef, const char *cmd)
+{
+   const char *sep = strchr(cmd, '='), *body = sep ? sep+1 : "1";
+   uint namelen = sep ? sep - cmd : strlen(cmd);
+   char line[1024];
+   struct wbuf wbuf = MEMBUF(line, sizeof line);
+   if (!ppcmdline.p) vinit(&ppcmdline, NULL, 1<<10);
+   int n = bfmt(&wbuf, "%s %S %s\n", undef ? "#undef" : "#define", cmd, namelen, body);
+   assert(n <= sizeof line);
+   vpushn(&ppcmdline, line, n);
+}
+
 static void
 mac__file__handler(struct lexer *lx, struct token *tk)
 {
@@ -1916,10 +1933,21 @@ mac__has_builtin(struct lexer *lx, struct token *tk, struct rlist arg)
    tk->s = &"01"[has];
 }
 
+static const struct token tok_1 = { TKNUMLIT, .s = "1", .len = 1, .litlit = 1 };
 static void
-addpredefmacros(void)
+putdef1(const char *name)
+{
+   struct macro mac = {
+      .name = intern(name),
+      .predefined = 1,
+      .rlist = { &tok_1, 1 },
+   };
+   putmac(&mac);
+}
+
+static void
+addpredefmacros(struct arena **tmparena)
 {
-   static const struct token tok_1 = { TKNUMLIT, .s = "1", .len = 1 };
    static struct token tok_ver = { TKNUMLIT };
    static struct macro macs[] = {
       { "__FILE__", .predefined = 1, .special = 1, .handler = mac__file__handler },
@@ -1931,7 +1959,6 @@ addpredefmacros(void)
       { "__STDC_VERSION__", .predefined = 1, .rlist = { &tok_ver, 1 } },
       { "__STDC_HOSTED__", .predefined = 1, .rlist = { &tok_1, 1 } },
       { "__antcc__", .predefined = 1, .rlist = { &tok_1, 1 } },
-      { "__x86_64__", .predefined = 1, .rlist = { &tok_1, 1 } },
    };
    switch (ccopt.cstd) {
    default: assert(0);
@@ -1945,6 +1972,27 @@ addpredefmacros(void)
       macs[i].name = intern(macs[i].name);
       putmac(&macs[i]);
    }
+
+   switch (targ_mcisa) {
+   case ISamd64:
+      putdef1("__x86_64__");
+      putdef1("__x86_64");
+      break;
+   }
+
+   if (ppcmdline.n) {
+      struct memfile *f;
+      struct lexer lx[1] = {0};
+      vpushn(&ppcmdline, "\0\0\0\0", 5);
+      lx->fileid = getpredeffile(&f, "<command line>");
+      assert(!f->p);
+      lx->dat = f->p = ppcmdline.p;
+      lx->ndat = f->n = ppcmdline.n;
+      lx->tmparena = tmparena;
+      lx->chrbuf0 = arraylength(lx->chrbuf);
+      lx->firstdirective = 1;
+      while (!lx->eof) lex(lx, NULL);
+   }
 }
 
 enum initlexer
@@ -1954,8 +2002,8 @@ initlexer(struct lexer *lx, const char **err, const char *file)
    static union { char m[sizeof(struct arena) + NARENA]; struct arena *_align; } amem;
    static struct arena *tmparena = (void *)amem.m;
 
-   if (!macros.n) addpredefmacros();
    if (!tmparena->cap) tmparena->cap = NARENA;
+   if (!macros.n) addpredefmacros(&tmparena);
 
    struct memfile *f;
    int fileid = openfile(err, &f, file);
diff --git a/common.h b/common.h
index 20716d2..1e34ba5 100644
--- a/common.h
+++ b/common.h
@@ -148,7 +148,9 @@ extern struct inclpaths {
 /* Target */
 /**********/
 
+enum mcisa { ISamd64 };
 extern const struct mctarg *mctarg;
+extern enum mcisa targ_mcisa;
 void targ_init(const char *);
 
 /*********/
@@ -377,6 +379,7 @@ struct memfile mapopen(const char **err, const char *path);
 void mapclose(struct memfile *);
 void *mapzeros(uint);
 int munmap(void *, size_t);
+int getpredeffile(struct memfile **, const char *name);
 int openfile(const char **err, struct memfile **, const char *path);
 const char *getfilename(int id);
 struct memfile *getfile(int id);
diff --git a/io.c b/io.c
index 6e1d425..f9e34b7 100644
--- a/io.c
+++ b/io.c
@@ -827,6 +827,37 @@ static struct file {
 } *fileht[1<<SPANFILEBITS];
 static int nfiles;
 
+int
+getpredeffile(struct memfile **pf, const char *name)
+{
+   struct file *f;
+   struct fileuid uid;
+   uint h, id, n = arraylength(fileht);
+
+   uid.dev = -11;
+   uid.ino = hashs(0, name);
+   for (id = h = uid.dev ^ uid.ino;; ++id) {
+      id &= arraylength(fileht) - 1;
+      f = fileht[id];
+      if (f && f->uid.dev == uid.dev && f->uid.ino == uid.ino) {
+         break;
+      } else if (!f) {
+         f = allocz(&globarena, sizeof *f, 0);
+         f->uid = uid;
+         f->path = name;
+         f->f = (struct memfile) { .statik = 1 };
+         fileht[id] = f;
+         vinit(&f->lineoffs, NULL, 10);
+         vpush(&f->lineoffs, 0);
+         ++nfiles;
+         break;
+      }
+      assert(--n > 0 && "fileht full");
+   }
+   *pf = &f->f;
+   return id;
+}
+
 int
 openfile(const char **err, struct memfile **pf, const char *path)
 {
@@ -873,14 +904,14 @@ openfile(const char **err, struct memfile **pf, const char *path)
 const char *
 getfilename(int id)
 {
-   assert(id < arraylength(fileht) && fileht[id]);
+   assert((uint)id < arraylength(fileht) && fileht[id]);
    return fileht[id]->path;
 }
 
 struct memfile *
 getfile(int id)
 {
-   assert(id < arraylength(fileht) && fileht[id]);
+   assert((uint)id < arraylength(fileht) && fileht[id]);
    return &fileht[id]->f;
 }
 
@@ -889,7 +920,7 @@ addfileline(int id, uint off)
 {
    vec_of(uint) *lineoffs;
 
-   assert(id < arraylength(fileht) && fileht[id]);
+   assert((uint)id < arraylength(fileht) && fileht[id]);
    lineoffs = (void *)&fileht[id]->lineoffs;
    if (lineoffs->n && off > lineoffs->p[lineoffs->n-1])
       vpush(lineoffs, off);
@@ -901,7 +932,7 @@ getfilepos(int *line, int *col, int id, uint off)
    uint *offs, n;
    int l = 0, h, i = 0;
 
-   assert(id < arraylength(fileht) && fileht[id]);
+   assert((uint)id < arraylength(fileht) && fileht[id]);
    offs = fileht[id]->lineoffs.p;
    n = fileht[id]->lineoffs.n;
    h = n - 1;
diff --git a/ir/ir.h b/ir/ir.h
index 6cab245..b2077a0 100644
--- a/ir/ir.h
+++ b/ir/ir.h
@@ -179,7 +179,6 @@ struct function {
 #define FREQUIRE(_prop) assert((fn->prop & (_prop)) && "preconditions not met")
 
 enum objkind { OBJELF };
-enum mcisa { ISamd64 };
 
 struct mctarg {
    short gpr0, /* first gpr */
@@ -192,7 +191,6 @@ struct mctarg {
           rglob;   /* globally live (never used for regalloc) */
    const char (*rnames)[6];
    enum objkind objkind;
-   enum mcisa isa;
    /* abiret: lower return type:
     *  scalar/small struct -> returns number of regs (1..2),
     *                         r & cls filled with reg and irclass of each scalar return
diff --git a/main.c b/main.c
index 4b904a0..ac45cc5 100644
--- a/main.c
+++ b/main.c
@@ -179,8 +179,11 @@ optparse(char **args)
          }
       } else if (*arg == 'g') {
          /* TODO debug info */
-      } else if (*arg == 'D') {
-         /* TODO cmdline defines */
+      } else if (*arg == 'D' || *arg == 'U') {
+         void cpppredef(bool undef, const char *cmd);
+         const char *def = arg[1] ? arg+1 : *++args;
+         if (!def) fatal(NULL, "macro name missing after `-%c`", *arg);
+         cpppredef(*arg == 'U', def);
       } else if (*arg == 'O') {
          /* TODO optimization level */
       } else if (*arg == 'I') {
diff --git a/obj/elf.c b/obj/elf.c
index 5578452..771d3c0 100644
--- a/obj/elf.c
+++ b/obj/elf.c
@@ -42,7 +42,7 @@ elfinit(void)
    hdr.i_osabi = ELFOSABI_SYSV;
    hdr.i_abiversion = 0;
    hdr.h32.type = ET_REL;
-   switch (mctarg->isa) {
+   switch (targ_mcisa) {
    case ISamd64: hdr.h32.machine = EM_X86_64; break;
    }
    hdr.h32.version = ELFVERSION;
@@ -148,7 +148,7 @@ elfreloc(const char *sym, enum relockind kind, enum section section, uint off, v
    case Sdata:   ++ndatarel; break;
    }
    assert(kind < NRELOCKIND);
-   vpush(&relocs, ((struct reloc) { section, relktab[mctarg->isa][kind], snam, off, addend }));
+   vpush(&relocs, ((struct reloc) { section, relktab[targ_mcisa][kind], snam, off, addend }));
 }
 
 static void
@@ -365,7 +365,7 @@ elffini(struct wbuf *out)
       shnam_strtab = 36, shnam_symtab = 44, shnam_reltext = 52, shnam_relrodata = 63, shnam_reldata = 76
    };
    int align = targ_64bit ? 8 : 4;
-   bool userela = userelatab[mctarg->isa];
+   bool userela = userelatab[targ_mcisa];
    char shstrs[] = "\0.text\0.rodata\0.data\0.bss\0.shstrtab\0.strtab\0.symtab\0"
                    ".rela.text\0.rela.rodata\0.rela.data";
    if (!userela) {
diff --git a/targ.c b/targ.c
index 019f784..6a4a5bd 100644
--- a/targ.c
+++ b/targ.c
@@ -9,8 +9,9 @@ static const struct targ {
    bool charsigned;
    uchar sizetype, ptrdifftype, wchartype;
    const struct mctarg *mctarg;
+   enum mcisa isa;
 } targs[] = {
-   { "amd64-sysv", {8, 8, 8, 24}, {8, 8, 8, 8}, 1, TYULONG, TYLONG, TYINT, &t_amd64_sysv },
+   { "amd64-sysv", {8, 8, 8, 24}, {8, 8, 8, 8}, 1, TYULONG, TYLONG, TYINT, &t_amd64_sysv, ISamd64 },
    { "i686-sysv",  {4, 8, 4,  8}, {4, 4, 4, 4}, 1, TYUINT,  TYINT,  TYINT }
 };
 
@@ -19,6 +20,7 @@ uchar targ_primalign[TYPTR+1];
 uint targ_valistsize;
 enum typetag targ_sizetype, targ_ptrdifftype, targ_wchartype;
 bool targ_charsigned, targ_bigendian, targ_64bit;
+enum mcisa targ_mcisa;
 const struct mctarg *mctarg;
 
 void
diff --git a/test/07-pp.c b/test/07-pp.c
index c26105d..6a50571 100644
--- a/test/07-pp.c
+++ b/test/07-pp.c
@@ -1,3 +1,4 @@
+/* CFLAGS: -D CMD_WORKING -DV=void */
 /* EXPECT:
 ok /1 "\n"n ;.& 05.5 ADD(1,2)
 hi from header ;73
@@ -30,9 +31,10 @@ u\
 t\
 s
 
-
+#ifdef CMD_WORKING
 int
-main(void)
+main(V)
+#endif
 {
    int CATl(foo);
    ++foobar;
diff --git a/test/run.sh b/test/run.sh
index 5e0bc0f..34d8101 100755
--- a/test/run.sh
+++ b/test/run.sh
@@ -16,11 +16,12 @@ run() {
     echo ----  $f ---- >> log.txt
     mkdir -p build/
     args=$(awk '/\/\* ARGS:.*$/ {ORS=" ";for (i=3;i<NF;++i)print $i;ORS="\n";print""}' "$f")
+    cflags=$(awk '/\/\* CFLAGS:.*$/ {ORS=" ";for (i=3;i<NF;++i)print $i;ORS="\n";print""}' "$f")
     awk '/\/\* EXPECT:$/ {x=k=any=1} x && /\*\// {x=0} x {if (!k)print $0;k=0} END{if(x||!any)exit 1;}' "$f" > "$expected"
     if [ $? == 0 ]; then
         obj=build/"$(echo "$f" | sed -s 's/\.c$/.o/')"
         exe=build/"$(echo "$f" | sed -s 's/\.c$//')"
-        if ! ( x $ANTCC "$f" -c -o "$obj" && x $ANTCC "$obj" -o "$exe" ); then
+        if ! ( x $ANTCC $cflags "$f" -c -o "$obj" && x $ANTCC $cflags "$obj" -o "$exe" ); then
             echo !TEST ERROR $f
             echo !FAILED TO COMPILE
             echo '-------'
-- 
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