From c13e1ec500a8a7ce6d41f0610ee1e71da50bb3b7 Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Sun, 22 Feb 2026 19:05:52 +0100
Subject: driver: recognize shared libraries; & backend: misc fixes for PIC
 isel edgecases

---
 main.c        | 13 ++++++++-----
 x86_64/emit.c |  2 +-
 x86_64/isel.c | 10 ++++++----
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/main.c b/main.c
index 12374af..3eb56ea 100644
--- a/main.c
+++ b/main.c
@@ -52,7 +52,7 @@ fileext(const char *path)
    return dot ? dot+1 : "";
 }
 
-enum inft { IFTauto, IFTc, IFTasm, IFTobj, IFTar };
+enum inft { IFTauto, IFTc, IFTasm, IFTobj, IFTar, IFTdll };
 
 static enum inft
 ftdetect(const char *s)
@@ -62,6 +62,7 @@ ftdetect(const char *s)
    if (!strcmp(ext, "o")) return IFTobj;
    if (!strcmp(ext, "a")) return IFTar;
    if (!strcmp(ext, "s")) return IFTasm;
+   if (!strcmp(ext, "so")) return IFTdll;
    warn(NULL, "assuming %'s is C source file", s);
    return IFTc;
 }
@@ -198,7 +199,7 @@ optparse(char **args)
          const char *s = *++args;
          if (!s) fatal(NULL, "missing target name");
          task.targ = s;
-      } else if (*arg == 'l' || *arg == 'L' || *arg == 'B') {
+      } else if (*arg == 'l' || *arg == 'L' || *arg == 'B' || !strcmp(arg, "shared")) {
          vpush(&task.linkargs, arg-1);
       } else if (!strcmp(arg, "v") || !strcmp(arg, "-verbose")) {
          task.verbose = 1;
@@ -359,7 +360,8 @@ compileobjs(void)
 
    if (!ccopt.dbg.any && !task.syntaxonly) mktemps();
    for (int i = 0; i < task.inf.n; ++i) {
-      if (task.inf.p[i].ft == IFTc) {
+      enum inft ft = task.inf.p[i].ft;
+      if (ft == IFTc) {
          if ((p = fork()) < 0) {
             error(NULL, "fork(): %s\n", strerror(errno));
             exit(1);
@@ -372,7 +374,8 @@ compileobjs(void)
             cleantemps();
             exit(WEXITSTATUS(wstat));
          }
-      } else if (task.inf.p[i].ft == IFTobj || task.inf.p[i].ft == IFTar) {
+      } else if (ft == IFTobj || ft == IFTar || ft == IFTdll) {
+         // passthru
       } else assert(!"not obj");
    }
    if (!ccopt.dbg.any && !task.syntaxonly) {
@@ -474,7 +477,7 @@ dolink(void)
       const char *o;
       switch (task.inf.p[i].ft) {
       case IFTc: o = task.inf.p[i].temp; break;
-      case IFTobj: case IFTar:
+      case IFTobj: case IFTar: case IFTdll:
          o = task.inf.p[i].path; break;
       default: assert(!"link obj?");
       }
diff --git a/x86_64/emit.c b/x86_64/emit.c
index 0d7b77a..e54b7dd 100644
--- a/x86_64/emit.c
+++ b/x86_64/emit.c
@@ -880,7 +880,7 @@ gencopy(uchar **pcode, enum irclass cls, struct block *blk, int curi, struct ope
       /* dst = 0 -> xor dst, dst; but only if it is ok to clobber flags */
       Xxor(pcode, kisint(cls) ? KI32 : cls, dst, dst);
    } else if (isaddrcon(val,0)) {
-      if ((ccopt.pic || (contab.p[val.i].flag & SFUNC)) && !(contab.p[val.i].flag & SLOCAL)) {
+      if ((ccopt.pic || (contab.p[val.i].flag & SFUNC)) && (contab.p[val.i].flag & (SLOCAL|SFUNC)) != (SLOCAL|SFUNC)) {
       GOTLoad:
          /* for  mov reg, [rip(sym@GOTPCREL)] */
          Xmov(pcode, cls, dst, mkoper(OSYMGOT, .con = val.i, .cindex = NOINDEX));
diff --git a/x86_64/isel.c b/x86_64/isel.c
index 7f82984..c3857c7 100644
--- a/x86_64/isel.c
+++ b/x86_64/isel.c
@@ -90,8 +90,8 @@ fixarg(union ref *r, struct instr *ins, struct block *blk, int *curi)
          }
          if (docopy)
             *r = insertinstr(blk, (*curi)++, mkinstr(Ocopy, con->cls, *r));
-      } else if (op != Omove && con->issym && ins && r == &ins->r) {
-         *r = insertinstr(blk, (*curi)++, mkinstr(Ocopy, KPTR, mkaddr((struct addr){*r})));
+      } else if (op != Omove && (con->issym || (con->isdat && !con->deref)) && ins && r == &ins->r) {
+         *r = insertinstr(blk, (*curi)++, mkinstr(Ocopy, KPTR, *r));
       } else if (in_range(op, Odiv, Ourem) && kisint(ins->cls))
          goto DivImm;
    } else if (r->t == RICON && in_range(op, Odiv, Ourem) && kisint(ins->cls) && r == &ins->r) {
@@ -107,6 +107,8 @@ fixarg(union ref *r, struct instr *ins, struct block *blk, int *curi)
          *ins = adr;
       else
          *r = insertinstr(blk, (*curi)++, adr);
+   } else if (r->bits == UNDREF.bits && ins->op != Ocopy) {
+      *r = insertinstr(blk, (*curi)++, mkinstr(Ocopy, ins->cls, *r));
    }
    picfixsym(r, blk, curi);
 }
@@ -387,7 +389,7 @@ sel(struct function *fn, struct instr *ins, struct block *blk, int *curi)
    case Ointrin:
       break;
    case Oshl: case Osar: case Oslr:
-      if (!iscon(ins->r)) {
+      if (!isintcon(ins->r)) {
          /* shift amount register is always CL */
          insertinstr(blk, (*curi)++, mkinstr(Omove, KI32, mkref(RREG, RCX), ins->r));
          ins->r = mkref(RREG, RCX);
@@ -396,7 +398,7 @@ sel(struct function *fn, struct instr *ins, struct block *blk, int *curi)
    case Oequ: case Oneq:
    case Olth: case Ogth: case Olte: case Ogte:
    case Oulth: case Ougth: case Oulte: case Ougte:
-      if (iscon(ins->l)) {
+      if (iscon(ins->l) && !iscon(ins->r)) {
          /* lth imm, x -> gth x, imm */
          if (!in_range(ins->op, Oequ, Oneq))
             ins->op = ((op - Olth) ^ 1) + Olth;
-- 
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