evalstr: add helper functions to compute expressions from a stringevalstr

In far too many places, especially in directives, we don't accept an
actual expression because, realistically, there have been way too many
hoops to jump through to do so. Add helper functions to make that far
easier.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

5 files changed, 247 insertions, 5 deletions

diff --git a/Makefile.in b/Makefile.in
index 1b9bc40c..c225cf46 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -123,8 +123,9 @@ LIBOBJ = stdlib/snprintf.$(O) stdlib/vsnprintf.$(O) stdlib/strlcpy.$(O) \
 	asm/pragma.$(O) \
 	asm/assemble.$(O) asm/labels.$(O) asm/parser.$(O) \
 	asm/preproc.$(O) asm/quote.$(O) asm/pptok.$(O) \
-	asm/listing.$(O) asm/eval.$(O) asm/exprlib.$(O) asm/exprdump.$(O) \
+	asm/listing.$(O) \
 	asm/stdscan.$(O) \
+	asm/eval.$(O) asm/exprlib.$(O) asm/evalstr.$(O) asm/exprdump.$(O) \
 	asm/strfunc.$(O) asm/tokhash.$(O) \
 	asm/segalloc.$(O) \
 	asm/preproc-nop.$(O) \
diff --git a/Mkfiles/msvc.mak b/Mkfiles/msvc.mak
index 9c7d60e0..9f1c128f 100644
--- a/Mkfiles/msvc.mak
+++ b/Mkfiles/msvc.mak
@@ -86,14 +86,15 @@ LIBOBJ = stdlib\snprintf.$(O) stdlib\vsnprintf.$(O) stdlib\strlcpy.$(O) \
 	x86\regs.$(O) x86\regvals.$(O) x86\regflags.$(O) x86\regdis.$(O) \
 	x86\disp8.$(O) x86\iflag.$(O) \
 	\
-	asm\error.$(O) \
+	asm\error.$(O) asm\warnings.$(O) \
 	asm\float.$(O) \
 	asm\directiv.$(O) asm\directbl.$(O) \
 	asm\pragma.$(O) \
 	asm\assemble.$(O) asm\labels.$(O) asm\parser.$(O) \
 	asm\preproc.$(O) asm\quote.$(O) asm\pptok.$(O) \
-	asm\listing.$(O) asm\eval.$(O) asm\exprlib.$(O) asm\exprdump.$(O) \
+	asm\listing.$(O) \
 	asm\stdscan.$(O) \
+	asm\eval.$(O) asm\exprlib.$(O) asm\evalstr.$(O) asm\exprdump.$(O) \
 	asm\strfunc.$(O) asm\tokhash.$(O) \
 	asm\segalloc.$(O) \
 	asm\preproc-nop.$(O) \
@@ -143,6 +144,7 @@ PERLREQ = x86\insnsb.c x86\insnsa.c x86\insnsd.c x86\insnsi.h x86\insnsn.c \
 	  x86\iflag.c x86\iflaggen.h \
 	  macros\macros.c \
 	  asm\pptok.ph asm\directbl.c asm\directiv.h \
+	  asm\warnings.c include\warnings.h \
 	  version.h version.mac version.mak nsis\version.nsh
 
 INSDEP = x86\insns.dat x86\insns.pl x86\insns-iflags.ph
@@ -211,6 +213,23 @@ x86\regs.h: x86\regs.dat x86\regs.pl
 	$(RUNPERL) $(srcdir)\x86\regs.pl h \
 		$(srcdir)\x86\regs.dat > x86\regs.h
 
+# Extract warnings from source code. Since this depends on
+# ALL the source files, this is only done on demand.
+WARNFILES = asm\warnings.c include\warnings.h doc\warnings.src
+
+warnings:
+	rm -f $(WARNFILES)
+	$(MAKE) $(WARNFILES)
+
+asm\warnings.c: asm\warnings.pl
+	$(RUNPERL) $(srcdir)\asm\warnings.pl c asm\warnings.c $(srcdir)
+
+include\warnings.h: asm\warnings.pl
+	$(RUNPERL) $(srcdir)\asm\warnings.pl h include\warnings.h $(srcdir)
+
+doc\warnings.src: asm\warnings.pl
+	$(RUNPERL) $(srcdir)\asm\warnings.pl doc doc\warnings.src $(srcdir)
+
 # Assembler token hash
 asm\tokhash.c: x86\insns.dat x86\regs.dat asm\tokens.dat asm\tokhash.pl \
 	perllib\phash.ph
diff --git a/Mkfiles/openwcom.mak b/Mkfiles/openwcom.mak
index 2babe5dc..23a8dbf6 100644
--- a/Mkfiles/openwcom.mak
+++ b/Mkfiles/openwcom.mak
@@ -75,14 +75,15 @@ LIBOBJ = stdlib\snprintf.$(O) stdlib\vsnprintf.$(O) stdlib\strlcpy.$(O) &
 	x86\regs.$(O) x86\regvals.$(O) x86\regflags.$(O) x86\regdis.$(O) &
 	x86\disp8.$(O) x86\iflag.$(O) &
 	&
-	asm\error.$(O) &
+	asm\error.$(O) asm\warnings.$(O) &
 	asm\float.$(O) &
 	asm\directiv.$(O) asm\directbl.$(O) &
 	asm\pragma.$(O) &
 	asm\assemble.$(O) asm\labels.$(O) asm\parser.$(O) &
 	asm\preproc.$(O) asm\quote.$(O) asm\pptok.$(O) &
-	asm\listing.$(O) asm\eval.$(O) asm\exprlib.$(O) asm\exprdump.$(O) &
+	asm\listing.$(O) &
 	asm\stdscan.$(O) &
+	asm\eval.$(O) asm\exprlib.$(O) asm\evalstr.$(O) asm\exprdump.$(O) &
 	asm\strfunc.$(O) asm\tokhash.$(O) &
 	asm\segalloc.$(O) &
 	asm\preproc-nop.$(O) &
@@ -156,6 +157,7 @@ PERLREQ = x86\insnsb.c x86\insnsa.c x86\insnsd.c x86\insnsi.h x86\insnsn.c &
 	  x86\iflag.c x86\iflaggen.h &
 	  macros\macros.c &
 	  asm\pptok.ph asm\directbl.c asm\directiv.h &
+	  asm\warnings.c include\warnings.h &
 	  version.h version.mac version.mak nsis\version.nsh
 
 INSDEP = x86\insns.dat x86\insns.pl x86\insns-iflags.ph
@@ -224,6 +226,23 @@ x86\regs.h: x86\regs.dat x86\regs.pl
 	$(RUNPERL) $(srcdir)\x86\regs.pl h &
 		$(srcdir)\x86\regs.dat > x86\regs.h
 
+# Extract warnings from source code. Since this depends on
+# ALL the source files, this is only done on demand.
+WARNFILES = asm\warnings.c include\warnings.h doc\warnings.src
+
+warnings:
+	rm -f $(WARNFILES)
+	$(MAKE) $(WARNFILES)
+
+asm\warnings.c: asm\warnings.pl
+	$(RUNPERL) $(srcdir)\asm\warnings.pl c asm\warnings.c $(srcdir)
+
+include\warnings.h: asm\warnings.pl
+	$(RUNPERL) $(srcdir)\asm\warnings.pl h include\warnings.h $(srcdir)
+
+doc\warnings.src: asm\warnings.pl
+	$(RUNPERL) $(srcdir)\asm\warnings.pl doc doc\warnings.src $(srcdir)
+
 # Assembler token hash
 asm\tokhash.c: x86\insns.dat x86\regs.dat asm\tokens.dat asm\tokhash.pl &
 	perllib\phash.ph
diff --git a/asm/evalstr.c b/asm/evalstr.c
new file mode 100644
index 00000000..5183f4e5
--- /dev/null
+++ b/asm/evalstr.c
@@ -0,0 +1,143 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2018 The NASM Authors - All Rights Reserved
+ *   See the file AUTHORS included with the NASM distribution for
+ *   the specific copyright holders.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following
+ *   conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *
+ *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Wrapper routine for evaluation
+ *
+ * Useful in directives etc. where we have a string and want a number
+ * or possibly a relocatable expression.
+ */
+
+#include "compiler.h"
+#include "nasm.h"
+#include "stdscan.h"
+#include "eval.h"
+#include "evalstr.h"
+
+/*
+ * Evaluate a simple value from a string. A segment and/or WRT MAY be
+ * permitted, but if NULL is passed into the respective pointers, then
+ * that is an error.
+ */
+static int stdscan_save(void *pvt, struct tokenval *tv)
+{
+    char **strptr = pvt;
+
+    *strptr = stdscan_get();
+    return stdscan(NULL, tv);
+}
+
+int64_t evaluate_str(char **str, bool crit, int32_t *segment, int32_t *wrt)
+{
+    struct tokenval tokval;
+    expr *e;
+    int32_t seg;
+
+    stdscan_reset();
+    stdscan_set(*str);
+
+    tokval.t_type = TOKEN_INVALID;
+    e = evaluate(stdscan_save, str, &tokval, NULL, crit, NULL);
+    *str = nasm_skip_spaces(*str);
+
+    if (segment)
+        *segment = NO_SEG;
+
+    if (is_unknown(e) && !crit)
+        return 0;
+
+    if (!is_reloc(e)) {
+        nasm_nonfatal("invalid expression");
+        return 0;
+    }
+
+    seg = reloc_seg(e);
+    if (*segment) {
+        *segment = seg;
+    } else if (seg != NO_SEG) {
+        nasm_nonfatal("expression cannot contain a segment reference");
+    }
+
+    seg = reloc_wrt(e);
+    if (*wrt) {
+        *wrt = seg;
+    } else if (seg != NO_SEG) {
+        nasm_nonfatal("expression cannot contain WRT");
+    }
+
+    return reloc_value(e);
+}
+
+/*
+ * Evaluate a size expression: a pure integer, but size specifiers like
+ * BYTE are treated like integer constants.
+ */
+static int stdscan_save_size(void *pvt, struct tokenval *tv)
+{
+    char **strptr = pvt;
+    int t;
+
+    *strptr = stdscan_get();
+    t = stdscan(NULL, tv);
+
+    if (t == TOKEN_SIZE) {
+        /* Treat size specifiers as integer constants */
+        tv->t_type = t = TOKEN_NUM;
+        tv->t_integer = tv->t_inttwo; /* Contains the size equivalent */
+    }
+
+    return t;
+}
+
+int64_t evaluate_size(char **str, bool crit)
+{
+    struct tokenval tokval;
+    expr *e;
+
+    stdscan_reset();
+    stdscan_set(*str);
+
+    tokval.t_type = TOKEN_INVALID;
+    e = evaluate(stdscan_save_size, str, &tokval, NULL, crit, NULL);
+    *str = nasm_skip_spaces(*str);
+
+    if (is_unknown(e) && !crit)
+        return 0;
+
+    if (!is_reloc(e) || reloc_seg(e) != NO_SEG || reloc_wrt(e) != NO_SEG) {
+        nasm_nonfatal("invalid size expression");
+        return 0;
+    }
+
+    return reloc_value(e);
+}
diff --git a/asm/evalstr.h b/asm/evalstr.h
new file mode 100644
index 00000000..4d06628b
--- /dev/null
+++ b/asm/evalstr.h
@@ -0,0 +1,60 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2018 The NASM Authors - All Rights Reserved
+ *   See the file AUTHORS included with the NASM distribution for
+ *   the specific copyright holders.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following
+ *   conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *
+ *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Wrappers around stdscan() and evaluate() for computing expressions
+ * directly from strings.
+ */
+
+#ifndef NASM_EVALSTR_H
+#define NASM_EVALSTR_H
+
+#include "compiler.h"
+
+/*
+ * Evaluate a string, returning the offset component. The string pointer
+ * is advanced to the beginning of the first token following the
+ * end of the expression.
+ *
+ * If the "segment" and/or "wrt" pointers are NULL, then those
+ * components are explicitly forbidden and will throw an error.
+ */
+int64_t evaluate_str(char **str, bool crit, int32_t *segment, int32_t *wrt);
+
+/*
+ * Evaluate a size expression: a pure integer, but size specifiers like
+ * BYTE are treated like integer constants.
+ */
+int64_t evaluate_size(char **str, bool crit);
+
+#endif  /* NASM_EVALSTR_H */