follow-up to [r5114] check for internal memory bounds with new flag "…

…memory-check" (implied with --debug)

* increased fence to 8 bytes
* increased tests
* fixed CALL with BASED items to not use a fence
* doc update

cobc/codegen.c

@@ -1855,7 +1855,7 @@ output_call_cache (void)
 		/* note: we explicit do _not_ initialize it directly as that
 		   will more likely lead to a non-consecutive memory layout,
 		   which makes the whole purpose of the fence useless */
-		output_local ("static char\tcall_fence_pre[5];\n");
+		output_local ("static char\tcall_fence_pre[8];\n");
 	}
 	call_cache = call_list_reverse (call_cache);
 	for (call = call_cache; call; call = call->next) {
@@ -1869,7 +1869,7 @@ output_call_cache (void)
 	}
 	if ((call_cache || func_call_cache)
 	 && (cb_flag_memory_check & CB_MEMCHK_POINTER)) {
-		output_local ("static char\tcall_fence_post[5];\n");
+		output_local ("static char\tcall_fence_post[8];\n");
 	}
 	if (static_call_cache) {
 		const char			*convention_modifier;
@@ -2094,10 +2094,10 @@ output_local_base_cache (void)
 				output_local ("static ");
 			}
 #ifdef  HAVE_ATTRIBUTE_ALIGNED
-			output_local ("cob_u8_t	%s%d_fence_pre[5]%s;\n",
+			output_local ("cob_u8_t	%s%d_fence_pre[8]%s;\n",
 				CB_PREFIX_BASE, fld->id, COB_ALIGN);
 #else
-			output_local ("%scob_u8_t%s	%s%d_fence_pre[5];\n",
+			output_local ("%scob_u8_t%s	%s%d_fence_pre[8];\n",
 				COB_ALIGN_DECL_8, COB_ALIGN_ATTR_8,
 				CB_PREFIX_BASE, fld->id);
 #endif
@@ -2129,10 +2129,10 @@ output_local_base_cache (void)
 				output_local ("static ");
 			}
 #ifdef  HAVE_ATTRIBUTE_ALIGNED
-			output_local ("cob_u8_t	%s%d_fence_post[5]%s;\n",
+			output_local ("cob_u8_t	%s%d_fence_post[8]%s;\n",
 				CB_PREFIX_BASE, fld->id, COB_ALIGN);
 #else
-			output_local ("%scob_u8_t%s	%s%d_fence_post[5];\n",
+			output_local ("%scob_u8_t%s	%s%d_fence_post[8];\n",
 				COB_ALIGN_DECL_8, COB_ALIGN_ATTR_8,
 				CB_PREFIX_BASE, fld->id);
 #endif
@@ -2165,13 +2165,13 @@ output_nonlocal_base_cache (void)
 
 		if (fld->flag_used_in_call) {
 #ifdef  HAVE_ATTRIBUTE_ALIGNED
-			output_storage ("static cob_u8_t	%s%d_fence_pre[5]%s;\n",
+			output_storage ("static cob_u8_t	%s%d_fence_pre[8]%s;\n",
 				CB_PREFIX_BASE, fld->id, COB_ALIGN);
 #else
 #if defined(COB_ALIGN_PRAGMA_8)
 			output_storage ("#pragma align 8 (%s%d_fence_pre)\n", CB_PREFIX_BASE, fld->id);
 #endif
-			output_storage ("static %scob_u8_t%s	%s%d_fence_pre[5];\n",
+			output_storage ("static %scob_u8_t%s	%s%d_fence_pre[8];\n",
 				COB_ALIGN_DECL_8, COB_ALIGN_ATTR_8,
 				CB_PREFIX_BASE, fld->id);
 #endif
@@ -2200,13 +2200,13 @@ output_nonlocal_base_cache (void)
 		output_storage ("\t/* %s */\n", fld->name);
 		if (fld->flag_used_in_call) {
 #ifdef  HAVE_ATTRIBUTE_ALIGNED
-			output_storage ("static cob_u8_t	%s%d_fence_post[5]%s;\n",
+			output_storage ("static cob_u8_t	%s%d_fence_post[8]%s;\n",
 				CB_PREFIX_BASE, fld->id, COB_ALIGN);
 #else
 #if defined(COB_ALIGN_PRAGMA_8)
 			output_storage ("#pragma align 8 (%s%d_fence_post)\n", CB_PREFIX_BASE, fld->id);
 #endif
-			output_storage ("static %scob_u8_t%s	%s%d_fence_post[5];\n",
+			output_storage ("static %scob_u8_t%s	%s%d_fence_post[8];\n",
 				COB_ALIGN_DECL_8, COB_ALIGN_ATTR_8,
 				CB_PREFIX_BASE, fld->id);
 #endif
@@ -6462,12 +6462,12 @@ output_memory_check_call (struct cb_call *p, const enum cob_statement stmt)
 				const struct cb_field *fchck = cb_field_founder (CB_FIELD (x));
 				if (fchck->flag_used_in_call) {
 					if (stmt == STMT_BEFORE_CALL) {
-						output_line ("if (memcmp (%s%d_fence_pre, \"\\x00\\x00\\x00\\x00\", 5) == 0) {",
+						output_line ("if (memcmp (%s%d_fence_pre, \"\\x00\\x00\\x00\\x00\\x00\\x00\\x00\", 8) == 0) {",
 							CB_PREFIX_BASE, fchck->id);
 						output_indent_level += indent_adjust_level;
-						output_line ("memcpy (%s%d_fence_pre, \"\\xFF\\xFE\\xFD\\xFC\", 5);",
+						output_line ("memcpy (%s%d_fence_pre, \"\\xFF\\xFE\\xFD\\xFC\\xFB\\xFA\\xFF\", 8);",
 							CB_PREFIX_BASE, fchck->id);
-						output_line ("memcpy (%s%d_fence_post, \"\\xFA\\xFB\\xFC\\xFD\", 5);",
+						output_line ("memcpy (%s%d_fence_post, \"\\xFA\\xFB\\xFC\\xFD\\xFE\\xFF\\xFA\", 8);",
 							CB_PREFIX_BASE, fchck->id);
 						output_indent_level -= indent_adjust_level;
 						output_line ("} else {");
@@ -12523,8 +12523,8 @@ output_internal_function (struct cb_program *prog, cb_tree parameter_list)
 	if ((call_cache || func_call_cache)
 	 && (cb_flag_memory_check & CB_MEMCHK_POINTER)) {
 		output_line ("/* Initialize call-pointer memory fence */");
-		output_line ("memcpy (call_fence_pre, \"\\xFF\\xFE\\xFD\\xFC\", 5);");
-		output_line ("memcpy (call_fence_post, \"\\xFA\\xFB\\xFC\\xFD\", 5);");
+		output_line ("memcpy (call_fence_pre, \"\\xFF\\xFE\\xFD\\xFC\\xFB\\xFA\\xFF\", 8);");
+		output_line ("memcpy (call_fence_post, \"\\xFA\\xFB\\xFC\\xFD\\xFE\\xFF\\xFA\", 8);");
 		output_newline ();
 	}
 

cobc/codeoptim.c

@@ -196,8 +196,8 @@ cob_gen_optim (const enum cb_optim val)
 		output_storage ("cob_check_fence_inline (const char *fence_pre, const char *fence_post,");
 		output_storage ("	const enum cob_statement stmt, const char *name)");
 		output_storage ("{");
-		output_storage ("	if (memcmp (fence_pre, \"\\xFF\\xFE\\xFD\\xFC\", 5)");
-		output_storage ("	 || memcmp (fence_post, \"\\xFA\\xFB\\xFC\\xFD\", 5)) {");
+		output_storage ("	if (memcmp (fence_pre, \"\\xFF\\xFE\\xFD\\xFC\\xFB\\xFA\\xFF\", 8)");
+		output_storage ("	 || memcmp (fence_post, \"\\xFA\\xFB\\xFC\\xFD\\xFE\\xFF\\xFA\", 8)) {");
 		output_storage ("		cob_check_fence (fence_pre, fence_post, stmt, name);");
 		output_storage ("	}");
 		output_storage ("}");

cobc/typeck.c

@@ -8798,7 +8798,8 @@ cb_emit_call (cb_tree prog, cb_tree par_using, cb_tree returning,
 				if ((cb_flag_memory_check & CB_MEMCHK_USING)
 				 && f->storage != CB_STORAGE_LINKAGE
 				 && f->storage != CB_STORAGE_LOCAL
-				 && !f->flag_external) {
+				 && !f->flag_external
+				 && !f->flag_item_based) {
 					f = cb_field_founder (f);
 					if (f->redefines) {
 						f = f->redefines;

doc/ChangeLog

@@ -1,8 +1,13 @@
 
+2023-07-10  Simon Sobisch <[email protected]>
+
+	* gnucobol.texi: updated "Build target" (change of -P / -E),
+	  updated "Debug switches" (changed -g and new memory-check)
+
 2023-05-24  Simon Sobisch <[email protected]>
 
 	* gnucobol.texi: document warning and optimization options
-	  related to unreachable code; add node on core dumps
+	  related to unreachable code; add note on core dumps
 
 2023-01-31  Fabrice Le Fessant <[email protected]>
 

doc/gnucobol.texi

@@ -353,6 +353,9 @@ The special input name @file{-} takes input from @file{stdin} which is
 assumed to be COBOL source, and uses a default output name of
 @file{a.out} (or @file{a.so/c/o/i}, selected as appropriate) for the build type.
 
+You may also use @file{-} as output name for the listing file or the preprocessor
+result, for example with @code{cobc -t - prog.cob} / @code{cobc -P- prog.cob}.
+
 By default, the compiler builds a dynamically loadable module.
 
 The following options specify the target type produced by the compiler:
@@ -361,12 +364,17 @@ The following options specify the target type produced by the compiler:
 @item -E
 Preprocess only: compiler directives are executed, comment lines are
 removed and @code{COPY} statements are expanded.
-The output is saved in file @file{*.i}.
+The output is sent to stdout, allowing you to directly use it as input for
+another process. You can manually set an output file using @option{-o}.
 
 @item -C
 Translation only.  COBOL source files are translated into C files.
 The output is saved in file @file{*.c}.
 
+@item --save-temps
+Normal compilation with additional storing the preprocessed files as @file{*.i}
+and the translated C files as file @file{*.c}.
+
 @item -S
 Compile only.  Translated C files are compiled by the C compiler
 to assembler code. The output is saved in file @file{*.s}.
@@ -878,13 +886,17 @@ Produce C debugging information in the output.
 @item --debug, -d
 Enable all run-time error checks.
 
+@item -fmemory-check=scope
+Enable checking of internal storage during CALL (implied by @option{--debug}.
+
 @item -fec=exception-name, -fno=ec=exception-name
 Enable/disable specified exception checks,
-@pxref{Appendix F, Exception Names, Exception Names}.
+@pxref{Appendix F, Exception Names, Exception Names};
+@option{--debug} implies @option{-fec=ALL}.
 
 @item -fsource-location
-Generate source location code (implied by @option{--debug}, @option{-g} and
-@option{-fec}); @option{--debug} implies @option{-fec=ALL}.
+Generate source location code (implied by @option{--debug}, @option{-fdump} and
+@option{-fec}).
 
 @item -fstack-check
 Enable @code{PERFORM} stack checking (implied by @option{--debug} or @option{-g}).
@@ -1692,7 +1704,7 @@ In addition, setting the option @code{binary-size} to @code{2-4-8} or
 
 The compiler option @option{--debug} can be used, especially during the
 development of your programs.  It enables all run-time error checking, such as
-subscript boundary checks and numeric data checks, and displays
+subscript boundary checks and numeric data checks, and leads to display of
 run-time errors with source locations.
 Exceptions may also be enabled/disabled separately.
 @xref{Debug switches, Debug switches,,,}.

libcob/common.c

@@ -4150,8 +4150,8 @@ void
 cob_check_fence (const char *fence_pre, const char *fence_post,
 		const enum cob_statement stmt, const char *name)
 {
-	if (memcmp (fence_pre, "\xFF\xFE\xFD\xFC", 5)
-	 || memcmp (fence_post, "\xFA\xFB\xFC\xFD", 5)) {
+	if (memcmp (fence_pre, "\xFF\xFE\xFD\xFC\xFB\xFA\xFF", 8)
+	 || memcmp (fence_post, "\xFA\xFB\xFC\xFD\xFE\xFF\xFA", 8)) {
 		/* LCOV_EXCL_START */
 		if (name) {
 			/* note: reserved, currently not generated in libcob */

tests/testsuite.src/run_misc.at

@@ -14113,14 +14113,26 @@ AT_DATA([caller.cob], [
        DATA DIVISION.
        WORKING-STORAGE SECTION.
 
-       01 var                   PIC  x.
+       01 var                   PIC  X.
+
+       01 varg                  PIC  X GLOBAL.
+       01 vare                  PIC  X EXTERNAL.
+       01 varb                  PIC  X BASED.
+       LINKAGE SECTION.
+       01 varl                  PIC  X.
 
        PROCEDURE DIVISION.
       *
            CALL "callee" USING var
       *    without the check this second call would SIGSEGV
            CALL "callee" USING var
 
+      *    the following are mostly in to co-test the codegen
+           CALL "callee" USING varg
+           CALL "callee" USING vare
+           CALL "callee" USING varb
+           CALL "callee" USING varl
+
            GOBACK.
 ])
 
@@ -14147,22 +14159,22 @@ AT_DATA([callee.cob], [
 AT_CHECK([$COMPILE -fno-ec=program-arg-mismatch -fmemory-check=pointer caller.cob], [0], [], [])
 AT_CHECK([$COMPILE_MODULE -fno-ec=program-arg-mismatch callee.cob], [0], [], [])
 AT_CHECK([$COBCRUN_DIRECT ./caller], [1], [],
-[libcob: caller.cob:12: error: memory violation detected after CALL
+[libcob: caller.cob:18: error: memory violation detected after CALL
 ])
 
 AT_CHECK([$COMPILE -fno-ec=program-arg-mismatch -fmemory-check=using caller.cob], [0], [], [])
 AT_CHECK([$COBCRUN_DIRECT ./caller], [1], [],
-[libcob: caller.cob:12: error: memory violation detected for 'var' after CALL
+[libcob: caller.cob:18: error: memory violation detected for 'var' after CALL
 ])
 
 AT_CHECK([$COMPILE -fno-ec=program-arg-mismatch -fmemory-check caller.cob], [0], [], [])
 AT_CHECK([$COBCRUN_DIRECT ./caller], [1], [],
-[libcob: caller.cob:12: error: memory violation detected for 'var' after CALL
+[libcob: caller.cob:18: error: memory violation detected for 'var' after CALL
 ])
 
 AT_CHECK([$COMPILE -fno-ec=program-arg-mismatch -fmemory-check=all caller.cob], [0], [], [])
 AT_CHECK([$COBCRUN_DIRECT ./caller], [1], [],
-[libcob: caller.cob:12: error: memory violation detected for 'var' after CALL
+[libcob: caller.cob:18: error: memory violation detected for 'var' after CALL
 ])
 
 AT_CLEANUP
@@ -14184,21 +14196,22 @@ AT_DATA([prog.cob], [
        DATA DIVISION.
        WORKING-STORAGE SECTION.
 
+       77 PNT USAGE POINTER EXTERNAL.
+
        01 REC.
-          03  VAR                   PIC  X(16).
-          03  VAR2                  PIC  X(16).
-       77 PNT USAGE POINTER.
+          03  VAR                   PIC  X.
+          03  VAR2                  PIC  X.
 
        LINKAGE SECTION.
        01 LREC.
-          03  LVAR                  PIC  X(32).
-          03  LVAR2                 PIC  X(32).
+          03  LVAR                  PIC  X(64).
+          03  LVAR2                 PIC  X(64).
 
        PROCEDURE DIVISION.
       *    using a (not working) call prevents the C compiler
       *    to know that we (do not) change the pointer variable
       *    and therefore disallows it to check
-      *    "that points to VAR2, you only have 32 bytes" (done with gcc -O)
+      *    "that points to VAR2, you only have 2 bytes" (done with gcc -O)
            SET PNT TO ADDRESS OF VAR2.
            CALL "notthere" USING PNT ON EXCEPTION CONTINUE.
            SET ADDRESS OF LREC TO PNT.
@@ -14210,7 +14223,7 @@ AT_DATA([prog.cob], [
 
 AT_CHECK([$COMPILE prog.cob], [0], [], [])
 AT_CHECK([$COBCRUN_DIRECT ./prog], [1], [],
-[libcob: prog.cob:27: error: memory violation detected after INIT CALL
+[libcob: prog.cob:28: error: memory violation detected after INIT CALL
 ])
 
 AT_CLEANUP