From 1f64e47d6bf109b304d0ebcd3c3097720b1a25bb Mon Sep 17 00:00:00 2001
From: LuisHsu <luishsuplus@gmail.com>
Date: Sat, 23 Mar 2024 02:52:36 -0700
Subject: [PATCH] [PP] Pragma directive

---
 src/include/PreProcessor.hpp          |  8 +++++-
 src/lib/PreProcessor/PreProcessor.cpp | 40 ++++++++++++++++++++++++++-
 test/pp_directive/pp_directive.cpp    | 39 ++++++++++++++++++++++++++
 test/pp_directive/pragma.c            | 17 ++++++++++++
 4 files changed, 102 insertions(+), 2 deletions(-)
 create mode 100644 test/pp_directive/pragma.c

diff --git a/src/include/PreProcessor.hpp b/src/include/PreProcessor.hpp
index fea8036..d4b79fb 100644
--- a/src/include/PreProcessor.hpp
+++ b/src/include/PreProcessor.hpp
@@ -43,6 +43,12 @@ struct PreProcessor {
     PreProcessor(std::filesystem::path path, std::string source, std::vector<std::filesystem::path> include_paths = {});
     PPToken get();
 
+    struct {
+        std::optional<bool> fp_contract;
+        std::optional<bool> fenv_access;
+        std::optional<bool> cx_limited_value;
+    } pragma;
+
 #ifndef CCTEST
 private:
 #endif
@@ -148,7 +154,7 @@ struct PreProcessor {
     void undef_directive();
     void line_directive();
     void error_directive();
-    // void pragma_directive(PPToken& token); // TODO:
+    void pragma_directive();
 };
 
 } // namespace WasmVM
diff --git a/src/lib/PreProcessor/PreProcessor.cpp b/src/lib/PreProcessor/PreProcessor.cpp
index e7be3b1..98d14eb 100644
--- a/src/lib/PreProcessor/PreProcessor.cpp
+++ b/src/lib/PreProcessor/PreProcessor.cpp
@@ -126,7 +126,7 @@ PreProcessor::PPToken PreProcessor::get(){
                 }else if(direcitve_name == "error"){
                     error_directive();
                 }else if(direcitve_name == "pragma"){
-                    // TODO:
+                    pragma_directive();
                 }else if(direcitve_name == "include"){
                     include_directive();
                 }else{
@@ -378,3 +378,41 @@ void PreProcessor::error_directive(){
     }
     throw Exception::Error(pos, message.str());
 }
+
+void PreProcessor::pragma_directive(){
+    Line::iterator cur = skip_whitespace(line.begin(), line.end());
+    SourcePos pos = cur->value().pos;
+    if(cur != line.end() && cur->hold<TokenType::Identifier>()){
+        if(((TokenType::Identifier)cur->value()).sequence == "STDC"){
+            cur = skip_whitespace(std::next(cur), line.end());
+            if(cur != line.end() && cur->hold<TokenType::Identifier>()){
+                TokenType::Identifier name = cur->value();
+                cur = skip_whitespace(std::next(cur), line.end());
+                if(cur != line.end() && cur->hold<TokenType::Identifier>()){
+                    TokenType::Identifier on_off = cur->value();
+                    std::optional<bool> toggle;
+                    if(on_off.sequence == "ON"){
+                        toggle = true;
+                    }else if(on_off.sequence == "OFF"){
+                        toggle = false;
+                    }else if(on_off.sequence == "DEFAULT"){
+                        toggle.reset();
+                    }else{
+                        throw Exception::Error(cur->value().pos, "invalid value of ON/OFF switch");
+                    }
+                    if(name.sequence == "FP_CONTRACT"){
+                        pragma.fp_contract.swap(toggle);
+                        return;
+                    }else if(name.sequence == "FENV_ACCESS"){
+                        pragma.fenv_access.swap(toggle);
+                        return;
+                    }else if(name.sequence == "CX_LIMITED_RANGE"){
+                        pragma.cx_limited_value.swap(toggle);
+                        return;
+                    }
+                }
+            }
+        }
+    }
+    throw Exception::Error(pos, "unknown pragma");
+}
\ No newline at end of file
diff --git a/test/pp_directive/pp_directive.cpp b/test/pp_directive/pp_directive.cpp
index 27559d9..2214a3b 100644
--- a/test/pp_directive/pp_directive.cpp
+++ b/test/pp_directive/pp_directive.cpp
@@ -213,4 +213,43 @@ Suite pp_directive {
         PreProcessor pp(std::filesystem::path("error.c"));
         Throw(Exception::Exception, pp.get());
     })
+    Test("pragma", {
+        PreProcessor pp(std::filesystem::path("pragma.c"));
+        PreProcessor::PPToken token;
+        pp.get();
+        Expect(pp.pragma.fp_contract.has_value() && (pp.pragma.fp_contract.value() == true));
+        pp.get();
+
+        pp.get();
+        Expect(pp.pragma.fp_contract.has_value() && (pp.pragma.fp_contract.value() == false));
+        pp.get();
+
+        pp.get();
+        Expect(!pp.pragma.fp_contract.has_value());
+        pp.get();
+
+        pp.get();
+        Expect(pp.pragma.fenv_access.has_value() && (pp.pragma.fenv_access.value() == true));
+        pp.get();
+
+        pp.get();
+        Expect(pp.pragma.fenv_access.has_value() && (pp.pragma.fenv_access.value() == false));
+        pp.get();
+
+        pp.get();
+        Expect(!pp.pragma.fenv_access.has_value());
+        pp.get();
+
+        pp.get();
+        Expect(pp.pragma.cx_limited_value.has_value() && (pp.pragma.cx_limited_value.value() == true));
+        pp.get();
+
+        pp.get();
+        Expect(pp.pragma.cx_limited_value.has_value() && (pp.pragma.cx_limited_value.value() == false));
+        pp.get();
+
+        pp.get();
+        Expect(!pp.pragma.cx_limited_value.has_value());
+        pp.get();
+    })
 };
\ No newline at end of file
diff --git a/test/pp_directive/pragma.c b/test/pp_directive/pragma.c
new file mode 100644
index 0000000..1a567a1
--- /dev/null
+++ b/test/pp_directive/pragma.c
@@ -0,0 +1,17 @@
+#pragma STDC FP_CONTRACT ON
+;
+#pragma STDC FP_CONTRACT OFF
+;
+#pragma STDC FP_CONTRACT DEFAULT
+;
+#pragma STDC FENV_ACCESS ON
+;
+#pragma STDC FENV_ACCESS OFF
+;
+#pragma STDC FENV_ACCESS DEFAULT
+;
+#pragma STDC CX_LIMITED_RANGE ON
+;
+#pragma STDC CX_LIMITED_RANGE OFF
+;
+#pragma STDC CX_LIMITED_RANGE DEFAULT
\ No newline at end of file