From f5c274b3b1d416c2209c618bed79d4ffdc5ad9e2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 2 Mar 2019 19:52:15 +0100
Subject: [PATCH] Added '--check-headers=no' option.

---
 cli/cmdlineparser.cpp |  6 ++++++
 lib/settings.cpp      |  1 +
 lib/settings.h        |  4 ++++
 lib/tokenize.cpp      | 36 ++++++++++++++++++++++++++++++++++++
 lib/tokenize.h        |  7 +++++++
 5 files changed, 54 insertions(+)

diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
index 3189d3094..aaec81ad4 100644
--- a/cli/cmdlineparser.cpp
+++ b/cli/cmdlineparser.cpp
@@ -155,6 +155,10 @@ bool CmdLineParser::parseFromArgs(int argc, const char* const argv[])
             else if (std::strcmp(argv[i], "--dump") == 0)
                 mSettings->dump = true;
 
+            // --check-headers=no
+            else if (std::strcmp(argv[i], "--check-headers=no") == 0)
+                mSettings->checkHeaders = false;
+
             // max ctu depth
             else if (std::strncmp(argv[i], "--max-ctu-depth=", 16) == 0)
                 mSettings->maxCtuDepth = std::atoi(argv[i] + 16);
@@ -914,6 +918,8 @@ void CmdLineParser::printHelp()
               "                         incremental analysis, distributed analysis.\n"
               "    --check-config       Check cppcheck configuration. The normal code\n"
               "                         analysis is disabled by this flag.\n"
+              "    --check-headers=no   Turn off checking of included files, to make the\n"
+              "                         analysis faster.\n"
               "    --check-library      Show information messages when library files have\n"
               "                         incomplete info.\n"
               "    --config-exclude=<dir>\n"
diff --git a/lib/settings.cpp b/lib/settings.cpp
index 63de049e1..9d4c7438d 100644
--- a/lib/settings.cpp
+++ b/lib/settings.cpp
@@ -49,6 +49,7 @@ Settings::Settings()
       maxConfigs(12),
       enforcedLang(None),
       reportProgress(false),
+      checkHeaders(true),
       checkConfiguration(false),
       checkLibrary(false)
 {
diff --git a/lib/settings.h b/lib/settings.h
index b39ba49d7..e6c9f38b7 100644
--- a/lib/settings.h
+++ b/lib/settings.h
@@ -285,6 +285,10 @@ public:
     /** Check for incomplete info in library files? */
     bool checkLibrary;
 
+    /** Check code in the headers, this is on by default but can
+     * be turned off to save CPU */
+    bool checkHeaders;
+
     /** Struct contains standards settings */
     Standards standards;
 
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 4ab0bd1c1..1b53532bf 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3630,6 +3630,8 @@ bool Tokenizer::simplifyTokenList1(const char FileName[])
 
     createLinks();
 
+    simplifyHeaders();
+
     // Remove __asm..
     simplifyAsm();
 
@@ -4257,6 +4259,40 @@ void Tokenizer::dump(std::ostream &out) const
         list.front()->printValueFlow(true, out);
 }
 
+void Tokenizer::simplifyHeaders()
+{
+    // TODO : can we remove anything in headers here? Like unused declarations.
+    // Maybe if --dump is used we want to have _everything_.
+
+    if (mSettings->checkHeaders)
+        // Default=full analysis. All information in the headers are kept.
+        return;
+
+    // We want to remove selected stuff from the headers but not *everything*.
+    // The intention here is to not damage the analysis of the source file.
+
+    // TODO: Remove unused types/variables/etc in headers..
+
+    for (Token *tok = list.front(); tok; tok = tok->next()) {
+        if (tok->fileIndex() == 0)
+            // Keep all code in the source file
+            continue;
+
+        // Remove executable code
+        if (tok->str() == "{") {
+            const Token *prev = tok->previous();
+            while (prev && prev->isName())
+                prev = prev->previous();
+            if (Token::simpleMatch(prev, ")")) {
+                // Replace all tokens from { to } with a ";".
+                Token::eraseTokens(tok,tok->link()->next());
+                tok->str(";");
+                tok->link(nullptr);
+            }
+        }
+    }
+}
+
 void Tokenizer::removeMacrosInGlobalScope()
 {
     for (Token *tok = list.front(); tok; tok = tok->next()) {
diff --git a/lib/tokenize.h b/lib/tokenize.h
index 2a9872ed2..e08f3c8e5 100644
--- a/lib/tokenize.h
+++ b/lib/tokenize.h
@@ -164,6 +164,13 @@ public:
     */
     bool simplifyTokenList2();
 
+    /**
+     * If --check-headers=no has been given; then remove unneeded code in headers.
+     * - All executable code.
+     * - Unused types/variables/etc
+     */
+    void simplifyHeaders();
+
     /**
      * Deletes dead code between 'begin' and 'end'.
      * In general not everything can be erased, such as: