Implement -X/--max-errors for RGBASM (#1262)

Co-authored-by: Eldred Habert <me@eldred.fr>

contrib/bash_compl/_rgbasm.bash

@@ -43,6 +43,7 @@ _rgbasm_completions() {
 		[Q]="q-precision:unk"
 		[r]="recursion-depth:unk"
 		[W]="warning:warning"
+		[X]="max-errors:unk"
 	)
 	# Parse command-line up to current word
 	local opt_ena=true

contrib/zsh_compl/_rgbasm

@@ -60,6 +60,7 @@ local args=(
 	'(-Q --q-precision)'{-Q,--q-precision}'+[Set fixed-point precision]:precision:'
 	'(-r --recursion-depth)'{-r,--recursion-depth}'+[Set maximum recursion depth]:depth:'
 	'(-W --warning)'{-W,--warning}'+[Toggle warning flags]:warning flag:_rgbasm_warnings'
+	'(-X --max-errors)'{-X,--max-errors}'+[Set maximum errors before aborting]:maximum errors:'
 
 	":assembly sources:_files -g '*.asm'"
 )

include/asm/warning.hpp

@@ -5,7 +5,7 @@
 
 #include "helpers.hpp"
 
-extern unsigned int nbErrors;
+extern unsigned int nbErrors, maxErrors;
 
 enum WarningState {
 	WARNING_DEFAULT,

man/rgbasm.1

@@ -24,6 +24,7 @@
 .Op Fl Q Ar fix_precision
 .Op Fl r Ar recursion_depth
 .Op Fl W Ar warning
+.Op Fl X Ar max_errors
 .Ar asmfile
 .Sh DESCRIPTION
 The
@@ -176,6 +177,13 @@ See the
 section for a list of warnings.
 .It Fl w
 Disable all warning output, even when turned into errors.
+.It Fl X Ar max_errors , Fl \-max-errors Ar max_errors
+If more than this number of errors (not warnings) occur, then abort the assembly process;
+.Fl X 0
+disables this behavior.
+The default is 100 if
+.Nm
+is printing errors to a terminal, and 0 otherwise.
 .El
 .Sh DIAGNOSTICS
 Warnings are diagnostic messages that indicate possibly erroneous behavior that does not necessarily compromise the assembling process.

src/asm/main.cpp

@@ -4,6 +4,7 @@
 #include <errno.h>
 #include <float.h>
 #include <inttypes.h>
+#include <limits.h>
 #include <math.h>
 #include <stdarg.h>
 #include <stdio.h>
@@ -83,7 +84,7 @@ static char *make_escape(char const *str)
 }
 
 // Short options
-static const char *optstring = "b:D:Eg:Hhi:I:LlM:o:P:p:Q:r:VvW:w";
+static const char *optstring = "b:D:Eg:Hhi:I:LlM:o:P:p:Q:r:VvW:wX:";
 
 // Variables for the long-only options
 static int depType; // Variants of `-M`
@@ -110,6 +111,7 @@ static struct option const longopts[] = {
 	{ "MG",               no_argument,       &depType, 'G' },
 	{ "MP",               no_argument,       &depType, 'P' },
 	{ "MT",               required_argument, &depType, 'T' },
+	{ "warning",          required_argument, NULL,     'W' },
 	{ "MQ",               required_argument, &depType, 'Q' },
 	{ "output",           required_argument, NULL,     'o' },
 	{ "preinclude",       required_argument, NULL,     'P' },
@@ -119,6 +121,7 @@ static struct option const longopts[] = {
 	{ "version",          no_argument,       NULL,     'V' },
 	{ "verbose",          no_argument,       NULL,     'v' },
 	{ "warning",          required_argument, NULL,     'W' },
+	{ "max-errors",       required_argument, NULL,     'X' },
 	{ NULL,               no_argument,       NULL,     0   }
 };
 
@@ -128,7 +131,7 @@ static void printUsage(void)
 "Usage: rgbasm [-EHhLlVvw] [-b chars] [-D name[=value]] [-g chars] [-I path]\n"
 "              [-M depend_file] [-MG] [-MP] [-MT target_file] [-MQ target_file]\n"
 "              [-o out_file] [-P include_file] [-p pad_value] [-Q precision]\n"
-"              [-r depth] [-W warning] <file>\n"
+"              [-r depth] [-W warning] [-X max_errors] <file>\n"
 "Useful options:\n"
 "    -E, --export-all         export all labels\n"
 "    -M, --dependfile <path>  set the output dependency file\n"
@@ -171,6 +174,10 @@ int main(int argc, char *argv[])
 	char const *dependFileName = NULL;
 	size_t targetFileNameLen = 0;
 
+	// Maximum of 100 errors only applies if rgbasm is printing errors to a terminal.
+	if (isatty(STDERR_FILENO))
+		maxErrors = 100;
+
 	for (int ch; (ch = musl_getopt_long_only(argc, argv, optstring, longopts, NULL)) != -1;) {
 		switch (ch) {
 			char *endptr;
@@ -316,6 +323,19 @@ int main(int argc, char *argv[])
 			warnings = false;
 			break;
 
+			unsigned int maxValue;
+		case 'X':
+			maxValue = strtoul(musl_optarg, &endptr, 0);
+
+			if (musl_optarg[0] == '\0' || *endptr != '\0')
+				errx("Invalid argument for option 'X'");
+
+			if (maxValue > UINT_MAX)
+				errx("Argument for option 'X' must be between 0 and %u", UINT_MAX);
+
+			maxErrors = maxValue;
+			break;
+
 		// Long-only options
 		case 0:
 			switch (depType) {
@@ -399,8 +419,7 @@ int main(int argc, char *argv[])
 	sect_CheckUnionClosed();
 
 	if (nbErrors != 0)
-		errx("Assembly aborted (%u error%s)!", nbErrors,
-			nbErrors == 1 ? "" : "s");
+		errx("Assembly aborted (%u error%s)!", nbErrors, nbErrors == 1 ? "" : "s");
 
 	// If parse aborted due to missing an include, and `-MG` was given, exit normally
 	if (failedOnMissingInclude)

src/asm/warning.cpp

@@ -16,6 +16,7 @@
 #include "itertools.hpp"
 
 unsigned int nbErrors = 0;
+unsigned int maxErrors = 0;
 
 static const enum WarningState defaultWarnings[ARRAY_SIZE(warningStates)] = {
 	AT(WARNING_ASSERT)               WARNING_ENABLED,
@@ -343,7 +344,12 @@ void error(char const *fmt, ...)
 	va_start(args, fmt);
 	printDiag(fmt, args, "error: ", ":\n    ", NULL);
 	va_end(args);
+
+	// This intentionally makes 0 act as "unlimited" (or at least "limited to sizeof(unsigned)")
 	nbErrors++;
+	if (nbErrors == maxErrors)
+		errx("The maximum of %u error%s was reached (configure with \"-X/--max-errors\"); assembly aborted!",
+		     maxErrors, maxErrors == 1 ? "" : "s");
 }
 
 [[noreturn]] void fatalerror(char const *fmt, ...)

test/asm/max-errors.asm

@@ -0,0 +1,3 @@
+section "s", rom0
+db 42
+println @ ; causes an error before println occurs

test/asm/max-errors.err

@@ -0,0 +1,3 @@
+error: max-errors.asm(3):
+    Expected constant expression: PC is not constant at assembly time
+error: The maximum of 1 error was reached (configure with "-X/--max-errors"); assembly aborted!

test/asm/max-errors.flags

@@ -0,0 +1 @@
+-Weverything -X 1