Use a unique pointer instead of a custom structure.

Signed-off-by: fruffy <[email protected]>
p4lang · Jul 16, 2024 · 70c3f92 · 70c3f92
1 parent 8ca399d
commit 70c3f92
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Showing 4 changed files with 22 additions and 39 deletions.
diff --git a/frontends/common/parseInput.h b/frontends/common/parseInput.h
@@ -18,6 +18,7 @@ limitations under the License.
 #define FRONTENDS_COMMON_PARSEINPUT_H_
 
 #include "frontends/common/options.h"
+#include "frontends/common/parser_options.h"
 #include "frontends/p4/fromv1.0/converters.h"
 #include "frontends/parsers/parserDriver.h"
 #include "lib/error.h"
@@ -77,14 +78,15 @@ const IR::P4Program *parseP4File(const ParserOptions &options) {
         fclose(file);
     } else {
         auto preprocessorResult = options.preprocess();
-        if (::errorCount() > 0 || preprocessorResult.file() == nullptr) {
+        if (::errorCount() > 0 || !preprocessorResult.has_value()) {
             return nullptr;
         }
         // Need to assign file here because the parser requires an lvalue.
-        result = options.isv1()
-                     ? parseV1Program<FILE *, C>(preprocessorResult.file(), options.file.string(),
-                                                 1, options.getDebugHook())
-                     : P4ParserDriver::parse(preprocessorResult.file(), options.file.string());
+        result =
+            options.isv1()
+                ? parseV1Program<FILE *, C>(preprocessorResult.value().get(), options.file.string(),
+                                            1, options.getDebugHook())
+                : P4ParserDriver::parse(preprocessorResult.value().get(), options.file.string());
     }
 
     if (::errorCount() > 0) {

diff --git a/frontends/common/parser_options.cpp b/frontends/common/parser_options.cpp
@@ -23,6 +23,7 @@ limitations under the License.
 #include <sys/types.h>
 #include <sys/wait.h>
 
+#include <memory>
 #include <regex>
 #include <unordered_set>
 
@@ -45,11 +46,11 @@ const char *p4_14includePath = CONFIG_PKGDATADIR "/p4_14include";
 
 using namespace P4::literals;
 
-void ParserOptions::PreprocessorResult::closeFile() {
-    if (!_closeInput || _file == nullptr) {
+void ParserOptions::closeFile(FILE *file) {
+    if (file == nullptr) {
         return;
     }
-    int exitCode = pclose(_file);
+    int exitCode = pclose(file);
     if (WIFEXITED(exitCode) && WEXITSTATUS(exitCode) == 4) {
         ::error(ErrorType::ERR_IO, "input file does not exist");
         return;
@@ -416,7 +417,7 @@ const char *ParserOptions::getIncludePath() const {
     return path.c_str();
 }
 
-ParserOptions::PreprocessorResult ParserOptions::preprocess() const {
+std::optional<ParserOptions::PreprocessorResult> ParserOptions::preprocess() const {
     FILE *in = nullptr;
     bool closeInput = false;
 
@@ -437,7 +438,7 @@ ParserOptions::PreprocessorResult ParserOptions::preprocess() const {
         if (in == nullptr) {
             ::error(ErrorType::ERR_IO, "Error invoking preprocessor");
             perror("");
-            return {};
+            return std::nullopt;
         }
         closeInput = true;
     }
@@ -450,9 +451,9 @@ ParserOptions::PreprocessorResult ParserOptions::preprocess() const {
         while ((read = getline(&line, &len, in)) != -1) {
             printf("%s", line);
         }
-        return {};
+        return std::nullopt;
     }
-    return {in, closeInput};
+    return ParserOptions::PreprocessorResult(in, &closeFile);
 }
 
 // From (folder, file.ext, suffix)  returns

diff --git a/frontends/common/parser_options.h b/frontends/common/parser_options.h
@@ -19,6 +19,7 @@ limitations under the License.
 #ifndef FRONTENDS_COMMON_PARSER_OPTIONS_H_
 #define FRONTENDS_COMMON_PARSER_OPTIONS_H_
 
+#include <cstdio>
 #include <filesystem>
 #include <set>
 
@@ -53,31 +54,10 @@ class ParserOptions : public Util::Options {
     std::vector<const char *> *process(int argc, char *const argv[]) override;
     enum class FrontendVersion { P4_14, P4_16 };
 
+    /// Tries to close the input stream associated with the result.
+    static void closeFile(FILE *file);
     /// Records the result of the preprocessor.
-    class PreprocessorResult {
-     private:
-        /// The input stream.
-        FILE *_file = nullptr;
-        /// Whether the input stream should be closed.
-        bool _closeInput = false;
-
-        /// Tries to close the input stream associated with the result.
-        void closeFile();
-
-     public:
-        PreprocessorResult() = default;
-        PreprocessorResult &operator=(PreprocessorResult &&) = default;
-        PreprocessorResult(PreprocessorResult &&) = default;
-        /// There must only be one PreprocessorResult per file handle. Delete the copy constructor.
-        PreprocessorResult(const PreprocessorResult &) = delete;
-        PreprocessorResult &operator=(const PreprocessorResult &) = delete;
-        PreprocessorResult(FILE *file, bool closeInput) : _file(file), _closeInput(closeInput) {}
-
-        ~PreprocessorResult() { closeFile(); }
-
-        /// @return the input stream.
-        [[nodiscard]] FILE *file() const { return _file; }
-    };
+    using PreprocessorResult = std::unique_ptr<FILE, decltype(&closeFile)>;
 
     /// Name of executable that is being run.
     cstring exe_name;
@@ -104,7 +84,7 @@ class ParserOptions : public Util::Options {
     /// Return target specific include path.
     const char *getIncludePath() const override;
     /// Returns the output of the preprocessor.
-    PreprocessorResult preprocess() const;
+    std::optional<ParserOptions::PreprocessorResult> preprocess() const;
     /// True if we are compiling a P4 v1.0 or v1.1 program
     bool isv1() const;
     /// Get a debug hook function suitable for insertion

diff --git a/frontends/p4/fromv1.0/programStructure.cpp b/frontends/p4/fromv1.0/programStructure.cpp
@@ -681,9 +681,9 @@ void ProgramStructure::include(cstring filename, cstring ppoptions) {
     options.file = path;
     if (::errorCount() == 0U) {
         auto preprocessorResult = options.preprocess();
-        if (preprocessorResult.file() != nullptr) {
+        if (preprocessorResult.has_value()) {
             const auto *code =
-                P4::P4ParserDriver::parse(preprocessorResult.file(), options.file.string());
+                P4::P4ParserDriver::parse(preprocessorResult.value().get(), options.file.string());
             if ((code != nullptr) && (::errorCount() == 0U)) {
                 for (const auto *decl : code->objects) {
                     declarations->push_back(decl);