Use LCOV_EXCL comments to exclude some lines from test coverage

.gitignore

@@ -14,4 +14,5 @@ CMakeCache.txt
 CMakeFiles/
 cmake_install.cmake
 build/
+*.dSYM/
 callgrind.out.*

include/asm/symbol.hpp

@@ -82,7 +82,6 @@ Symbol *sym_RedefEqu(std::string const &symName, int32_t value);
 Symbol *sym_AddVar(std::string const &symName, int32_t value);
 int32_t sym_GetRSValue();
 void sym_SetRSValue(int32_t value);
-uint32_t sym_GetConstantValue(std::string const &symName);
 // Find a symbol by exact name, bypassing expansion checks
 Symbol *sym_FindExactSymbol(std::string const &symName);
 // Find a symbol, possibly scoped, by name

include/either.hpp

@@ -103,7 +103,7 @@ union Either {
 		} else if (other._tag == other._t2.tag_value) {
 			*this = other._t2.value;
 		} else {
-			_tag = nulltag;
+			_tag = nulltag; // LCOV_EXCL_LINE
 		}
 		return *this;
 	}

src/asm/fstack.cpp

@@ -119,9 +119,11 @@ void fstk_SetPreIncludeFile(std::string const &path) {
 		warnx("Overriding pre-included filename %s", preIncludeName.c_str());
 	}
 	preIncludeName = path;
+	// LCOV_EXCL_START
 	if (verbose) {
 		printf("Pre-included filename %s\n", preIncludeName.c_str());
 	}
+	// LCOV_EXCL_STOP
 }
 
 static void printDep(std::string const &path) {
@@ -308,9 +310,11 @@ void fstk_RunInclude(std::string const &path, bool preInclude) {
 
 	if (!fullPath) {
 		if (generatedMissingIncludes && !preInclude) {
+			// LCOV_EXCL_START
 			if (verbose) {
 				printf("Aborting (-MG) on INCLUDE file '%s' (%s)\n", path.c_str(), strerror(errno));
 			}
+			// LCOV_EXCL_STOP
 			failedOnMissingInclude = true;
 		} else {
 			error("Unable to open included file '%s': %s\n", path.c_str(), strerror(errno));
@@ -319,7 +323,7 @@ void fstk_RunInclude(std::string const &path, bool preInclude) {
 	}
 
 	if (!newFileContext(*fullPath, false)) {
-		fatalerror("Failed to set up lexer for file include\n");
+		fatalerror("Failed to set up lexer for file include\n"); // LCOV_EXCL_LINE
 	}
 }
 

src/asm/lexer.cpp

@@ -77,6 +77,7 @@ struct FileUnmapDeleter {
 
 static char *mapFile(int fd, std::string const &path, size_t size) {
 	void *mappingAddr = mmap(nullptr, size, PROT_READ, MAP_PRIVATE, fd, 0);
+	// LCOV_EXCL_START
 	if (mappingAddr == MAP_FAILED && errno == ENOTSUP) {
 		// The implementation may not support MAP_PRIVATE; try again with MAP_SHARED
 		// instead, offering, I believe, weaker guarantees about external modifications to
@@ -86,6 +87,7 @@ static char *mapFile(int fd, std::string const &path, size_t size) {
 		}
 		mappingAddr = mmap(nullptr, size, PROT_READ, MAP_SHARED, fd, 0);
 	}
+	// LCOV_EXCL_STOP
 	return mappingAddr != MAP_FAILED ? static_cast<char *>(mappingAddr) : nullptr;
 }
 
@@ -412,21 +414,27 @@ bool LexerState::setFileAsNextState(std::string const &filePath, bool updateStat
 	if (filePath == "-") {
 		path = "<stdin>";
 		content.emplace<BufferedContent>(STDIN_FILENO);
+		// LCOV_EXCL_START
 		if (verbose) {
 			printf("Opening stdin\n");
 		}
+		// LCOV_EXCL_STOP
 	} else {
 		struct stat statBuf;
 		if (stat(filePath.c_str(), &statBuf) != 0) {
+			// LCOV_EXCL_START
 			error("Failed to stat file \"%s\": %s\n", filePath.c_str(), strerror(errno));
 			return false;
+			// LCOV_EXCL_STOP
 		}
 		path = filePath;
 
 		int fd = open(path.c_str(), O_RDONLY);
 		if (fd < 0) {
+			// LCOV_EXCL_START
 			error("Failed to open file \"%s\": %s\n", path.c_str(), strerror(errno));
 			return false;
+			// LCOV_EXCL_STOP
 		}
 
 		bool isMmapped = false;
@@ -438,16 +446,19 @@ bool LexerState::setFileAsNextState(std::string const &filePath, bool updateStat
 				content.emplace<ViewedContent>(
 				    std::shared_ptr<char[]>(mappingAddr, FileUnmapDeleter(size)), size
 				);
+				// LCOV_EXCL_START
 				if (verbose) {
 					printf("File \"%s\" is mmap()ped\n", path.c_str());
 				}
+				// LCOV_EXCL_STOP
 				isMmapped = true;
 			}
 		}
 
 		if (!isMmapped) {
 			// Sometimes mmap() fails or isn't available, so have a fallback
 			content.emplace<BufferedContent>(fd);
+			// LCOV_EXCL_START
 			if (verbose) {
 				if (statBuf.st_size == 0) {
 					printf("File \"%s\" is empty\n", path.c_str());
@@ -457,6 +468,7 @@ bool LexerState::setFileAsNextState(std::string const &filePath, bool updateStat
 					);
 				}
 			}
+			// LCOV_EXCL_STOP
 		}
 	}
 
@@ -552,7 +564,9 @@ size_t BufferedContent::readMore(size_t startIndex, size_t nbChars) {
 	ssize_t nbReadChars = read(fd, &buf[startIndex], nbChars);
 
 	if (nbReadChars == -1) {
+		// LCOV_EXCL_START
 		fatalerror("Error while reading \"%s\": %s\n", lexerState->path.c_str(), strerror(errno));
+		// LCOV_EXCL_STOP
 	}
 
 	size += nbReadChars;
@@ -761,7 +775,9 @@ int LexerState::peekCharAhead() {
 		// and `.peekCharAhead()` will continue with its parent
 		assume(exp.offset <= exp.size());
 		if (exp.offset + distance < exp.size()) {
-			return static_cast<uint8_t>((*exp.contents)[exp.offset + distance]);
+			// Macro args can't be recursive, since `peek()` marks them as scanned, so
+			// this is a failsafe that (as far as I can tell) won't ever actually run.
+			return static_cast<uint8_t>((*exp.contents)[exp.offset + distance]); // LCOV_EXCL_LINE
 		}
 		distance -= exp.size() - exp.offset;
 	}
@@ -1323,8 +1339,11 @@ static void appendEscapedString(std::string &str, std::string const &escape) {
 			str += "\\n";
 			break;
 		case '\r':
+			// A literal CR in a string may get treated as a LF, so '\r' is not tested.
+			// LCOV_EXCL_START
 			str += "\\r";
 			break;
+			// LCOV_EXCL_STOP
 		case '\t':
 			str += "\\t";
 			break;
@@ -2163,7 +2182,8 @@ static Token skipIfBlock(bool toEndc) {
 
 				case T_(POP_ELIF):
 					if (lexer_ReachedELSEBlock()) {
-						fatalerror("Found ELIF after an ELSE block\n");
+						// This should be redundant, as the parser handles this error first.
+						fatalerror("Found ELIF after an ELSE block\n"); // LCOV_EXCL_LINE
 					}
 					if (!toEndc && lexer_GetIFDepth() == startingDepth) {
 						return token;
@@ -2255,9 +2275,8 @@ static Token yylex_SKIP_TO_ENDR() {
 
 				case T_(POP_ENDR):
 					depth--;
-					if (!depth) {
-						return Token(T_(YYEOF)); // yywrap() will finish the REPT/FOR loop
-					}
+					// `lexer_CaptureRept` has already guaranteed that the `ENDR`s are balanced
+					assume(depth > 0);
 					break;
 
 				case T_(POP_IF):

src/asm/main.cpp

@@ -87,6 +87,7 @@ static option const longopts[] = {
     {nullptr,           no_argument,       nullptr,  0  }
 };
 
+// LCOV_EXCL_START
 static void printUsage() {
 	fputs(
 	    "Usage: rgbasm [-EhVvw] [-b chars] [-D name[=value]] [-g chars] [-I path]\n"
@@ -107,6 +108,7 @@ static void printUsage() {
 	    stderr
 	);
 }
+// LCOV_EXCL_STOP
 
 int main(int argc, char *argv[]) {
 	time_t now = time(nullptr);
@@ -176,8 +178,10 @@ int main(int argc, char *argv[]) {
 			break;
 
 		case 'h':
+			// LCOV_EXCL_START
 			printUsage();
 			exit(0);
+			// LCOV_EXCL_STOP
 
 		case 'I':
 			fstk_AddIncludePath(musl_optarg);
@@ -195,7 +199,7 @@ int main(int argc, char *argv[]) {
 				dependFileName = "<stdout>";
 			}
 			if (dependFile == nullptr) {
-				err("Failed to open dependfile \"%s\"", dependFileName);
+				err("Failed to open dependfile \"%s\"", dependFileName); // LCOV_EXCL_LINE
 			}
 			break;
 
@@ -302,9 +306,11 @@ int main(int argc, char *argv[]) {
 			if (stateFileSpecs.find(name) != stateFileSpecs.end()) {
 				warnx("Overriding state filename %s", name);
 			}
+			// LCOV_EXCL_START
 			if (verbose) {
 				printf("State filename %s\n", name);
 			}
+			// LCOV_EXCL_STOP
 			stateFileSpecs.emplace(name, std::move(features));
 			break;
 		}
@@ -314,8 +320,10 @@ int main(int argc, char *argv[]) {
 			exit(0);
 
 		case 'v':
+			// LCOV_EXCL_START
 			verbose = true;
 			break;
+			// LCOV_EXCL_STOP
 
 		case 'W':
 			opt_W(musl_optarg);
@@ -367,8 +375,10 @@ int main(int argc, char *argv[]) {
 
 		// Unrecognized options
 		default:
+			// LCOV_EXCL_START
 			printUsage();
 			exit(1);
+			// LCOV_EXCL_STOP
 		}
 	}
 
@@ -391,7 +401,7 @@ int main(int argc, char *argv[]) {
 	std::string mainFileName = argv[musl_optind];
 
 	if (verbose) {
-		printf("Assembling %s\n", mainFileName.c_str());
+		printf("Assembling %s\n", mainFileName.c_str()); // LCOV_EXCL_LINE
 	}
 
 	if (dependFile) {

src/asm/output.cpp

@@ -61,7 +61,7 @@ void out_RegisterNode(std::shared_ptr<FileStackNode> node) {
 	}
 }
 
-// Return a section's ID, or UINT32_MAX if the section is not in the list
+// Return a section's ID, or UINT32_MAX if the section does not exist
 static uint32_t getSectIDIfAny(Section *sect) {
 	if (!sect) {
 		return UINT32_MAX;
@@ -71,7 +71,8 @@ static uint32_t getSectIDIfAny(Section *sect) {
 		return static_cast<uint32_t>(search->second);
 	}
 
-	fatalerror("Unknown section '%s'\n", sect->name.c_str());
+	// Every section that exists should be in `sectionMap`
+	fatalerror("Unknown section '%s'\n", sect->name.c_str()); // LCOV_EXCL_LINE
 }
 
 static void writePatch(Patch const &patch, FILE *file) {
@@ -175,7 +176,7 @@ static void writeRpn(std::vector<uint8_t> &rpnexpr, std::vector<uint8_t> const &
 			sym = sym_FindExactSymbol(symName);
 			if (sym->isConstant()) {
 				rpnexpr[rpnptr++] = RPN_CONST;
-				value = sym_GetConstantValue(symName);
+				value = sym->getConstantValue();
 			} else {
 				rpnexpr[rpnptr++] = RPN_SYM;
 				registerUnregisteredSymbol(*sym); // Ensure that `sym->ID` is set
@@ -323,7 +324,7 @@ void out_WriteObject() {
 		file = stdout;
 	}
 	if (!file) {
-		err("Failed to open object file '%s'", objectFileName.c_str());
+		err("Failed to open object file '%s'", objectFileName.c_str()); // LCOV_EXCL_LINE
 	}
 	Defer closeFile{[&] { fclose(file); }};
 
@@ -343,14 +344,7 @@ void out_WriteObject() {
 		writeFileStackNode(node, file);
 
 		// The list is supposed to have decrementing IDs
-		if (it + 1 != fileStackNodes.end() && it[1]->ID != node.ID - 1) {
-			fatalerror(
-			    "Internal error: fstack node #%" PRIu32 " follows #%" PRIu32
-			    ". Please report this to the developers!\n",
-			    it[1]->ID,
-			    node.ID
-			);
-		}
+		assume(it + 1 == fileStackNodes.end() || it[1]->ID == node.ID - 1);
 	}
 
 	for (Symbol const *sym : objectSymbols) {
@@ -373,9 +367,11 @@ void out_SetFileName(std::string const &name) {
 		warnx("Overriding output filename %s", objectFileName.c_str());
 	}
 	objectFileName = name;
+	// LCOV_EXCL_START
 	if (verbose) {
 		printf("Output filename %s\n", objectFileName.c_str());
 	}
+	// LCOV_EXCL_STOP
 }
 
 static void dumpString(std::string const &escape, FILE *file) {
@@ -528,7 +524,7 @@ void out_WriteState(std::string name, std::vector<StateFeature> const &features)
 		file = stdout;
 	}
 	if (!file) {
-		err("Failed to open state file '%s'", name.c_str());
+		err("Failed to open state file '%s'", name.c_str()); // LCOV_EXCL_LINE
 	}
 	Defer closeFile{[&] { fclose(file); }};