Implement warning diagnostic flags for RGBLINK (#1754)

contrib/bash_compl/_rgblink.bash

@@ -21,6 +21,7 @@ _rgblink_completions() {
 		[O]="overlay:glob-*.gb *.gbc *.sgb"
 		[o]="output:glob-*.gb *.gbc *.sgb"
 		[p]="pad:unk"
+		[W]="warning:warning"
 	)
 	# Parse command-line up to current word
 	local opt_ena=true
@@ -136,6 +137,18 @@ _rgblink_completions() {
 	case "$state" in
 		unk) # Return with no replies: no idea what to complete!
 			;;
+		warning)
+			mapfile -t COMPREPLY < <(compgen -W "
+				assert
+				div
+				obsolete
+				shift
+				shift-amount
+				truncation
+				all
+				everything
+				error" -P "${cur_word:0:$optlen}" -- "${cur_word:$optlen}")
+			;;
 		normal) # Acts like a glob...
 			state="glob-*.o *.obj"
 			;&

contrib/zsh_compl/_rgbasm

@@ -23,7 +23,7 @@ _rgbasm_warnings() {
 		'obsolete:Warn when using deprecated features'
 		'purge:Warn when purging exported symbols or labels'
 		'shift:Warn when shifting negative values'
-		'shift-amount:Warn when a shift'\''s operand it negative or \> 32'
+		'shift-amount:Warn when a shift'\''s operand is negative or \> 32'
 		'truncation:Warn when implicit truncation loses bits'
 		'unmapped-char:Warn on unmapped character'
 		'unmatched-directive:Warn on unmatched directive pair'

contrib/zsh_compl/_rgblink

@@ -1,5 +1,22 @@
 #compdef rgblink
 
+_rgblink_warnings() {
+	local warnings=(
+		'error:Turn all warnings into errors'
+
+		'all:Enable most warning messages'
+		'everything:Enable literally everything'
+
+		'assert:Warn when WARN-type asserts fail'
+		'div:Warn when dividing the smallest int by -1'
+		'obsolete:Warn when using deprecated features'
+		'shift:Warn when shifting negative values'
+		'shift-amount:Warn when a shift'\''s operand is negative or \> 32'
+		'truncation:Warn when implicit truncation loses bits'
+	)
+	_describe warning warnings
+}
+
 local args=(
 	# Arguments are listed here in the same order as in the manual, except for the version and help
 	'(- : * options)'{-V,--version}'[Print version number and exit]'
@@ -19,6 +36,7 @@ local args=(
 	'(-o --output)'{-o,--output}"+[Write ROM image to this file]:rom file:_files -g '*.{gb,sgb,gbc}'"
 	'(-p --pad-value)'{-p,--pad-value}'+[Set padding byte]:padding byte:'
 	'(-S --scramble)'{-s,--scramble}'+[Activate scrambling]:scramble spec'
+	'(-W --warning)'{-W,--warning}'+[Toggle warning flags]:warning flag:_rgblink_warnings'
 
 	'*'":object files:_files -g '*.o'"
 )

include/link/warning.hpp

@@ -5,12 +5,37 @@
 
 #include <stdint.h>
 
+#include "diagnostics.hpp"
+
 #define warningAt(where, ...) warning(where.src, where.lineNo, __VA_ARGS__)
 #define errorAt(where, ...)   error(where.src, where.lineNo, __VA_ARGS__)
 #define fatalAt(where, ...)   fatal(where.src, where.lineNo, __VA_ARGS__)
 
+enum WarningLevel {
+	LEVEL_DEFAULT,    // Warnings that are enabled by default
+	LEVEL_ALL,        // Warnings that probably indicate an error
+	LEVEL_EVERYTHING, // Literally every warning
+};
+
+enum WarningID {
+	WARNING_ASSERT,       // Assertions
+	WARNING_DIV,          // Undefined division behavior
+	WARNING_OBSOLETE,     // Obsolete/deprecated things
+	WARNING_SHIFT,        // Undefined `SHIFT` behavior
+	WARNING_SHIFT_AMOUNT, // Strange `SHIFT` amount
+	WARNING_TRUNCATION,   // Implicit truncation loses some bits
+
+	NB_PLAIN_WARNINGS,
+
+	NB_WARNINGS = NB_PLAIN_WARNINGS,
+};
+
+extern Diagnostics<WarningLevel, WarningID> warnings;
+
 struct FileStackNode;
 
+[[gnu::format(printf, 4, 5)]]
+void warning(FileStackNode const *src, uint32_t lineNo, WarningID id, char const *fmt, ...);
 [[gnu::format(printf, 3, 4)]]
 void warning(FileStackNode const *src, uint32_t lineNo, char const *fmt, ...);
 [[gnu::format(printf, 1, 2)]]

man/rgbasm.1

@@ -350,11 +350,7 @@ Block comments cannot be nested, so the first
 .Ql */
 will end the whole comment.
 .It Fl Wno-obsolete
-Warn when obsolete constructs such as the
+Warn when obsolete features are encountered, which have been deprecated and may later be removed.
-.Ic _PI
-constant or
-.Ic PRINTT
-directive are encountered.
 .It Fl Wnumeric-string=
 Warn when a multi-character string is treated as a number.
 .Fl Wnumeric-string=0

man/rgblink.1

@@ -16,6 +16,7 @@
 .Op Fl o Ar out_file
 .Op Fl p Ar pad_value
 .Op Fl S Ar spec
+.Op Fl W Ar warning
 .Ar
 .Sh DESCRIPTION
 The
@@ -114,6 +115,15 @@ Useful for ROMs that fit in 32 KiB.
 Print the version of the program and exit.
 .It Fl v , Fl \-verbose
 Verbose: enable printing more information to standard error.
+.It Fl W Ar warning , Fl \-warning Ar warning
+Set warning flag
+.Ar warning .
+A warning message will be printed if
+.Ar warning
+is an unknown warning flag.
+See the
+.Sx DIAGNOSTICS
+section for a list of warnings.
 .It Fl w , Fl \-wramx
 Expand the WRAM0 section size from 4 KiB to the full 8 KiB assigned to WRAM.
 WRAMX sections that are fixed to a bank other than 1 become errors, other WRAMX sections are treated as WRAM0.
@@ -176,6 +186,84 @@ as
 .Ic WRAMX
 sections will be treated as
 .Ic WRAM0 .
+.Sh DIAGNOSTICS
+Warnings are diagnostic messages that indicate possibly erroneous behavior that does not necessarily compromise the linking process.
+The following options alter the way warnings are processed.
+.Bl -tag -width Ds
+.It Fl Werror
+Make all warnings into errors.
+This can be negated as
+.Fl Wno-error
+to prevent turning all warnings into errors.
+.It Fl Werror=
+Make the specified warning or meta warning into an error.
+A warning's name is appended
+.Pq example: Fl Werror=assert ,
+and this warning is implicitly enabled and turned into an error.
+This can be negated as
+.Fl Wno-error=
+to prevent turning a specified warning into an error, even if
+.Fl Werror
+is in effect.
+.El
+.Pp
+The following warnings are
+.Dq meta
+warnings, that enable a collection of other warnings.
+If a specific warning is toggled via a meta flag and a specific one, the more specific one takes priority.
+The position on the command-line acts as a tie breaker, the last one taking effect.
+.Bl -tag -width Ds
+.It Fl Wall
+This enables warnings that are likely to indicate an error or undesired behavior, and that can easily be fixed.
+.It Fl Weverything
+Enables literally every warning.
+.El
+.Pp
+The following warnings are actual warning flags; with each description, the corresponding warning flag is included.
+Note that each of these flag also has a negation (for example,
+.Fl Wobsolete
+enables the warning that
+.Fl Wno-obsolete
+disables; and
+.Fl Wall
+enables every warning that
+.Fl Wno-all
+disables).
+Only the non-default flag is listed here.
+Ignoring the
+.Dq no-
+prefix, entries are listed alphabetically.
+.Bl -tag -width Ds
+.It Fl Wno-assert
+Warn when
+.Ic WARN Ns No -type
+assertions fail. (See
+.Dq Aborting the assembly process
+in
+.Xr rgbasm 5
+for
+.Ic ASSERT ) .
+.It Fl Wdiv
+Warn when dividing the smallest negative integer (-2**31) by -1, which yields itself due to integer overflow.
+This warning is enabled by
+.Fl Wall .
+.It Fl Wno-obsolete
+Warn when obsolete features are encountered, which have been deprecated and may later be removed.
+.It Fl Wshift
+Warn when shifting right a negative value.
+Use a division by 2**N instead.
+This warning is enabled by
+.Fl Wall .
+.It Fl Wshift-amount
+Warn when a shift's operand is negative or greater than 32.
+This warning is enabled by
+.Fl Wall .
+.It Fl Wno-truncation
+Warn when an implicit truncation (for example,
+.Ic db
+to an 8-bit value) loses some bits.
+This occurs when an N-bit value is 2**N or greater, or less than -2**N.
+.El
 .Sh EXAMPLES
 All you need for a basic ROM is an object file, which can be made into a ROM image like so:
 .Pp

src/link/main.cpp

@@ -69,7 +69,7 @@ std::string const &FileStackNode::dump(uint32_t curLineNo) const {
 }
 
 // Short options
-static char const *optstring = "dhl:m:Mn:O:o:p:S:tVvwx";
+static char const *optstring = "dhl:m:Mn:O:o:p:S:tVvW:wx";
 
 // Equivalent long options
 // Please keep in the same order as short opts.
@@ -92,6 +92,7 @@ static option const longopts[] = {
     {"tiny",          no_argument,       nullptr, 't'},
     {"version",       no_argument,       nullptr, 'V'},
     {"verbose",       no_argument,       nullptr, 'v'},
+    {"warning",       required_argument, nullptr, 'W'},
     {"wramx",         no_argument,       nullptr, 'w'},
     {"nopad",         no_argument,       nullptr, 'x'},
     {nullptr,         no_argument,       nullptr, 0  }
@@ -347,6 +348,9 @@ int main(int argc, char *argv[]) {
 			beVerbose = true;
 			break;
 			// LCOV_EXCL_STOP
+		case 'W':
+			warnings.processWarningFlag(musl_optarg);
+			break;
 		case 'w':
 			isWRAM0Mode = true;
 			break;

src/link/patch.cpp

@@ -33,6 +33,25 @@ static void pushRPN(int32_t value, bool comesFromError) {
 // has popped any values with the error flag set.
 static bool isError = false;
 
+#define diagnosticAt(patch, id, ...) \
+	do { \
+		bool errorDiag = warnings.getWarningBehavior(id) == WarningBehavior::ERROR; \
+		if (!isError || !errorDiag) { \
+			warningAt(patch, id, __VA_ARGS__); \
+		} \
+		if (errorDiag) { \
+			isError = true; \
+		} \
+	} while (0)
+
+#define firstErrorAt(...) \
+	do { \
+		if (!isError) { \
+			errorAt(__VA_ARGS__); \
+			isError = true; \
+		} \
+	} while (0)
+
 static int32_t popRPN(Patch const &patch) {
 	if (rpnStack.empty()) {
 		fatalAt(patch, "Internal error, RPN stack empty");
@@ -98,23 +117,26 @@ static int32_t computeRPNExpr(Patch const &patch, std::vector<Symbol> const &fil
 		case RPN_DIV:
 			value = popRPN(patch);
 			if (value == 0) {
-				if (!isError) {
+				firstErrorAt(patch, "Division by 0");
-					errorAt(patch, "Division by 0");
-					isError = true;
-				}
 				popRPN(patch);
-				value = INT32_MAX;
+				value = 0;
+			} else if (int32_t lval = popRPN(patch); lval == INT32_MIN && value == -1) {
+				diagnosticAt(
+				    patch,
+				    WARNING_DIV,
+				    "Division of %" PRId32 " by -1 yields %" PRId32,
+				    INT32_MIN,
+				    INT32_MIN
+				);
+				value = INT32_MIN;
 			} else {
-				value = op_divide(popRPN(patch), value);
+				value = op_divide(lval, value);
 			}
 			break;
 		case RPN_MOD:
 			value = popRPN(patch);
 			if (value == 0) {
-				if (!isError) {
+				firstErrorAt(patch, "Modulo by 0");
-					errorAt(patch, "Modulo by 0");
-					isError = true;
-				}
 				popRPN(patch);
 				value = 0;
 			} else {
@@ -127,10 +149,7 @@ static int32_t computeRPNExpr(Patch const &patch, std::vector<Symbol> const &fil
 		case RPN_EXP:
 			value = popRPN(patch);
 			if (value < 0) {
-				if (!isError) {
+				firstErrorAt(patch, "Exponent by negative value %" PRId32, value);
-					errorAt(patch, "Exponent by negative value %" PRId32, value);
-					isError = true;
-				}
 				popRPN(patch);
 				value = 0;
 			} else {
@@ -204,14 +223,49 @@ static int32_t computeRPNExpr(Patch const &patch, std::vector<Symbol> const &fil
 
 		case RPN_SHL:
 			value = popRPN(patch);
+			if (value < 0) {
+				diagnosticAt(
+				    patch, WARNING_SHIFT_AMOUNT, "Shifting left by negative amount %" PRId32, value
+				);
+			}
+			if (value >= 32) {
+				diagnosticAt(
+				    patch, WARNING_SHIFT_AMOUNT, "Shifting left by large amount %" PRId32, value
+				);
+			}
 			value = op_shift_left(popRPN(patch), value);
 			break;
-		case RPN_SHR:
+		case RPN_SHR: {
 			value = popRPN(patch);
-			value = op_shift_right(popRPN(patch), value);
+			int32_t lval = popRPN(patch);
+			if (lval < 0) {
+				diagnosticAt(patch, WARNING_SHIFT, "Shifting right negative value %" PRId32, lval);
+			}
+			if (value < 0) {
+				diagnosticAt(
+				    patch, WARNING_SHIFT_AMOUNT, "Shifting right by negative amount %" PRId32, value
+				);
+			}
+			if (value >= 32) {
+				diagnosticAt(
+				    patch, WARNING_SHIFT_AMOUNT, "Shifting right by large amount %" PRId32, value
+				);
+			}
+			value = op_shift_right(lval, value);
 			break;
+		}
 		case RPN_USHR:
 			value = popRPN(patch);
+			if (value < 0) {
+				diagnosticAt(
+				    patch, WARNING_SHIFT_AMOUNT, "Shifting right by negative amount %" PRId32, value
+				);
+			}
+			if (value >= 32) {
+				diagnosticAt(
+				    patch, WARNING_SHIFT_AMOUNT, "Shifting right by large amount %" PRId32, value
+				);
+			}
 			value = op_shift_right_unsigned(popRPN(patch), value);
 			break;
 
@@ -324,14 +378,13 @@ static int32_t computeRPNExpr(Patch const &patch, std::vector<Symbol> const &fil
 		case RPN_HRAM:
 			value = popRPN(patch);
 			if (value < 0 || (value > 0xFF && value < 0xFF00) || value > 0xFFFF) {
-				if (!isError) {
+				firstErrorAt(patch, "Address $%" PRIx32 " for LDH is not in HRAM range", value);
-					errorAt(patch, "Address $%" PRIx32 " for LDH is not in HRAM range", value);
-					isError = true;
-				}
 				value = 0;
 			} else if (value >= 0 && value <= 0xFF) {
 				warningAt(
-				    patch, "LDH is deprecated with values from $00 to $FF; use $FF00 to $FFFF"
+				    patch,
+				    WARNING_OBSOLETE,
+				    "LDH is deprecated with values from $00 to $FF; use $FF00 to $FFFF"
 				);
 			}
 			value &= 0xFF;
@@ -341,10 +394,7 @@ static int32_t computeRPNExpr(Patch const &patch, std::vector<Symbol> const &fil
 			value = popRPN(patch);
 			// Acceptable values are 0x00, 0x08, 0x10, ..., 0x38
 			if (value & ~0x38) {
-				if (!isError) {
+				firstErrorAt(patch, "Value $%" PRIx32 " is not a RST vector", value);
-					errorAt(patch, "Value $%" PRIx32 " is not a RST vector", value);
-					isError = true;
-				}
 				value = 0;
 			}
 			value |= 0xC7;
@@ -355,10 +405,7 @@ static int32_t computeRPNExpr(Patch const &patch, std::vector<Symbol> const &fil
 			int32_t mask = getRPNByte(expression, size, patch);
 			// Acceptable values are 0 to 7
 			if (value & ~0x07) {
-				if (!isError) {
+				firstErrorAt(patch, "Value $%" PRIx32 " is not a bit index", value);
-					errorAt(patch, "Value $%" PRIx32 " is not a bit index", value);
-					isError = true;
-				}
 				value = 0;
 			}
 			value = mask | (value << 3);
@@ -437,6 +484,7 @@ void patch_CheckAssertions() {
 			case ASSERT_WARN:
 				warningAt(
 				    assert.patch,
+				    WARNING_ASSERT,
 				    "%s",
 				    !assert.message.empty() ? assert.message.c_str() : "assert failure"
 				);
@@ -486,8 +534,8 @@ static void applyFilePatches(Section &section, Section &dataSection) {
 			uint16_t address = patch.pcSection->org + patch.pcOffset + 2;
 			int16_t jumpOffset = value - address;
 
-			if (!isError && (jumpOffset < -128 || jumpOffset > 127)) {
+			if (jumpOffset < -128 || jumpOffset > 127) {
-				errorAt(
+				firstErrorAt(
 				    patch,
 				    "JR target must be between -128 and 127 bytes away, not %" PRId16
 				    "; use JP instead",
@@ -497,12 +545,13 @@ static void applyFilePatches(Section &section, Section &dataSection) {
 			dataSection.data[offset] = jumpOffset & 0xFF;
 		} else {
 			// Patch a certain number of bytes
-			if (!isError && (value < type.min || value > type.max)) {
+			if (value < type.min || value > type.max) {
-				errorAt(
+				diagnosticAt(
 				    patch,
-				    "Value %" PRId32 "%s is not %u-bit",
+				    WARNING_TRUNCATION,
+				    "Value $%" PRIx32 "%s is not %u-bit",
 				    value,
-				    value < 0 ? " (maybe negative?)" : "",
+				    value < 0 ? " (may be negative?)" : "",
 				    type.size * 8U
 				);
 			}

src/link/warning.cpp

@@ -9,14 +9,43 @@
 
 static uint32_t nbErrors = 0;
 
+// clang-format off: nested initializers
+Diagnostics<WarningLevel, WarningID> warnings = {
+    .metaWarnings = {
+        {"all",          LEVEL_ALL       },
+        {"everything",   LEVEL_EVERYTHING},
+    },
+    .warningFlags = {
+        {"assert",       LEVEL_DEFAULT   },
+        {"div",          LEVEL_ALL       },
+        {"obsolete",     LEVEL_DEFAULT   },
+        {"shift",        LEVEL_ALL       },
+        {"shift-amount", LEVEL_ALL       },
+        {"truncation",   LEVEL_DEFAULT   },
+    },
+    .paramWarnings = {},
+    .state = DiagnosticsState<WarningID>(),
+};
+// clang-format on
+
 static void printDiag(
-    FileStackNode const *src, uint32_t lineNo, char const *fmt, va_list args, char const *type
+    FileStackNode const *src,
+    uint32_t lineNo,
+    char const *fmt,
+    va_list args,
+    char const *type,
+    char const *flagfmt,
+    char const *flag
 ) {
 	fprintf(stderr, "%s: ", type);
 	if (src) {
 		src->dump(lineNo);
 		fputs(": ", stderr);
 	}
+	if (flagfmt) {
+		fprintf(stderr, flagfmt, flag);
+		fputs("\n    ", stderr);
+	}
 	vfprintf(stderr, fmt, args);
 	putc('\n', stderr);
 }
@@ -42,21 +71,21 @@ static void abortLinking(char const *verb) {
 void warning(FileStackNode const *src, uint32_t lineNo, char const *fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
-	printDiag(src, lineNo, fmt, args, "warning");
+	printDiag(src, lineNo, fmt, args, "warning", nullptr, 0);
 	va_end(args);
 }
 
 void warning(char const *fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
-	printDiag(nullptr, 0, fmt, args, "warning");
+	printDiag(nullptr, 0, fmt, args, "warning", nullptr, 0);
 	va_end(args);
 }
 
 void error(FileStackNode const *src, uint32_t lineNo, char const *fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
-	printDiag(src, lineNo, fmt, args, "error");
+	printDiag(src, lineNo, fmt, args, "error", nullptr, 0);
 	va_end(args);
 
 	incrementErrors();
@@ -65,7 +94,7 @@ void error(FileStackNode const *src, uint32_t lineNo, char const *fmt, ...) {
 void error(char const *fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
-	printDiag(nullptr, 0, fmt, args, "error");
+	printDiag(nullptr, 0, fmt, args, "error", nullptr, 0);
 	va_end(args);
 
 	incrementErrors();
@@ -96,7 +125,7 @@ void argErr(char flag, char const *fmt, ...) {
 void fatal(FileStackNode const *src, uint32_t lineNo, char const *fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
-	printDiag(src, lineNo, fmt, args, "FATAL");
+	printDiag(src, lineNo, fmt, args, "FATAL", nullptr, 0);
 	va_end(args);
 
 	incrementErrors();
@@ -107,7 +136,7 @@ void fatal(FileStackNode const *src, uint32_t lineNo, char const *fmt, ...) {
 void fatal(char const *fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
-	printDiag(nullptr, 0, fmt, args, "FATAL");
+	printDiag(nullptr, 0, fmt, args, "FATAL", nullptr, 0);
 	va_end(args);
 
 	incrementErrors();
@@ -119,3 +148,27 @@ void requireZeroErrors() {
 		abortLinking("failed");
 	}
 }
+
+void warning(FileStackNode const *src, uint32_t lineNo, WarningID id, char const *fmt, ...) {
+	char const *flag = warnings.warningFlags[id].name;
+	va_list args;
+
+	va_start(args, fmt);
+
+	switch (warnings.getWarningBehavior(id)) {
+	case WarningBehavior::DISABLED:
+		break;
+
+	case WarningBehavior::ENABLED:
+		printDiag(src, lineNo, fmt, args, "warning", "[-W%s]", flag);
+		break;
+
+	case WarningBehavior::ERROR:
+		printDiag(src, lineNo, fmt, args, "error", "[-Werror=%s]", flag);
+
+		incrementErrors();
+		break;
+	}
+
+	va_end(args);
+}

test/link/assert.out

@@ -1,4 +1,5 @@
-warning: assert.asm(5): Worry about me, but not too much.
+warning: assert.asm(5): [-Wassert]
+    Worry about me, but not too much.
 error: assert.asm(6): Okay, this is getting serious!
 FATAL: assert.asm(7): It all ends now.
 Linking aborted with 2 errors

test/link/invalid-patches.out

@@ -1,5 +1,6 @@
 error: invalid-patches.asm(10): JR target must be between -128 and 127 bytes away, not 190; use JP instead
-warning: invalid-patches.asm(9): LDH is deprecated with values from $00 to $FF; use $FF00 to $FFFF
+warning: invalid-patches.asm(9): [-Wobsolete]
+    LDH is deprecated with values from $00 to $FF; use $FF00 to $FFFF
 error: invalid-patches.asm(8): Requested SIZEOF() of section "NonexistentSection", which was not found
 error: invalid-patches.asm(7): Requested STARTOF() of section "NonexistentSection", which was not found
 error: invalid-patches.asm(6): Requested BANK() of section "NonexistentSection", which was not found

test/link/patch-diagnostics.asm

@@ -0,0 +1,10 @@
+def fzero equs "startof(\"test\")"
+section "test", rom0
+ld a, $8000_0000 / (fzero - 1)
+ld a, 1 << (fzero - 1)
+ld a, 1 << (fzero + 32)
+ld a, (fzero - 1) >> 1
+ld a, 1 >> (fzero - 1)
+ld a, 1 >> (fzero + 32)
+ld a, 1 >>> (fzero - 1)
+ld a, 1 >>> (fzero + 32)

test/link/patch-diagnostics.out

@@ -0,0 +1,18 @@
+warning: patch-diagnostics.asm(10): [-Wshift-amount]
+    Shifting right by large amount 32
+warning: patch-diagnostics.asm(9): [-Wshift-amount]
+    Shifting right by negative amount -1
+warning: patch-diagnostics.asm(8): [-Wshift-amount]
+    Shifting right by large amount 32
+warning: patch-diagnostics.asm(7): [-Wshift-amount]
+    Shifting right by negative amount -1
+warning: patch-diagnostics.asm(6): [-Wshift]
+    Shifting right negative value -1
+warning: patch-diagnostics.asm(5): [-Wshift-amount]
+    Shifting left by large amount 32
+warning: patch-diagnostics.asm(4): [-Wshift-amount]
+    Shifting left by negative amount -1
+warning: patch-diagnostics.asm(3): [-Wdiv]
+    Division of -2147483648 by -1 yields -2147483648
+warning: patch-diagnostics.asm(3): [-Wtruncation]
+    Value $80000000 (may be negative?) is not 8-bit

test/link/patch-overflow.out

@@ -1,3 +1,4 @@
-error: patch-overflow.asm(3): Value 81920 is not 16-bit
+warning: patch-overflow.asm(3): [-Wtruncation]
-error: patch-overflow.asm(2): Value 16384 is not 8-bit
+    Value $14000 is not 16-bit
-Linking failed with 2 errors
+warning: patch-overflow.asm(2): [-Wtruncation]
+    Value $4000 is not 8-bit

test/link/test.sh

@@ -71,7 +71,7 @@ tryCmpRomSize () {
 }
 
 rgblinkQuiet () {
-	out="$(env $RGBLINK "$@")" || return $?
+	out="$(env $RGBLINK -Weverything "$@")" || return $?
 	if [[ -n "$out" ]]; then
 		echo "$bold${red}Linking shouldn't produce anything on stdout!${rescolors}${resbold}"
 		false