From fb85f272a15d2f2c3fe073eec8fea4e754510da3 Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Sat, 21 Nov 2020 14:39:01 +0100
Subject: [PATCH] Added pragmas to pattern language

---
 include/lang/preprocessor.hpp | 14 +++++--
 source/lang/preprocessor.cpp  | 79 ++++++++++++++++++++++++++++++-----
 2 files changed, 79 insertions(+), 14 deletions(-)

diff --git a/include/lang/preprocessor.hpp b/include/lang/preprocessor.hpp
index 35640beba..98fee1631 100644
--- a/include/lang/preprocessor.hpp
+++ b/include/lang/preprocessor.hpp
@@ -4,9 +4,11 @@
 
 #include "token.hpp"
 
-#include <string>
-#include <utility>
+#include <functional>
 #include <set>
+#include <string>
+#include <unordered_map>
+#include <utility>
 
 namespace hex::lang {
 
@@ -14,10 +16,16 @@ namespace hex::lang {
     public:
         Preprocessor();
 
-        std::pair<Result, std::string> preprocess(const std::string& code, bool applyDefines = true);
+        std::pair<Result, std::string> preprocess(const std::string& code, bool initialRun = true);
+
+        void addPragmaHandler(std::string pragmaType, std::function<bool(std::string)> function);
+        void addDefaultPragramHandlers();
 
     private:
+        std::unordered_map<std::string, std::function<bool(std::string)>> m_pragmaHandlers;
+
         std::set<std::pair<std::string, std::string>> m_defines;
+        std::set<std::pair<std::string, std::string>> m_pragmas;
     };
 
 }
\ No newline at end of file
diff --git a/source/lang/preprocessor.cpp b/source/lang/preprocessor.cpp
index d54090b9a..4000328da 100644
--- a/source/lang/preprocessor.cpp
+++ b/source/lang/preprocessor.cpp
@@ -6,11 +6,13 @@ namespace hex::lang {
 
     }
 
-    std::pair<Result, std::string> Preprocessor::preprocess(const std::string& code, bool applyDefines) {
+    std::pair<Result, std::string> Preprocessor::preprocess(const std::string& code, bool initialRun) {
         u32 offset = 0;
 
-        if (applyDefines)
+        if (initialRun) {
             this->m_defines.clear();
+            this->m_pragmas.clear();
+        }
 
         std::string output;
         output.reserve(code.length());
@@ -76,45 +78,100 @@ namespace hex::lang {
                     std::string defineName;
                     while (!std::isblank(code[offset])) {
                         defineName += code[offset];
-                        offset += 1;
 
                         if (offset >= code.length() || code[offset] == '\n' || code[offset] == '\r')
                             return { ResultPreprocessingError, "" };
+                        offset += 1;
                     }
 
                     while (std::isblank(code[offset]))
                         offset += 1;
 
                     std::string replaceValue;
-                    do {
+                    while (code[offset] != '\n' && code[offset] != '\r') {
                         if (offset >= code.length())
                             return { ResultPreprocessingError, "" };
 
                         replaceValue += code[offset];
                         offset += 1;
-                    } while (code[offset] != '\n' && code[offset] != '\r');
+                    }
+
+                    if (replaceValue.empty())
+                        return { ResultPreprocessingError, "" };
 
                     this->m_defines.emplace(defineName, replaceValue);
-                }
+                } else if (code.substr(offset, 6) == "pragma") {
+                    offset += 6;
+
+                    while (std::isblank(code[offset]))
+                        offset += 1;
+
+                    std::string pragmaKey;
+                    while (!std::isblank(code[offset])) {
+                        pragmaKey += code[offset];
+
+                        if (offset >= code.length() || code[offset] == '\n' || code[offset] == '\r')
+                            return { ResultPreprocessingError, "" };
+
+                        offset += 1;
+                    }
+
+                    while (std::isblank(code[offset]))
+                        offset += 1;
+
+                    std::string pragmaValue;
+                    while (code[offset] != '\n' && code[offset] != '\r') {
+                        if (offset >= code.length())
+                            return { ResultPreprocessingError, "" };
+
+                        pragmaValue += code[offset];
+                        offset += 1;
+                    }
+
+                    if (pragmaValue.empty())
+                        return { ResultPreprocessingError, "" };
+
+                    this->m_pragmas.emplace(pragmaKey, pragmaValue);
+                } else
+                    return { ResultPreprocessingError, "" };
             }
 
             output += code[offset];
             offset += 1;
         }
 
-        if (applyDefines) {
+        if (initialRun) {
+            // Apply defines
             for (const auto &[define, value] : this->m_defines) {
                 s32 index = 0;
                 while((index = output.find(define, index)) != std::string::npos) {
-                    if (index > 0) {
-                        output.replace(index, define.length(), value);
-                        index += value.length();
-                    }
+                    output.replace(index, define.length(), value);
+                    index += value.length();
                 }
             }
+
+            // Handle pragmas
+            for (const auto &[type, value] : this->m_pragmas) {
+                if (this->m_pragmaHandlers.contains(type)) {
+                    if (!this->m_pragmaHandlers[type](value))
+                        return { ResultPreprocessingError, { } };
+                } else
+                    return { ResultPreprocessingError, { } };
+            }
         }
 
         return { ResultSuccess, output };
     }
 
+    void Preprocessor::addPragmaHandler(std::string pragmaType, std::function<bool(std::string)> function) {
+        if (!this->m_pragmaHandlers.contains(pragmaType))
+            this->m_pragmaHandlers.emplace(pragmaType, function);
+    }
+
+    void Preprocessor::addDefaultPragramHandlers() {
+        this->addPragmaHandler("MIME", [](std::string value) {
+            return !std::all_of(value.begin(), value.end(), isspace) && !value.ends_with('\n') && !value.ends_with('\r');
+        });
+    }
+
 }
\ No newline at end of file